Excess adiposity mostly accrues from young adulthood to midlife, however the impact of weight change in early life on mortality risk in later life is unclear.
A total of 26724 individuals aged 40 years and older from the 1988-2010 U.S. National Health and Nutrition Examination Survey (NHANES) recalled their weight at young adulthood (at age of 25 years) and middle adulthood (at ten years before the NHANES survey cycle started). Based on these two weight status, they were categorized into four weight change groups: those who maintained as non-obese (stable non-obese of BMI <30 in both times), those who changed from non-obese to an obese body shape (gaining), those who moved from an obese BMI to a non-obese BMI (losing) and those who remained obese (stable obese). Mortality status was linked with death certificate records from National Death Index up to December 31, 2011. Cox proportional hazard models adjusting for covariates were used for calculating hazard ratios (HRs) and 95% confidence intervals (CI).
During a mean follow-up of 18.9 years, 6732 deaths occurred. Compared with stable non-obese category, those in the gaining group had a 27% (HR 1.27; 95% CI 1.16-1.39) and 40% (1.40; 1.17-1.66) increased risk of total mortality and cardiovascular mortality respectively; those in the stable obese group had significantly higher risk of total mortality (1.87; 1.62-2.15) and cardiovascular mortality (2.40; 1.79-3.22). Weight change was not significantly associated with cancer mortality. Although the weight loss category was associated with a non-significant modest increased risk of total mortality (1.36; 0.96-1.92), the association was mainly driven by non-cardiovascular and non-cancer causes (1.80; 1.13-2.87), rather than cardiovascular mortality (0.82; 0.50-1.33) or cancer mortality (1.18; 0.58-2.42). Analysis in never smokers, different sex and age groups showed similar results.
Maintaining a non-obese body shape from young adulthood to midlife is important for preventing premature death in later life.
C. Chen: None. X. Pan: None. A. Pan: None.
National Key Research and Development Program of China (2017YFC0907504)