If obesity and a high-salt diet are two factors of heart disease, women would be more susceptible to them than men, shows a new study.
- Presented at the American Physiological Society’s annual meeting at Experimental Biology 2021, a new study shows that women have a higher heart risk than men with obesity and a high-salt diet.
- In question: the differentiated reaction to two hormones, leptin and aldosterone. In women, the production of these two hormones contributes to the calcification of blood vessels, which increases arterial hypertension, and therefore the risk of heart disease.
Numerous studies have shown that obesity and a high salt diet are two major factors in high blood pressure. According to a new study, conducted by the Medical College of Georgia at the University of Augusta (United States), the cardiovascular risk would be greater in women than in men. The findings were presented this week at the American Physiological Society’s annual meeting at Experimental Biology 2021.
“We see younger and younger women suffering from cardiovascular disease and the question is what is the cause, explains Dr. Eric Belin de Chantemele, lead author of the work. We believe that the fact that women are more sensitive to salt and more susceptible to obesity is part of the reason why they have lost the natural protection that youth and estrogen are supposed to give them.”
The role of leptin, which stiffens blood vessels
In premenopausal women, the sex hormone estrogen indeed has certain protective powers such as keeping the blood vessels more flexible. Yet with skyrocketing rates of severe obesity among young women, heart disease is now the third leading cause of death among women aged 20-44.
The researchers showed that a poor diet, too fatty, too sweet and too salty was a major risk factor for hypertension for both sexes, but that obesity and high salt consumption were even greater risks for the women. In question, according to them: naturally higher levels of two hormones called leptin and aldosterone.
Leptin is the “satiety hormone”, which tells the brain to stop eating when the stomach is full. However, in obesity, the brain usually does not listen to the message in its entirety, even though the cardiovascular system begins to receive unhealthy signals. The study showed that in women, leptin causes the adrenal glands, which produce aldosterone, to make even more of this powerful blood vessel constrictor.
Result: Obesity leads to a greater increase in blood pressure in women. Previous studies have also shown that women are also more prone to vascular dysfunction associated with obesity, such as more rigid blood vessels and therefore less able to dilate.
Differential treatment for women and men
Aldosterone, which helps regulate blood volume, is the other hormone implicated in increasing heart risk in women. Produced by the adrenal glands, it also helps the body maintain a salt balance. In women, high aldosterone levels are responsible for high sodium levels, which also increases blood volume. However, a high sodium intake increases blood pressure by promoting water retention, especially in women.
Thus, experiments carried out on female mice showed that in just seven days of a high-salt diet, the ability of female mice to relax blood vessels decreased as blood pressure increased. Treatment with eplerenone, an aldosterone agonist, corrected these two phenomena.
The fact that women and men do not react in the same way to identical salt levels leads the authors of the study to conclude that different treatments according to sex would undoubtedly be relevant to reduce cardiac risk.
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