The distribution of eGFR by age in a community-based healthy population: the Japan specific health checkups study (J-SHC study)

Renal function gradually declines with age. However, the association between changes in renal function and healthy aging has not been determined. This study examined the distribution of estimated glomerular filtration rate (eGFR) values in healthy subjects by age using large-scale cross-sectional data of health check-up participants in Japan. Among the 394,180 health check-up participants, 75,217 (19.1%) subjects without hypertension, diabetes, hyperlipidemia, obesity, proteinuria, smoking, past history of cardiovascular diseases, and renal failure/not undergoing dialysis were included in the healthy group. The distribution of eGFR values was determined at each age between 39 and 74 years. Results: in healthy subjects, the mean (± 2 SD range) values of eGFR (mL/min/1.73 m2) at ages 40, 50, 60, and 70 were 88.0 (55.4–121.7), 82.3 (51.2–113.3), 77.8 (48.1–107.6), and 72.9 (44.7–101.1), respectively. The difference in the mean eGFR by age was almost constant across all ages. In the linear regression analysis adjusted for sex, the regression coefficient of mean eGFR for a one-year increase in age was -0.46 mL/min/1.73 m2 in healthy subjects (P < 0.001). By sex, the distribution of eGFR and the 1-year change in eGFR showed similar results in both men and women. Renal function slowly declined with age in a healthy population; however, it was relatively preserved until the mid 70 s. This result suggests that a decline in renal function often observed in the elderly does not attribute to aging alone, and further examination might be required to clarify the cause of renal impairment.