Effects of Experimental Sleep Restriction on Ambulatory and Sleep Blood Pressure in Healthy Young Adults: A Randomized Crossover Study

Abstract

Although insufficient sleep is associated with increased cardiovascular risk, evidence of a causal relationship is lacking. We investigated the effects of prolonged sleep restriction on 24-hour ambulatory blood pressure (BP) and other cardiovascular measures in 20 healthy young participants (aged 23.4±4.8 years, 9 females), who underwent a randomized, controlled, crossover, 16-day inpatient study consisting of 4 days of acclimation, 9 days of sleep restriction (4 hours of sleep/night) or control sleep (9 hours), and 3 days of recovery. Subjects consumed a weight maintenance diet with controlled nutrient composition throughout. A 24-hour BP (primary outcome) and cardiovascular biomarkers were measured repeatedly. Polysomnographic monitoring was continuous. Comparing sleep restriction versus control sleep, 24-hour mean BP was higher (adjusted mean difference, day 12: 2.1 mm Hg [95% CI, 0.6–3.6], corrected P =0.016), endothelial function was attenuated ( P <0.001), and plasma norepinephrine increased ( P =0.011). Despite increased deep sleep, BP was elevated while asleep during sleep restriction and recovery. Post hoc analysis revealed that 24-hour BP, wakefulness, and sleep BP increased during experimental and recovery phases of sleep restriction only in women, in whom 24-hour and sleep systolic BP increased by 8.0 (5.1–10.8) and 11.3 (5.9–16.7) mm Hg, respectively (both P <0.001). Shortened sleep causes persistent elevation in 24-hour and sleep-time BP. Pressor effects are evident despite closely controlled food intake and weight, suggesting that they are primarily driven by the shortened sleep duration. BP increases are especially striking and sustained in women, possibly suggesting lack of adaptation to sleep loss and thus greater vulnerability to its adverse cardiovascular effects.

The Effect of Sleep Restriction, With or Without Exercise, on Skeletal Muscle Transcriptomic Profiles in Healthy Young Males

“…Furthermore, Sweeney et al (56) assessed glucose tolerance after each night of sleep restriction (4 h TIB for 4 nights) and observed that although glucose tolerance was reduced with SR, this impairment did not occur in a cumulative manner. Similarly, sleep-loss-induced changes in blood pressure and endothelial function are highest after one night of sleep (4 h TIB) and gradually decrease over multiple nights (57), and increased energy intake is reported in the early phases of sleep restriction protocols before returning to baseline levels on subsequent nights (58,59). These findings suggest an adaptive physiological response to the stress of sleep restriction that occurs over extended periods; this same phenomenon may help to explain the results in this study.…”

Isolated nocturnal hypertension in relation to host and environmental factors and clock genes

“…Endothelial function was impaired and plasma norepinephrine increased during the phase of sleep restriction. 27 …”

“…Endothelial function was impaired and plasma norepinephrine increased during the phase of sleep restriction. 27 Environmental factors including seasonality and atmospheric conditions also have impact on the diurnal BP profile. 17,18,28 In a metaanalysis involving 856 539 participants in 47 studies, 28 office, daytime and home BPs, but not nighttime BP, were significantly lower in summer than in winter.…”

Orexin, Sleep, Sympathetic Neural Activity, and Cardiovascular Function

“…Experimental sleep deprivation and sleep restriction paradigms have reported elevated levels of sympathetic activity following acute sleep impairment. [7][8][9] Dysfunction of the sympathetic nervous system is similarly observed within sleep disorders, 10,11 as well as cardiometabolic disorders such as hypertension and 12 heart failure. 13 Despite these findings, the central regulatory mechanisms underpinning these associations has not been established in humans.…”