Prevalence of metabolic syndrome and its components according to altitude levels: a systematic review and meta-analysis

Metabolic syndrome has a multifactorial origin; however, epidemiological data correspond to populations located at sea level. It has been reported that the altitude can affected the prevalence due to physiological changes. The aim of this study is to show the global prevalence of metabolic syndrome at altitude and its components. We use four databases, all studies published up to November 2023. The prevalences from studies were meta-analyzed using a random-effects model. To assess sources of heterogeneity, subgroup analyses were performed. We included 28 studies. The number of participants was 29 195. The prevalence of metabolic syndrome was 30.3% (95% CI 22.8-38.4%). According to the altitude level, at 1500-2500 was 36.5%, 2500-3500 (21.8%), and > 3500 (30.9%), also it was higher in women (35.5%) that men (26.8%). It was observed that there is an inverse relationship between higher altitude and the prevalence of metabolic syndrome. Among its components, abdominal obesity and low HDL were present in more than 40.0%, while high blood pressure, high triglycerides and impaired glucose were present in less than 30.0%. We recommend that our results be considered for future research in populations living at altitude since they have different characteristics from populations at sea level.