Adults with serum sodium levels greater than 142 mEq/L are at higher risk of being biologically older, according to a study published in the journal eBioMedicine.1 They are also more prone to chronic diseases and premature death.

To examine the link between serum levels of sodium, as a marker of hydration and indicators of health, researchers examined data for 11,255 adults from the Atherosclerosis Risk in Communities study. Five medical visits were considered; two when the participants were in their 50s and the rest between 70-90 years of age. Fifteen health indicators were evaluated during the 25 years follow-up including systolic blood pressure, cholesterol, and blood sugar. Individuals with high baseline sodium levels or those with comorbid conditions were not included in the trial.

Analysis showed that individuals with serum sodium levels >142 mEq/L tended to have more chronic conditions such as heart failure, diabetes, chronic lung disease, peripheral artery disease and dementia compared to those with mid-range values with a 64% increased risk.

Participants with higher serum sodium levels also showed presence of faster and advanced biological aging. The odds of biological aging increased by half (50%) with serum sodium levels greater than 144 mEq/L. Among those with levels above 142 mEq/L, the probability of biological aging increased 10-15% vs those with sodium levels ranging from 137 mEq/L to142 mEq/L. Participants with higher sodium levels (144.5-146 mEq/L) also had 21% higher risk of mortality at a younger age compared to levels between 137 mEq/L and 142 mEq/L. The risk of chronic diseases and premature death increased among the study subjects with higher biological aging with hazard ratios of 1.70 and 1.59, respectively.

This study shows that optimal hydration slows down aging. But this is an observational study and does not conclusively establish a cause and effect relationship. Further studies are needed to corroborate these observations. However, it has delineated serum sodium value of 142 mEq/l as a cut-off level to identify at-risk people. Since insufficient intake of fluids increases serum sodium levels, it also highlights the need to evaluate daily fluid intake among those with serum sodium towards the upper limit of the normal range (135-146 mEq/L), in particular those with heart failure, where fluid restriction is part of the management to avoid overloading the heart.

Reference

1. Dmitrieva NI, et al. Middle-age high normal serum sodium as a risk factor for accelerated biological aging, chronic diseases, and premature mortality. EBioMedicine. Published: January 02, 2023DOI:https://doi.org/10.1016/j.ebiom.2022.104404.