An investigation was done by Covassin N et al. from Mayo Clinic, Rochester, on continuous sleep restriction on ambulatory and 24-hour blood pressure (BP) and various cardiovascular measures. Overall, 20 healthy individuals were enrolled with a mean age of 23.4±4.8 years, where 9 participants were female. The investigation was a randomized, crossover, controlled, 16-day inpatient study where days of acclimation was 4. Sleep restriction was nine days (4 hours of sleep per night) versus a 9-hour control sleep and recovery period of 3 days. In addition, participants were kept on a controlled nutrition weight maintenance diet. The study aimed to measure cardiovascular biomarkers, and the primary outcome was to monitor 24-hour BP due to shortened sleep. The polysomnography was monitored continuously.
When sleep restriction was compared to control sleep, it was noted that the mean 24-hour BP was greater (adjusted mean difference- at day 12 was 2.1 mmHg; 95% confidence interval- 0.6 to 3.6; corrected P=0.016), plasma norepinephrine was raised, and attenuated endothelial function was observed. Also, during sleep restriction and recovery, a rise in BP was observed irrespective of increased deep sleep.
There was a rise in sleep BP, wakefulness, 24-hour BP only in women during the sleep restriction experimental and recovery stages, as per post hoc analysis. The systolic sleep BP and 24-hour BP were raised by 11.3 and 8.0 mm Hg, respectively.
Sleep-time and 24-hour BP are elevated persistently due to shortened sleep. Also, despite controlling weight and food intake, pressor effects are apparent, and it can be derived that they are affected by the decreased duration of sleep. Moreover, women are at a higher risk of cardiovascular problems related to increasing BP due to lack of sleep. This could be a result of the inability to adapt to sleep loss.