Cumulative average lipoprotein combined index-waist circumference and incident cardiovascular disease in Chinese middle-aged and older adults

Cardiovascular disease (CVD) is a major public health burden among middle-aged and older adults in China. Dyslipidemia and central obesity jointly contribute to CVD risk, but the association between long-term cumulative exposure to composite lipid-abdominal obesity indicators and incident CVD remains unclear. This study examined whether cumulative average lipoprotein combined index–waist circumference (LCI-WC), defined using natural log-transformed lipoprotein combined index (LCI) and waist circumference (WC), was associated with incident CVD. Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS). Cumulative average LCI-WC was calculated as the mean of LCI-WC values measured in 2011 and 2015, where LCI-WC was defined as ln (LCI)×WC. Incident CVD was assessed at the 2018 follow-up. Logistic regression models and restricted cubic spline analyses were used to evaluate the association between cumulative average LCI-WC and incident CVD. A total of 4,597 participants were included, of whom 2,473 (53.8%) were women. The mean age was 58.4 (8.5) years. By the 2018 follow-up, 638 participants (13.9%) had developed incident CVD. In the fully adjusted model, each 1-standard deviation (SD) increase in cumulative average LCI-WC was associated with a higher odds of incident CVD [odds ratio (OR), 1.137; 95% confidence interval (CI), 1.040–1.242]. Compared with quartile 1 (Q1), participants in Q4 had a higher odds of incident CVD (OR, 1.352; 95% CI, 1.041–1.755; P for trend = 0.023). Restricted cubic spline analysis suggested a positive linear association (P overall = 0.019; P for nonlinearity = 0.374). Higher cumulative average LCI-WC was associated with increased odds of incident CVD among middle-aged and older Chinese adults. This composite index may serve as an exploratory epidemiological marker of combined lipid-related and central-adiposity burden.