U-shaped association between average daily sleep duration and depression among individuals with hypertension: a cross-sectional study based on NHANES 2017–2020

BACKGROUND: Depression is increasingly prevalent among individuals with hypertension, contributing to the worldwide disease burden. The link between sleep and depression, while extensively studied in the general population, remains underexplored in hypertensive individuals. METHODS: We assessed 2,912 hypertensive participants in the National Health and Nutrition Examination Surveys (NHANES) dataset (2017-2020). Average daily sleep duration was categorized < 7 h, 7-9 h, and ≥ 9 h. Depression was identified via the 9-item Patient Health Questionnaire (PHQ-9), with a cutoff score of ≥ 10.Logistic regression, curve-fitting analyses and threshold effects analyses were employed to evaluate the association between average daily sleep duration and depression after adjusting for confounding factors. RESULTS: Compared to the reference group with average daily sleep duration of 7-9 h, both short (< 7 h) and long (≥ 9 h) sleep durations were significantly linked to depression. In the fully adjusted model, short sleepers had an OR of 1.99 (95% CI: 1.69-2.35, p < 0.0001) and long sleepers had an OR of 1.74 (95% CI: 1.12-2.71, p = 0.0404). Smooth curve fitting analysis revealed a U-shaped relationship with an inflection point at 7.29 h. Below this point, increased average daily sleep duration reduced depression risk (OR = 0.62, 95% CI: 0.54-0.69, p < 0.0001), while above it, prolonged sleep increased risk (OR = 1.30, 95% CI: 1.16-1.45, p < 0.0001). CONCLUSIONS: Among individuals with hypertension, average daily sleep duration exhibits a U-shaped association with depression. Both insufficient and excessive average daily sleep durations are associated with a higher risk of depression. Future research should incorporate longitudinal designs to establish temporal relationships and potential causality. Future research should also include actigraphy or polysomnography for at least a subset of participants to further validate the relationship. CLINICAL TRIAL NUMBER: Not applicable.