Prevalence of hypertension and its relationship with altitude in highland areas: a systematic review and meta-analysis

• Published in: Hypertension research Vol. 45; no. 8; pp. 1225 - 1239
• Main Authors: Zhang, Xin, Zhang, Zhipeng, Ye, Runyu, Meng, Qingtao, Chen, Xiaoping
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.08.2022
• Subjects: Altitude; Blood Pressure; Epidemiology; Frailty; Health risks; Humans; Hypertension; Hypertension - epidemiology; Meta-analysis; Mountains; Prevalence; Systematic review; Hypertension; Prevalence; Tibetan; Altitude; Highland
• ISSN: 0916-9636; 1348-4214; 1348-4214
• DOI: 10.1038/s41440-022-00955-8

This systematic review and meta-analysis synthesized the pooled prevalence of hypertension at high altitudes and explored its correlation with altitude using studies published in Chinese and English from database inception to February 2021. A systematic literature search was conducted among bibliographic databases (PubMed, Embase, and Web of Science) and three Chinese databases (CNKI, VIP, and Wanfang data) to identify eligible studies. A random-effects model was used to calculate the overall pooled prevalence of hypertension. The I statistic was used to assess heterogeneity across studies. Random-effects meta-regression was conducted to investigate covariates that may have influenced between-study heterogeneity. The pooled prevalence of hypertension among the general population in high-altitude areas was 33.0% (95% CI: 29.0-38.0%), with high between-study heterogeneity (I  = 99.4%, P < 0.01). Subgroup analyses showed the pooled prevalence of hypertension in Tibetan individuals was significantly higher than that in non-Tibetan individuals living in the Himalayas and Pamir Mountains (41% vs. 18%). A trend toward an increase in the prevalence of hypertension was found with every 100-m increase in elevation (coefficient: 0.012, 95% CI: -0.001 to 0.025, P = 0.069) only in Tibetan individuals. In addition, in these individuals, we found an increase in mean diastolic BP with each 100-m increase in altitude (coefficient: 0.763, 95% CI: 0.122-1.403, P = 0.025). Our meta-analysis suggests that the pooled prevalence of hypertension among the general population in high-altitude areas is 33.0%. Subjects of Tibetan ethnicity were more prone to developing hypertension at high altitudes. However, a very weak relationship between altitude and the prevalence of hypertension was found only in Tibetan individuals.