An article published in eBioMedicine – part of The Lancet Discovery Science – suggests that individuals with high serum sodium tend to be biologically older, develop more chronic diseases, and have a lower life expectancy.
The rapidly aging population and prevalence of chronic diseases worldwide highlight the importance of identifying pathogenic mechanisms and implementing preventive measures to combat the aging process and development of related diseases. Researchers from the Laboratory of Cardiovascular Regenerative Medicine at the National Heart, Lung, and Blood Institute, building on evidence that lifelong water restriction shortens lifespan and promotes degenerative changes in mice, sought to test the hypothesis that optimal hydration may slow down the aging process in humans.
“There has been a shift in thinking about the roles of good hydration. Traditionally, the focus has been on short-term effects of big water losses that occur, for example, during prolonged exercise or exposure to heat. In recent years, a growing number of epidemiological studies show links between poor hydration and adverse long-term health outcomes such as [heart failure], diabetes and kidney function decline, and now also with chronic diseases in general and premature mortality.” – Natalia Dmitrieva, PhD, study author
Study lead author Natalia Dmitrieva, PhD, and colleagues performed a cohort analysis of biological data from the Atherosclerosis Risk in Communities (ARIC) study, an ongoing population-based prospective cohort of 11,255 Black and white men and women (45–66 years old) from four U.S. communities in the late 1980s, and followed them at three-year intervals until 2013.
“To access speed of aging, we used three indicators of faster aging process. Two main age-related outcomes/endpoints were analyzed: 1) age-related chronic diseases and 2) all-cause mortality. We used these aging indicators as outcome variables in the time-to-event analyses with middle age serum sodium as exposure variable. [The] third measure of the aging process that we used in this study was biological age (BA) that was calculated from age-dependent biomarkers. BA have been shown to characterize aging process and predicts mortality better than chronological age.” – Dmitrieva, et al.
Although normal serum sodium range is defined as 135 to 146 mmol/L, participants with serum sodium levels over 142 mmol/L were up to twice as likely to be biologically older than their chronological age. This means that even individuals who fell into the mid- and high-range of normal sodium serum levels showed a higher biological age associated with an increased risk (39%) of chronic diseases like heart failure, dementia, chronic lung disease, stroke, diabetes, peripheral vascular disease and atrial fibrillation, as well as elevated risk (21%) for premature mortality.
According to Cardiometabolic Health Congress (CMHC) faculty member Deepak L. Bhatt, MD, MPH, director of Mount Sinai Heart, these findings are in line with the standard advice to drink six to eight glasses of water per day — but may pose harder to implement in older adults or those with clinical or subclinical dementia, when a person can lose their sense of thirst. There, it is important for providers to make sure vulnerable people stay hydrated. The current peripandemic era calls for another consideration; where many people may work from home and live a more sedentary lifestyle, it is important to remind these patients not to lose track of their fluid intake.
Because decreased hydration is a key factor in elevated serum sodium, the results of the present study are consistent with the hypothesis that decreased hydration may accelerate aging. The authors estimate that almost half of the worldwide population is underhydrated and point to their results as cause for developing personalized recommendations for fluid intake based on patients’ overall health status.
“Decreased body water content is the most common factor that increases serum sodium, which is why the results suggest that staying well hydrated may slow down the aging process and prevent or delay chronic disease.” – Natalia Dmitrieva, PhD