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author:("Li, stuying")
1.  Risk Factors for ESRD in Individuals With Preserved Estimated GFR With and Without Albuminuria: Results From the Kidney Early Evaluation Program (KEEP) 
Given the increasing costs and poor outcomes of end-stage renal disease (ESRD), we sought to identify risk factors for ESRD in people with preserved estimated glomerular filtration rate (eGFR), with or without albuminuria, who were at high risk of ESRD.
This cohort study included participants in the National Kidney Foundation’s Kidney Early Evaluation Program (KEEP) with eGFR ≥60 mL/min/1.73 m2 at baseline stratified by the presence or absence of albuminuria. The Chronic Kidney Disease Epidemiology Collaboration equation was used to calculate eGFR. Urine was tested for albuminuria by semiquantitative dipstick. The outcome was the development of treated chronic kidney failure, defined as initiation of maintenance dialysis therapy or kidney transplantation, determined by linkage to the US Renal Data System. We used a Cox model with the Fine-Gray method to assess risk factors for treated chronic kidney failure while accounting for the competing risk of death.
During a median follow-up of 4.8 years, 126 of 13,923 participants with albuminuria (16/10,000 patient-years) and 56 of 109,135 participants without albuminuria (1.1/10,000 patient-years) developed treated chronic kidney failure. Diabetes was a strong risk factor for developing treated chronic kidney failure in participants with and without albuminuria (adjusted HRs of 9.3 [95% CI, 5.7–15.3] and 7.8 [95% CI, 4.1–14.8], respectively). Black race, lower eGFR, and higher systolic blood pressure also were associated with higher adjusted risks of developing treated chronic kidney failure.
In a diverse high-risk cohort of KEEP participants with preserved eGFR, we showed that diabetes, higher systolic blood pressure, lower eGFR, and black race were risk factors for developing treated chronic kidney failure irrespective of albuminuria status, although the absolute risk of kidney failure in participants without albuminuria was very low. Our findings support testing for kidney disease in high-risk populations, which often have otherwise unrecognized kidney disease.
PMCID: PMC4117734  PMID: 23507268
Albuminuria; blood pressure; chronic kidney disease; diabetes; dialysis risk factors; end-stage renal disease; public health
2.  No independent association of serum phosphorus with risk for death or progression to end-stage renal disease in a large screen for chronic kidney disease 
Kidney international  2013;84(5):989-997.
Whether higher serum phosphorus levels are associated with a higher risk for death and/or progression of chronic kidney disease (CKD) is not well established, and whether the association is confounded by access and barriers to care is unknown. To answer these questions, data of 10,672 individuals identified to have CKD (estimated glomerular filtration rate <60 ml/min per 1.73 m2) from those participating in a community-based screening program were analyzed. Over a median follow-up of 2.3 years, there was no association between quartiles of serum phosphorus and all-cause mortality (adjusted hazards ratio for serum phosphorus over 3.3 to 3.7, over 3.7 to 4.1, and over 4.1 mg/dl, respectively: 1.22 (0.95–1.56), 1.00 (0.76–1.32), and 1.00 (0.75–1.33); reference, serum phosphorus of 3.3 mg/dl and below). Individuals in the highest quartile for serum phosphorus had a significantly higher risk for progression to end-stage renal disease (ESRD) (unadjusted hazards ratio, 6.72 (4.16–10.85)); however, the risk became nonsignificant on adjustment for potential confounders. There was no appreciable change in hazards ratio with inclusion of variables related to access and barriers to care. Additional analyses in subgroups based on 12 different variables yielded similar negative associations. Thus, in the largest cohort of individuals with early-stage CKD to date, we could not validate an independent association of serum phosphorus with risk for death or progression to ESRD.
PMCID: PMC4103660  PMID: 23615501
barrier to care; cardiovascular disease; chronic kidney disease; end-stage renal disease; mortality; phosphorus
3.  Association Between Lack of Health Insurance and Risk of Death and ESRD: Results From the Kidney Early Evaluation Program (KEEP) 
Uninsured adults in the United States have poor access to health care services and worse health outcomes than insured adults. Little is known about the association between lack of insurance and chronic kidney disease (CKD) progression to end-stage renal disease (ESRD) or death in patients at high risk of kidney disease. We used 2000–2011 data from the National Kidney Foundation’s Kidney Early Evaluation Program (KEEP) to examine this association.
The study population included KEEP participants younger than 65 years. Outcomes were time to ESRD (chronic kidney failure treated by renal replacement therapy) and time to death. Incident ESRD was ascertained by linkage to the US Renal Data System, and vital status, by linkage to the Social Security Administration Death Master File. We used Cox proportional hazard regression to examine the association between insurance and risk of death or ESRD after adjusting for demographic variables.
Of 86,588 participants, 27.8% had no form of insurance, 10.3% had public insurance, and 61.9% had private insurance; 15.0% had CKD (defined as estimated glomerular filtration rate <60 mL/min/1.73 m2 or urine albumin-creatinine ratio ≥30 mg/g), 63.3% had hypertension, and 27.7% had diabetes. Of participants with CKD, 29.3% had no health insurance. Participants without insurance were younger, more likely to be Hispanic and to have 12 or fewer years of education, and less likely to have seen a physician in the past year. After adjustment for demographic characteristics, uninsured KEEP participants were 82% more likely than privately insured participants to die (HR, 1.82; 95% CI, 1.56–2.12; P < 0.001) and 72% more likely to develop ESRD (HR, 1.72; 95% CI, 1.33–2.22; P < 0.001). The association between insurance and outcomes varied by CKD stage.
Lack of insurance is an independent risk factor for early death and ESRD in this population at high risk of kidney disease. Considering the high morbidity and mortality and increasing cost associated with ESRD, access to appropriate health insurance coverage is warranted.
PMCID: PMC3739048  PMID: 23507267
Chronic kidney disease; end-stage renal disease; health insurance; mortality; public health
4.  Awareness of Kidney Disease and Relationship to End-Stage Renal Disease and Mortality 
The American Journal of Medicine  2012;125(7):661-669.
Patients with chronic kidney disease are often reported to be unaware. We prospectively evaluated the association between awareness of kidney disease to end-stage renal disease and mortality.
We utilized 2000–2009 data from the National Kidney Foundation-Kidney Early Evaluation Program (KEEP™). Mortality was determined by cross reference to the Social Security Administration Death Master File, and development of end-stage by cross reference with the United States Renal Data System.
Of 109,285 participants, 28,244 (26%) had chronic kidney disease defined by albuminuria or eGFR <60ml/min/1.73m2. Only 9% (n=2660) reported being aware of kidney disease. Compared to those who were not aware, participants aware of chronic kidney disease had lower eGFR (49 vs 62ml/min/1.73m2) and a higher prevalence of albuminuria (52 vs 46%), diabetes (47 vs 42%), cardiovascular disease (43 vs 28%) and cancer (23 vs 14%). Over 8.5 years of follow-up, aware participants compared to those unaware had a lower rate of survival for end-stage (83% and 96%) and mortality (78 vs 81%), p<0.001 respectively. After adjustment for demographics, socioeconomic factors, comorbidity, and severity of kidney disease, aware participants continued to demonstrate an increased risk for end-stage renal disease [hazard ratio (95% CI) 1.37(1.07–1.75); p<0.0123] and mortality [1.27(1.07–1.52); p<0.0077] relative to unaware participants with chronic kidney disease.
Among persons identified as having chronic kidney disease at a health screening, only a small proportion had been made aware of their diagnosis previously by clinicians. This subgroup was at a disproportionately high risk for mortality and end-stage renal disease.
PMCID: PMC3383388  PMID: 22626510
KEEP; CKD; awareness; ESRD; mortality
5.  Access to Health Care Among Adults Evaluated for CKD: Findings From the Kidney Early Evaluation Program (KEEP) 
Data are scant regarding access to health care in patients with chronic kidney disease (CKD). We performed descriptive analyses using data from the National Kidney Foundation’s Kidney Early Evaluation Program (KEEP), a nationwide health screening program for adults at high risk of CKD.
From 2000–2010, a total of 122,502 adults without end-stage renal disease completed KEEP screenings; 27,927 (22.8%) met criteria for CKD (10,082, stages 1–2; 16,684, stage 3; and 1,161, stages 4–5). CKD awareness, self-rated health status, frequency of physician visits, difficulty obtaining medical care, types of caregivers, insurance status, and medication coverage and estimated costs were assessed.
Participants with CKD were more likely to report fair/poor health status than those without CKD. Health care utilization increased at later CKD stages; ~95% of participants at stages 3–5 had visited a physician during the preceding year compared with 83.7% of participants without CKD. More Hispanic and African American than white participants at all CKD stages reported not having a physician. Approximately 40% of participants younger than 65 years reported fair/poor health status at stages 4–5 compared with ~30% who were 65 years and older. Younger participants at all stages were more likely to report extreme or somewhat/moderate difficulty obtaining medical care. Comorbid conditions (diabetes, hypertension, and prior cardiovascular events) were associated with increased utilization of care. Utilization of nephrology care was poor at all CKD stages; <6% of participants at stage 3 and <30% at stages 4–5 reported ever seeing a nephrologist.
Lack of health insurance and perceived difficulty obtaining medical care with lower health care utilization, both of which are consistent with inadequate access to health care, are more likely for KEEP participants who are younger than 65 years, nonwhite, and without previously diagnosed comorbid conditions. Nephrology care is infrequent in elderly participants with advanced CKD who are nonwhite, have comorbid disease, and have high-risk states for cardiovascular disease.
PMCID: PMC3694584  PMID: 22339901
Chronic kidney disease; health care access; health insurance; medication payment; socioeconomic status; educational status
6.  The Association between Parathyroid Hormone Levels and Hemoglobin in Diabetic and Nondiabetic Participants in the National Kidney Foundation's Kidney Early Evaluation Program 
Cardiorenal Medicine  2013;3(2):120-127.
Both anemia and secondary hyperparathyroidism are reflections of hormonal failure in chronic kidney disease (CKD). While the association of elevated levels of parathyroid hormone (PTH) and anemia has been studied among those with advanced CKD, less is known about this association in mild-to-moderate CKD.
In a cross-sectional analysis, the relationship between PTH and hemoglobin levels was investigated in 10,750 participants in the National Kidney Foundation's Kidney Early Evaluation Program with an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2.
In the unadjusted analysis, higher PTH levels were associated with lower hemoglobin levels. However, after multivariable adjustment for age, race, gender, smoking status, education, cardiovascular disease, diabetes, hypertension, cancer, albuminuria, BMI, baseline eGFR, calcium, and phosphorus, the direction of association changed. As compared to the first PTH quintile, hemoglobin levels were 0.09 g/dl (95% CI: 0.01-0.18), 0.15 g/dl (95% CI: 0.07-0.24), 0.18 g/dl (95% CI: 0.09-0.26), and 0.13 g/dl (95% CI: 0.07-0.25) higher for the second, third, fourth, and fifth quintiles, respectively. Similarly, each standard deviation increase in natural log transformed PTH was associated with a 0.06 g/dl (95% CI: 0.03-0.09, p = 0.0003) increase in hemoglobin. However, a significant effect modification was seen for diabetes (p = 0.0003). Each standard deviation increase in natural log transformed PTH was associated with a 0.10 g/dl (95% CI: 0.054-0.138, p < 0.0001) increase in hemoglobin, while no association was seen among those without diabetes mellitus.
After multivariable adjustment, there was a small positive association between PTH and hemoglobin among diabetics but not among nondiabetics.
PMCID: PMC3721130  PMID: 23922552
Chronic kidney disease; Anemia; Secondary hyperparathyroidism

7.  Physician Utilization, Risk-Factor Control, and CKD Progression Among Participants in the Kidney Early Evaluation Program (KEEP) 
Chronic kidney disease (CKD) is a well-known risk factor for cardiovascular mortality, but little is known about the association between physician utilization and cardiovascular disease risk-factor control in patients with CKD. We used 2005–2010 data from the National Kidney Foundation’s Kidney Early Evaluation Program (KEEP) to examine this association at first and subsequent screenings.
Control of risk factors was defined as control of blood pressure, glycemia, and cholesterol levels. We used multinomial logistic regression to examine the association between participant characteristics and seeing a nephrologist after adjusting for kidney function and paired t tests or McNemar tests to compare characteristics at first and second screenings.
Of 90,009 participants, 61.3% had a primary care physician only, 2.9% had seen a nephrologist, and 15.3% had seen another specialist. The presence of 3 risk factors (hypertension, diabetes, and hypercholesterolemia) increased from 26.8% in participants with CKD stages 1–2 to 31.9% in those with stages 4–5. Target levels of all risk factors were achieved in 7.2% of participants without a physician, 8.3% of those with a primary care physician only, 9.9% of those with a nephrologist, and 10.3% of those with another specialist. Of up to 7,025 participants who met at least one criterion for nephrology consultation at first screening, only 12.3% reported seeing a nephrologist. Insurance coverage was associated strongly with seeing a nephrologist. Of participants who met criteria for nephrology consultation, 406 (5.8%) returned for a second screening, of whom 19.7% saw a nephrologist. The percentage of participants with all risk factors controlled was higher at the second screening (20.9% vs 13.3%).
Control of cardiovascular risk factors is poor in the KEEP population. The percentage of participants seeing a nephrologist is low, although better after the first screening. Identifying communication barriers between nephrologists and primary care physicians may be a new focus for KEEP.
PMCID: PMC3654535  PMID: 22339899
Cardiovascular disease risk factors; chronic kidney disease; nephrologist care; primary care
8.  Racial and Ethnic Differences in Albuminuria in Individuals With Estimated GFR Greater Than 60 mL/min/1.73 m2: Results From the Kidney Early Evaluation Program (KEEP) 
Albuminuria is an important marker for chronic kidney disease and progression to end-stage renal disease in the general population; understanding racial and ethnic differences can help inform efforts to reduce health disparities. We sought to estimate independent associations of race/ethnicity with albuminuria to determine whether observed differences were attributable to known kidney disease risk factors.
This cross-sectional study included 64,161 Kidney Early Evaluation Program (KEEP) participants, 2000–2008, with estimated glomerular filtration rate ≥ 60 mL/min/1.73 m2, not on regular dialysis, and without previous kidney transplant. Albuminuria (urine albumin-creatinine ratio [ACR] ≥ 30 mg/g) was examined by self-reported race and ethnicity. Covariates were age, sex, educational level, body mass index, diabetes status or glucose level, hypertension status or blood pressure measurement, smoking status, health insurance status, and geographic region.
Albuminuria prevalence was 8% (n = 2303) in whites, 11% (n = 2310) in African Americans, 9% (n = 730) in Hispanics, 10% (n = 381) in Asians, and 15% (n = 344) in American Indians/Alaska Natives. Compared with whites, odds of albuminuria were higher for all groups after multivariate adjustment. Odds were highest for American Indians/Alaska Natives (adjusted odds ratio 1.93, 95% confidence interval 1.70–2.20), then Asians (1.42, 1.26–1.61), African Americans (1.38, 1.29–1.47), and Hispanics (1.19, 1.08–1.31).
In the KEEP study population, albuminuria prevalence was higher among African Americans, Hispanics, Asians, and American Indians/Alaska Natives than among non-Hispanic whites, suggesting a need for screening for early detection of kidney damage, especially among people at increased risk, in the community primary care setting.
PMCID: PMC3507474  PMID: 20172444
9.  Dysglycemia but not lipids is associated with abnormal urinary albumin excretion in diabetic kidney disease: a report from the Kidney Early Evaluation Program (KEEP) 
BMC Nephrology  2012;13:104.
The relationship between glycemic control and lipid abnormalities with urinary albumin-creatinine ratio (ACR) in chronic kidney disease (CKD) patients with diabetes mellitus (DM) is unknown. We sought to investigate the association of dyslipidemia and glycemic control with levels of albuminuria in the National Kidney Foundation (NKF) Kidney Early Evaluation Program (KEEP) participants with DM and CKD stage 3 or higher.
We performed a cross-sectional study of 6639 eligible KEEP patients with DM and CKD Stage 3 to 5 from June 2008 to December 2009. Multivariate logistic regression was used to evaluate the association of lipid parameters (per 10 mg/dl change in serum level) and glycosylated hemoglobin (HbA1c) values with three degrees of albuminuria normo (<30 mg⁄g), micro (30 to 300 mg⁄g) and macro (>300 mg⁄g).
2141 KEEP participants were included. HbA1c levels were strongly associated with micro-albuminuria (compared to normo-albuminuria) and macro-albuminuria (compared to normo-albuminuria and micro-albuminuria). Each 1.0% increase in HbA1c increased the odds of micro-albuminuria by 32% (OR 1.32, 95% CI 1.23-1.42) and the odds of macro-albuminuria (vs. microalbuminuria) by 16% (OR 1.16, 95% CI 1.05-1.28). Only increases in serum HDL were associated with decreased odds of micro-albuminuria; otherwise, the association between other components of the serum lipid profile with urinary ACR did not reach statistical significance.
In this cross-sectional study of 2141 KEEP participants with DM and CKD stages 3–5, overall glycemic control but not lipids were associated with abnormal urinary albumin excretion, a marker of increased risk for progressive disease.
PMCID: PMC3480932  PMID: 22958709
Chronic Kidney Disease; Diabetes Mellitus; Proteinuria; Dyslipidemia; Glycosylated hemoglobin
10.  Blood Pressure Components and End-stage Renal Disease in Persons With Chronic Kidney Disease 
Archives of internal medicine  2012;172(1):41-47.
Treatment of hypertension is difficult in chronic kidney disease (CKD), and blood pressure goals remain controversial. The association between each blood pressure component and end-stage renal disease (ESRD) risk is less well known.
We studied associations of systolic and diastolic blood pressure (SBP and DBP, respectively) and pulse pressure (PP) with ESRD risk among 16 129 Kidney Early Evaluation Program (KEEP) participants with an estimated glomerular filtration rate of 60 mL/min/1.73 m2 using Cox proportional hazards. We estimated the prevalence and characteristics associated with uncontrolled hypertension (SBP≥150 or DBP≥90 mm Hg).
The mean (SD) age of participants was 69 (12) years; 25% were black, 6% were Hispanic, and 43% had diabetes mellitus. Over 2.87 years, there were 320 ESRD events. Higher SBP was associated with higher ESRD risk, starting at SBP of 140 mm Hg or higher. After sex and age adjustment, compared with SBP lower than 130 mm Hg, hazard ratios (HRs) were 1.08 (95% CI, 0.74–1.59) for SBP of 130 to 139 mm Hg, 1.72 (95% CI, 1.21–2.45) for SBP of 140 to 149 mm Hg, and 3.36 (95% CI, 2.51–4.49) for SBP of 150 mm Hg or greater. After full adjustment, HRs for ESRD were 1.27 (95% CI, 0.88–1.83) for SBP of 140 to 149 mm Hg and 1.36 (95% CI, 1.02–1.85) for SBP of 150 mm Hg or higher. Persons with DBP of 90 mm Hg or higher were at higher risk for ESRD compared with persons with DBP of 60 to 74 mm Hg (HR, 1.81; 95% CI, 1.33–2.45). Higher PP was also associated with higher ESRD risk (HR, 1.44 [95% CI, 1.00–2.07] for PP≥80 mm Hg compared with PP<50 mm Hg). Adjustment for SBP attenuated this association. More than 33% of participants had uncontrolled hypertension (SBP≥150 mm Hg or DBP≥90 mm Hg), mostly due to isolated systolic hypertension (54%).
In this large, diverse, community-based sample, we found that high SBP seemed to account for most of the risk of progression to ESRD. This risk started at SBP of 140 mm Hg rather than the currently recommended goal of less than 130 mm Hg, and it was highest among those with SBP of at least 150 mm Hg. Treatment strategies that preferentially lower SBP may be required to improve BP control in CKD.
PMCID: PMC3417125  PMID: 22232147
11.  Association of Educational Attainment With Chronic Disease and Mortality: The Kidney Early Evaluation Program (KEEP) 
Recent reports have suggested a close relationship between education and health, including mortality, in the United States.
Study Design
Observational cohort
Setting and Participants
We studied 61,457 participants enrolled in a national health screening initiative, the National Kidney Foundation’s Kidney Early Evaluation Program (KEEP).
Self-reported educational attainment
Chronic diseases (hypertension, diabetes, cardiovascular disease, reduced kidney function, and albuminuria) and mortality
We evaluated the cross-sectional associations between self-reported educational attainment with the chronic diseases listed above using logistic regression models adjusted for demographics, access to care, behaviors, and co-morbidities. The association of educational attainment with survival was determined by multivariable Cox proportional hazards regression.
Higher educational attainment was associated with lower prevalence of each of the chronic conditions listed above. In multivariable models, compared with persons not completing high school, college graduates had a lower risk of each chronic condition, ranging from 11% lower odds of reduced kidney function to 37% lower odds of cardiovascular disease. Over a mean follow-up time of 3.9 years (median, 3.7 years), 2,384 (4%) deaths occurred. In the fully adjusted Cox model, those who had completed college had a 24% lower mortality, compared to participants who had completed at least some high school.
A lack of income data does not allow us to disentangle the independent effects of education from income.
In this diverse, contemporary cohort, higher educational attainment was independently associated with lower prevalence of chronic diseases and short-term mortality among all age and race/ethnicity groups.
PMCID: PMC3144262  PMID: 21601328
education; mortality; chronic kidney disease
12.  Comparison of the CKD Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) Study Equations: Risk Factors for and Complications of CKD and Mortality in the Kidney Early Evaluation Program (KEEP) 
American Journal of Kidney Diseases  2011;57(3 Suppl 2):S9-16.
The National Kidney Foundation has recommended that the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation replace the Modification of Diet in Renal Disease (MDRD) Study equation. Before implementing this change in the Kidney Early Evaluation Program (KEEP), we compared characteristics of reclassified individuals and mortality risk predictions using the new equation.
Of 123,704 eligible KEEP participants, 116,321 with data available for this analysis were included. Glomerular filtration rate (GFR) was estimated using the MDRD Study (eGFRMDRD) and CKD-EPI (eGFRCKD-EPI) equations with creatinine level calibrated to standardized methods. Participants were characterized by eGFR category: >120, 90-119, 60-89, 45-59, 30-44, and <30 mL/min/1.73 m2. Clinical characteristics ascertained included age, race, sex, diabetes, hypertension, coronary artery disease, congestive heart failure, cerebrovascular disease, peripheral vascular disease, and anemia. Mortality was determined over a median of 3.7 years of follow-up.
The prevalence of eGFRCKD-EPI <60 mL/min/1.73 m2 was 14.3% compared with 16.8% using eGFRMDRD. Using eGFRCKD-EPI, 20,355 participants (17.5%) were reclassified to higher eGFR categories, and 3,107 (2.7%), to lower categories. Participants reclassified upward were younger and less likely to have chronic conditions, with a lower risk of mortality. A total of 3,601 deaths (3.1%) were reported. Compared with participants classified to eGFR of 45-59 mL/min/1.73 m2 using both equations, those with eGFRCKD-EPI of 60-89 mL/min/1.73 m2 had a lower mortality incidence rate (6.4 [95% CI, 5.1-7.7] vs 18.5 [95% CI, 17.1-19.9]). Results were similar for all eGFR categories. Net reclassification improvement was 0.159 (P < 0.001).
The CKD-EPI equation reclassifies people at lower risk of CKD and death into higher eGFR categories, suggesting more accurate categorization. The CKD-EPI equation will be used to report eGFR in KEEP.
PMCID: PMC3298760  PMID: 21338849
Chronic kidney disease; glomerular filtration rate estimation; mortality; risk factors
13.  Comparison of CKD Awareness in a Screening Population Using the Modification of Diet in Renal Disease (MDRD) Study and CKD Epidemiology Collaboration (CKD-EPI) Equations 
Low awareness of chronic kidney disease (CKD) may reflect uncertainty about the accuracy or significance of a CKD diagnosis in individuals otherwise perceived to be low-risk. Whether reclassification of CKD severity using the CKD Epidemiology Collaboration (CKD-EPI) equation to estimate glomerular filtration rate (GFR) modifies estimates of CKD awareness is unknown.
In this cross-sectional study, we used data collected from 2000 to 2009 for 26,213 participants in the Kidney Early Evaluation Program (KEEP), a community-based screening program, with CKD based on GFR estimated using the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation and measurement of albuminuria. We assessed CKD awareness after CKD stage was reclassified using the CKD-EPI equation.
Of 26,213 participants with CKD based on eGFRMDRD, 23,572 (90%) were also classified with CKD based on eGFRCKD-EPI. Based on eGFRMDRD, 9.5% of participants overall were aware of CKD, as were 4.9%, 6.3%, 9.2%, 41.9%, and 59.2% with Stages 1-5, respectively. Based on eGFRCKD-EPI, 10.0% of participants overall were aware of CKD, as were 5.1%, 6.6%, 10.0%, 39.3%, and 59.4% with Stages 1-5, respectively. Reclassification to a less advanced CKD stage with eGFRCKD-EPI was associated with lower odds for awareness (OR, 0.58; 95% CI, 0.50-0.67); reclassification to a more advanced stage was associated with higher odds for awareness (OR, 1.50; 95% CI, 1.05-2.13) after adjustment for confounding factors. Of participants unaware of CKD, 10.6% were reclassified as not having CKD using eGFRCKD-EPI.
Using eGFRCKD-EPI led to a modest increase in overall awareness rates, primarily due to reclassification of low-risk unaware participants.
PMCID: PMC3075598  PMID: 21338846
awareness; chronic kidney disease; CKD-EPI; estimated glomerular filtration rate
14.  Comparison of the CKD Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) Study Equations: Prevalence of and Risk Factors for Diabetes Mellitus in CKD in the Kidney Early Evaluation Program (KEEP) 
Diabetes is a leading cause of chronic kidney disease (CKD). Whether reclassification of CKD stages based on glomerular filtration rate estimated using the CKD Epidemiology Collaboration (CKD-EPI) equation versus the Modification of Diet in Renal Disease (MDRD) Study equation modifies estimates of prevalent risk factors across stages is unknown.
This is a cross-sectional analysis of data from the Kidney Early Evaluation Program (KEEP), a community-based health screening program targeting individuals 18 years and older with diabetes, hypertension, or a family history of diabetes, hypertension, or kidney disease. Of 109,055 participants, 68.2% were women and 31.8% were African American. Mean age was 55.3 ± 0.05 years. Clinical, demographic, and laboratory data were collected from August 2000 through December 2009. Glomerular filtration rate was estimated using the CKD-EPI and MDRD Study equations.
CKD was present in 25.6% and 23.5% of the study population using the MDRD Study and CKD-EPI equations, respectively. Diabetes was present in 42.4% and 43.8% of participants with CKD, respectively. Prevalent risk factors for diabetes included obesity (body mass index >30 kg/m2), 44.0%; hypertension, 80.5%; cardiovascular disease, 23.2%; family history of diabetes, 55.9%; and dyslipidemia, 43.0%. In a logistic regression model after adjusting for age and other risk factors, odds for diabetes increased significantly compared with no CKD with each CKD stage based on the CKD-EPI equation and similarly with stages based on the MDRD Study equation. Using a CKD-EPI–adjusted model, ORs were: stage 1, 2.08 (95% CI, 1.90–2.27); stage 2, 1.86 (95% CI, 1.72–2.02); stage 3, 1.23 (95% CI, 1.17–1.30); stage 4, 1.69 (95% CI, 1.42–2.03); and stage 5, 2.46 (95% CI, 1.46–4.14).
Using the CKD-EPI equation led to a lower prevalence of CKD but to similar diabetes prevalence rates associated with CKD across all stages compared with the MDRD Study equation. Diabetes and other CKD risk factor prevalence was increased compared with the non-CKD population.
PMCID: PMC3237700  PMID: 21338847
Chronic kidney disease; diabetes mellitus; estimated glomerular filtration rate
15.  Gestational Diabetes Mellitus Alone in the Absence of Subsequent Diabetes Is Associated With Microalbuminuria 
Diabetes Care  2010;33(12):2586-2591.
Women with gestational diabetes mellitus (GDM) maintain a higher risk for recurrent GDM and overt diabetes. Overt diabetes is a risk factor for development of chronic kidney disease (CKD), but GDM alone, without subsequent development of overt diabetes, may also pose a risk for CKD.
This cross-sectional analysis included Kidney Early Evaluation Program (KEEP) participants from 2000 to 2009. Patient characteristics and kidney function among three categories (GDM alone, overt diabetes, and no history of diabetes) were compared. The prevalence of microalbuminuria, macroalbuminuria, and CKD stages 1–2 and 3–5 was assessed using logistic regression.
Of 37,716 KEEP female participants, 571 (1.5%) had GDM alone and 12,100 (32.1%) had overt diabetes. Women with GDM had a higher rate of microalbuminuria but not macroalbuminuria than their nondiabetic peers (10.0 vs. 7.7%) that was substantially lower than the 13.6% prevalence in diabetic women. In multivariate analysis, women with GDM alone, compared with nondiabetic women, demonstrated increased odds of CKD stages 1–2 (multivariate odds ratio 1.54 [95% CI 1.16–2.05]) similar to the odds for women with overt diabetes (1.68 [1.55–1.82]). In stratified analyses, age, race, BMI, and hypertension modified the odds for CKD stages 1 –2 but not CKD stages 3–5 among women with GDM.
Women with GDM alone have a higher prevalence of microalbuminuria than women without any history of diabetes, translating to higher rates of CKD stages 1–2. These results suggest that GDM, even in the absence of subsequent overt diabetes, may increase the risk for future cardiovascular and kidney disease.
PMCID: PMC2992195  PMID: 20807871
16.  Cardiovascular Disease in Chronic Kidney Disease: Data from the Kidney Early Evaluation Program (KEEP) 
Current diabetes reports  2011;11(1):47-55.
Diabetes mellitus (DM) and hypertension (HTN) are leading joint risk factors for both cardiovascular disease (CVD) and chronic kidney disease (CKD). In the nationwide KEEP (Kidney Early Evaluation Program) an estimated glomerular filtration rate less than 60 mL/min/1.73 m2 or a urine albumin:creatinine ratio ≥30 mg/g (3.4 mg/mmol) defines CKD. Overall in KEEP, the rates of identified CKD and self-reported CVD are 25.7% and 22.1%, respectively. The presence of CKD has been associated with younger ages of self-reported myocardial infarction and stroke. The combination of CVD and CKD in KEEP has been associated with shorter survival time. Finally, the presence of CVD or a prior history of coronary revascularization has been associated with modestly better rates of CVD risk factor control; however, the majority of patients with CKD have suboptimally controlled blood pressure, glucose, or lipids. These data suggest that patients with CKD are not only at higher risk for CVD and subsequent mortality, but are also ideal for targeted community—and practice-based interventions to improve risk factor control and, hopefully, reduce rates of subsequent cardiovacular events.
PMCID: PMC3206095  PMID: 21076895
Cardiovascular disease; Chronic kidney disease; Atherosclerosis; Myocardial infarction; Percutaneous coronary intervention; Microalbuminuria; Bypass surgery; Risk factors
17.  The Association between Parathyroid Hormone Levels and the Cardiorenal Metabolic Syndrome in Non-Diabetic Chronic Kidney Disease 
Cardiorenal Medicine  2011;1(2):123-130.
The relationship between parathyroid hormone (PTH) and the cardiorenal metabolic syndrome was examined among non-diabetic persons with chronic kidney disease (CKD).
In a cross-sectional analysis, the relationship between PTH levels and the cardiorenal metabolic syndrome was investigated in 3,215 non-diabetic participants in the National Kidney Foundation-Kidney Early Evaluation Program (KEEP 2.0) found to have CKD (eGFR <60 ml/min/1.73 m2).
In unadjusted analyses, the prevalence of the cardiorenal metabolic syndrome increased along increasing PTH quartiles (31.7, 33.8, 37.3, and 48.7%, respectively, p for trend <0.0001). After multivariate adjustment, as compared to the first PTH quartile, odds of the cardiorenal metabolic syndrome were 16% (p = 0.18), 35% (p = 0.006), and 80% (p < 0.0001) higher for the second, third, and fourth quartiles, respectively. When taken as a continuous predictor, each standard deviation increase of natural log transformed PTH was associated with 26% (p < 0.0001) higher odds of the cardiorenal metabolic syndrome. The association of PTH with the cardiorenal metabolic syndrome was not modified by age or gender (p for interaction was not significant for both modifiers).
Among an outpatient non-diabetic population with CKD, higher PTH levels were associated with a higher prevalence of the cardiorenal metabolic syndrome.
PMCID: PMC3101512  PMID: 22258399
Chronic kidney disease; Hyperparathyroidism; KEEP; Metabolic syndrome
18.  Diabetic Cardiovascular Disease Predicts Chronic Kidney Disease Awareness in the Kidney Early Evaluation Program 
Cardiorenal Medicine  2011;1(1):45-52.
Lack of chronic kidney disease (CKD) awareness is common. Recent data suggest that the presence of concurrent diabetes may heighten CKD awareness, but current data have not supported the hypothesis that healthcare delivery or insurance status improves awareness in the diabetic population. Diabetes is associated with high cardiovascular disease (CVD) morbidity, especially in patients with CKD. We hypothesized that a highly prevalent co-morbid condition such as CVD in patients with diabetes would predict CKD awareness.
We utilized data from the National Kidney Foundation-Kidney Early Evaluation Program (KEEPTM), a large screening program designed to identify high-risk individuals for CKD and promote awareness.
Among 77,077 participants, CKD was identified in 20,200 and diabetes in 23,082. Prevalence of CVD was higher in participants with than without diabetes (39.5 vs. 22.0%) and in stage 3–5 compared to stage 1–2 CKD (43.3 vs. 34.4%). Patients with diabetes and CVD had a higher level of awareness than those without diabetes (8.2 vs. 2.2%). Among patients with diabetes and CVD, the presence of congestive heart failure was a better predictor of awareness [odds ratio (OR) 1.84; 95% confidence interval (CI) 1.40–2.43] than endpoints such as myocardial infarction or stroke [OR 1.35 (95% CI 1.04–1.73) and OR 1.34 (95% CI 1.04–1.72), respectively].
While prevalence of CKD awareness remained low, our data suggest that in patients with diabetes the presence of CVD was associated with increased awareness in a targeted screening program for CKD awareness.
PMCID: PMC3101520  PMID: 22258465
Cardiovascular disease; Chronic kidney disease; Diabetes mellitus; KEEP
20.  Race and Sex Differences in Hypertension Control in CKD: Results From the Kidney Early Evaluation Program (KEEP) 
African American men with chronic kidney disease (CKD) progress to end-stage renal disease more rapidly than African American women or whites. Uncontrolled hypertension worsens CKD, and disparities in hypertension control may contribute to disparities in CKD progression.
Study Design
Setting & Participants
10,827 individuals with CKD and self-reported hypertension screened in the Kidney Early Evaluation Program.
African American race, sex.
Hypertension control (blood pressure <130 mm Hg systolic and/or <80 mm Hg diastolic).
Self-report, physical examination (blood pressure), laboratory data (serum creatinine, microalbuminuria by urine dipstick). We calculated estimated glomerular filtration rates by using the 4-variable isotope dilution mass spectrometry Modification of Diet in Renal Disease Study equation. We classified CKD as early (stages 1 to 2) or late (stages 3 to 5) based on estimated glomerular filtration rate and microalbuminuria.
In individuals with early CKD, African American women (odds ratio [OR], 1.47; 95% confidence interval [CI], 1.14 to 1.88), white men (OR, 1.85; 95% CI, 1.39 to 2.46), and white women (OR, 1.69; 95% CI, 1.28 to 2.22) had greater odds of hypertension control (blood pressure <130/80 mm Hg) than African American men. In individuals with late CKD, white men (OR, 1.66; 95% CI, 1.10 to 2.52) and white women (OR, 1.67; 95% CI, 1.13 to 2.46) had greater odds of hypertension control than African American men. No differences were seen between African American men and women with late CKD.
No information for medication regimens.
African American men with CKD have poorly controlled hypertension compared with African American women and whites, particularly in the early stages of disease. Efforts to aggressively treat hypertension in this population may help narrow the race and sex disparities in progression to end-stage renal disease.
PMCID: PMC2866650  PMID: 18215697
Hypertension; chronic kidney disease; ethnic groups; sex
21.  Risk Factors for Chronic Kidney Disease among American Indians and Alaska Natives – Findings from the Kidney Early Evaluation Program 
American Journal of Nephrology  2008;29(5):440-446.
American Indians and Alaska Natives (AIAN) have a high incidence of end-stage renal disease. Less is known about chronic kidney disease (CKD) among AIAN and whether risk factors differ for low estimated glomerular filtration rate (eGFR) versus albuminuria with a normal eGFR.
Cross-sectional study examining the associations of age, sex, smoking, obesity, diabetes, hypertension, family history, and geographic region with CKD among a screened population of AIAN participants in the Kidney Early Evaluation Program from 2000 to 2006. CKD was defined by the presence of either a low eGFR, <60 ml/min/1.73 m2, or albuminuria, a urine albumin/creatinine ratio ≥30 mg/g.
The prevalence of any CKD was 29%, of low eGFR was 17%, and of albuminuria with a normal eGFR was 12%. Older age was the strongest predictor of low eGFR (61+ years OR 8.42, 95% CI 5.92–11.98), followed by hypertension (OR 2.38, 95% CI 1.74–3.26). In contrast, diabetes (OR 2.04, 95% CI 1.57–2.64) and hypertension (OR 2.63, 95% CI 1.93–3.59) were the only predictors of albuminuria among persons with a normal eGFR.
The burden of CKD was high among this screened population of AIAN, and different risk factor patterns were associated with low eGFR and albuminuria. Innovative programs and longitudinal research are needed to address CKD among AIAN.
PMCID: PMC2821946  PMID: 19011277
Chronic kidney disease; Risk factors; American Indians; Alaska Natives

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