Association of changes in waist circumference with cardiovascular disease and all-cause mortality among the elderly Chinese population: a retrospective cohort study

BACKGROUND: To examine the association of baseline waist circumference (WC) and changes in WC with cardiovascular disease (CVD) and all-cause mortality among elderly people. METHODS: A total of 30,041 eligible participants were included from a retrospective cohort in China. The same questionnaire, anthropometric and laboratory measurements were performed at baseline (2010) and the first follow-up (2013). The percent change in WC between baseline and the first follow-up was calculated to evaluate three years change of WC. We collected the occurrence of CVD and all-cause death from the first follow-up to December 31, 2018. Restricted cubic splines and Cox proportional-hazards regression models were used to evaluate the relationship between baseline WC/ changes in WC and mortality. RESULTS: The dose-response relationships between baseline WC and CVD mortality were U- or J-shaped. In low WC group, compared with stable group, the fully adjusted hazard ratio (aHR) for CVD mortality was 1.60 (95% CI: 1.24−2.06) in WC gain group among men. In normal WC group, the CVD mortality risk increased with WC gain (men: aHR = 1.86, 95% CI: 1.36−2.56; women: aHR = 1.83, 95% CI: 1.29−2.58). In moderate-high WC group, the CVD mortality risk increased with WC gain (men: aHR = 1.76, 95% CI: 1.08−2.88; women: aHR = 1.46, 95% CI: 1.04−2.05) and risk decreased with WC loss (men: aHR = 0.54, 95% CI: 0.30−0.98; women: aHR = 0.59, 95% CI: 0.37−0.96). CONCLUSIONS: For the elderly population, WC gain may increase CVD mortality risk regardless of baseline WC, whereas WC reduction could decrease the risk only in the moderate-high WC group.