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

Abstract

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.