Voluntary sleep restriction is common;30% of the US adult population reports <6 h of sleep per night, and those who do are 24% more likely to have cardiovascular disease and have twice the risk of hypertension. Sleep deprivation may be one of the commonest preventable cardiovascular risk factors. Prehypertension is also highly prevalent, affecting >25% of adults, and this population is at particularly high risk of developing frank hypertension and cardiovascular disease. The comorbidity of inadequate sleep and prehypertension is likely to be very common, with implications for frank hypertension and cardiovascular complications. No definitive experimental studies in humans show whether partial sleep deprivation indeed results in impaired cardiovascular function, nor are there conclusive experiments addressing the underlying physiologic and molecular mechanisms that may be involved, especially with regard to any changes in blood pressure. We propose to conduct a randomized, cross-over study in individuals with prehypertension, incorporating a 3-day acclimation period with 9 nights of sleep restricted to 4 hours per night. These data will be compared to a control/normal sleep sequence. Subjects will complete both sleep restriction and control sequences, separated by a 3-month washout period. Thus, each subject will serve as his or her own control in an experiment that closely matches real-world sleep restriction. We will combine this robust model with a state-of-the-art sleep monitoring system that provides continuous and accurate sleep/wake data in an unobtrusive way. We are currently using this model of sleep restriction in successful ongoing studies and have several decades of experience in conducting human studies of cardiovascular physiology. Comprehensive serial physiologic data will be complemented by detailed translational molecular studies of microvessels and adipocytes obtained by tissue biopsy before and after sleep restriction. Upon completion of these studies we will be able to ascertain: 1. The effects of sleep restriction on blood pressure throughout the entire 24-hour period 2. The effects of sleep restriction on neural circulatory control 3. The effects of sleep restriction on vascular function 4. The effects of slep restriction on systemic and adipose tissue inflammation Important strengths of this application include our compelling preliminary data, the ability to accomplish the specific aims while minimizing potential confounders, our focus on a group at high risk of developing frank hypertension and cardiovascular disease, the integration of widely accepted surrogates of cardiovascular risk with mechanistic molecular studies at the level of the vascular endothelial cell and the adipocyte, and a statistical plan that will provide a rich summary of the effects of sleep restriction on the four specific aims. Our long-term goal is to identify the fundamental biologic mechanisms that link sleep restriction to cardiovascular disease so as to define targets for interventions directed at reducing cardiovascular risk.
We propose to examine whether 9 nights of modest sleep restriction results in activation of cardiovascular disease mechanisms in individuals with prehypertension, thus potentially increasing the risk of frank hypertension and cardiovascular disease. These findings will help explain whether the reduced sleep duration in the general population may be contributing to the current epidemic of cardiovascular disease, and suggest strategies to reduce this risk.
|Olson, Christy A; Hamilton, Nancy A; Somers, Virend K (2016) Percentage of REM sleep is associated with overnight change in leptin. J Sleep Res 25:419-25|
|Shivkumar, Kalyanam; Ajijola, Olujimi A; Anand, Inder et al. (2016) Clinical neurocardiology defining the value of neuroscience-based cardiovascular therapeutics. J Physiol 594:3911-54|
|Covassin, Naima; Somers, Virend K (2016) Somnolence: The Silent Partner in the Sleep Apnea-Hypertension Relationship. Hypertension 68:1100-1102|
|Covassin, Naima; Singh, Prachi (2016) Sleep Duration and Cardiovascular Disease Risk: Epidemiologic and Experimental Evidence. Sleep Med Clin 11:81-9|
|Covassin, Naima; Singh, Prachi; Somers, Virend K (2016) Keeping Up With the Clock: Circadian Disruption and Obesity Risk. Hypertension 68:1081-1090|
|Calvin, Andrew D; Covassin, Naima; Kremers, Walter K et al. (2014) Experimental sleep restriction causes endothelial dysfunction in healthy humans. J Am Heart Assoc 3:e001143|
|Calvin, Andrew D; Carter, Rickey E; Adachi, Taro et al. (2013) Effects of experimental sleep restriction on caloric intake and activity energy expenditure. Chest 144:79-86|
|Calvin, Andrew D; Somers, Virend K (2013) Response. Chest 144:711-2|
|Hering, Dagmara; Kara, Tomas; Kucharska, WiesÅ‚awa et al. (2013) High-normal blood pressure is associated with increased resting sympathetic activity but normal responses to stress tests. Blood Press 22:183-7|
|Olson, Lyle J; Somers, Virend K (2013) Chemoreflexes, sympathetic excitation, and heart failure-challenges and opportunities. J Card Fail 19:416-8|