Associations of weight change and weight variability with cardiovascular and all-cause mortality in the Chicago Western Electric Company Study.

Few studies of associations between weight loss or weight fluctuations and mortality have been sufficiently long term to permit exclusion of early deaths for a portion of follow-up long enough to eliminate likely effects of illness-related weight loss. This study examined associations of the variation (standard deviation and standard deviation about the trend (slope)) and trend (weight loss or weight gain) in body mass index (weight (kg)/height (m2) between 1958 and 1966 (minimum of five measurements) with subsequent 25-year mortality among 1,281 men originally aged 40-56 years from the Chicago Western Electric Company Study. In multivariate Cox regression models that included two slope variables representing weight loss and weight gain and each variability measure separately, weight loss and weight gain were significantly related to 15-year mortality but weight variability was not. Relative risks for cardiovascular disease mortality were 1.25 (95% confidence interval (CI): 1.09, 1.45) and 1.14 (95% CI: 0.97, 1.33), respectively, for weight loss and weight gain slopes larger by 0.12 kg/m2 per year; corresponding relative risks for all-cause mortality were 1.23 (95% CI: 1.10, 1.38) and 1.15 (95% CI: 1.03, 1.29), respectively. For follow-up years 16-25, none of these weight variables were significantly related to mortality. These results indicate that an association between weight loss and mortality may not persist beyond 15 years, and that weight variability may not be related to mortality independently of weight loss or weight gain.