Am J Physiol Heart Circ Physiol. 2026 May 14. doi: 10.1152/ajpheart.00123.2026. Online ahead of print.
ABSTRACT
Study Objectives: Chronic short sleep duration is associated with cardiovascular disease (CVD) risk, especially in females. The impact of biological sex on hemodynamic reactivity to spontaneous nocturnal arousals following experimental sleep restriction remains largely unknown. We therefore investigated the effect of nine-day four-hour sleep restriction on heart rate (HR) and pulse transit time (PTT) changes following spontaneous arousals in healthy males and females. We hypothesized that HR and PTT reactivity would be augmented following sleep restriction, and these responses would be more robust in females. Methods: Nineteen participants (8 females; 23±5 years) were enrolled into this study, which included two 16-day in-patient studies comprised of sleep restriction (four-hour sleep opportunity) and normal sleep (nine-hour sleep opportunity) study arms. Overnight polysomnography on days 2 (acclimation), 5 (early experimental), 11 (late experimental), and 14 (recovery) of each sleep intervention was used to analyze HR and PTT responses to spontaneous arousals. Results: Sleep restriction did not alter HR or PTT reactivity in males or females during the early experimental phase (Day 5; interaction: p>0.05). The HR response to arousal was altered in a sex-dependent manner following sleep restriction during the late experimental phase (Day 11, interaction: p=0.013). Continued sleep loss resulted in greater PTT reduction following spontaneous arousals in females, but not in males (Day 11, interaction: p=0.007) Conclusions: Sustained sleep curtailment disrupts nocturnal vascular responsiveness to spontaneous arousals, more evident in females than males. These findings provide mechanistic insight into the sex-specific relationship between shortened sleep duration and CVD risk in females.
PMID:42133047 | DOI:10.1152/ajpheart.00123.2026