Mild sleep restriction increases 24-hour ambulatory blood pressure in premenopausal women with no indication of mediation by psychological effects.
Level 2 - randomized trial
Randomized crossover trial
PubMed 32135337 · doi:10.1016/j.ahj.2020.02.006
What was done
A community cohort of 237 women (mean age 34.1 ± 13.5 years, BMI 25.4 ± 5.4 kg/m²) was assessed for cross-sectional associations between sleep and psychosocial factors. Within this group, a randomized crossover trial was conducted in 41 premenopausal women (24 completed; mean age 30.2 ± 6.5 years, BMI 24.3 ± 2.8 kg/m²) comparing habitual sleep to mild sleep restriction (reduced by 1.5 hours per night) for 6 weeks. In-office blood pressure was measured weekly, 24-hour ambulatory blood pressure and psychological factors were measured at endpoint, and mixed-model analyses were used to assess changes and mediation.
What was found
In the cohort, higher stress, stressful events, distress, and lower resilience correlated with shorter sleep, worse sleep quality, and insomnia symptoms (P < .05). In the crossover trial, systolic blood pressure increased as total sleep time decreased (interaction coefficient -0.0097 ± 0.0046, P = .036). Wake ambulatory diastolic blood pressure (-0.059 ± 0.022, P = .021) and mean arterial pressure (-0.067 ± 0.023, P = .018) were significantly higher following sleep restriction compared to habitual sleep. Psychological distress measures were unchanged by sleep restriction and did not mediate the rise in blood pressure.
Why it matters
It provides causal evidence that sustained, mild sleep reduction—typical of everyday sleep loss—directly elevates ambulatory blood pressure in young, healthy women via mechanisms independent of psychological distress.
Limits
The intervention had a small sample size with high attrition (17 of 41 participants did not complete the trial). The study was restricted to premenopausal women, limiting generalizability to men and older populations. Psychological factors were measured by self-report rather than continuous physiological stress markers.
Cited by
- supports Six weeks of mild sustained sleep restriction (reduced by 1.5 hours per night to roughly 6 hours) in free-living individuals increases insulin resistance, reduces insulin sensitivity, and increases blood pressure.