Meda E. Pavkov

Prevalence of Chronic Kidney Disease in US Adults with Undiagnosed Diabetes or Prediabetes

BACKGROUND AND OBJECTIVES Prevalence of chronic kidney disease (CKD) in people with diagnosed diabetes is known to be high, but little is known about the prevalence of CKD in those with undiagnosed diabetes or prediabetes. We aimed to estimate and compare the community prevalence of CKD among people with diagnosed diabetes, undiagnosed diabetes, prediabetes, or no diabetes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The 1999 through 2006 National Health and Nutrition Examination Survey is a representative survey of the civilian, noninstitutionalized US population. Participants who were aged > or =20 years; responded to the diabetes questionnaire; and had fasting plasma glucose (FPG), serum creatinine, and urinary albumin-creatinine ratio measurements were included (N = 8188). Diabetes status was defined as follows: Diagnosed diabetes, self-reported provider diagnosis (n = 826); undiagnosed diabetes, FPG > or =126 mg/dl without self-reported diagnosis (n = 299); prediabetes, FPG > or =100 and <126 mg/dl (n = 2272); and no diabetes, FPG <100 mg/dl (n = 4791). Prevalence of CKD was defined by estimated GFR 15 to 59 ml/min per 1.73 m(2) or albumin-creatinine ratio > or =30 mg/g; adjustment was performed with multivariable logistic regression. RESULTS Fully 39.6% of people with diagnosed and 41.7% with undiagnosed diabetes had CKD; 17.7% with prediabetes and 10.6% without diabetes had CKD. Age-, gender-, and race/ethnicity-adjusted prevalence of CKD was 32.9, 24.2, 17.1, and 11.8%, for diagnosed, undiagnosed, pre-, and no diabetes, respectively. Among those with CKD, 39.1% had undiagnosed or prediabetes. CONCLUSIONS CKD prevalence is high among people with undiagnosed diabetes and prediabetes. These individuals might benefit from interventions aimed at preventing development and/or progression of both CKD and diabetes.

Trajectories of Kidney Function Decline in the 2 Years Before Initiation of Long-term Dialysis

BACKGROUND Little is known about patterns of kidney function decline leading up to the initiation of long-term dialysis. STUDY DESIGN Retrospective cohort study. SETTING & PARTICIPANTS 5,606 Veterans Affairs patients who initiated long-term dialysis in 2001-2003. PREDICTOR Trajectory of estimated glomerular filtration rate (eGFR) during the 2-year period before initiation of long-term dialysis. OUTCOMES & MEASUREMENTS Patient characteristics and care practices before and at the time of dialysis initiation and survival after initiation. RESULTS We identified 4 distinct trajectories of eGFR during the 2-year period before dialysis initiation: 62.8% of patients had persistently low level of eGFR < 30 mL/min/1.73 m2 (mean eGFR slope, 7.7 ± 4.7 [SD] mL/min/1.73 m2 per year), 24.6% had progressive loss of eGFR from levels of approximately 30-59 ml/min/1.73 m2 (mean eGFR slope, 16.3 ± 7.6 mL/min/1.73 m2 per year), 9.5% had accelerated loss of eGFR from levels > 60 mL/min/1.73 m2 (mean eGFR slope, 32.3 ± 13.4 mL/min/1.73 m2 per year), and 3.1% experienced catastrophic loss of eGFR from levels > 60 mL/min/1.73 m2 within 6 months or less. Patients with steeper eGFR trajectories were more likely to have been hospitalized and have an inpatient diagnosis of acute kidney injury. They were less likely to have received recommended predialysis care and had a higher risk of death in the first year after dialysis initiation. CONCLUSIONS There is substantial heterogeneity in patterns of kidney function loss leading up to the initiation of long-term dialysis perhaps calling for a more flexible approach toward preparing for end-stage renal disease.

A Health Policy Model of CKD: 2. The Cost-Effectiveness of Microalbuminuria Screening

BACKGROUND Microalbuminuria screening may detect chronic kidney disease in its early stages, allowing for treatment that delays or prevents disease progression. The cost-effectiveness of microalbuminuria screening has not been determined. STUDY DESIGN A cost-effectiveness model simulating disease progression and costs. SETTING & POPULATION US patients. MODEL, PERSPECTIVE, AND TIMEFRAME: The microsimulation model follows up disease progression and costs in a cohort of simulated patients from age 50 to 90 years or death. Costs are evaluated from the health care system perspective. INTERVENTION Microalbuminuria screening at 1-, 2-, 5-, or 10-year intervals followed by treatment with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. We considered universal screening, as well as screening targeted at persons with diabetes, persons with hypertension but no diabetes, and persons with neither diabetes nor hypertension. OUTCOMES Costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. RESULTS For the full model population, universal screening increases costs and increases QALYs. Universal annual screening starting at age 50 years has a cost-effectiveness ratio of

A health policy model of CKD: 1. Model construction, assumptions, and validation of health consequences.

73,000/QALY relative to no screening and

Early Renal Function Decline in Type 2 Diabetes

145,000/QALY relative to usual care. Cost-effectiveness ratios improved with longer screening intervals. Relative to no screening, targeted annual screening has cost-effectiveness ratios of

Prognostic Implications of the Urinary Albumin to Creatinine Ratio in Veterans of Different Ages With Diabetes

21,000/QALY,

Elevation of circulating TNF receptors 1 and 2 increases the risk of end-stage renal disease in American Indians with type 2 diabetes.

55,000/QALY, and

Establishing a National Chronic Kidney Disease Surveillance System for the United States

155,000/QALY for persons with diabetes, those with hypertension, and those with neither current diabetes nor current hypertension, respectively. LIMITATIONS Results necessarily are based on a microsimulation model because of the long time horizon appropriate for chronic kidney disease. The model includes only health care costs. CONCLUSIONS Microalbuminuria screening is cost-effective for patients with diabetes or hypertension, but is not cost-effective for patients with neither diabetes nor hypertension unless screening is conducted at longer intervals or as part of existing physician visits.

Comparison of Serum Cystatin C, Serum Creatinine, Measured GFR, and Estimated GFR to Assess the Risk of Kidney Failure in American Indians With Diabetic Nephropathy

BACKGROUND A cost-effectiveness model that accurately represents disease progression, outcomes, and associated costs is necessary to evaluate the cost-effectiveness of interventions for chronic kidney disease (CKD). STUDY DESIGN We developed a microsimulation model of the incidence, progression, and treatment of CKD. The model was validated by comparing its predictions with survey and epidemiologic data sources. SETTING & POPULATION US patients. MODEL, PERSPECTIVE, & TIMEFRAME The model follows up disease progression in a cohort of simulated patients aged 30 until age 90 years or death. The model consists of 7 mutually exclusive states representing no CKD, 5 stages of CKD, and death. Progression through the stages is governed by a persons glomerular filtration rate and albuminuria status. Diabetes, hypertension, and other risk factors influence CKD and the development of CKD complications in the model. Costs are evaluated from the health care system perspective. INTERVENTION Usual care, including incidental screening for persons with diabetes or hypertension. OUTCOMES Progression to CKD stages, complications, and mortality. RESULTS The model provides reasonably accurate estimates of CKD prevalence by stage. The model predicts that 47.1% of 30-year-olds will develop CKD during their lifetime, with 1.7%, 6.9%, 27.3%, 6.9%, and 4.4% ending at stages 1-5, respectively. Approximately 11% of persons who reach stage 3 will eventually progress to stage 5. The model also predicts that 3.7% of persons will develop end-stage renal disease compared with an estimate of 3.0% based on current end-stage renal disease lifetime incidence. LIMITATIONS The model synthesizes data from multiple sources rather than a single source and relies on explicit assumptions about progression. The model does not include acute kidney failure. CONCLUSION The model is well validated and can be used to evaluate the cost-effectiveness of CKD interventions. The model also can be updated as better data for CKD progression become available.

Albuminuria Prevalence in First Morning Void Compared with Previous Random Urine from Adults in the National Health and Nutrition Examination Survey, 2009–2010

BACKGROUND AND OBJECTIVES Early decline in GFR may reflect progressive kidney disease in type 1 diabetes, but its predictive value in type 2 diabetes is uncertain. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In this longitudinal study, GFR was measured serially over approximately 4.0 years in 195 Pima Indians with type 2 diabetes. Renal function decline (RFD) was defined during this initial period by an average GFR loss ≥3.3%/yr, as defined previously in type 1 diabetes. Subsequently, participants were followed for up to 17.8 years to ESRD onset, death, or December 31, 2010, whichever came first. RESULTS RFD prevalence during the initial period was 32% in 68 participants with normal baseline albuminuria (albumin/creatinine ratio [ACR] < 30 mg/g), 42% in 88 with microalbuminuria (ACR 30 to <300 mg/g), and 74% in 39 with macroalbuminuria (ACR ≥300 mg/g; P<0.001). The cumulative incidence of ESRD 10 years after the initial period was 41% in those with RFD and 15% in those without (P<0.001); 41 of the 49 ESRD cases (83.7%) occurred in participants who had or developed macroalbuminuria during the initial period. When adjusted for age, sex, diabetes duration, and hemoglobin A1c, the ESRD hazard rate was 4.78 times (95% confidence interval, 2.39-9.58) as high in those with RFD as in those without; further adjustment for albuminuria attenuated this association (hazard ratio, 1.79; 95% confidence interval, 0.82-3.91). CONCLUSIONS In type 2 diabetes, loss of GFR often occurs before the onset of macroalbuminuria, but a decline predictive of ESRD is strongly dependent on progression to macroalbuminuria.