Glomerular filtration rate and 10-year mortality in a 70-year-old community-dwelling Japanese population

Abstract

The equation for Japanese estimated glomerular filtration rate (eGFR) was revised by measuring GFR by inulin clearance. The association of the new eGFR with all-cause mortality and mortality from cardiovascular disease (CVD) was assessed in an elderly Japanese population. Seventy-year-old subjects, residents of Niigata, Japan, participated. Baseline examinations were carried out in June 1998. The new eGFR measure, 194 × (serum creatinine)-1.094 × Age-0.287 × (0.739 if female), was calculated. According to eGFR results, subjects were classified into normal or slightly impaired (≥60 mL/min/1.73 m2), moderately impaired (40-59 mL/min/1.73 m2) and severely impaired (<40 mL/min/1.73 m2). Participants were under survey for 10 years. The overall survival rate with the Kaplan-Meier method was shorter in subjects with severely impaired eGFR than in those with normal, slightly or moderately impaired eGFR. Similarly, mortality from CVD was higher for individuals with severely impaired eGFR than those with normal or slightly impaired eGFR. There were no associations of mortality from cancer or pneumonia with eGFR. The hazard ratio by the Cox proportional regression model for total mortality was 3.9 times higher in the severely impaired group than in normal or slightly impaired groups, with adjustment for confounding factors. Mortality from CVD was 13.6 times higher in the former than in the latter, with adjustment. There is an association of the new Japanese eGFR with total mortality and CVD mortality, suggesting that the new equation may be independently predictive of all-cause mortality and mortality from CVD in the general 70- year-old Japanese population.