The incidence of gout rises with increasing age. Management of elderly (≥65 years) gout patients can be challenging due to high rates of comorbidities, such as renal impairment and cardiovascular disease, and concomitant medication use. However, there is little data specifically addressing the efficacy and safety of available urate-lowering therapies (ULT) in the elderly. The objective of this post hoc analysis was to examine the efficacy and safety of ULT with febuxostat or allopurinol in a subset of elderly subjects enrolled in the CONFIRMS trial.
Hyperuricemic (serum urate [sUA] levels ≥ 8.0 mg/dL) gout subjects were enrolled in the 6-month, double-blind, randomized, comparative CONFIRMS trial and randomized, 1:1:1, to receive febuxostat, 40 mg or 80 mg, or allopurinol (200 mg or 300 mg based on renal function) once daily. Flare prophylaxis was provided throughout the study duration.
Study endpoints were the percent of elderly subjects with sUA <6.0 mg/dL at the final visit, overall and by renal function status, percent change in sUA from baseline to final visit, flare rates, and rates of adverse events (AEs).
Of 2,269 subjects enrolled, 374 were elderly. Febuxostat 80 mg was significantly more efficacious (82.0%) than febuxostat 40 mg (61.7%; p < 0.001) or allopurinol (47.3%; p < 0.001) for achieving the primary efficacy endpoint. Febuxostat 40 mg was also superior to allopurinol in this population (p = 0.029). In subjects with mild-to-moderate renal impairment, significantly greater ULT efficacy was observed with febuxostat 40 mg (61.6%; p = 0.028) and febuxostat 80 mg (82.5%; p < 0.001) compared to allopurinol 200/300 mg (46.9%). Compared to allopurinol 200/300 mg, the mean percent change in sUA from baseline was significantly greater for both febuxostat 80 mg (p < 0.001) and febuxostat 40 mg (p = 0.011) groups. Flare rates declined steadily in all treatment groups. Rates of AEs were low and comparable across treatments.
These data suggest that either dose of febuxostat is superior to commonly prescribed fixed doses of allopurinol (200/300 mg) in subjects ≥65 years of age with high rates of renal dysfunction. In addition, in this high-risk population, ULT with either drug was well tolerated.
There is a disproportionate burden of gout in African-Americans in the U.S. due to a higher disease prevalence and lower likelihood of receiving urate-lowering therapy (ULT), compared to Caucasians. There is an absence of strong data as to whether the response to ULT differs by race/ethnicity. BMC Musculoskeletal Disorders recently published a secondary analyses of the CONFIRMS trial, a large randomized controlled, double-blind trial of 2,269 gout patients. The authors reported that the likelihood of achieving the primary study efficacy end-point of achieving serum urate < 6 mg/dl was similar between African-Americans and Caucasians, for all three treatment arms (Febuxostat 40 mg and 80 mg and allopurinol 300/200 mg). More importantly, rates were similar in subgroups of patients with mild or moderate renal insufficiency. Adverse event rates were similar, as were the rates of gout flares. These findings constitute a convincing evidence to pursue aggressive ULT in gout patients, regardless of race/ethnicity. This approach will likely help to narrow the documented racial disparities in gout care.
Please see related article: http://www.biomedcentral.com/1471-2474/13/15
Gout; Disparity; Race; treatment; Febuxostat; Allopurinol; randomized; African-American
The purpose of this study was to compare urate-lowering (UL) efficacy and safety of daily febuxostat and allopurinol in subjects with gout and serum urate (sUA) ≥ 8.0 mg/dL in a six-month trial.
Subjects (n = 2,269) were randomized to febuxostat 40 mg or 80 mg, or allopurinol 300 mg (200 mg in moderate renal impairment). Endpoints included the proportion of all subjects with sUA <6.0 mg/dL and the proportion of subjects with mild/moderate renal impairment and sUA <6.0 mg/dL. Safety assessments included blinded adjudication of each cardiovascular (CV) adverse event (AE) and death.
Comorbidities included: renal impairment (65%); obesity (64%); hyperlipidemia (42%); and hypertension (53%). In febuxostat 40 mg, febuxostat 80 mg, and allopurinol groups, primary endpoint was achieved in 45%, 67%, and 42%, respectively. Febuxostat 40 mg UL was statistically non-inferior to allopurinol, but febuxostat 80 mg was superior to both (P < 0.001). Achievement of target sUA in subjects with renal impairment was also superior with febuxostat 80 mg (72%; P < 0.001) compared with febuxostat 40 mg (50%) or allopurinol (42%), but febuxostat 40 mg showed greater efficacy than allopurinol (P = 0.021). Rates of AEs did not differ across treatment groups. Adjudicated (APTC) CV event rates were 0.0% for febuxostat 40 mg and 0.4% for both febuxostat 80 mg and allopurinol. One death occurred in each febuxostat group and three in the allopurinol group.
Urate-lowering efficacy of febuxostat 80 mg exceeded that of febuxostat 40 mg and allopurinol (300/200 mg), which were comparable. In subjects with mild/moderate renal impairment, both febuxostat doses were more efficacious than allopurinol and equally safe. At the doses tested, safety of febuxostat and allopurinol was comparable.
Clinical Trial Registration
In a previous issue of the journal, Becker and colleagues present efficacy and safety data from a large study comparing febuxostat to allopurinol. The study showed non-inferiority of febuxostat 40 mg/day in lowering serum urate compared to allopurinol 200 to 300 mg/day. More importantly, the study showed a similar frequency of important cardiovascular adverse events (cardiovascular death, nonfatal myocardial infarction and nonfatal stroke) for febuxostat 40 mg/day (0%), febuxostat 80 mg/day (0.4%) and allopurinol groups (0.4%). Other cardiac adverse event rates (unstable angina, coronary revascularization, cerebral revascularization, transient ischemic attack, venous and peripheral arterial vascular thrombotic event, congestive heart failure, and arrhythmia) were also similar for febuxostat 40 mg/day (1.3%), febuxostat 80 mg/day (1.2%) and allopurinol groups (0.9%). A meta-analysis of safety data from published studies is presented.
The Western world appears to be in the midst of the third great gout epidemic of all time. In this century, gout is increasing in prevalence despite an increased understanding of its risk factors and pathophysiology, and the availability of reasonably effective treatment. The main cultural factors responsible for this appear to be diet, obesity, ethanol use and medications. Excess fructose consumption is a newly recognized modifiable risk factor. The debate has been renewed concerning hyperuricemia as an independent risk factor for renal insufficiency and cardiovascular disease. Prevention is still rooted in lifestyle choices. Existing treatments have proven to be unsatisfactory in many patients with comorbidities. New treatments are available today and on the horizon for tomorrow, which offer a better quality of life for gout sufferers. These include febuxostat, a nonpurine inhibitor of xanthine oxidase with a potentially better combination of efficacy and safety than allopurinol, and investigational inhibitors of URAT-1, an anion exchanger in the proximal tubule that is critical for uric acid homeostasis. New abortive treatments include interleukin-1 antagonists that can cut short the acute attack in 1 to 2 days in persons who cannot take nonsteroidal anti-inflammatory drugs, colchicine or corticosteroids. Lastly, newer formulations of uricase have the ability to dissolve destructive tophi over weeks or months in patients who cannot use currently available hypouricemic agents. Diagnostically, ultrasound and magnetic resonance imaging offer advanced ways to diagnose gout noninvasively, and just as importantly, a way to follow the progress of tophus dissolution. The close association of hyperuricemia with metabolic syndrome, hypertension and renal insufficiency ensures that nephrologists will see increasing numbers of gout-afflicted patients.
hyperuricemia; metabolic syndrome; tophi; colchicine; febuxostat; allopurinol
The past decade has witnessed an exponential increase of novel therapeutic modalities for a variety of rheumatic disorders, including gout. During the past few years two novel therapeutic agents have been approved by the US Food and Drug Administration for the treatment of hyperuricemia in patients with gout, one of them being febuxostat, a nonpurine selective inhibitor of xanthine oxidase. Review of its pharmacokinetics and pharmacodynamics, efficacy and safety profile, and use in gout patients with comorbid conditions reveals that age and gender have no clinically significant effect and dose adjustments based on age or gender are not required. In addition, febuxostat can be used in patients with mild-to-moderate renal or hepatic involvement. Its overall efficacy and safety profile is comparable and, in certain subsets such as gout patients with mild and moderate renal insufficiency, is superior to allopurinol.
hyperuricemia; febuxostat; gout; safety profile; efficacy profile
Febuxostat is a novel, potent, non-purine selective xanthine oxidase inhibitor, which in clinical trials demonstrated superior ability to lower and maintain serum urate levels below 6 mg/dL compared with conventionally used doses of allopurinol. Febuxostat was well tolerated in long term treatment in patients with hyperuricemia including those experiencing hypersensitity/intolerance to allopurinol. Dose adjustment appears unnecessary in patients with mild to moderate renal or liver insufficiency or advanced age. The most common adverse reactions reported were abnormal liver function tests, headache, and gastrointestinal symptoms, which were usually mild and transient. However, whether hepatotoxicity becomes a limitation in the use of febuxostat needs to be determined in further studies. An increased frequency of gout flares occurs for a prolonged period after treatment initiation, as with any aggressive lowering of serum urate, and prolonged prophylaxis with colchicine or NSAIDs is usually required. Febuxostat has been granted marketing authorization by the European Commission in early 2008 for the treatment of chronic hyperuricemia and gout. Febuxostat is the first major treatment alternative for gout in more than 40 years and is a promising alternative to allopurinol, although continued long-term surveillance on safety and efficacy is required.
febuxostat; TEI-6720; TMX-67; gout; hyperuricemia; xanthine oxidase inhibitor
Gout is a common and disabling cause of arthritis in middle-aged and elderly populations, with its main predisposing factor being hyperuricemia (serum urate > 6.8 mg/dL). Options for treatment of chronic gout until 2008 were allopurinol, a xanthine oxidase inhibitor, and the group of drugs known as uricosurics that stimulate the renal excretion of uric acid. A proportion of patients, including some with chronic kidney disease and solid organ transplantations, could not be treated with the those therapies because of intolerance, drug interactions, or adverse events. Febuxostat is a nonpurine xanthine oxidase inhibitor, recently approved in Europe and the United States for the treatment of chronic gout.
To review the clinical evidence (phase II and III studies) of the effectiveness and safety of febuxostat for treatment of hyperuricemia and gout.
Febuxostat, at doses ranging from 40 to 240 mg/day, is efficacious in reducing serum urate in patients with hyperuricemia and gout, comparing favorably with fixed doses of allopurinol in that respect. Early safety signals with respect to liver test abnormalities and cardiovascular outcomes have not been confirmed in recent large prospective trials but need to be further monitored.
Given its low cost and extensive clinical experience, allopurinol will likely remain the first-line drug for management of hyperuricemia and gout. Febuxostat may provide an important option in patients unable to use allopurinol, those with very high serum urate levels, or in the presence of refractory tophi.
febuxostat; gout; hyperuricemia; evidence
Gout is the most common inflammatory arthritis in an elderly population, and can be diagnosed with absolute certainty by polarization microscopy. However, diagnosis may be challenging because atypical presentations are more common in the elderly. Management of hyperuricemia in the elderly with gout requires special consideration because of co-medication, contra-indications, and risk of adverse reactions. Urate-lowering agents include allopurinol and uricosuric agents. These also must be used sensibly in the elderly, especially when renal function impairment is present. However, if used at the lowest dose that maintains the serum urate level below 5.0 to 6.0 mg/dL (0.30 to 0.36 mmol/L), the excess urate in the body will eventually be eliminated, acute flares will no longer occur, and tophi will resolve. Febuxostat, a new xanthine oxidase inhibitor, is welcomed, as few alternatives for allopurinol are available. Its pharmacokinetics and pharmacodynamics are not significantly altered in patients with moderate renal function or hepatic impairment. Its antihyperuricemic efficacy at 80 to 120 mg/day is better than “standard dosage” allopurinol (300 mg/day). Long-term safety data and efficacy data on tophus diminishment and reduction of gout flares have recently become available. Febuxostat may provide an important option in patients unable to use allopurinol, or refractory to allopurinol.
aging; febuxostat; hyperuricemia; gout; pharmacotherapy; xanthine oxidase
Gout recently passed rheumatoid arthritis to become the most common inflammatory arthritis in the United States (US). However, epidemiologic studies indicate that the quality of gout management is suboptimal owing to both patient and physician issues. Only three options for urate-lowering therapy are currently available in the US: allopurinol, probenecid, and recently, febuxostat. Probenecid is generally safe except for the occurrence of urolithiasis, but is only effective for the subset of patients with better kidney function. Allopurinol use is limited due to its side effects, potential toxicity of uncertain magnitude in patients with renal disease, and failure to achieve targeted serum urate levels. In part this failure may be due to the necessity for it to be titrated for optimal therapeutic effect. Febuxostat is a new medication that may offer several advantages and can be given as an alternative to allopurinol. We review the basic biology and clinical performance of febuxostat, and consider the potential utility of this agent in comparison to the older, better-established gout therapeutics.
allopurinol; gout suppressants; nephrolithiasis; uric acid; urolithiasis
To assess concordance of the management of chronic gout in UK primary care with the European League Against Rheumatism (EULAR) gout recommendations.
A postal questionnaire was sent to all adults aged >30 years registered with two general practices. Patients with possible gout attended for clinical assessment, at which the diagnosis was verified clinically. Aspects of chronic gout management, including provision of lifestyle modification advice, use of urate‐lowering therapies (ULT) including dose titration to serum urate (SUA) level, prophylaxis against acute attacks, and diuretic cessation were assessed in accordance with the EULAR recommendations.
Of 4249 (32%) completed questionnaires returned, 488 reported gout or acute attacks and were invited for clinical assessment. Of 359 attendees, 164 clinically confirmed cases of gout were identified. Advice regarding alcohol consumption was recalled by 59 (41%), weight loss by 36 (25%) and diet by 42 (29%). Allopurinol was the only ULT used and was taken by 44 (30%); 31 (70%) were taking 300 mg daily. Mean SUA was lower in allopurinol users than non‐users (318 vs 434 μmol/l) and was less often >360 μmol/l in allopurinol users (23% vs 75%). Eight patients had recently commenced allopurinol; two of these also were taking prophylactic colchicine or non‐steroidal anti‐inflammatory drugs. Of 25 patients with diuretic‐induced gout, 16 (64%) were still taking a diuretic.
Treatment of chronic gout is often suboptimal and poorly concordant with EULAR recommendations. Lifestyle advice is infrequently offered, and allopurinol is restricted to a minority. Persistent hyperuricaemia was often seen in allopurinol non‐users, but was also in allopurinol users, suggesting that doses >300 mg are often necessary.
gout; primary health care; lifestyle risk reduction; allopurinol; EULAR recommendations
OBJECTIVES—To study the efficacy of allopurinol and benzbromarone to reduce serum urate concentrations in patients with primary chronic gout.
METHODS—Prospective, parallel, open study of 86 consecutive male patients with primary chronic gout. Forty nine patients (26 normal excretors and 23 under excretors) were given allopurinol 300 mg/day and 37 under excretors benzbromarone 100 mg/day. After achieving steady plasma urate concentrations with such doses, treatment was then adjusted to obtain optimal plasmatic urate concentrations (under 6 mg/dl).
RESULTS—Patients receiving allopurinol 300 mg/day showed a mean reduction of plasmatic urate of 2.75 mg/dl (from 8.60 to 5.85 mg/dl) and 3.34 mg/dl (from 9.10 to 5.76 mg/dl) in normal excretors and under excretors respectively. Patients receiving benzbromarone 100 mg/day achieved a reduction of plasmatic urate of 5.04 mg/dl (from 8.58 to 3.54 mg/dl). Fifty three per cent of patients receiving allopurinol and 100% receiving benzbromarone achieved optimal plasma urate concentrations at such doses. The patients with poor results with allopurinol 300 mg/day achieved a proper plasma urate concentration with allopurinol 450 to 600 mg/day, the mean final dose being 372 mg/day. Renal fuction improved and no case of renal lithiasis was observed among benzbromarone treated patients, whose mean final dose was 76 mg/day.
CONCLUSION—Benzbromarone is very effective to control plasma urate concentrations at doses ranging from 50 to 100 mg/day. Uricosuric treatment is a suitable approach to the treatment of patients with gout who show underexcretion of urate.
Keywords: gout; gout suppressants; allopurinol; benzbromarone
The prevalence of gout is increasing with increased life expectancy. Approximately half of the patients with gout have some degree of renal impairment. If both conditions persistently coexist, and in severe tophaceous gout, in particular, treatment has been difficult. We here report on the case of an 87-year-old woman, who had been suffering from recurrent gouty arthritis over 4 years. Monthly polyarthritis attacks were accompanied by subcutaneous tophi. Serum uric acid levels were constantly above 600 μmol/L (10 mg/dL). Allopurinol was no option because of intolerance, while benzbromarone was ineffective because of renal impairment. Therefore, the novel xanthin oxidase inhibitor febuxostat was started, achieving rapid control of serum urate levels (<360 μmol/L). After initial worsening of inflammation in the first weeks, gouty attacks stopped and all tophi resolved within the following 10 months. Renal function remained stable.
Objective. Short Form-36 (SF-36) is a validated outcome measure to assess health-related quality of life (HRQOL) in patients with gout. We assessed responsiveness to change of SF-36 in patients with gout.
Methods. SF-36 was administered at baseline and at yearly intervals. We assessed the minimal clinically important differences (MCIDs) at the first and second year. We also assessed the responsiveness to change (effect size) and interpreted it based on Cohen’s criteria. We modelled the improvement (defined as ≥MCID) in SF-36 scales and summary scores. Covariates included age, presence of tophi, comorbidities, baseline joint involvement, baseline serum urate, change in serum urate and the number of flares from baseline to 12 months.
Results. Of 99 subjects, 96 were male, mean age was 57.1 years, disease duration was 8.2 years and 40.4% had tophi. Ninety-two patients were treated with urate-lowering therapy (ULT) and daily colchicine, and seven were only on colchicine. Baseline mean serum urate level was 8.9 mg/dl and mean number of flares was 4.7 over last year. ULTs were associated with reduction in serum uric acid and number of flares (P < 0.001 for both) over 12 months. Therapy was associated with 22–70% of the patients achieving MCID in SF-36 scores at 12 months. Effect size estimates ranged from negligible to large (SF-36 mental component summary 0.08–bodily pain 1.09). Reduction in flares independently predicted improvements in three SF-36 physical scales (P = 0.001–0.06). Improvement in SF-36 scores was maintained at 2 years.
Conclusion. In our real-life observational cohort, chronic urate lowering therapy and colchicine was associated with clinically meaningful improvements in HRQOL at 1 year and then maintained at 2 years. SF-36, especially physical domains and physical component summary, are responsive to change in gout.
Gout; Health-related quality of life; Quality of life; Flares; Urate-lowering therapy; Minimal clinically important differences; Minimally important differences; Short Form-36, Gout prophylaxis
Gout is a metabolic disorder characterized by elevated uric acid levels in the body, associated with painful arthritis, tophi and nephropathy. The most frequently used pharmacologic urate lowering strategies involve reducing urate production with a xanthine oxidase inhibitor and enhancing urinary excretion of uric acid with a uricosuric agent. Urate lowering agents are limited in number, availability and effectiveness. The emergence of a new medication, febuxostat, to lower serum urate levels is welcome as no new drug have been approved since the introduction of allopurinol, in 1964, and the drugs that are available have limitations owing to inefficacy or toxicity. Febuxostat is a novel, nonpurine selective inhibitor of xanthine oxidase, is a potential alternative to allopurinol for patients with hyperuricemia and gout.
Gout; hyperuricemia; xanthine oxidase inhibitor
To examine evidence-based quality indicators (QIs) in US veterans with gout diagnosis, and to examine the effect of demographics, heath care utilization/access, comorbid conditions, or physican characteristics as predictors of quality of gout care.
Using the Minneapolis Veterans Affairs electronic medical record system, we identified a cohort of veterans receiving medication to treat gout between January 1, 1999 and December 31, 2003, and evaluated 3 recently published evidence-based QIs for gout management: QI 1 = allopurinol dose <300 mg in gout patients with renal insufficiency, QI 2 = uric acid check within 6 months of starting a new allopurinol prescription, and QI 3 = complete blood count and creatine kinase check every 6 months for gout patients receiving prolonged colchicine therapy. We calculated the proportion of patients whose therapy adhered to each QI and to all applicable indicators (overall physician adherence). Logistic regression analysis examined association of overall physician adherence with sociodemographics, health care utilization, comorbidity, and provider characteristics.
Of 3,658 patients with a diagnosis of gout, 663 patients qualified for examination of ≥1 QI. Of these 663 patients, therapy in only 144 (22%) adhered to all applicable QIs; 59 (78%) of 76 adhered to QI 1, 155 (24%) of 643 adhered to QI 2, and 18 (35%) of 52 adhered to QI 3. Overall physician adherence to QIs was significantly lower in older veterans and in those with more inpatient visits per year, but was higher in those with more primary care visits or more health care providers.
Suboptimal physician adherence to QIs was seen for all 3 QIs tested in this cohort of veterans with gout. These findings can guide quality improvement efforts.
Gout; Veterans; Quality of care; Quality indicators; Physician adherence
Fifty-nine patients with primary gout were treated with either a combination of colchicine and allopurinol or colchicine alone. Assessments of renal function over 2 years revealed a statistically significant fall of glomerular filtration rate an urine concentrating ability in those receiving only colchicine. The renal function of patients given allopurinol did not change. Treatment with allopurinol resulted ina significant reduction of ammonium excretion, a phenomenon which could not be readily explained. Urate clearance also declined during allopurinol treatment, and the impaired urate clearance associated with gout became more evident. The most important observation was that allopurinol retarded an apparent decline of renal function. Presumably this was achieved through its hypouricaemic effect and implies that the hyperuricaemia of gouty patients is deleterious to the kidneys.
To evaluate the long-term safety (up to 3 years) of treatment with pegloticase in patients with refractory chronic gout.
This open-label extension (OLE) study was conducted at 46 sites in the USA, Canada and Mexico. Patients completing either of two replicate randomised placebo-controlled 6-month trials received pegloticase 8 mg every 2 weeks (biweekly) or every 4 weeks (monthly). Safety was evaluated as the primary outcome, with special interest in gout flares and infusion-related reactions (IRs). Secondary outcomes included urate-lowering and clinical efficacy.
Patients (n=149) received a mean±SD of 28±18 pegloticase infusions and were followed for a mean of 25±11 months. Gout flares and IRs were the most frequently reported adverse events; these were least common in patients with a sustained urate-lowering response to treatment and those receiving biweekly treatment. In 10 of the 11 patients with a serious IR, the event occurred when uric acid exceeded 6 mg/dl. Plasma and serum uric acid levels remained <6 mg/dl in most randomised controlled trial (RCT)-defined pegloticase responders throughout the OLE study and were accompanied by sustained and progressive improvements in tophus resolution and flare incidence.
The safety profile of long-term pegloticase treatment was consistent with that observed during 6 months of RCT treatment; no new safety signals were identified. Improvements in clinical status, in the form of flare and tophus reduction initiated during RCT pegloticase treatment in patients maintaining goal range urate-lowering responses were sustained or advanced during up to 2.5 years of additional treatment.
Gout; Treatment; Rheumatoid Arthritis
Allopurinol (4-hydroxypyrazolo (3,4-d)-pyrimidine) is a potent xanthine oxidase inhibitor which inhibits the oxidation of naturally occurring oxypurines, thus decreasing uric acid formation. The clinical and metabolic effects of this agent were studied in 80 subjects with primary and secondary gout and other disorders of uric acid metabolism. Allopurinol has been universally successful in lowering the serum uric acid concentration and uric acid excretion to normal levels, while not significantly affecting the clearance of urate or other aspects of renal function. Oxypurine excretion increased concomitantly with the fall in urine uric acid. The agent is particularly valuable in the management of problems of gout with azotemia, acute uric acid nephropathy and uric acid urolithiasis. The minor side effects, clinical indications and theoretical complications are discussed.
Gout is a common disease caused by hyperuricemia, which shows elevated serum uric acid (SUA) levels. From a viewpoint of urate handling in humans, gout patients can be divided into those with renal overload (ROL) gout with intestinal urate underexcretion, and those with renal underexcretion (RUE) gout. Recent genome-wide association studies (GWAS) revealed an association between SUA and a variant in human monocarboxylate transporter 9 (MCT9/SLC16A9) gene. Although the function of MCT9 remains unclear, urate is mostly excreted via intestine and kidney where MCT9 expression is observed. In this study, we investigated the relationship between a variant of MCT9 and gout in 545 patients and 1,115 healthy volunteers. A missense variant of MCT9 (K258T), rs2242206, significantly increased the risk of ROL gout (p = 0.012), with odds ratio (OR) of 1.28, although it revealed no significant association with all gout cases (p = 0.10), non-ROL gout cases (p = 0.83), and RUE gout cases (p = 0.34). In any case groups and the control group, minor allele frequencies of rs2242206 were >0.40. Therefore, rs2242206 is a common missense variant and is revealed to have an association with ROL gout, indicating that rs2242206 relates to decreased intestinal urate excretion rather than decreased renal urate excretion. Our study provides clues to better understand the pathophysiology of gout as well as the physiological roles of MCT9.
Gouty arthritis; Single nucleotide polymorphism (SNP); Gut urate excretion; Carnitine; Solute carrier (SLC) family transporter
Clinically, gout is generally considered as a preferential male disease. However, it definitely does not occur exclusively in males. Our aim was to assess differences in the clinical features of gout arthritis between female and male patients. Five electronic databases were searched to identify relevant original studies published between 1977 and 2007. The included studies had to focus on adult patients with primary gout arthritis and on sex differences in clinical features. Two reviewers independently assessed eligibility and quality of the studies. Out of 355 articles, 14 were selected. Nine fulfilled the quality and score criteria. We identified the following sex differences in the clinical features of gout in women compared to men: the onset of gout occurs at a higher age, more comorbidity with hypertension or renal insufficiency, more often use of diuretics, less likely to drink alcohol, less often podagra but more often involvement of other joints, less frequent recurrent attacks. We found interesting sex differences regarding the clinical features of patients with gout arthritis. To diagnose gout in women, knowledge of these differences is essential, and more research is needed to understand and explain the differences , especially in the general population.
Female; Gender; Gout; Sex characteristics; Sex differences
This study assessed the efficacy and safety of canakinumab, a fully human anti-interleukin 1β monoclonal antibody, for prophylaxis against acute gouty arthritis flares in patients initiating urate-lowering treatment.
In this double-blind, double-dummy, dose-ranging study, 432 patients with gouty arthritis initiating allopurinol treatment were randomised 1:1:1:1:1:1:2 to receive: a single dose of canakinumab, 25, 50, 100, 200, or 300 mg subcutaneously; 4×4-weekly doses of canakinumab (50+50+25+25 mg subcutaneously); or daily colchicine 0.5 mg orally for 16 weeks. Patients recorded details of flares in diaries. The study aimed to determine the canakinumab dose having equivalent efficacy to colchicine 0.5 mg at 16 weeks.
A dose-response for canakinumab was not apparent with any of the four predefined dose-response models. The estimated canakinumab dose with equivalent efficacy to colchicine was below the range of doses tested. At 16 weeks, there was a 62% to 72% reduction in the mean number of flares per patient for canakinumab doses ≥50 mg versus colchicine based on a negative binomial model (rate ratio: 0.28–0.38, p≤0.0083), and the percentage of patients experiencing ≥1 flare was significantly lower for all canakinumab doses (15% to 27%) versus colchicine (44%, p<0.05). There was a 64% to 72% reduction in the risk of experiencing ≥1 flare for canakinumab doses ≥50 mg versus colchicine at 16 weeks (hazard ratio (HR): 0.28–0.36, p≤0.05). The incidence of adverse events was similar across treatment groups.
Single canakinumab doses ≥50 mg or four 4-weekly doses provided superior prophylaxis against flares compared with daily colchicine 0.5 mg.
We quantified the impact of hypertension on gout incidence in middle-aged white and African American, men and women. ARIC is a prospective population-based cohort recruited between 1987–1989 from 4 US communities. Using a time-dependent Cox Proportional Hazards model, we estimated the adjusted hazard ratio (HR) of incident gout by time-varying hypertension and tested for mediation by serum urate level. There were 10,872 participants among whom 45% had hypertension over follow-up; 43% were men and 21% were African-American. Over 9 years, 274 (2.5%) participants developed gout; 1.8% of women and 3.5% of men. The unadjusted HR of incident gout was approximately 3 times (HR=2.87; 95% CI: 2.24, 3.78) greater for those with hypertension. Adjusting for confounders resulted in an attenuated but still significant association between hypertension and gout (HR= 2.00; 95% CI: 1.54, 2.61). Adjustment for serum urate level further attenuated but did not abrogate the association (HR=1.36, 95% CI: 1.04, 1.79). There was no evidence of effect modification by sex (p-value=0.35), race (p-value=0.99), or obesity at baseline (p-value=0.82). Hypertension was independently associated with increased gout risk in middle-aged African American and white adults. Serum urate level may be a partial intermediate on the pathway between hypertension and gout.
hypertension; uric acid; gout
Gout is the most common form of inflammatory arthritis in the elderly. In the last two decades, both hyperuricemia and gout have increased markedly and similar trends in the epidemiology of the metabolic syndrome have been observed. Recent studies provide new insights into the transporters that handle uric acid in the kidney as well as possible links between these transporters, hyperuricemia, and hypertension. The treatment of established hyperuricemia has also seen new developments. Febuxostat and PEG-uricase are two novel treatments that have been evaluated and shown to be highly effective in the management of hyperuricemia, thus enlarging the therapeutic options available to lower uric acid levels. Monosodium urate (MSU) crystals are potent inducers of inflammation. Within the joint, they trigger a local inflammatory reaction, neutrophil recruitment, and the production of pro-inflammatory cytokines as well as other inflammatory mediators. Experimentally, the uptake of MSU crystals by monocytes involves interactions with components of the innate immune system, namely Toll-like receptor (TLR)-2, TLR-4, and CD14. Intracellularly, MSU crystals activate multiple processes that lead to the formation of the NALP-3 (NACHT, LRR, and pyrin domain-containing-3) inflammasome complex that in turn processes pro-interleukin (IL)-1 to yield mature IL-1β, which is then secreted. The inflammatory effects of MSU are IL-1-dependent and can be blocked by IL-1 inhibitors. These advances in the understanding of hyperuricemia and gout provide new therapeutic targets for the future.
A study of renal function of 51 patients with gout and an equal number of normouricaemic controls revealed significant differences. A relative impairment of the glomerular filtration rate and urine concentrating ability in the gouty subjects could not be wholly explained on the basis of aging or hypertension. Renal dysfunction was generally mild and was not associated with specific clinical characteristics higher levels of uric acid excretion, or hypertriglyceridaemia. Gout patients excreted urine with a significantly lower pH. This was associated with a relatively high excretion of titratable acid and a deficit of ammonium excretion, which was accentuated by ingestion of an acid load. Urate clearance was significantly reduced in gout, even when expressed as a fraction of the glomerular filtration rate.