A lifetime of hydration may be the key to helping your heart take a licking and keep on ticking.
Research presented this week at the European Society of Cardiology Congress 2021 found that adhering to the recommended daily fluid intake in middle age can pay big dividends decades later. “Our study suggests that maintaining good hydration can prevent or at least slow down the changes within the heart that lead to heart failure,” said Natalia Dmitrieva, author of the study from the National Heart, Lung, and Blood Institute at the National Institutes of Health, Bethesda, U.S.
“The findings indicate that we need to pay attention to the amount of fluid we consume every day and take action if we find that we drink too little.”
While guidance varies, women are generally advised to consume between 1.6 and 2.1 litres of water per day and men in the range of between two and three litres. Surveys have shown many struggle to reach even the lower end of the scale. When people consume less water, their serum sodium — a reliable measure of hydration status — increases in concentration. This increase prompts the body to begin to conserve water, initiating internal processes that raise the risk of heart failure.
“It is natural to think that hydration and serum sodium should change day to day depending on how much we drink on each day,” Dmitrieva said. “However, serum sodium concentration remains within a narrow range over long periods, which is likely related to habitual fluid consumption.”
Researchers sought to explore the impact of this sodium concentration in middle age (as a function of hydration habits) on the emergence of heart failure 25 years later. They were also interested in how hydration during this stage of life affects the thickening of the heart’s left ventricle — or left ventricular hypertrophy — a condition that often precedes the failure of the blood-pumping organ.
The team recruited 15,792 members of the Atherosclerosis Risk in Communities (ARIC) Study, all between 44 and 66 years of age at the outset, and assessed them at five separate points in time until they were between the ages of 70 and 90. After the first two visits — which occurred in the first three years of study — subjects were split into four groups based on serum sodium concentration: Those between 135–139.5 millimoles per litre; 140–141.5 mmol/l; 142–143.5; and 144–146 mmol/l. They used these baselines to determine the risk of heart failure and left ventricular hypertrophy for each group upon their fifth and final visit, 25 years later.
Researchers reported that higher serum sodium concentration in middle age was significantly associated with both conditions at the 25-year mark, even after accounting for other factors that impact heart health, including age, blood pressure, kidney function, blood cholesterol, blood glucose, body mass index, sex and smoking status. Each 1 mmol/l increase in the concentration of serum sodium in midlife raised the odds of left ventricular hypertrophy and heart failure by 1.20 and 1.11, respectively, a quarter century later.
The risk of experiencing both conditions between the ages of 70 and 90 increased once an individual’s serum sodium surpassed 142 mmol/l 25 years earlier. “The results suggest that good hydration throughout life may decrease the risk of developing left ventricular hypertrophy and heart failure,” Dmitrieva said. “In addition, our finding that serum sodium exceeding 142mmol/l increases the risk of adverse effects in the heart may help to identify people who could benefit from an evaluation of their hydration level.
“This sodium level is within the normal range and would not be labelled as abnormal in lab test results but could be used by physicians during regular physical exams to identify people whose usual fluid intake should be assessed.”
Dave Yasvinski is a writer with Healthing.ca