(Reuters Health) – Losing just 1.5 hours of sleep a night leads to elevated systolic blood pressure in women, a small clinical trial suggests.
The randomized crossover trial included metabolically healthy premenopausal (n=26) and postmenopausal women (n=10) who were not obese based ON BMI, and had at least one first-degree family member with a cardiovascular disease or CVD risk factors such as obesity or type 2 diabetes. Participants habitually got adequate sleep of 7-9 hours per night, based on baseline actigraphy and sleep diaries.
During the trial, all the women went through 6 weeks of habitual sleep as well as 6 weeks of sleep restriction (delay of habitual bedtime by 1.5 hours per night, and usual wakeup time), separated by a 6-week washout period. Participants had nightly sleep assessments with actigraphy and sleep diaries, weekly resting blood pressure measurements in the clinic, and ambulatory blood pressure monitoring during week 6 of each phase.
Mean 24-hour systolic blood pressure rose from 105.3 mmHg during the final week of the habitual sleep phase to 108.3 mmHg during the final week of the sleep restriction phase, researchers report in Hypertension.
Similarly, mean 24-hour arterial pressure increased from 78.7 mmHG during the final week of the habitual sleep phase to 80.8 mmHg during the final week of the sleep restriction phase.
“Our continuous blood pressure monitoring showed higher blood pressure after short compared to adequate sleep,” said senior study author Marie-Pierre St-Onge, an associate professor and center director at the Sleep Center of Excellence at Columbia University Irving Medical Center in New York City.
“Some studies suggest that short sleep upregulates the sympathetic nervous system and downregulates the parasympathetic nervous system which could promote elevated blood pressure,” St-Onge said by email.
Previous data from the Nurses’ Health Study suggest that short sleep is more strongly associated with hypertension in pre-menopausal women compared to post-menopausal women, St-Onge said. Some studies also show stronger associations in women than men, but more studies are needed that assess sex differences in health outcomes in response to sleep restriction, St-Onge added.
In the current study, participants’ mean age was 37 years, with a mean age of 30 years among the premenopausal women and 56 years among the postmenopausal women.
Mean BMI was 25.4, with 38% of participants in the overweight category and 11% in the obese category.
The slope of change for mean resting systolic blood pressure measured in the clinic was 1.01 mmHg higher during the sleep restriction phase among premenopausal women, the study also found.
“It’s important to note that office systolic blood pressure decreased over time but this was more pronounced in the adequate sleep condition than restricted sleep condition,” St-Onge said.
It is possible that encouraging participants to maintain consistent sleep schedules and stabilizing sleep times led to improved circadian alignment, which could improve blood pressure, and that this is hindered in conditions of short sleep, St-Onge added.
More clinical trials are needed in postmenopausal women, given their increased risk for both hypertension and sleep disturbances, the study team notes.
“The take-home message for clinicians is that the body of evidence in the literature strongly suggests that sleep time and quality are fundamental determinants of health and, therefore, should be considered in the risk evaluation of the patient,” said Jose Ordovas, director of the Nutrition and Genomics Lab at the USDA-Human Nutrition Research Center on Aging at Tufts University in Boston.
“Normalization of sleep should be part of preventive and therapeutic strategies that will affect a wide range of physical and mental disorders,” Ordovas, who wasn’t involved in the study, said by email.
SOURCE: https://bit.ly/3tFpG7z Hypertension, online March 29, 2021.