A prospective study of waist circumference trajectories and incident cardiovascular disease in China: the Kailuan Cohort Study

Background: Single measurements of waist circumference (WC) predict the incident cardiovascular disease (CVD); however, long-term patterns of WC and their association with the incidence of CVD are poorly characterized. Objective: We aimed to identify WC trajectories and determine their association with incident CVD (stroke and myocardial infarction) and examine whether the association persisted among individuals without obesity. Methods: We included 75.535 participants from a community-based cohort in China who were aged >18 y and free of stroke, coronary artery disease, and cancer in 2010 (the baseline). WC and other covariates were repeatedly measured in 2006. 2008, and 2010. WC trajectories were identified by latent mixture modeling. A Cox proportional hazards model was used to examine the association between WC trajectories and incident CVD, after adjustment for age, sex, income, education, systolic blood pressure, lipid profiles, plasma concentrations of glucose. C-reactive protein, smoking, and alcohol drinking. Results: We identified 4 WC trajectories based on 2006 WC measurement and change patterns during 2006-2010: low stable (n = 12,072; mean WC 74.1-75.1 cm), moderate stable (n = 41.750; mean WC 85.1-86.6 cm), moderate-high stable (n = 19,914; mean WC 95.6-97.2 cm), and high stable (n = 1,799; mean WC 106.3-110.9 cm). During 2010-2016, we documented 2819 incident CVD events. Compared with the low-stable group, groups with elevated WC trajectories had a higher risk of CVD events during 6 y of followup (2010-2016). Adjusted HRs (95% CIs) were 1.49 (1.21, 1.83) for the moderate stable group, 1.71(1.38, 2.12) for the moderate-high stable group, and 1.45 (1.06, 2.00) for the high stable group. After further adjusting for BMI or excluding obese participants, we observed similar results. The positive association between WC and incident CVD was higher in individuals who were aged <60 y (P-interaction < 0.0001). Conclusions: WC trajectory patterns were associated with altered risk of CVD among Chinese adults, even among people without BMI-defined obesity. When stratifying by age, the association was observed to be higher in younger adults.