Blood pressure readings during nighttime sleep can reveal important details about how the heart and kidneys function, according to infohub.kz.
Normally, a person's blood pressure should drop by roughly 10–20% during nighttime rest compared with daytime levels. This physiological dip gives the cardiovascular system the relief it needs. In some people, however, blood pressure stays elevated at night or does not fall enough, significantly raising the risk of cardiovascular disease.
Using computer modeling, scientists found that a disruption of the kidneys' internal biorhythms may be behind the absence of a nighttime blood pressure dip. When this organ's biological clock runs just a few hours late, the kidneys begin regulating salt and fluid levels in the body differently. As a result, the body needs to maintain higher blood pressure at night to rid itself of excess sodium.
The researchers also noted that this effect is much more pronounced with high dietary salt intake. Understanding how the kidneys' circadian rhythms affect nighttime readings will help doctors diagnose hidden problems more accurately and tailor individual treatment for patients.