Among U.S. adults with diabetes from 1988 to 2014, the overall prevalence of diabetic kidney disease did not change significantly, while the prevalence of albuminuria declined and the prevalence of reduced estimated glomerular filtration rate increased, according to a study appearing in the Aug. 9 issue of JAMA.

Diabetes mellitus is the most common cause of chronic kidney disease in the world, leading to multiple complications including end-stage renal disease, cardiovascular disease, infection, and death. Chronic kidney disease in the setting of diabetes or diabetic kidney disease (DKD), manifests clinically as albuminuria (the presence of excessive protein in the urine), reduced glomerular filtration rate (GFR; a measure of kidney function), or both. Changes in demographics and treatments may affect the prevalence and clinical manifestations of diabetic kidney disease.

Ian H. de Boer, MD, MS, of the University of Washington, , and colleagues analyzed data of 6,251 adults with diabetes mellitus participating in National Health and Nutrition Examination Surveys from 1988 through 2014.

The researchers found that the prevalence of any diabetic kidney disease, defined as persistent albuminuria, persistent reduced estimated GFR, or both, did not significantly change over time from 28% in 1988-1994 to 26% in 2009-2014. However, the prevalence of albuminuria decreased progressively over time from 21% in 1988-1994 to 165 in 2009-2014. In contrast, the prevalence of reduced eGFR increased from 9% in 1988-1994 to 14% in 2009-2014, with a similar pattern for severely reduced eGFR.

Significant heterogeneity in the trend for albuminuria was noted by age and race/ethnicity, 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 had albuminuria, reduced eGFR, or both.

The authors wrOte that the lower prevalence of albuminuria observed over time may be attributable to a higher rate of prescribed diabetes therapies (glucose-lowering medications, renin-angiotensin-aldosterone system inhibitors, and statins). And that while reasons for the increasing prevalence of reduced eGFR cannot be conclusively discerned from these data, it is possible that hemodynamic effects of RAAS inhibitors and improved blood pressure control could contribute to lower eGFR. Alternatively, an increasing duration of diabetes may be contributing to kidney damage.