Associations of weight changes with all-cause, cancer and cardiovascular mortality: A prospective cohort study.

Objectives: Previous studies suggest that changes in body weight can lead to an increased risk of mortality in the general population, although the results are controversial. The current study sought to investigate this association further using data from the UK Biobank. Study design: This is a large prospective population-based cohort study. Data were derived from the UK Biobank, with the initial assessments commencing between 2006 and 2010. Methods: Proportional hazard models were used to assess the association between self-reported weight change and risk of all-cause, cancer and cardiovascular mortality. The effect of gender was also investigated. Results: Of 433,829 participants with data for self-reported weight change, the mean age was 56 (standard deviation [SD]: 8.1) years and 55% were female. In total, 55% of participants reported no weight change, 28% gained weight, 15% lost weight, 2% did not know and 0.1% preferred not to give an answer. The median follow-up was 7.1 (interquartile range [IQR]: 6.4-7.8) years. Compared with participants with no weight change, those with weight loss had an increased risk of all-cause mortality (adjusted hazard ratio [HR] 1.25, 95% confident interval [CI] 1.18-1.32), cancer death (HR 1.17, 95% CI 1.08-1.27) and cardiovascular death (HR 1.26, 95% CI 1.12-1.43). Similarly, participants reporting weight gain also had an increased risk of all-cause mortality (HR 1.08, 95% CI 1.02-1.13), cancer death (HR 1.14, 95% CI 1.07-1.22) and cardiovascular death (HR 1.27, 95% CI 1.14-1.42). Participants who had a response 'do not know' or 'prefer not to answer' showed an increased risk of all-cause and cardiovascular mortality, particularly in men. Conclusions: The results of this study highlight the importance of maintaining a stable weight in middle-aged adults. Further studies are needed to understand the pathophysiology of weight change and its effects on mortality.