Some people may have been told during a health checkup that their blood pressure is on the high side, and are worried because their numbers aren't going down even though they're cutting back on salt and alcohol.
High blood pressure may be caused not only by excessive salt intake but also by a decrease in muscle mass. Muscles are not only essential for physical movement, but are also vital organs deeply involved in blood pressure regulation.
This article explains the medical mechanism by which age-related muscle loss leads to high blood pressure.
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The horror of sarcopenia (muscle loss) that begins in your 40s
Medically, the decrease in muscle mass with age is called sarcopenia. Even if you think "I'm still young," a 2010 study of Japanese people reported that men's muscle mass increases slightly until around age 40, and then begins to decline (women's muscle mass remains stable until around age 50). In other words, your 40s can be considered a turning point for muscle growth.
So why does a decrease in muscle mass lead to a rise in blood pressure? One factor is a change in the body's thermoregulatory function. Muscles generate a lot of heat even at rest, but when muscle mass decreases, the basal metabolic rate drops, making it easier for body temperature to fall. The body then tries to maintain the temperature of vital organs such as the brain and heart by constricting peripheral blood vessels, such as those on the skin's surface, to prevent heat from escaping. This constriction of blood vessels narrows the passage for blood, resulting in increased blood pressure and increased strain on the blood vessel walls.
Of particular concern is "sarcopenic obesity," where muscle mass decreases and fat increases while weight remains the same. Even if you don't look overweight, in many cases the strain on your blood vessels is silently progressing internally, so it's crucial not to rely solely on the number on the scale after the age of 40.
References: Japan Sarcopenia and Frailty Society | Sarcopenia Treatment Guidelines 2017 Edition ; J-stage | Age-related Characteristics of Muscle Mass in Japanese People ; J-stage | Sarcopenic Obesity
Muscles are the "second heart." Understanding their pumping function and vasodilation mechanism.
Two terms are essential when discussing the relationship between muscles and blood pressure: "pump function" and "vascular resistance." Muscles are not only physical pumps, but they also act as the body's chemical factories, producing components that widen blood vessels like medication.
Why muscles are called the "second heart"
The heart is a powerful pump that sends blood throughout the body, but it has very little ability to collect the blood it has pumped out. In particular, the blood that has reached the extremities needs to return to the heart against gravity. This is where the leg muscles play the role of a pump. The muscles in the calves and other areas repeatedly contract and relax, compressing the blood vessels and pushing the blood upwards (milking action). This pumping function is why muscles are called the "second heart."
However, if you sit for long periods, such as during desk work, this pumping function does not work. As a result, blood accumulates in the lower extremities, which not only increases the risk of swelling and blood clots, but also reduces the amount of blood returning to the heart, placing an excessive burden on the entire circulatory system.
Why not using muscles increases peripheral vascular resistance
Another important mechanism involves the "stiffness" and "resistance" of blood vessels. When you exercise using your muscles and blood flow increases, a substance called nitric oxide (NO) is secreted from the inner wall of the blood vessels (endothelial cells). This NO has the effect of softening and widening the blood vessels. In other words, exercise itself acts like an antihypertensive drug.
Conversely, aging and decreased muscle mass lead to a lack of exercise, which reduces the secretion of nitric oxide (NO). When NO is deficient, blood vessels tend to remain constricted and harden, making it difficult for blood to flow (high vascular resistance). As the body tries to force blood through these narrow, hardened vessels, blood pressure inevitably rises.
In other words, a decrease in muscle stimulation is equivalent to accelerating the aging of blood vessels. To reduce the risk of arteriosclerosis, where blood vessels harden and become brittle, it is necessary to keep the muscles, the body's natural blood pressure-lowering system, constantly functioning.
The relationship between muscles and blood vessels has been attracting attention in recent years.
Studies have been published that support the theory that "people with more muscle mass are less likely to develop high blood pressure." A large cohort study (a research method that tracks participants for a certain period) of 872 middle-aged and elderly people in Europe, reported in 2025, showed that skeletal muscle mass (total amount, relative amount to body weight, etc.) was inversely correlated with the development of high blood pressure. In other words, the more muscle mass you have, the lower your risk of high blood pressure, and the less muscle you have, the higher your risk. This trend was particularly pronounced in women in this study, but it suggests that muscle is an important factor in protecting cardiovascular health regardless of gender.
Until now, health management has tended to focus solely on reducing body fat, but recent findings indicate that maintaining muscle mass is also crucial for blood pressure management.
summary
Protecting your muscles is linked to protecting your blood vessels. While dietary therapy, such as salt restriction, is important, fundamental vascular management is impossible without supplementing muscles that weaken with age. Let's start by correctly understanding your own muscle mass and the condition of your blood vessels. At our clinic, we also offer approaches to maintaining health and addressing muscle weakness at the cellular level, based on insights from regenerative medicine. Let's take measures now to ensure your future health.
The new health strategy for the 100-year life era is not simply symptomatic treatment that lowers numbers with medication, but rather about maintaining youthful blood vessels and muscles by enhancing the body's own cellular repair capabilities.
Supervised by: Yuzo Terakawa, M.D. (Board-certified neurosurgeon)
