Changes in body mass index, waist and hip circumferences, waist to hip ratio and risk of all-cause mortality in men

Background: There is a paucity of data about the impact of changes in anthropometric measurements on the risk of mortality events, especially in men. Methods: The study sample consists of 1805 Iranian men, aged≥30 years, free from cardiovascular disease at baseline; they had undergone health examinations in both phases I (1999-2001) and II (2001-2003) and were followed up until March 2010. Participants were categorized by changes in anthropometric measurements into four groups: Group 1, change percentage<-5%; Group 2, -5% ≤change percentages<+5%; Group 3, 5%≤change percentage<10%; and Group 4, change percentage≥10%. Cox proportional hazard regression was performed to assess the hazard ratios (HRs) of the anthropometric changes for all-cause mortality, given group 2 as the reference. Results: During 6.6 years of follow-up, 88 cases of mortality events occurred. The confounder-adjusted multivariate HRs for the first, third and fourth groups of hip circumference (HC) changes were 3.13(1.28-7.64), 0.75(0.43-1.31) and 0.82(0.23-2.99); the corresponding values for waist to hip ratio (WHR) change were 1.80(0.75-4.33), 1.21(0.70-2.1) and 2.32(1.25-4.3). After further adjustment for mediator covariates, results did not change. The equivalent values for body mass index and waist circumference did not reach statistical significance. Conclusions: In Middle Eastern Caucasian men, increase in WHR was associated with incident mortality, which was more prominent in those with ≥10% increase in the ratio. Moreover, decrease in HC was highly associated with excess risk of mortality.