Five Nights of Sleep Restriction Attenuates Microvascular Endothelial Function

Adequate sleep is requisite for optimal physiological function, including microvascular endothelial function. Short‐term sleep restriction (5 hours/night) negatively alters glucose metabolism and may also impair microvascular endothelial function via increased sympathetic nervous system activity and inflammatory pathways. The cutaneous microvasculature represents an accessible, well‐described vascular bed to non‐invasively assess the effects of sleep restriction on microvascular function. Our objective was to evaluate cutaneous microvascular endothelial function during baseline sleep replete conditions (10 hours/night time in bed), after 5 nights of sleep restriction (5 hours/night), and again after 2 nights of recovery sleep repletion. This was part of the Sleep Restriction Study (PI: Chang), an 11‐day inpatient study that took place in the Penn State University Clinical Research Center, during which diet and physical activity were controlled. Eight young, healthy men (23.3 ± 3.4 years) participated in the study. Cutaneous microvascular function was measured utilizing a standardized local skin heating protocol to induce endothelial nitric oxide‐synthase‐dependent vasodilation during all three study phases (baseline, sleep restricted, recovery). Red cell flux (laser Doppler flowmetry) was continuously measured on the ventral forearm at thermoneutral temperature (33 °C) and throughout local heating 0.5°C·5 s −1 to 42 °C until a stable (20 min) plateau had been reached. Red cell flux was normalized to cutaneous vascular conductance (CVC: flux·MAP −1 ) and expressed as a percentage of maximum CVC (43°C: %CVC max ). Compared to the baseline sleep replete state, the response to local heating was attenuated by 10% after 5 nights of sleep restriction (baseline: 89.2 ± 2.0, restricted: 80.4 ± 3.0 %CVC max ; p=0.045) and fully recovered after 2 nights of recovery sleep (88.7 ± 1.8 %CVC max ; p=0.99 compared to baseline). Maximum CVC was not affected by sleep restriction (all p>0.05). These results suggest that 5 nights of sleep restriction impairs microvascular endothelial function, likely through attenuated nitric oxide‐dependent vasodilation, but that 2 nights of recovery sleep restores microvascular endothelial function in young, healthy men. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .