Background: The reason why coexistence of preserved estimated glomerular filtration rate (eGFR) and albuminuria contributes to a high risk of death and which cause of death increases all-cause mortality have not been elucidated.
Methods: A total of 16,759 participants aged 40 to 69 years with normal or mildly reduced eGFR (45-119 ml/min/1.73 m(2)) were enrolled and divided into six groups (group 1, eGFR: 90-119 without albuminuria; group 2, eGFR: 90-119 with albuminuria; group 3, eGFR: 60-89 without albuminuria (reference); group 4, eGFR: 60-89 with albuminuria; group 5, eGFR: 45-59 without albuminuria; group 6, eGFR: 45-59 with albuminuria) based on GFR estimated by using the CKD-EPI study equation modified by a Japanese coefficient and albuminuria (urine albumin-creatinine ratio ≥ 30 mg/g). Outcomes included all-cause death (ACD), cardiovascular death (CVD) and neoplasm-related death (NPD). Multivariable-adjusted mortality rate ratios (RR) and their 95% confidence intervals (CIs) in the groups were estimated by Poisson's regression analysis.
Results: The highest risk of ACD (RR (95% CIs): 3.95 (2.08-7.52)), CVD (7.15 (2.25-22.7)) and NPB (3.25 (1.26-8.38)) was observed in group 2. Subjects in group 2 were relatively young and had the highest levels of body mass index, blood pressure and HbA1c and the highest prevalence of diabetes and metabolic syndrome.
Conclusion: Coexistence of preserved eGFR and albuminuria increases risks for ACD, CVD and NPD. Relatively young metabolic persons having both preserved eGFR and albuminuria should be considered as a very high-risk population.
Keywords: Albuminuria; Chronic kidney disease; Estimated glomerular filtration rate; Mortality.