The association between altitude and the prevalence of hypertension among permanent highlanders

Hypertension (HTN) is a growing contributor to the global disease burden, and it is prevalent among people living at high altitudes (H-ALTs). This study aimed to explore the relationship between altitude and the prevalence of HTN among inhabitants living at H-ALTs. We searched electronic databases, including PubMed, Embase, and Web of Science, up to April 30, 2022. The quality of included studies was assessed using the Joanna Briggs Institute (JBI) checklist for prevalence studies. A total of 1273 articles were screened, and 32 studies (86,487 participants) were eligible for further analyses. The pooled prevalence among highlanders was 28.7%. General additive model (GAM)-based meta-regression analysis was conducted to explore the association between altitude and the prevalence of HTN. A curve-shaped line was found between altitude and the prevalence of HTN (β = 0.998, p = 0.039) after adjusting for factors including publication year, sample size, age, sex, ethnic group, body mass index (BMI), smoking and alcohol consumption. The turning point was observed at 3300 m. The predictive parameter indicated that the smoothness and goodness of model fit were good (GCV = 0.014, R² = 0.60, respectively). The findings may provide clues for further mechanistic studies that can improve HTN prevention among highlanders.