Risk of hypertension among different metabolic phenotypes: a systematic review and meta-analysis of prospective cohort studies

We performed a meta-analysis to assess the association of body mass index (BMI) and metabolic status with the risk of incident hypertension. Relevant studies were identified by searching comprehensive search via PubMed and Scopus search engines up to May 2018 and were analyzed using a random-effects model. Eight prospective studies were included in the analyses with metabolically healthy normal weight (MHNW) as the reference group. Pooled relative risks (RRs) and their 95% confidence intervals (CI) were calculated using random-effects or fixed-effect models when appropriate. Subgroup analysis was applied to define possible sources of heterogeneity. Overall, among 79090 participants, the risk of hypertension in metabolically unhealthy obese (MUHO) and metabolically healthy obese phenotypes (MHO) increased compared with the reference group (pooled effect size = 1.95, 95%CI: 1.87-2.04, P < 0.001 vs pooled effect size: 1.54, 95%CI: 1.48-1.61, P < 0.001, respectively). Also, a significant positive association between metabolically unhealthy normal weight (MUHNW) phenotype and the risk of hypertension was observed (pooled effect size =1.48, 95%CI: 1.41-1.55, P < 0.001). Metabolically unhealthy overweight (MUHOW) and metabolically healthy overweight (MHOW) phenotypes had greater risk of hypertension compared with the MHNW phenotype (pooled effect size = 1.50, 95%CI: 1.13-1.71, P < 0.001 and pooled effect size = 1.18, 95%CI: 1.11-1.27, P < 0.001). This meta-analysis revealed that individuals with metabolic abnormality had a higher risk for hypertension and also suggests that MHOW/ MHO are not a benign condition. We are refuting the notion that overweight and obesity without metabolic abnormalities are benign conditions in all population.