The association between bedtime at night and hypertension in adults

This research was conducted to explore the association between bedtime at night and the prevalence of hypertension in adults.
We conducted a cross-sectional study of 14,536 participants with data from the NHANES database. Bedtime was determined from the question in the sleep questionnaire: ‘What time do you usually fall asleep on weekdays or workdays?.’ Hypertension was defined as systolic blood pressure (SBP) ≥ 140 mmHg, or diastolic blood pressure (DBP) ≥ 90 mmHg, or having been told by a doctor to have high blood pressure, or taking antihypertensive medication. We conducted a weighted multiple logistic regression analysis to explore the relationship between bedtime at night and the prevalence of hypertension in adults.
The association between bedtime and hypertension showed a significantly U-shaped relationship. People who went to bed at 23:00 had the lowest risk of developing hypertension (OR, 0.68 [95%CI, 0.58, 0.81]). This U-shaped association still existed in different genders. In males (n = 7159), the adjusted OR was still lowest at 23:00. However, the adjusted OR was lowest at 0:00 in females(n = 7377). The interaction effect between bedtime and gender was significant (P = 0.0187).
With the delay in bedtime, the association between bedtime and hypertension showed a significantly U-shaped relationship. Falling asleep at 23:00 has the lowest risk of developing hypertension.