Objective: To investigate the longitudinal association between long-term exposure to different altitude and the risk of incident hypertension. Design and method: This large-scale longitudinal study utilized data from community health screenings conducted in Xinjiang from 2017 to 2024. A total of 5,934,577 adults aged 18 years and older without hypertension at baseline were enrolled. Individual average residential elevation was obtained via digital elevation models and categorized into four groups: 500 m, 500–1500 m, 1500–2500 m, and >2500 m. The primary outcome was new-onset hypertension (defined as SBP >=140 mmHg and/or DBP>=90 mmHg or currently taking of antihypertensive medication). Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models, multivariable adjusted for demographic characteristics, lifestyle factors, and clinical indicators. Robustness was assessed via restricted cubic splines, stratified analyses, and sensitivity analyses (e.g., inverse probability weighting, adjusting for altitude strata). Results: After a median follow-up of 6.21 years, 1,749,650 new cases of hypertension were identified. Compared with residents at altitude 2500 m had elevated risk (HR=1.07, 95% CI=1.05–1.10). Altitude exhibited a nonlinear relationship with hypertension risk (P<0.001). Stratified analysis revealed that the altitude effect interacted with subgroups including gender, age, and waist circumference (P<0.001). Sensitivity analysis results were consistent with the primary findings. Conclusions: This study demonstrates a complex, non-linear association between long-term residential altitude and the risk of incident hypertension. Residing at altitudes between 500 and 2,500 meters may constitute a range beneficial to health, while altitudes exceeding 2,500 meters represent a clear risk factor. These findings suggest that residential altitude may serve as a important environmental determinant in the risk of hypertension.
Liu et al. (Fri,) studied this question.