In a recent study, researchers emphasize the importance of staying well hydrated on a daily basis, especially from the age of 40 onwards. This good habit is indeed essential to avoid that the blood sodium level becomes too high, and favors the appearance of a cardiac problem years later.

Drinking enough water may prevent heart failure

Water is an essential element of the organism and should be consumed as much as possible every day, in the absence of medical contraindication. Every day, we lose a part of it through urine, perspiration and breathing, which is why it is recommended to compensate for these losses by drinking at least 1 to 1.5 liters of water per day to maintain the body's balance. This recommendation is all the more important because a study presented at the European Society of Cardiology Congress (August 27-30, 2021) states that staying well hydrated throughout one's life reduces the risk of developing heart failure, which is the inability of the heart muscle to propel blood through the body normally.

"Our study suggests that maintaining good hydration can prevent or at least slow the changes in the heart that lead to heart failure," says study author Dr. Natalia Dmitrieva of the National Heart, Lung, and Blood Institute. "The results indicate that we need to pay attention to the amount of fluid consumed each day and take action if we find that we are drinking too little." Daily fluid intake recommendations range from 1.6 to 2.1 liters for women and 2 to 3 liters for men. But several studies have shown that many people don't even reach the lower end of these ranges.

Poor hydration at age 40 has an impact 25 years later

Researchers looked at serum sodium (sodium levels in the blood), a measure of the body's hydration status. They found that when people drink less fluid, serum sodium concentration increases and the body then attempts to conserve water, activating processes known to contribute to the development of heart failure. The study examined whether serum sodium concentration in middle age predicted the development of heart failure 25 years later. The researchers also examined the link between poor hydration and the risk of left ventricular hypertrophy, a heart condition that acts as a precursor to the diagnosis of heart failure.

The analysis was conducted in 15,792 adults aged 44 to 66 years at recruitment, assessed over five visits through age 70 to 90 years. Participants were divided into four groups based on their average serum sodium concentration at the first two visits conducted during the first three years of study. For each sodium group, the researchers then analyzed the proportion who developed heart failure and left ventricular hypertrophy at the fifth visit (25 years later). The results showed that a higher serum sodium concentration in midlife was associated with both heart failure and left ventricular hypertrophy 25 years later.

Regularly assess hydration levels in selected individuals

Furthermore, serum sodium remained associated with heart failure and left ventricular hypertrophy after adjustment for other factors related to the development of heart failure: age, blood pressure, renal function, blood glucose cholesterol, BMI, sex, and smoking. Each 1-mmol/L increase in serum sodium concentration in midlife was associated with a 1.20 increased probability of developing left ventricular hypertrophy and 1.11 for heart failure 25 years later. Both risks began to increase when serum sodium levels exceeded 142 mmol/l from midlife onward.

"The results suggest that good hydration throughout life can reduce the risk of left ventricular hypertrophy and heart failure. Our finding that serum sodium above 142 mmol/l increases the risk of adverse cardiac events may help identify individuals who could benefit from an assessment of their hydration levels," says Dr. Natalia Dmitrieva. The scientific team concludes that while this sodium level should not be immediately labeled as abnormal in blood test results, it could be used by physicians during regular check-ups to identify people whose fluid intake needs to be assessed over the long term and then corrected if necessary.