Are older adults with excessive sodium intake at increased risk of hypohydration?

Abstract

Background Sodium intake is expected to affect water needs, although compensation mechanisms may not work efficiently particularly in older adults. The aim of this cross‐sectional study was to quantify the association between sodium excretion and hydration status in a representative sample of Portuguese older adults. Methods A cluster sampling approach was used, representing Portuguese older adults (≥65 years) according to sex, education level and region. From a sample size of 1500 participants, 1318 were eligible for the present analysis. A 24‐h urine sample was collected, and volume, osmolality, creatinine and sodium were quantified. Free water reserve (FWR) was used to assess hydration status. Excessive sodium intake was defined as above 2000 mg day–1 as recommended by the World Health Organization. A multivariable binary logistic regression model was used to estimate the association between FWR and sodium excretion. Odds ratios (OR) and respective 95% confidence intervals (95% CI) were calculated. Results Excessive sodium excretion was observed in 80.0% of women and 91.5% of men, whereas hypohydration affected 10.9% of women and 23.6% of men. After adjusting for confounders, excessive sodium excretion was associated with an increased risk of hypohydration among men (OR = 2.75; 95% CI = 1.06–7.15). Conclusions These results stress the positive association between excessive sodium intake and hypohydration in men and highlight the need for implementing strategies regarding the reduction of salt consumption and the promotion of water intake.

Urinary Hydration Biomarkers and Water Sources in Older Adults with Neurocognitive Disorder

“…Unlike Gamba et al, who found that excessive sodium excretion was associated with an increased risk of hypohydration in men, suggesting that sodium intake may not be offset by the intake of water needed to excrete it [ 8 ], no significant statistical association was observed between excessive sodium excretion and hydration status in the present study.…”

“…Palmisano et al reported that, during the summer, older adults are more susceptible to dehydration [ 1 ]. The same was reported in women by Gamba et al [ 8 ]. Therefore, it can be speculated that the prevalence of hydration inadequacy in our population could be higher if samples had been collected in the summer, when more water is lost through transpiration and may not be adequately compensated by dietary intake.…”

“…Water is the main component of the human body and is essential for life and the maintenance of homeostasis. In older adults, water accounts for approximately 50% of the body weight [ 1 , 2 , 3 , 4 , 5 , 6 ], and this period is one of the life cycle phases in which the risk of dehydration is most imminent [ 2 , 5 , 7 , 8 , 9 , 10 ]. Age-related changes may cause an increased risk of dehydration by decreasing the sensitivity to thirst and decreasing the total body water (TBW).…”

“…An example is ingested sodium, which plays a role in controlling urinary volume and fluid intake; that is, a diet with high levels of sodium can generate an increase in fluid intake to compensate for the salt ingested and, consequently, a greater urine volume (to excrete excess salt). In addition to this, a high sodium and low potassium intake is a well-known risk factor for cerebrovascular disease, which tends to affect the elderly and the elderly with NCD [ 3 , 8 , 20 , 21 , 22 ].…”