Short-term weight gain is associated with accumulation of multimorbidity in mid-aged women: a 20-year cohort study.

Abstract

Although weight change has been studied in relation to many individual chronic conditions, limited studies have focused on weight change and multimorbidity. This study examines the relationship between short-term weight change and the accumulation of multimorbidity in midlife. We used data from 7357 women aged 45-50 years without a history of any chronic conditions. The women were surveyed approximately every 3 years from 1996 to 2016. Associations between short-term weight change and accumulation of multimorbidity (two or more of nine chronic conditions) over each 3-year period, adjusting for baseline body mass index (BMI) or time-varying BMI (3-year period), were examined using repeated measures models. Short-term weight change was categorised into seven groups of annual weight change from high weight loss ( ≤ -5%) to high weight gain (> + 5%). Over 20 years, 60.4% (n = 4442) of women developed multimorbidity. Baseline BMI, time-varying BMI and short-term weight gain were all associated with the accumulation of multimorbidity. After controlling for sociodemographic, lifestyle factors and menopausal status, high weight gain was associated with a 25% increased odds of multimorbidity (odds ratio (OR) 1.25, 95% confidence interval (CI) 1.08-1.45) compared with maintaining a stable weight. The results were consistent among models adjusting for baseline BMI (OR 1.24, 95% CI 1.07-1.44) or time-varying BMI (OR 1.34, 95% CI 1.16-1.54). Weight loss was associated with increased odds of multimorbidity in women with normal BMI (baseline or time-varying). Short-term weight gain is associated with significantly increased odds of multimorbidity in mid-aged women. This association is independent from baseline BMI (at 45-50 years) and time-varying BMI. These findings support a persistent weight management regime and prevention of weight gain throughout women's midlife.