Improved Survival and Renal Prognosis of Patients With Type 2 Diabetes and Nephropathy With Improved Control of Risk Factors

Abstract

OBJECTIVE To evaluate long-term survival, development of renal end points, and decline in glomerular filtration rate (GFR) in patients with type 2 diabetes and diabetic nephropathy (DN) after renin-angiotensin system (RAS) inhibition and multifactorial treatment of cardiovascular risk factors have become standard of care. RESEARCH DESIGN AND METHODS All patients with type 2 diabetes and DN (n = 543) at the Steno Diabetes Center were followed during 2000–2010. GFR was measured yearly with 51Cr-EDTA plasma clearance. Annual decline in GFR was determined in patients with at least three measurements over a minimum of 3 years (∆GFR cohort, n = 286). Results were compared with historical data, obtained using identical criteria at our hospital, before implementation of current treatment guidelines. RESULTS Baseline mean (SD) GFR was 74 (32) mL/min/1.73 m2. More than 93% received RAS inhibition. During median 7.8 (interquartile range 5.7–9.8) years, mean (SE) annual GFR decline was 4.4 (0.24) compared with previously 5.2 (0.27) mL/min/1.73 m2/year (P = 0.04). Doubling of plasma creatinine or end-stage renal disease (ESRD) developed in 19%, and 37% died during 5.7 (3.3–8.8) years. Mortality from onset of DN in the ∆GFR cohort was compared with that of our prior ∆GFR cohort from 1983 to 2003 (n = 227). Crude mortality risk was reduced by 42% and after age adjustment by 50% (P < 0.001 for both). In a multistate model accounting for competing risks of ESRD and death, prior cardiovascular disease and lower GFR were predictors of mortality, whereas albuminuria, HbA1c, and low GFR predicted ESRD. CONCLUSIONS Overall prognosis has improved considerably with current multifactorial treatment of DN in type 2 diabetes, including long-term RAS inhibition.