How much excess weight loss can reduce the risk of hypertension?

Background: A 25% relative reduction in the prevalence of hypertension is a global target. This meta-analysis estimated the effect of excess weight loss on hypertension. Methods: We searched PubMed, Web of Science and Scopus until January 2016. We included prospective cohort studies addressing the association between overweight/obesity and hypertension. We expressed the strength of association using risk ratio and the excess risk using attributable risk fraction with 95% CI based on the random-effects model. Results: We found 7617 references and included 10 studies with 173 828 participants. Compared with normal weight, the risk ratio of hypertension was 1.52 (1.37, 1.67; 9 studies, I2 = 82.4%) for overweight and 2.17 (1.84, 2.50; 9 studies, I2 = 88.9%) for obesity. The excess risk of hypertension attributable to overweight was 32% (24%, 40%; 8 studies, I2 = 85.5%) and that attributable to obesity was 47% (40%, 54%; 8 studies, I2 = 88.2%). That means, excess weight loss may reduce the risk of hypertension by between 24% and 40% in people who are overweight and by between 40% and 54% in people who are obese. Conclusions: Excess weight loss is a vital strategy for controlling hypertension and is sufficient for achieving the global target, particularly if it is accompanied with other preventive measures.