High blood pressure, also known as hypertension, can interrupt the normal patterns of blood pressure changes between day and night, a condition affecting both men and women, according to a study from Tulane University School of Medicine.
The research was recently published in the American Journal of Physiology-Heart and Circulatory Physiology.
Under normal conditions, blood pressure dips 10% to 20% lower at night than during the day. This natural drop, known as “dipping,” helps the body recover.
However, when this doesn’t happen—a condition called “nondipping”—the risk of heart diseases and organ damage increases.
While it’s known that physical activity, stress, and other factors can interfere with daytime blood pressure readings, the exact reasons for nondipping are not fully understood.
Researchers at Tulane, led by the Lindsey Lab, conducted a study on mice to explore this issue. They used a special method called radiotelemetry, which continuously monitors blood pressure, to track how it changes during the day and night.
They specifically looked at how hypertension, caused by factors like high salt intake, aging, and poor sleep, affected the animals’ blood pressure rhythms.
In addition to monitoring blood pressure, the researchers collected samples from the mice’s blood vessels at different times of the day and night.
Using an advanced technique called droplet digital PCR, they studied how clock genes (genes that help control the body’s natural rhythms) and estrogen receptors (proteins affected by the hormone estrogen) work together to manage blood pressure.
The study revealed two important findings: first, high blood pressure can disrupt the natural rhythms of blood pressure; second, estrogen receptors and specific clock genes—known as period genes—work in sync to control this rhythm.
Interestingly, the study found that these clock genes and estrogen receptors behaved similarly in both male and female mice, suggesting that the impact of high blood pressure on blood pressure rhythms is similar in both sexes.
Lead researcher Dr. Bruna Visniauskas explained that understanding these patterns could help doctors develop better treatments, including using “chronotherapy,” which means adjusting treatment based on the time of day.
This approach could be an important step in reducing the risks associated with hypertension for both men and women.
