Glomerular Filtration Rate, Cardiorenal End Points, and All-Cause Mortality in Type 2 Diabetic Patients

OBJECTIVE:--Chronic kidney disease (CKD) predicts cardiovascular disease (CVD) in the general population. We investigated the effects of stages of renal function using the estimated glomerular filtration rate (eGFR) on all-cause mortality and cardiovascular end points in a prospective cohort of Chinese type 2 diabetic patients. RESEARCH DESIGN AND METHODS--Between 1995 and 2000, 4,421 patients without macrovascular disease or end-stage renal disease were recruited. Renal function was assessed by eGFR, as calculated by the abbreviated Modification of Diet in Renal Disease Study Group formula. Clinical end points included all-cause mortality, cardiovascular end point (cardiovascular death, new admissions due to angina, myocardial infarction, stroke, revascularization, or heart failure), and renal end point (reduction in eGFR by >50%, progression of eGFR to stage 5, or dialysis or renal death). RESULTS:--After a median follow-up period of 39.4 months (interquartile range 20.3-55), all-cause mortality rate increased from 1.2% (95% CI 0.8-1.7) to 18.3% (9.1-27.5) (P for trend <0.001) as renal function deteriorated from stage 1 (eGFR >=90 ml/min per 1.73 m²) to stage 4 (15-29 ml/min per 1.73 m²). The respective rate of new cardiovascular end points also increased from 2.6% (2.0-3.3) to 25.3% (15.0-35.7) (P for trend <0.001). After adjustment for covariates (age, sex, albuminuria, use of renin-angiotensin-aldosterone system [RAAS] inhibitors, lipids, blood pressure, and glycemic control), hazard ratios across different stages of eGFR (>=90, 60-89, 30-59, and 15-29 ml/min per 1.73 m²) for all-cause mortality were 1.00, 1.27, 2.34, and 9.82 (P for trend <0.001), for cardiovascular end points were 1.00, 1.04, 1.05, and 3.23 (P for trend <0.001), and for renal end points were 1.00, 1.36, 3.34, and 27.3 (P for trend <0.001), respectively. CONCLUSIONS:--Chinese type 2 diabetic patients with reduced eGFR were at high risk of developing cardiovascular end points and all-cause mortality, independent of albuminuria and metabolic control.