BACKGROUND: Glomerular hyperfiltration has been reported to be associated with adverse renal outcomes in general population. It is not known whether drinking pattern is associated with the risk of glomerular hyperfiltration in healthy individuals.
METHODS: We prospectively followed middle-aged 8,640 Japanese men with normal renal function, no proteinuria, no diabetes, and no use of antihypertensive medications at entry. Data on alcohol consumption were gathered by questionnaire. Glomerular hyperfiltration was defined as estimated glomerular filtration rate (eGFR) >/=117 mL/min/1.73 m(2), which was the upper 2.5th percentile value of eGFR in the entire cohort.
RESULTS: During 46,186 person-years of follow-up, 330 men developed glomerular hyperfiltration. In a multivariate model, for men who consumed alcohol on 1-3 days per week, alcohol consumption of >/=69.1g ethanol/drinking day was significantly associated with the risk of glomerular hyperfiltration (hazard ratio (HR), 2.37 (95% CI, 1.18-4.74)) compared with non-drinkers. For those who consumed alcohol on 4-7 days per week, higher alcohol consumption per drinking day was associated with a higher risk of glomerular hyperfiltration: the HRs (95% CI) for alcohol consumption of 46.1-69.0, and >/=69.1 g ethanol/drinking day were 1.55 (1.01-2.38), and 1.78 (1.02-3.12), respectively.
CONCLUSIONS: For high drinking frequency per week, more alcohol intake per drinking day was associated with an increased risk of glomerular hyperfiltration, while for low drinking frequency per week, only very high alcohol intake per drinking day was associated with an increased risk of glomerular hyperfiltration in middle-aged Japanese men.