HealthDay News — Serum sodium in the upper part of normal range is associated with an increased risk for heart failure, according to a study published online March 29 in the European Heart Journal.

Natalia I. Dmitrieva, PhD, from the National Heart, Lung, and Blood Institute in Bethesda, Maryland, and colleagues examined the association of serum sodium at middle age as a measure of hydration habits with the risk to develop heart failure using data from the Atherosclerosis Risk in Communities study, with enrollment at middle age (45 to 66 years) and 25 years of follow-up. Participants without water balance dysregulation were selected; they had a normal range of serum sodium (135 to 146 mmol/L) without diabetes, obesity, or heart failure at baseline (11,814 participants).

The researchers found that the risk for heart failure was increased significantly if middle-age sodium exceeded 143 mmol/L, corresponding to 1% body weight water deficit (hazard ratio, 1.39) in a time-to-event analysis. In a retrospective case-control analysis, including 4,961 70- to 90-year-old attendees of visit 5, serum sodium of 142.5 to 143 mmol/L was associated with increased odds of left ventricular hypertrophy (LVH) diagnosis (odds ratio, 1.62). Serum sodium above 143 mmol/L was associated with significantly increased odds of LVH and heart failure (odds ratios, 2.07 and 1.54, respectively).

“Similar to reducing salt intake, drinking enough water and staying hydrated are ways to support our hearts and may help reduce long-term risks for heart disease,” Dmitrieva said in a statement.

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