Objective: This research was conducted to explore the association between bedtime at night and the prevalence of hypertension in adults.
Methods: 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.
Results: 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).
Conclusion: 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.
Keywords: NHANES; bedtime; hypertension.