Asymmetric U-shaped association between hypertension and wearable-derived sleep duration

To investigate associations between hypertension and wearable-derived sleep duration, including Sleep Period Time (SPT) and Total Sleep Time (TST), in community-dwelling adults.

In this cross-sectional study, nocturnal SPT and TST were objectively quantified from single-lead electrocardiograms and analyzed using multimodal regression approaches including covariate-adjusted binary logistic regression, restricted cubic splines, and segmented linear regression.

Our analysis of 1,459 valid sleep records from 759 participants showed asymmetric U-shaped associations between objective sleep duration and both hypertension prevalence and blood pressure levels. After adjusting for confounding factors, participants with SPT < 6 h had a 2.05-fold higher prevalence of hypertension (95% CI: 1.18-3.54), while those with TST ≥ 8 h had a 1.82-fold increased odds (95% CI: 1.03-3.22). For SPT, blood pressure nadirs occurred at 7.6-7.7 h for both systolic blood pressure (SBP) and diastolic blood pressure (DBP). For TST, the optimal duration was 7.0-7.2 h in different models. Below optimal SPT thresholds, each 1-h increase was associated with a reduction of 2.94 mmHg in SBP (95% CI: -4.82 to -1.06) and 1.21 mmHg (95% CI: -2.05 to -0.36) in DBP. In partially adjusted models, each 1-h increase above the optimal SPT was associated with an increase in SBP of 2.27 mmHg (95% CI: 0.15 to 4.39). This effect was no longer significant in the fully adjusted analysis. For TST, similar dose-response patterns were significant only for DBP, in partially adjusted models.

Wearable-derived objective sleep duration demonstrates an asymmetric U-shaped association with both hypertension prevalence and blood pressure parameters. Blood pressure nadirs occurred at 7.6-7.7 h for SPT and 7.0-7.2 h for TST.