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1.  Cost Effectiveness of Paricalcitol Versus Cinacalcet with Low-Dose Vitamin D for Management of Secondary Hyperparathyroidism in Haemodialysis Patients in the USA 
Clinical Drug Investigation  2013;34:107-115.
Background
The IMPACT SHPT [Improved Management of Intact Parathyroid Hormone (iPTH) with Paricalcitol-Centered Therapy Versus Cinacalcet Therapy with Low-Dose Vitamin D in Hemodialysis Patients with Secondary Hyperparathyroidism] study compared the effectiveness of paricalcitol and cinacalcet in the management of secondary hyperparathyroidism in haemodialysis patients but did not report the costs or cost effectiveness of these treatments.
Aim
The aim of this study was to compare the cost effectiveness of a paricalcitol-based regimen versus cinacalcet with low-dose vitamin D for management of secondary hyperparathyroidism in haemodialysis patients from a US payer perspective, using a 1-year time horizon.
Methods
This was a post hoc cost-effectiveness analysis of data collected for US patients enrolled in the IMPACT SHPT study—a 28-week, randomized, open-label, phase 4, multinational study (ClinicalTrials.gov identifier: NCT00977080). Patients eligible for the IMPACT SHPT study were aged ≥18 years with stage 5 chronic kidney disease, had been receiving maintenance haemodialysis three times weekly for at least 3 months before screening and were to continue haemodialysis during the study. Only US patients who reached the evaluation period (weeks 21–28) were included in this secondary analysis. US subjects in the IMPACT SHPT study were randomly assigned to receive intravenous paricalcitol, or oral cinacalcet plus fixed-dose intravenous doxercalciferol, for 28 weeks. Patients in the paricalcitol group could also receive supplemental cinacalcet for hypercalcaemia. The primary effectiveness endpoint in the IMPACT SHPT study was the proportion of subjects who achieved a mean intact parathyroid hormone (iPTH) level of 150–300 pg/mL during the evaluation period. In this secondary analysis, we estimated the incremental cost-effectiveness ratio (ICER), comparing paricalcitol-treated patients with cinacalcet-treated patients on the basis of this primary endpoint and several secondary endpoints. Costs were estimated by examining the dosage of the study drug (paricalcitol or cinacalcet) and phosphate binders used by each participant during the trial. Nonparametric bootstrap analysis was used to examine the accuracy of the ICER point estimates.
Results
The percentages of patients achieving the treatment goal of a mean iPTH level between 150–300 pg/mL during weeks 21–28 of therapy were 56.9 % in the paricalcitol group and 34.0 % in the cinacalcet group (a difference of 23 %, p = 0.0235). Paricalcitol was also more effective for each of the secondary endpoints. When annualized, the total drug costs were US$10,153 in the paricalcitol group and US$15,967 in the cinacalcet group, a difference of US$5,814 (57.3 %, p = 0.0053). Because the paricalcitol-based treatment was less expensive and more effective, it was ‘dominant’, compared with cinacalcet, in this cost-effectiveness analyses. In our bootstrap analysis, 99.1 % of bootstrap replicates for the ICER of the primary endpoint fell within the lower right quadrant of the cost-effectiveness plane—where paricalcitol is considered dominant. For all of the other endpoints, paricalcitol was dominant in 100 % of replicates.
Conclusion
On the basis of dosing and effectiveness data from US patients in the IMPACT SHPT study, we found that a regimen of intravenous paricalcitol was more cost effective than cinacalcet plus low-dose vitamin D in the management of iPTH in patients with SHPT requiring haemodialysis.
doi:10.1007/s40261-013-0151-4
PMCID: PMC3899451  PMID: 24214232
2.  Treatment of secondary hyperparathyroidism in haemodialysis patients: a randomised clinical trial comparing paricalcitol and alfacalcidol 
BMC Nephrology  2009;10:28.
Background
Secondary hyperparathyroidism is a common feature in patients with chronic kidney disease. Its serious clinical consequences include renal osteodystrophy, calcific uremic arteriolopathy, and vascular calcifications that increase morbidity and mortality.
Reduced synthesis of active vitamin D contributes to secondary hyperparathyroidism. Therefore, this condition is managed with activated vitamin D. However, hypercalcemia and hyperphosphatemia limit the use of activated vitamin D.
In Denmark alfacalcidol is the primary choice of vitamin D analog.
A new vitamin D analog, paricalcitol, may be less prone to induce hypercalcemia and hyperphosphatemia.
However, a randomised controlled clinical study comparing alfacalcidol and paricalcitol has never been performed.
The primary objective of this study is to compare alfacalcidol and paricalcitol. We evaluate the suppression of the secondary hyperparathyroidism and the tendency towards hyperphosphatemia and hypercalcemia.
Methods/Design
This is an investigator-initiated cross-over study. Nine Danish haemodialysis units will recruit 117 patients with end stage renal failure on maintenance haemodialysis therapy.
Patients are randomised into two treatment arms. After a wash out period of 6 weeks they receive increasing doses of alfacalcidol or paricalcitol for a period of 16 weeks and after a further wash out period of 6 weeks they receive the contrary treatment (paricalcitol or alfacalcidol) for 16 weeks.
Discussion
Hyperparathyroidism, hypercalcemia and hyperphosphatemia are associated with increased cardiovascular mortality in patients with chronic kidney disease.
If there is any difference in the ability of these two vitamin D analogs to decrease the secondary hyperparathyroidism without causing hypercalcemia and hyperphosphatemia, there may also be a difference in the risk of cardiovascular mortality depending on which vitamin D analog that are used. This has potential major importance for this group of patients.
Trial registration
ClinicalTrials.gov NCT004695
doi:10.1186/1471-2369-10-28
PMCID: PMC2760547  PMID: 19778452
3.  Comparison of oral and intravenous Alfacalcidol in chronic hemodialysis patients 
BMC Nephrology  2014;15:27.
Background
Activated vitamin D is the mainstay of treatment for secondary hyperparathyroidism (SHPT) in chronic hemodialysis patients. However, the optimal route of administration is still debated. The aim of our study was to compare efficacy of oral vs intravenous (IV) administration of alfacalcidol in hemodialysis. A secondary objective was to determine the cost-effectiveness advantage of oral administration.
Methods
Eighty-eight chronic hemodialysis patients receiving IV alfacalcidol three times a week were included in the study. All were switched to the same dose of alfacalcidol given orally three times a week during the hemodialysis session. A budget impact analysis was performed.
Results
Mean patient age was 64 years old and 43% were males. The mean alfacalcidol dose administered was 2.1 μg three times a week. After three months, serum parathormone (PTH) levels decreased from 80 to 59 pmol/L (p = 0.001) and total serum calcium levels increased from 2.34 to 2.40 mmol/L (p = 0.002). After six months, total serum calcium levels were still significantly higher. Alfacalcidol dosage was significantly decreased during study period; the mean reduction was 0.44 μg per dose. Finally, oral administration was associated with an annual cost reduction of 197 678$CAN and an annual nursing time reduction of 25 days.
Conclusion
Our findings support that switching IV to oral administration of alfacalcidol during hemodialysis sessions may lead to a similar control of SHPT with lower doses of activated vitamin D. This is a good strategy for optimizing compliance and may allow a dose reduction because of a greater efficacy to suppress PTH. Oral administration also has significant cost-effectiveness advantages.
doi:10.1186/1471-2369-15-27
PMCID: PMC3915223  PMID: 24495277
Alfacalcidol administration; End-stage renal failure; Hyperparathyroidism
4.  Effect of alfacalcidol on natural course of renal bone disease in mild to moderate renal failure. 
BMJ : British Medical Journal  1995;310(6976):358-363.
OBJECTIVE--To determine whether alfacalcidol--used in management of overt renal bone disease--may safely prevent renal bone disease when used earlier in course of renal failure. DESIGN--Double blind, prospective, randomised, placebo controlled study. SETTING--17 nephrology centres from Belgium, France, the Netherlands, and the United Kingdom. SUBJECTS--176 patients aged 18-81 with mild to moderate chronic renal failure (creatinine clearance 15-50 ml/min) and with no clinical, biochemical, or radiographic evidence of bone disease. INTERVENTIONS--Alfacalcidol 0.25 micrograms (titrated according to serum calcium concentration) or placebo given for two years. MAIN OUTCOME MEASURES--Quantitative histology of bone to assess efficacy of treatment and renal function to assess safety. RESULTS--132 patients had histological evidence of bone disease at start of study. Biochemical, radiographic, and histological indices of bone metabolism were similar for the 89 patients given alfacalcidol and the 87 controls given placebo. After treatment, mean serum alkaline phosphatase activity and intact parathyroid hormone concentration had increased by 13% and 126% respectively in controls but had not changed in patients given alfacalcidol (P < 0.001). Hypercalcaemic episodes occurred in 10 patients given alfacalcidol (but responded to decreases in drug dose) and in three controls. Histological indices of bone turnover significantly improved in patients given alfacalcidol and significantly deteriorated in controls: among patients with abnormal bone histology before treatment, bone disease resolved in 23 (42%) of those given alfacalcidol compared with two (4%) of the controls (P < 0.001). There was no difference in rate of progression of renal failure between the two groups. CONCLUSION--Early administration of alfacalcidol can safely and beneficially alter the natural course of renal bone disease in patients with mild to moderate renal failure.
PMCID: PMC2548761  PMID: 7677827
5.  Effect of paricalcitol on renin and albuminuria in non-diabetic stage III-IV chronic kidney disease: a randomized placebo-controlled trial 
BMC Nephrology  2013;14:163.
Background
Vitamin D receptor activators reduce albuminuria, and may improve survival in chronic kidney disease (CKD). Animal studies suggest that these pleiotropic effects of vitamin D may be mediated by suppression of renin. However, randomized trials in humans have yet to establish this relationship.
Methods
In a randomized, placebo-controlled, double-blinded crossover study, the effect of oral paricalcitol (2 μg/day) was investigated in 26 patients with non-diabetic, albuminuric stage III-IV CKD. After treatment, plasma concentrations of renin (PRC), angiotensin II (AngII) and aldosterone (Aldo) were measured. GFR was determined by 51Cr-EDTA clearance. Assessment of renal NO dependency was performed by infusion of NG-monomethyl-L-arginine (L-NMMA). Albumin excretion rate (AER) was analyzed in 24-h urine and during 51Cr-EDTA clearance.
Results
Paricalcitol did not alter plasma levels of renin, AngII, Aldo, or urinary excretion of sodium and potassium. A modest reduction of borderline significance was observed in AER, and paricalcitol abrogated the albuminuric response to L-NMMA.
Conclusions
In this randomized, placebo-controlled trial paricalcitol only marginally decreased AER and did not alter circulating levels of renin, AngII or Aldo. The abrogation of the rise in albumin excretion by paricalcitol during NOS blockade may indicate that favourable modulation of renal NO dependency could be involved in mediating reno-protection and survival benefits in CKD.
Trial registration
ClinicalTrials.gov identifier: NCT01136564
doi:10.1186/1471-2369-14-163
PMCID: PMC3729723  PMID: 23889806
Albuminuria; Chronic kidney disease; Nitric oxide; Vitamin D; Renin-angiotensin system
6.  Meta-Analysis: The Efficacy and Safety of Paricalcitol for the Treatment of Secondary Hyperparathyroidism and Proteinuria in Chronic Kidney Disease 
BioMed Research International  2012;2013:320560.
Introduction. Previous studies have demonstrated the safety and efficacy of using Paricalcitol for the treatment of secondary hyperparathyroidism (SHPT) in patients on dialysis. The aim of the current meta-analysis was to assess the safety and efficacy of Paricalcitol for the management of SHPT in patients with chronic kidney disease (CKD) not yet on dialysis. A secondary aim was to determine if sufficient data was available to assess the effect of Paricalcitol for the management of proteinuria. Methods. A meta-analysis was conducted using the Cochrane Collaboration's RevMan 4.2 software. Results. Paricalcitol is effective in lowering PTH in patients with CKD not yet on dialysis and is also effective in lowering proteinuria in diabetic CKD patients. However, we uncovered a safety signal identifying an elevated calcium phosphate product and a trend towards the development of hypercalcemia. A phosphate elevation was not demonstrated because the target used in the clinical studies was a P > 5.5 mg/dl, a value appropriate for dialysis patients and not CKD patients. Conclusion. Although Paricalcitol is effective in lowering PTH, we advise caution in the use of any active Vitamin D analogues in patients with CKD because of the potential risk of exacerbating vascular calcification.
doi:10.1155/2013/320560
PMCID: PMC3591146  PMID: 23509710
7.  Effects of paricalcitol on calcium and phosphate metabolism and markers of bone health in patients with diabetic nephropathy: results of the VITAL study 
Nephrology Dialysis Transplantation  2013;28(9):2260-2268.
Background
Chronic kidney disease (CKD) is associated with elevations in serum phosphate, calcium–phosphorus product and bone-specific alkaline phosphatase (BAP), with attendant risks of cardiovascular and bone disorders. Active vitamin D can suppress parathyroid hormone (PTH), but may raise serum calcium and phosphate concentrations. Paricalcitol, a selective vitamin D activator, suppressed PTH in CKD patients (stages 3 and 4) with secondary hyperparathyroidism (SHPT) with minimal changes in calcium and phosphate metabolism.
Methods
The VITAL study enrolled patients with CKD stages 2–4. We examined the effect and relationship of paricalcitol to calcium and phosphate metabolism and bone markers in a post hoc analysis of VITAL. The study comprised patients with diabetic nephropathy enrolled in a double-blind, placebo-controlled, randomized trial of paricalcitol (1 or 2 μg/day). Urinary and serum calcium and phosphate, serum BAP, and intact PTH (iPTH) concentrations were measured throughout the study.
Results
Baseline demographics and calcium, phosphate, PTH (49% with iPTH <70 pg/mL), and BAP concentrations were similar between groups. A transient, modest yet significant increase in phosphate was observed for paricalcitol 2 μg/day (+0.29 mg/dL; P < 0.001). Dose-dependent increases in serum and urinary calcium were observed; however, there were few cases of hypercalcemia: one in the 1-μg/day group (1.1%) and three in the 2-μg/day group (3.2%). Significant reductions in BAP were observed that persisted for 60 days after paricalcitol discontinuation (P < 0.001 for combined paricalcitol groups versus placebo). Paricalcitol dose-dependent reductions in iPTH were observed. Paricalcitol in CKD patients (±SHPT) was associated with modest increases in calcium and phosphate.
Conclusion
Paricalcitol reduces BAP levels, which may be beneficial for reducing vascular calcification.
Trial registration
Trial is registered with ClinicalTrials.gov, number NCT00421733.
doi:10.1093/ndt/gft227
PMCID: PMC3769981  PMID: 23787544
bone-specific alkaline phosphatase; calcitriol; hypercalcemia; hyperphosphatemia; paricalcitol; vitamin D receptor activation
8.  Efficacy of Alfacalcidol on PEG-IFN/ Ribavirin Combination Therapy for Elderly Patients With Chronic Hepatitis C: A Pilot Study 
Hepatitis Monthly  2013;13(12):e14872.
Background
Serum vitamin D concentration is reported to show a decrease in older age. Patients with chronic hepatitis C (CHC) in Japan are older on average than those in Western countries. Moreover, the outcome of pegylated-interferon (PEG-IFN)/ ribavirin therapy combined with vitamin D in elderly patients is unclear.
Objectives
This pilot study explored the efficacy and safety of alfacalcidol as vitamin D source in PEG-IFN/ ribavirin combination therapy for elderly CHC patients infected with hepatitis C virus genotype 1b.
Patients and Methods
Consecutive twenty CHC patients aged ≥ 65 years were enrolled in this pilot study. Fifteen patients met the inclusion criteria and received PEG-IFN/ ribavirin therapy combined with alfacalcidol. Four-week lead-in of oral alfacalcidol was conducted, and it was subsequently and concurrently administered in PEG-IFN/ ribavirin combination therapy (vitamin D group). Age, gender, and IL28B genotype-matched patients, who received PEG-IFN/ ribavirin alone, were saved as control group (n = 15) to compare the treatment outcome with the vitamin D group.
Results
Subjects consisted of 14 males and 16 females, with a median age of 70 years (65-78). The serum 25 (OH) D3 concentration in females (20 ng/ml, 11-37) was significantly lower than males (27 ng/mL, 13-49) (P = 0.004). Sustained virological response (SVR) rates were 33.3% (5/15) in the control group and 80.0% (12/15) in the vitamin D group, respectively (P = 0.025). While no significant difference was shown in the (SVR) rate between the two groups among males (P = 0.592), in females the SVR rate was significantly higher in the vitamin D group (87.5%, 7/8) than the control group (25.0%, 2/8) (P = 0.041). The relapse rates in the groups with and without alfacalcidol were 7.7% (1/13) and 61.5% (8/13), respectively (P = 0.011). Interestingly, in females, the relapse in the control group was shown in 5 of 7 (71.4%), whereas in the vitamin D group the relapse rate was decreased (1/8, 12.5%) (P = 0.041). No specific adverse events were observed in the vitamin D group.
Conclusions
PEG-IFN/ ribavirin combined with alfacalcidol may be effective and safe in elderly CHC patients. In particular, concomitant administration of alfacalcidol may lead to a reduced relapse rate, and consequently improving the SVR rate in elderly females.
doi:10.5812/hepatmon.14872
PMCID: PMC3877658  PMID: 24403915
1-hydroxycholecalciferol; Vitamin D; Ribavirin; Aged; Hepatitis C, Chronic
9.  The importance of early referral for the treatment of chronic kidney disease: a Danish nationwide cohort study 
BMC Nephrology  2012;13:108.
Background
Many patients with advanced chronic kidney disease are referred late to renal units. This is associated with negative aspects. The purpose of the present study was to characterize late versus early referrals for renal replacement therapy including their renal disease, health care contacts and medical treatment before renal replacement therapy (RRT) and the consequences for RRT modality and mortality.
Methods
Nationwide cohort study including 4495 RRT patients identified in the Danish Nephrology Registry 1999–2006. The cohort was followed to end 2007 by linkage to other national registries. Late referral: follow-up ≤16 weeks in renal unit before RRT start. Cox proportional hazards models were used to estimate the relative risk of mortality or waiting list status within 365 days in late referrals versus early referrals.
Results
A total of 1727 (38%) incident RRT patients were referred late. Among these, 72% were treated in non-nephrology hospital departments and 91% in general practice 2 years to 16 weeks before RRT start. Fewer late referrals received recommended pre-RRT treatment as judged by renin-angiotensin-system blockade: 32% versus 57% or the D-vitamin analogue alfacalcidol: 5% versus 30% (P < .001). Primary RRT modality was peritoneal dialysis: 18% in late versus 32% in early referrals (P < .001), 7% versus 30%, respectively, had an arteriovenous dialysis-fistula (P < .001) and 0.2% versus 6% were on the waiting-list for renal transplantation (P < .001) before RRT start. One-year-mortality was higher in late referrals: hazard ratio 1.55 (CI 95% 1.35–1.78). In a subgroup, 30% (CI 95% 25–35%) late and 9% (CI 95% 6–12%) early referrals had plasma creatinine ≤150% of upper reference limit within 1 to 2 years before RRT start (P < .001).
Conclusions
Late nephrology referrals were well-known to the healthcare system before referral for RRT start and more often had near normal plasma creatinine levels within 2 years before RRT start. They infrequently received available treatment or optimal first RRT modality. An increased effort to identify these patients in the healthcare system in time for proper pre-dialysis care including preparation for RRT is needed.
doi:10.1186/1471-2369-13-108
PMCID: PMC3469388  PMID: 22963236
Chronic kidney failure; Epidemiology; Late diagnosis; Treatment; Renal replacement therapy
10.  An LRP5 Receptor with Internal Deletion in Hyperparathyroid Tumors with Implications for Deregulated WNT/β-Catenin Signaling 
PLoS Medicine  2007;4(11):e328.
Background
Hyperparathyroidism (HPT) is a common endocrine disorder with incompletely understood etiology, characterized by enlarged hyperactive parathyroid glands and increased serum concentrations of parathyroid hormone and ionized calcium. We have recently reported activation of the Wnt signaling pathway by accumulation of β-catenin in all analyzed parathyroid tumors from patients with primary HPT (pHPT) and in hyperplastic parathyroid glands from patients with uremia secondary to HPT (sHPT). Mechanisms that may account for this activation have not been identified, except for a few cases of β-catenin (CTNNB1) stabilizing mutation in pHPT tumors.
Methods and Findings
Reverse transcription PCR and Western blot analysis showed expression of an aberrantly spliced internally truncated WNT coreceptor low-density lipoprotein receptor–related protein 5 (LRP5) in 32 out of 37 pHPT tumors (86%) and 20 out of 20 sHPT tumors (100%). Stabilizing mutation of CTNNB1 and expression of the internally truncated LRP5 receptor was mutually exclusive. Expression of the truncated LRP5 receptor was required to maintain the nonphosphorylated active β-catenin level, transcription activity of β-catenin, MYC expression, parathyroid cell growth in vitro, and parathyroid tumor growth in a xenograft severe combined immunodeficiency (SCID) mouse model. WNT3 ligand and the internally truncated LRP5 receptor strongly activated transcription, and the internally truncated LRP5 receptor was insensitive to inhibition by DKK1.
Conclusions
The internally truncated LRP5 receptor is strongly implicated in deregulated activation of the WNT/β-catenin signaling pathway in hyperparathyroid tumors, and presents a potential target for therapeutic intervention.
Gunnar Westin and colleagues report the expression of an aberrantly spliced LRP5 receptor in primary and spontaneous parathyroid tumors and implicate it in the deregulated activation of the Wnt/β-catenin signaling pathway.
Editors' Summary
Background.
The parathyroid glands—four rice-sized glands in the neck—maintain a normal calcium balance in the body, to maintain strong bones and essential cellular functions. The glands release parathyroid hormone as a response to a decrease in blood calcium level. By stimulating calcium release from bone and its absorption in the gut, parathyroid hormone restores the blood calcium level. However, 100,000 new individuals in the US develop hyperparathyroidism (HPT) annually, characterized by enlarged, overactive parathyroid glands and high blood levels of calcium. Primary HPT (pHPT) is usually caused by a benign tumor (a non-life-threatening growth) in one of the parathyroid glands. Secondary HPT (sHPT) occurs in response to calcium regulatory disturbances, linked to vitamin D deficiency, and more or less invariably develops in patients with uremic kidney disease.
Why Was This Study Done?
HPT is usually treated by surgical removal of the enlarged parathyroid glands, which is done with great efficiency. However, ideally, doctors would like to know what drives the overgrowth of the parathyroid glands to be able to develop drugs for treatment or disease prophylaxis. Researchers recently reported that the cells in enlarged parathyroid glands from patients with HPT contain high amounts of β-catenin. This protein is part of the Wnt signaling pathway, which has been found to be disrupted in many tumor entities in other organs. In the absence of Wnt proteins, a group of proteins called the β-catenin destruction complex marks β-catenin so that it is rapidly destroyed. When Wnt proteins bind to a cell-surface receptor called Frizzled and a coreceptor called LRP5, the destruction complex is inhibited and β-catenin accumulates. This accumulation induces the production of other proteins (in particular, c-Myc) that stimulate cell growth and division. The accumulation of β-catenin in the enlarged parathyroid glands of patients with HPT could, therefore, significantly contribute to the overgrowth of their glands—but what causes β-catenin accumulation? In this study, the researchers have investigated this question to try to identify a target for drugs to treat HPT.
What Did the Researchers Do and Find?
The researchers looked for genetic changes (mutations) in β-catenin that stabilize the protein and measured the expression of LRP5 in abnormal parathyroid gland tissue from 37 patients with pHPT and 20 with uremia and sHPT. All the samples contained high levels of β-catenin, but only four contained a β-catenin–stabilizing mutation. All the sHPT samples and 32 pHPT samples (but none of the samples containing the β-catenin stabilizing mutation) expressed a mutated LRP5, with the central region deleted. To investigate the functional consequences of this internally deleted LRP5 protein, the researchers used a technique called RNA interference to block its expression in a human parathyroid tumor cell line. They found that expression of the mutated, short LRP5 is required for accumulation of β-catenin, expression of c-Myc, and continued growth of the cell line in test tubes and in animals.
What Do These Findings Mean?
The accumulation of β-catenin in all the enlarged parathyroid glands examined so far strongly implicates abnormal Wnt/β-catenin signaling in the development of pHPT and sHPT. These new findings identify which part of the signaling pathway is altered. The expression data and functional data together suggest that an internally deleted LRP5 coreceptor is often responsible for the accumulation of β-catenin. The functional data also show that expression of shortened LRP5 is necessary for the abnormal growth of parathyroid tumor cells. Exactly how the internally deleted coreceptor activates β-catenin signaling in parathyroid gland cells, or why a shorter-than-normal LRP5 is made, are not yet known. However, because these findings indicate that internally deleted LRP5 has a fundamental role in activating Wnt signaling in HPT, drugs that inactivate this aberrant protein but leave the normal protein unscathed might provide a nonsurgical treatment for this common hormone disorder.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040328.
edlinePlus has encyclopedia pages on hyperparathyroidism, primary hyperparathyroidism, and secondary hyperparathyroidim (in English and Spanish)
Information is available for patients from the US National Institute of Diabetes and Digestive and Kidney Diseases on hyperparathyroidism, which includes links to organizations that help people with hyperparathyroidism
Wikipedia maintains pages on Wnt signaling pathway and on β-catenin (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
doi:10.1371/journal.pmed.0040328
PMCID: PMC2082644  PMID: 18044981
11.  Cystatin C as an Early Biomarker of Nephropathy in Patients with Type 2 Diabetes 
Journal of Korean Medical Science  2011;26(2):258-263.
This study was done to evaluate clinical usefulness of cystatin C levels of serum and urine in predicting renal impairment in normoalbuminuric patients with type 2 diabetes and to evaluate the association between albuminuria and serum/urine cystatin C. Type 2 diabetic patients (n = 332) with normoalbuminuria (n = 210), microalbuminuria (n = 83) and macroalbuminuria (n = 42) were enrolled. Creatinine, urinary albumin levels, serum/urine cystatin C and estimated glomerular filtration rate (eGFR by MDRD [Modification of Diet in Renal Disease] and CKD-EPI [Chronic Kidney Disease Epidemiology Collaboration] equations) were determined. The cystatin C levels of serum and urine increased with increasing degree of albuminuria, reaching higher levels in macroalbuminuric patients (P < 0.001). In multiple regression analysis, serum cystatin C was affected by C-reactive protein (CRP), sex, albumin-creatinine ratio (ACR) and eGFR. Urine cystatin C was affected by triglyceride, age, eGFR and ACR. In multivariate logistic analysis, cystatin C levels of serum and urine were identified as independent factors associated with eGFR < 60 mL/min/1.73 m2 estimated by MDRD equation in patients with normoalbuminuria. On the other hand, eGFR < 60 mL/min/1.73 m2 estimated by CKD-EPI equation was independently associated with low level of high-density lipoprotein in normoalbuminuric patients. The cystatin C levels of serum and urine could be useful markers for renal dysfunction in type 2 diabetic patients with normoalbuminuria.
doi:10.3346/jkms.2011.26.2.258
PMCID: PMC3031011  PMID: 21286018
Cystatin C; Diabetic Nephropathies; Albuminuria
12.  Oral Paricalcitol for the Treatment of Secondary Hyperparathyroidism in Chronic Kidney Disease 
Secondary hyperparathyroidism (SHPT) is commonly seen in patients with chronic kidney disease (CKD). Even in early CKD, parathyroid hormone (PTH) levels are elevated, maintaining mineral homeostasis at the cost of long-term bone health. One potent stimulus for PTH secretion is a deficiency of active vitamin D. Replacement with calcitriol, the active form of vitamin D, lowers PTH but often raises calcium and phosphorus levels, predisposing patients to an increased risk of ectopic calcifications. Paricalcitol is a vitamin D analog designed to treat SHPT without raising serum calcium and phosphorus levels. The intravenous preparation of paricalcitol is used routinely in the hemodialysis population and has demonstrated a survival benefit over calcitriol in hemodialysis patients. A new oral preparation has now been developed for use in the pre-dialysis CKD population. Thus far, oral paricalcitol has been shown to reduce PTH by an average of 42% in CKD patients, while having minimal effects on serum calcium and phosphorus. While long term effects of the oral preparation have yet to be studied, emerging evidence suggests that paricalcitol mediates a variety of beneficial effects through the activation of vitamin D receptors which may result in improved survival.
PMCID: PMC1936265  PMID: 18360604
paricalcitol; secondary hyperparathyroidism; chronic kidney disease
13.  Angiopoietin-2 Is Associated with Albuminuria and Microinflammation in Chronic Kidney Disease 
PLoS ONE  2013;8(3):e54668.
Although cardiovascular disease (CVD) is the leading cause of mortality in patients with chronic kidney disease (CKD), the pathophysiology is not thoroughly understood. Given that elevated albuminuria or circulating angiopoietin-2 associates with CVD and mortality in CKD patients, we were intrigued by the relationship between albuminuria and angiopoietin-2. A total of 416 patients with CKD stages 3 to 5 were stratified by urine albumin-creatinine ratio as normoalbuminuria (<30 mg/g), microalbuminuria (30–300 mg/g), or macroalbuminuria (>300 mg/g). The levels of plasma angiopoietin-2 and vascular endothelial growth factor (VEGF) increased, and soluble Tie-2 decreased in the subgroups of albuminuria; whereas angiopoietin-1 did not change. Linear regression showed a positive correlation between urine albumin-creatinine ratio (ACR) and plasma angiopoietin-2 (correlation coefficient r = 0.301, 95% confidence interval 0.211–0.386, P<0.0001), but not between ACR and VEGF or soluble Tie-2. Multivariate linear regression analysis showed that plasma angiopoietin-2 was independently associated with ACR (P = 0.025). Furthermore, plasma angiopoietin-2 was positively correlated with high sensitive C-reactive protein (r = 0.114, 95% confidence interval 0.018–0.208, P = 0.020). In conclusion, plasma angiopoietin-2 was associated with albuminuria and markers of systemic microinflammation in CKD patients. Although previous evidence has shown that angiopoietin-2 destabilizes vasculature and induces inflammation in different scenarios, further study will be required to delineate the role of angiopoietin-2 in albuminuria and microinflammation in CKD patients.
doi:10.1371/journal.pone.0054668
PMCID: PMC3585725  PMID: 23469160
14.  Eldecalcitol reduces the risk of severe vertebral fractures and improves the health-related quality of life in patients with osteoporosis 
Eldecalcitol reduces the risk of vertebral fractures in comparison to alfacalcidol in osteoporotic patients under vitamin D repletion. The aim of this study was to evaluate the effects of eldecalcitol on the spinal location of incident vertebral fractures, the severity of the fractures, and the changes in health-related quality of life (HRQOL) compared with those of alfacalcidol. The post hoc analysis has been performed on the data from the three-year, double-blind, randomized, head-to-head clinical trial of eldecalcitol versus alfacalcidol conducted in Japan. A total of 1054 patients were enrolled and randomized to take 0.75 μg eldecalcitol or 1.0 μg alfacalcidol daily for 3 years. The incidence of vertebral fractures was re-evaluated based on the location on the spine (upper T4–T10; lower T11–L4). The severity of vertebral fractures was determined by the semi-quantitative method, and the change in HRQOL was analyzed by using the Medical Outcomes Study Short Form 36-item questionnaire. The incidence of vertebral fracture at the lower spine was less in the eldecalcitol group than in the alfacalcidol group (p = 0.029). The incidence of severe vertebral fracture (Grade 3) was 3.8 % in the eldecalcitol group and 6.7 % in the alfacalcidol group, demonstrated a significant difference between the 2 groups (p = 0.036). Both eldecalcitol and alfacalcidol improved HRQOL in osteoporotic patients. Although no significant differences in each HRQOL scores were observed between eldecalcitol and alfacalcidol during the observational period, overall improvement from baseline of HRQOL scores were clearly observed in the eldecalcitol group. In conclusion, the incidences of lower spinal vertebral fractures and severe vertebral fractures were reduced further by eldecalcitol compared to alfacalcidol in the 3-year clinical trial. Daily treatment with eldecalcitol is effective in improving HRQOL, possibly owing to the reduced risk of lower spinal vertebral fractures and/or severe vertebral fractures.
doi:10.1007/s00774-012-0397-6
PMCID: PMC3590407  PMID: 23129180
Eldecalcitol; Health-related quality of life; Osteoporosis; Vertebral fracture
15.  Cinacalcet HCl prevents development of parathyroid gland hyperplasia and reverses established parathyroid gland hyperplasia in a rodent model of CKD 
Nephrology Dialysis Transplantation  2011;27(6):2198-2205.
Background.
Secondary hyperparathyroidism (sHPT) represents an adaptive response to progressively impaired control of calcium, phosphorus and vitamin D in chronic kidney disease (CKD). It is characterized by parathyroid hyperplasia and excessive synthesis and secretion of parathyroid hormone (PTH). Parathyroid hyperplasia in uremic rats can be prevented by calcium-sensing receptor (CaSR) activation with the calcimimetic cinacalcet (Sensipar®/Mimpara®); however, it is unknown, how long the effects of cinacalcet persist after withdrawal of treatment or if cinacalcet is efficacious in uremic rats with established sHPT.
Methods.
We sought to determine the effect of cinacalcet discontinuation in uremic rats and whether cinacalcet was capable of influencing parathyroid hyperplasia in animals with established sHPT.
Results.
Discontinuation of cinacalcet resulted in reversal of the beneficial effects on serum PTH and parathyroid hyperplasia. In rats with established sHPT, cinacalcet decreased serum PTH and mediated regression of parathyroid hyperplasia. The cinacalcet-mediated decrease in parathyroid gland size was accompanied by increased expression of the cyclin-dependent kinase inhibitor p21. Prevention of cellular proliferation with cinacalcet occurred despite increased serum phosphorus and decreased serum calcium.
Conclusions.
The animal data provided suggest established parathyroid hyperplasia can be reversed by modulating CaSR activity with cinacalcet and that continued treatment may be necessary to maintain reductions in PTH.
doi:10.1093/ndt/gfr589
PMCID: PMC3363978  PMID: 22036941
calcimimetics; cinacalcet; parathyroid hormone; parathyroid hyperplasia; secondary hyperparathyroidism
16.  Prevalence and Determinants of Diabetic Nephropathy in Korea: Korea National Health and Nutrition Examination Survey 
Diabetes & Metabolism Journal  2014;38(2):109-119.
Background
Diabetic nephropathy is a leading cause of end stage renal disease and is associated with an increased risk of cardiovascular mortality. It manifests as albuminuria or impaired glomerular filtration rate (GFR), and the prevalence of diabetic nephropathy varies with ethnicity. The prevalence of diabetic nephropathy and its determinants in Korean adults have not previously been studied at the national level. This cross-sectional study was undertaken to ascertain the prevalence and determinants of albuminuria and chronic kidney disease (CKD) in Korean patients with diabetes.
Methods
The Korea National Health and Nutrition Examination Survey (KNHANES) V, conducted in 2011, was used to define albuminuria (n=4,652), and the dataset of KNHANES IV-V (2008-2011) was used to define CKD (n=21,521). Selected samples were weighted to represent the entire civilian population in Korea. Albuminuria was defined as a spot urine albumin/creatinine ratio >30 mg/g. CKD was defined as a GFR <60 mL/min/1.73 m2.
Results
Among subjects with diabetes, 26.7% had albuminuria, and 8.6% had CKD. Diabetes was associated with an approximate 2.5-fold increased risk of albuminuria, with virtually no difference between new-onset and previously diagnosed diabetes. Only systolic blood pressure was significantly associated with albuminuria, and old age, high serum triglyceride levels, and previous cardiovascular disease (CVD) were related with CKD in subjects with diabetes.
Conclusion
Korean subjects with diabetes had a higher prevalence of albuminuria and CKD than those without diabetes. Blood pressure was associated with albuminuria, and age, triglyceride level, and previous CVD were independent determinants of CKD in subjects with diabetes.
doi:10.4093/dmj.2014.38.2.109
PMCID: PMC4021298  PMID: 24851205
Albuminuria; Chronic renal disease; Diabetes mellitus; Diabetic nephropathy; Korea
17.  Vitamin D supplementation and mortality risk in chronic kidney disease: a meta-analysis of 20 observational studies 
BMC Nephrology  2013;14:199.
Background
Vitamin D insufficiency correlates with mortality risk among patients with chronic kidney disease (CKD). The survival benefits of active vitamin D treatment have been assessed in patients with CKD not requiring dialysis and in patients with end stage renal disease (ESRD) requiring dialysis.
Methods
MEDLINE, Embase, the Cochrance Library, and article reference lists were searched for relevant observational trials. The quality of the studies was evaluated using the Newcastle-Ottawa Scale (NOS) checklist. Pooled effects were calculated as hazard ratios (HR) using random-effects models.
Results
Twenty studies (11 prospective cohorts, 6 historical cohorts and 3 retrospective cohorts) were included in the meta-analysis., Participants receiving vitamin D had lower mortality compared to those with no treatment (adjusted case mixed baseline model: HR, 0.74; 95% confidence interval [95% CI], 0.67-0.82; P <0.001; time-dependent Cox model: HR, 0.71; 95% CI, 0.57-0.89; P <0.001). Participants that received calcitriol (HR, 0.63; 95% CI, 0.50-0.79; P <0.001) and paricalcitol (HR, 0.43 95% CI, 0.29-0.63; P <0.001) had a lower cardiovascular mortality. Patients receiving paricalcitol had a survival advantage over those that received calcitriol (HR, 0.95; 95% CI, 0.91-0.99; P <0.001).
Conclusions
Vitamin D treatment was associated with decreased risk of all-cause and cardiovascular mortality in patients with CKD not requiring dialysis and patients with end stage renal disease (ESRD) requiring dialysis. There was a slight difference in survival depending on the type of vitamin D analogue. Well-designed randomized controlled trials are necessary to assess the survival benefits of vitamin D.
doi:10.1186/1471-2369-14-199
PMCID: PMC3851063  PMID: 24066946
Vitamin D; Mortality; Calcitriol; Paricalcitol; Chronic kidney disease
18.  Three-Year Successful Cinacalcet Treatment of Secondary Hyperparathyroidism in a Patient with X-Linked Dominant Hypophosphatemic Rickets: A Case Report 
Case Reports in Endocrinology  2014;2014:479641.
Hypophosphatemic rickets (HR) is a rare inherited disorder characterized by a classic rickets phenotype with low plasma phosphate levels and resistance to treatment with vitamin D. Development of secondary hyperparathyroidism (SHPT) as a direct consequence of treatment is a frequent complication and a major clinical challenge, as this may increase risk of further comorbidity. Cinacalcet, a calcimimetic agent that reduces the secretion of PTH from the parathyroid glands, has been suggested as adjuvant treatment to SHPT in patients with HR. However, only two papers have previously been published and no data are available on effects of treatment for more than six months. We now report a case of 3-year treatment with cinacalcet in a patient with HR complicated by SHPT. A 53-year-old woman with genetically confirmed X-linked dominant hypophosphatemic rickets developed SHPT after 25 years of conventional treatment with alfacalcidol and phosphate supplements. Cinacalcet was added to her treatment, causing a sustained normalization of PTH. Ionized calcium decreased, requiring reduction of cinacalcet, though asymptomatical. Level of phosphate was unchanged, but alkaline phosphatase increased in response to treatment. Cinacalcet appeared to be efficient, safe, and well tolerated. We recommend close control of plasma calcium to avoid hypocalcemia.
doi:10.1155/2014/479641
PMCID: PMC3934321  PMID: 24660072
19.  Long-Term Survival and Dialysis Dependency Following Acute Kidney Injury in Intensive Care: Extended Follow-up of a Randomized Controlled Trial 
PLoS Medicine  2014;11(2):e1001601.
Martin Gallagher and colleagues examine the long-term outcomes of renal replacement therapy (RRT) dosing in patients with acute kidney injury randomized to normal vs. augmented RRT.
Please see later in the article for the Editors' Summary
Background
The incidence of acute kidney injury (AKI) is increasing globally and it is much more common than end-stage kidney disease. AKI is associated with high mortality and cost of hospitalisation. Studies of treatments to reduce this high mortality have used differing renal replacement therapy (RRT) modalities and have not shown improvement in the short term. The reported long-term outcomes of AKI are variable and the effect of differing RRT modalities upon them is not clear. We used the prolonged follow-up of a large clinical trial to prospectively examine the long-term outcomes and effect of RRT dosing in patients with AKI.
Methods and Findings
We extended the follow-up of participants in the Randomised Evaluation of Normal vs. Augmented Levels of RRT (RENAL) study from 90 days to 4 years after randomization. Primary and secondary outcomes were mortality and requirement for maintenance dialysis, respectively, assessed in 1,464 (97%) patients at a median of 43.9 months (interquartile range [IQR] 30.0–48.6 months) post randomization. A total of 468/743 (63%) and 444/721 (62%) patients died in the lower and higher intensity groups, respectively (risk ratio [RR] 1.04, 95% CI 0.96–1.12, p = 0.49). Amongst survivors to day 90, 21 of 411 (5.1%) and 23 of 399 (5.8%) in the respective groups were treated with maintenance dialysis (RR 1.12, 95% CI 0.63–2.00, p = 0.69). The prevalence of albuminuria among survivors was 40% and 44%, respectively (p = 0.48). Quality of life was not different between the two treatment groups. The generalizability of these findings to other populations with AKI requires further exploration.
Conclusions
Patients with AKI requiring RRT in intensive care have high long-term mortality but few require maintenance dialysis. Long-term survivors have a heavy burden of proteinuria. Increased intensity of RRT does not reduce mortality or subsequent treatment with dialysis.
Trial registration
www.ClinicalTrials.gov NCT00221013
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Throughout life, the kidneys perform the essential task of filtering waste products (from the normal breakdown of tissues and from food) and excess water from the blood to make urine. Chronic kidney disease (caused, for example, by diabetes) gradually destroys the kidneys' filtration units (the nephrons), eventually leading to life-threatening end-stage kidney disease. However, the kidneys can also stop working suddenly because of injury, infection, or poisoning. Acute kidney injury (AKI) is much more common than end-stage kidney disease and its incidence is increasing worldwide. In the US, for example, the number of hospitalizations that included an AKI diagnosis rose from 4,000 in 1996 to 23,000 in 2008. Moreover, nearly half of patients with AKI will die shortly after the condition develops. Symptoms of AKI include changes in urination, swollen feet and ankles, and tiredness. Treatments for AKI aim to prevent fluid and waste build up in the body and treat the underlying cause (e.g., severe infection or dehydration) while allowing the kidneys time to recover. In some patients, it is sufficient to limit the fluid intake and to reduce waste build-up by eating a diet that is low in protein, salt, and potassium. Other patients need renal replacement therapy (RRT), life-supporting treatments such as hemodialysis and hemofiltration, two processes that clean the blood by filtering it outside the body.
Why Was This Study Done?
The long-term outcomes of AKI (specifically, death and chronic kidney disease) and the effects of different RRT modalities on these outcomes are unclear. A recent controlled trial that randomly assigned patients with AKI who were managed in intensive care units (ICUs) to receive two different intensities of continuous hemodiafiltration (a combination of hemodialysis and hemofiltration) found no difference in all-cause mortality (death) at 90 days. Here, the researchers extend the follow-up of this trial (the Randomized Evaluation of Normal vs. Augmented Levels of renal replacement therapy [RENAL] study) to investigate longer-term mortality, the variables that predict mortality, treatment with long-term dialysis (an indicator of chronic kidney disease), and functional outcomes in patients with AKI treated with different intensities of continuous RRT.
What Did the Researchers Do and Find?
For the Prolonged Outcomes Study of RENAL (POST-RENAL), the researchers extended the follow-up of the RENAL participants up to 4 years. Over an average follow-up of 43.9 months, 63% of patients in the lower intensity treatment group died compared to 62% of patients in the higher intensity group. Overall, a third of patients who survived to 90 days died during the extended follow-up. Among the survivors to day 90, 5.1% and 5.8% of patients in the lower and higher intensity groups, respectively, were treated with maintenance dialysis during the extended follow-up. Among survivors who consented to analysis, 40% and 44% of patients in the lower and higher intensity groups, respectively, had albuminuria (protein in the urine, an indicator of kidney damage). Patients in both groups had a similar quality life (determined through telephone interviews). Finally, increasing age, APACHE III score (a scoring system that predicts the survival of patients in ICU), and serum creatinine level (an indicator of kidney function) at randomization were all predictors of long-term mortality.
What Do These Findings Mean?
These findings indicate that patients with AKI in ICUs who require RRT have a high long-term mortality. They show that few survivors require maintenance dialysis for chronic kidney disease but that there is a substantial rate of albuminuria among survivors despite relative preservation of kidney function. The findings also suggest that the intensity of RRT has no significant effect on mortality or the need for dialysis. Because these findings were obtained in a randomized controlled trial, they may not be generalizable to other patient populations. Moreover, although data on mortality and maintenance dialysis were available for all the trial participants, clinical and biochemical outcomes were only available for some participants and may not be representative of all the participants. Despite these study limitations, these findings suggest that survivors of AKI may be at a high risk of death or of developing chronic kidney disease. Survivors of AKI are, therefore, at high risk of further illness and long-term albuminuria reduction strategies may offer a therapeutic intervention for this group of patients.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001601.
The US National Kidney and Urologic Diseases Information Clearinghouse provides information about the kidneys and about all aspects of kidney disease and its treatment; the US National Kidney Disease Education Program provides resources to help improve the understanding, detection, and management of kidney disease (in English and Spanish)
The Mayo Clinic provides information for patients about acute kidney injury
Wikipedia has a page on acute kidney injury (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The not-for-profit UK National Kidney Federation provides support and information for patients with kidney disease and for their carers, including a link to a video about acute kidney injury
World Kidney Day, a joint initiative between the International Society of Nephrology and the International Federation of Kidney Foundations (IFKF), aims to raise awareness about kidneys and kidney disease; its website provides information about acute kidney injury
The MedlinePlus Encyclopedia has a pages about acute kidney failure and about renal dialysis
The UK National Institute for Health and Care Excellence (NICE) recently published new guidelines on the treatment of acute kidney injury; a clinical practice guideline for acute kidney injury produced by KDIGO (a not-for-profit organization that aims to improve the care and outcomes of kidney disease patients worldwide through the development and implementation of global clinical practice guidelines) is available; the Acute Kidney Injury app provides a fast and simple way to explore guidelines on the diagnosis, prevention, and management of AKI
doi:10.1371/journal.pmed.1001601
PMCID: PMC3921111  PMID: 24523666
20.  Phylloquinone and Vitamin D Status: Associations with Incident Chronic Kidney Disease in the Framingham Offspring Cohort 
American journal of nephrology  2012;36(1):68-77.
Background
Cardiovascular risk factors are associated with the development of chronic kidney disease (CKD), and CKD and vascular disease are etiologically linked. Evidence suggests deficiencies of vitamins D and K may adversely affect the cardiovascular system, but data from longitudinal studies are lacking. We hypothesized that deficiencies of vitamins D and K may be associated with incident CKD and/or incident albuminuria amongst members of the general population.
Methods
We analyzed 1442 Framingham Heart Study participants (mean age 58 years; 50.5% women), free of CKD (eGFR<60 ml/min/1.732), with a mean follow-up of 7.8 years in 2005–2008. Incident albuminuria was defined using sex-specific cutoffs of urine albumin-to-creatinine ratio (≥17 mg/g men and ≥25 mg/g women). Baseline log plasma phylloquinone (vitamin K1) and 25(OH)D levels, analyzed as continuous variables and by quartile, were related to risk of incident CKD (n=108) and incident albuminuria (n=106) using logistic regression models adjusted for standard risk factors.
Results
Participants in the highest phylloquinone quartile (≥1.78 nmol/L) had an increased risk of CKD (multivariable-adjusted OR Q4 vs. Q1 2.39; p=0.006) and albuminuria at follow-up (multivariable-adjusted OR Q4 vs. Q1 1.95; p=0.05), whereas no association was observed with continuous phylloquinone levels for either endpoint. Deficiency of 25(OH)D was not associated with incident CKD or albuminuria in either analysis.
Conclusions
Contrary to our hypothesis, higher plasma phylloquinone levels are associated with an increased risk of incident CKD. Whether plasma phylloquinone is a marker for another unmeasured risk factor requires further study. External validation is necessary given the unexpected nature of these results.
doi:10.1159/000339005
PMCID: PMC3435876  PMID: 22722822
Chronic kidney disease; vitamin K; vitamin D
21.  Assessment of Proteinuria in Patients with Chronic Kidney Disease Stage 3: Albuminuria and Non-Albumin Proteinuria 
PLoS ONE  2014;9(5):e98261.
Background and Objective
Proteinuria assessment is key in investigating chronic kidney disease (CKD) but uncertainty exists regarding optimal methods. Albuminuria, reflecting glomerular damage, is usually measured, but non-albumin proteinuria (NAP), reflecting tubular damage, may be important. This study investigated the prevalence and associations of albuminuria and NAP, and the optimum number of urine specimens required.
Methods
1,741 patients with CKD stage 3, recruited from primary care, underwent medical history, clinical assessment, blood sampling, and submitted three early morning urine samples for albumin to creatinine ratio (uACR) and protein to creatinine ratios (uPCR). Albuminuria was defined as uACR ≥3 mg/mmol in at least two of three samples. Isolated NAP was defined as uPCR ≥17 mg/mmol in two of three samples and uACR <3 mg/mmol in all three. Prevalence and associations of albuminuria and NAP, degree of agreement between single uACR and average of three uACRs, and urine albumin to protein ratio (uAPR = uACR/uPCR) were identified.
Results
Albuminuria prevalence was 16% and NAP 6%. Using a <1 mg/mmol threshold for uACR reduced NAP prevalence to 3.6%. Independent associations of albuminuria were: males (OR 3.06 (95% CI, 2.23–4.19)), diabetes (OR 2.14 (1.53–3.00)), lower estimated glomerular filtration rate ((OR 2.06 (1.48–2.85) 30–44 vs 45–59), and high sensitivity CRP ((OR 1.70 (1.25–2.32)). NAP was independently associated with females (OR 6.79 (3.48–13.26)), age (OR 1.62 (1.02–2.56) 80 s vs 70–79) and high sensitivity CRP ((OR 1.74 (1.14–2.66)). Of those with uPCR≥17 mg/mmol, 62% had uAPR<0.4. Sensitivity of single uACR was 95%, specificity 98%, PPV 90%. Bland Altman plot one vs average of three uACRs showed: mean difference 0.0064 mg/mmol (SD 4.69, limits of agreement −9.19 to +9.20, absolute mean difference 0.837).
Conclusions
In CKD stage 3, albuminuria has associations distinct from those of isolated NAP (except for inflammatory markers). Single uACR categorised albuminuria but average of three performed better for quantification.
doi:10.1371/journal.pone.0098261
PMCID: PMC4035283  PMID: 24867154
22.  25-hydroxyvitamin D Levels and chronic kidney disease in the AusDiab (Australian Diabetes, Obesity and Lifestyle) study 
BMC Nephrology  2012;13:55.
Background
Low 25-hydroxy vitamin D (25(OH)D) levels have been associated with an increased risk of albuminuria, however an association with glomerular filtration rate (GFR) is not clear. We explored the relationship between 25(OH)D levels and prevalent chronic kidney disease (CKD), albuminuria and impaired GFR, in a national, population-based cohort of Australian adults (AusDiab Study).
Methods
10,732 adults ≥25 years of age participating in the baseline survey of the AusDiab study (1999–2000) were included. The GFR was estimated using an enzymatic creatinine assay and the CKD-EPI equation, with CKD defined as eGFR <60 ml/min/1.73 m2. Albuminuria was defined as a spot urine albumin to creatinine ratio (ACR) of ≥2.5 mg/mmol for men and ≥3.5 for women. Serum 25(OH)D levels of <50 nmol/L were considered vitamin D deficient. The associations between 25(OH)D level, albuminuria and impaired eGFR were estimated using multivariate regression models.
Results
30.7% of the study population had a 25(OH)D level <50 nmol/L (95% CI 25.6-35.8). 25(OH)D deficiency was significantly associated with an impaired eGFR in the univariate model (OR 1.52, 95% CI 1.07-2.17), but not in the multivariate model (OR 0.95, 95% CI 0.67-1.35). 25(OH)D deficiency was significantly associated with albuminuria in the univariate (OR 2.05, 95% CI 1.58-2.67) and multivariate models (OR 1.54, 95% CI 1.14-2.07).
Conclusions
Vitamin D deficiency is common in this population, and 25(OH)D levels of <50 nmol/L were independently associated with albuminuria, but not with impaired eGFR. These associations warrant further exploration in prospective and interventional studies.
doi:10.1186/1471-2369-13-55
PMCID: PMC3441805  PMID: 22759247
Albuminuria; Chronic kidney disease; Glomerular filtration rate; and Vitamin D
23.  Moderate Antiproteinuric Effect of Add-On Aldosterone Blockade with Eplerenone in Non-Diabetic Chronic Kidney Disease. A Randomized Cross-Over Study 
PLoS ONE  2011;6(11):e26904.
Background
Reduction of proteinuria and blood pressure (BP) with blockers of the renin-angiotensin system (RAS) impairs the progression of chronic kidney disease (CKD). The aldosterone antagonist spironolactone has an antiproteinuric effect, but its use is limited by side effects. The present study evaluated the short-term antiproteinuric effect and safety of the selective aldosterone antagonist eplerenone in non-diabetic CKD.
Study Design
Open randomized cross-over trial.
Setting and Participants
Forty patients with non-diabetic CKD and urinary albumin excretion greater than 300 mg/24 hours.
Intervention
Eight weeks of once-daily administration of add-on 25–50 mg eplerenone to stable standard antihypertensive treatment including RAS-blockade.
Outcomes & Measurements
24 hour urinary albumin excretion, BP, p-potassium, and creatinine clearance.
Results
The mean urinary albumin excretion was 22% [CI: 14,28], P<0.001, lower during treatment with eplerenone. Mean systolic BP was 4 mmHg [CI: 2,6], P = 0.002, diastolic BP was 2 mmHg [CI: 0,4], P = 0.02, creatinine clearance was 5% [CI: 2,8], P = 0.005, lower during eplerenone treatment. After correction for BP and creatinine clearance differences between the study periods, the mean urinary albumin excretion was 14% [CI: 4,24], P = 0.008 lower during treatment. Mean p-potassium was 0.1 mEq/L [CI: 0.1,0.2] higher during eplerenone treatment, P<0.001. Eplerenone was thus well tolerated and no patients were withdrawn due to hyperkalaemia.
Limitations
Open label, no wash-out period and a moderate sample size.
Conclusions
In non-diabetic CKD patients, the addition of eplerenone to standard antihypertensive treatment including RAS-blockade caused a moderate BP independent fall in albuminuria, a minor fall in creatinine clearance and a 0.1 mEq/L increase in p-potassium.
Trial Registration
Clinicaltrials.gov NCT00430924
doi:10.1371/journal.pone.0026904
PMCID: PMC3208556  PMID: 22073219
24.  Calcimimetics or vitamin D analogs for suppressing parathyroid hormone in end-stage renal disease: time for a paradigm shift? 
SUMMARY
Considerable advances have been made in the understanding of the pathogenesis and treatment of secondary hyperparathyroidism (SHPT) in chronic kidney disease (CKD). These include the discovery that the calcium-sensing receptor has an important role in the regulation of parathyroid gland function, the development of calcimimetics to target this receptor, the recognition that vitamin D receptor activation has important functions beyond the regulation of mineral metabolism, the identification of the phosphaturic factor fibroblast growth factor 23 and the contribution of this hormone to disordered phosphate and vitamin D metabolism in CKD. However, despite the availability of calcimimetics, phosphate binders, and vitamin D analogs, control of SHPT remains suboptimal in many patients with advanced kidney disease. In this Review, we explore several unresolved issues regarding the pathogenesis and treatment of SHPT. Specifically, we examine the significance of elevated circulating fibroblast growth factor 23 levels in CKD, question the proposition that calcitriol deficiency is truly a pathological state, explore the relative importance of the vitamin D receptor and the calcium-sensing receptor in parathyroid gland function and evaluate the evidence to support the treatment of SHPT with calcimimetics and vitamin D analogs. Finally, we propose a novel treatment framework in which calcimimetics are the primary therapy for suppressing parathyroid hormone production in patients with end-stage renal disease.
doi:10.1038/ncpneph0977
PMCID: PMC3924719  PMID: 18957950
calcimimetics; calcium-sensing receptor; chronic kidney disease; secondary hyperparathyroidism; vitamin D
25.  Impact of cinacalcet introduction on MBD management: the MBD-5D study in Japan 
Kidney International Supplements  2013;3(5):436-441.
Chronic kidney disease-mineral and bone disorder (CKD-MBD) has recently attracted attention in light of its association with clinical outcomes, such as fracture, cardiovascular disease, and mortality. Management of CKD-MBD has therefore come to have a central role in dialysis practice. Cinacalcet, a newly developed drug, has changed prescription patterns in many centers based on different changes in MBD markers than those observed with active vitamin D derivatives. As physicians require real-world evidence to guide their treatment decisions with respect to MBD management, we conducted the Mineral and Bone Disorder Outcomes Study for Japanese CKD Stage 5D Patients (MBD-5D), a 3-year observational study involving prevalent hemodialysis patients with secondary hyperparathyroidism (SHPT). Here, we review the results from the MBD-5D and discuss issues of MBD management in the cinacalcet era. Three years since the introduction of cinacalcet, 40% of hemodialysis patients with SHPT have come to use cinacalcet, enjoying marked improvement in management of circulating MBD markers, such as intact parathyroid hormone (PTH), phosphorus, and calcium. Combination therapy with cinacalcet and a vitamin D receptor activator (VDRA) may allow physicians to choose more suitable prescription patterns based on patient characteristics and therapeutic purposes. We observed an additive association between ‘starting cinacalcet' and ‘increased VDRA dose,' with marked improvement in the control of intact PTH levels. Further, the combination pattern of ‘starting cinacalcet' and ‘decreased VDRA dose' was associated with better achievement of target serum phosphorus and calcium levels. Future studies should examine the effect of different prescription patterns for SHPT treatment on clinical outcomes.
doi:10.1038/kisup.2013.91
PMCID: PMC4089738  PMID: 25019026
cinacalcet; dialysis patients; mineral and bone disorder

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