UC Davis

Importance

Diabetic kidney disease is the leading cause of chronic and end-stage kidney disease in the United States and worldwide. Changes in demographics and treatments may affect the prevalence and clinical manifestations of diabetic kidney disease.

Objective

To characterize the clinical manifestations of kidney disease among US adults with diabetes over time.

Design, setting, and participants

Serial cross-sectional studies of adults aged 20 years or older with diabetes mellitus participating in National Health and Nutrition Examination Surveys from 1988 through 2014.

Exposures

Diabetes was defined as hemoglobin A1c greater than 6.5% or use of glucose-lowering medications.

Main outcomes and measures

Albuminuria (urine albumin-to-creatinine ratio ≥30 mg/g), macroalbuminuria (urine albumin-to-creatinine ratio ≥300 mg/g), reduced estimated glomerular filtration rate (eGFR <60 mL/min/1.73 m2), and severely reduced eGFR (<30 mL/min/1.73 m2), incorporating data on biological variability to estimate the prevalence of persistent abnormalities.

Results

There were 6251 adults with diabetes included (1431 from 1988-1994, 1443 from 1999-2004, 1280 from 2005-2008, and 2097 from 2009-2014). The prevalence of any diabetic kidney disease, defined as persistent albuminuria, persistent reduced eGFR, or both, did not significantly change over time from 28.4% (95% CI, 23.8%-32.9%) in 1988-1994 to 26.2% (95% CI, 22.6%-29.9%) in 2009-2014 (prevalence ratio, 0.95 [95% CI, 0.86-1.06] adjusting for age, sex, and race/ethnicity; P = .39 for trend). However, the prevalence of albuminuria decreased progressively over time from 20.8% (95% CI, 16.3%-25.3%) in 1988-1994 to 15.9% (95% CI, 12.7%-19.0%) in 2009-2014 (adjusted prevalence ratio, 0.76 [95% CI, 0.65-0.89]; P < .001 for trend). In contrast, the prevalence of reduced eGFR increased from 9.2% (95% CI, 6.2%-12.2%) in 1988-1994 to 14.1% (95% CI, 11.3%-17.0%) in 2009-2014 (adjusted prevalence ratio, 1.61 [95% CI, 1.33-1.95] comparing 2009-2014 with 1988-1994; P < .001 for trend), with a similar pattern for severely reduced eGFR (adjusted prevalence ratio, 2.86 [95% CI, 1.38-5.91]; P = .004 for trend). Significant heterogeneity in the temporal trend for albuminuria was noted by age (P = .049 for interaction) and race/ethnicity (P = .007 for interaction), with a decreasing prevalence of albuminuria observed only among adults younger than 65 years and non-Hispanic whites, whereas the prevalence of reduced GFR increased without significant differences by age or race/ethnicity. In 2009-2014, approximately 8.2 million adults with diabetes (95% CI, 6.5-9.9 million adults) had albuminuria, reduced eGFR, or both.

Conclusions and relevance

Among US adults with diabetes from 1988 to 2014, the overall prevalence of diabetic kidney disease did not change significantly, whereas the prevalence of albuminuria declined and the prevalence of reduced eGFR increased.