Mild decrease in estimated glomerular filtration rate and proteinuria are associated with all-cause and cardiovascular mortality in the general population.

BACKGROUND: A recent collaborative meta-analysis by Kidney Disease: Improving Global Outcomes reported that an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2) and an albumin-to-creatinine ratio of ≥ 10 mg/g were independent predictors for mortality in the general population. However, selection bias, heterogeneity of the cohorts and measurement issues could be limitations.

METHODS: We analyzed the relationship of eGFR and proteinuria with mortality in the Korean general population, represented by 112,115 participants, aged ≥ 20 years, who had a voluntary health check-up with homogenous calibration of creatinine measurement from 2003 to 2009. Proteinuria (trace or more) was determined by urine dipstick.

RESULTS: eGFR and proteinuria were independently associated with all-cause mortality (ACM) and cardiovascular mortality (CVM), and progressive increases in risks for mortality were noted according to eGFR level and the presence of proteinuria. Compared with eGFR 90-105 mL/min/1.73 m(2), hazard ratio (HRs) for ACM were 1.60 [95% confidence interval (CI) 1.12-2.30] for eGFR 60-74 mL/min/1.73 m(2) and 3.54 (2.20-5.68) for eGFR <60 mL/min/1.73 m(2) in participants with no proteinuria. In participants with proteinuria, HRs for ACM were 2.10 (1.41-3.12) for eGFR 75-89 mL/min/1.73 m(2), 2.30 (1.50-3.53) for eGFR 60-74 mL/min/1.73 m(2) and 3.77 (2.15-6.38) for eGFR <60 mL/min/1.73 m(2). Similar findings were observed for CVM.

CONCLUSIONS: eGFR <75 mL/min/1.73 m(2) and urine dipstick trace or more were independent risk factors of ACM and CVM. The risks of adverse outcomes are greater in the general population with mild renal impairment or mild proteinuria.