Mortality Risks for All Causes and Cardiovascular Diseases and Reduced GFR in a Middle-aged Working Population in Taiwan

Background: Effects of decreased estimated glomerular filtration rate (eGFR) on cardiovascular disease (CVD) mortality are uncertain in Chinese general populations. Study Design: Prospective cohort study. Setting & Participants: 17,026 adults 50 years and older in Taiwan. A subset of 7,968 had repeated measurements. Predictor: Decreased 9GFR and its progression. eGFR was calculated from serum creatinine level by using the Modification of Diet in Renal Disease Study equation. Outcomes: Mortality from all causes and CVD, including coronary heart disease (CHD) and stroke, from the National Death Registry. Measurements: Hazard ratios (HRs) and Kaplan-Meier survival curves were calculated for participants with a moderate to severe decrease in eGFR (< 60 mL/min/1.73 m(2)) compared with those with normal eGFR (>= 90mL/min/1.73 m(2)). HR of a rapid decrease (>= 20%) in eGFR was also calculated. Results: Mean age of all participants was 57.2 +/- 5.2 (SD) years. We observed 1,682 deaths in 15 years of follow-up. Participants with a moderate to severe decrease in eGFR had increased HRs for mortality from all causes (1.44; 95% confidence interval [Cl], 1.22 to 1.70), CVD (1.90; 95% Cl, 1.36 to 2.65), CHD (2.07; 95% Cl, 1.26 to 3.41), and stroke (2.16; 95% Cl, 1.29 to 3.62) after adjusting for confounders. Decreased eGFR was associated with ischemic stroke, but not hemorrhagic stroke. No significant interaction between decreased eGFR and anemia, diabetes, or smoking was found. There were 660 participants with a 20% or greater decrease in eGFR from baseline during 18 months of follow-up. They had increased HRs for all causes (1.45; 95% Cl, 1.13 to 1.86), CVD (2.48; 95% Cl, 1.58 to 3.89), CHD (2.14; 95% Cl, 1.07 to 4.29), and stroke (2.79; 95% Cl, 1.45 to 5.36) compared with those with less than a 20% decrease in eGFR during the same period. Limitations: Data for proteinuria were not available. Creatinine assay was not calibrated. Conclusions: A moderate to severe or fast decrease in eGFR was associated with all-cause and CVD mortality in this ethnic Chinese cohort.