Accelerated biological age linked to high normal serum sodium in general healthcare electronic medical records and NHANES

Jonathan Rabinowitz and colleagues tested whether serum sodium within the normal range tracks biological aging. They analyzed 363,286 adults aged 18 to 80 years from 20 years of electronic medical records and 24,611 adults from NHANES 1999 to 2018. Biological age was estimated with the Klemera-Doubal method using seven biomarkers, with a four-biomarker sensitivity model. Higher age-adjusted sodium was associated with accelerated biological age in both datasets, with the strongest associations in younger adults. In the electronic-record dataset, the highest versus lowest sodium category corresponded to 0.88 years of acceleration in men and 2.32 years in women. In NHANES, the largest reported male difference was 1.92 years. The study is observational and cannot show that drinking more water slows aging. Sodium can reflect diet, kidney function, medications, illness, and hydration status. Randomized hydration studies with validated aging outcomes are required.

Increased serum sodium in the normal range is associated with accelerated biological aging in the general population, especially among people aged 18-50. Intervention studies are needed to confirm the link between hydration and biological aging.