Weight change and all-cause and cause-specific mortality: A 25-year follow-up study

Abstract

Abstract Background: Whether the dynamic weight change is an independent risk factor for mortality remains controversial. This study aimed to examine the association between weight change and risk of all-cause and cause-specific mortality based on the Linxian Nutrition Intervention Trial (NIT) cohort. Methods: Body weight of 21,028 healthy residents of Linxian, Henan province, aged 40–69 years was measured two times from 1986 to 1991. Outcome events were prospectively collected up to 2016. Weight maintenance group (weight change <2 kg) or stable normal weight group was treated as the reference. Cox proportional hazard model was performed to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) to estimate the risk of mortality. Results: A total of 21,028 subjects were included in the final analysis. Compared with the weight maintenance group, subjects with weight loss ≥2 kg had an increased risk of death from all-cause (HRAll-cause = 1.14, 95% CI: 1.09–1.19, P <0.001), cancer (HRCancer = 1.12, 95% CI: 1.03–1.21, P = 0.009), and heart disease (HRHeart diseases = 1.21, 95% CI: 1.11–1.31, P <0.001), whereas subjects with weight gain ≥5 kg had 11% (HRCancer = 0.89, 95% CI: 0.79–0.99, P = 0.033) lower risk of cancer mortality and 23% higher risk of stroke mortality (HRStroke=1.23,95% CI: 1.12–1.34). For the change of weight status, both going from overweight to normal weight and becoming underweight within 5 years could increase the risk of total death (HROverweight to normal = 1.18, 95% CI: 1.09–1.27; HRBecoming underweight = 1.35, 95% CI: 1.25–1.46) and cancer death (HROverweight to normal = 1.20, 95% CI: 1.04–1.39; HRBecoming underweight = 1.44, 95% CI: 1.24–1.67), while stable overweight could increase the risk of total death (HRStable overweight = 1.11, 95% CI: 1.05–1.17) and death from stroke (HRStable overweight = 1.44, 95% CI: 1.33–1.56). Interaction effects were observed between age and weight change on cancer mortality, as well as between baseline BMI and weight change on all-cause, heart disease, and stroke mortality (all P interaction <0.01). Conclusions: Weight loss was associated with an increased risk of all-cause, cancer, and heart disease mortality, whereas excessive weight gain and stable overweight were associated with a higher risk of stroke mortality. Efforts of weight management should be taken to improve health status. Trial registration: NCT00342654, https://classic.clinicaltrials.gov/.