ABSTRACT
The natural history of diabetic nephropathy offered an average survival of only 5-7 years. During the past decades, multiple changes in therapy and lifestyle have occurred. The prognosis of diabetic nephropathy after implementing stricter control of blood pressure (including increased use of long-term renin-angiotensin system inhibition), lipids, and glycemia, along with less smoking and other lifestyle and treatment advancements, is inadequately analyzed. To clarify this, we studied 497 patients with type 1 diabetes and diabetic nephropathy at the Steno Diabetes Center and compared them with previous data, obtained using identical criteria at our hospital. The glomerular filtration rate, measured yearly by 51Cr-EDTA plasma clearance, was a mean of 71 ml/min per 1.73 m2 at baseline. The mean glomerular filtration rate decline was significantly reduced by 19% (95% confidence interval 5-34) from previously 4.0 to 3.3 ml/min per 1.73 m2/year. During a median follow-up of 9.1 years, 29% of participants doubled their plasma creatinine or developed end-stage renal disease. Mortality risk was similar to our prior study (hazard ratio 1.05 (0.76-1.43). However, after age adjustment, as both diabetes and nephropathy onset occurred later in life, mortality was reduced by 30%. Risk factors for decline in glomerular filtration rate, death, and other renal end points were generally in agreement with prior studies. Thus, with current treatment of nephropathy in type 1 diabetes, the prognosis and loss of renal function has improved along with better control of modifiable risk factors.
Subject(s)
Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/therapy , Diabetic Nephropathies/therapy , Adult , Cohort Studies , Denmark/epidemiology , Diabetes Mellitus, Type 1/physiopathology , Diabetic Nephropathies/mortality , Diabetic Nephropathies/physiopathology , Disease Progression , Female , Follow-Up Studies , Glomerular Filtration Rate , Humans , Kidney Failure, Chronic/etiology , Kidney Failure, Chronic/mortality , Kidney Failure, Chronic/physiopathology , Male , Middle Aged , Prognosis , Time FactorsABSTRACT
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.
