Obesity and the Development of Cardiometabolic Multimorbidity: A Cross‐Lagged Panel Network Analysis of Three National Chinese Cohorts

AIMS: To explore longitudinal and bidirectional associations between obesity and cardiometabolic diseases (CMDs) using a cross-lagged panel network (CLPN) framework in three nationally representative Chinese cohorts. MATERIALS AND METHODS: We analysed participants aged 45 years and older from CHARLS (2011-2015; n = 12 491), CHNS (2004-2015; n = 8412) and CFPS (2010-2022; n = 22 193). A CLPN model was used to estimate bidirectional longitudinal associations between obesity and CMDs between participant-specific first and last eligible surveys. CMDs included hypertension (HBP), diabetes (DM), ischaemic heart disease (IHD) and cerebrovascular disease (CVD). Network replicability was assessed across cohorts. RESULTS: Across cohorts, 3.43%-5.49% of participants transitioned from non-obese to obese status, while 16.44%-26.03% transitioned from no CMD to CMD status. Three networks showed moderate structural similarity, with 12 directionally concordant obesity-CMD edges and moderate edge-weight correlations (r = 0.59-0.64; all p < 0.01). The obesity-to-diabetes edge was the strongest directed association in CHARLS (OR 2.59, 95% CI:2.18-3.11) and CFPS (2.77, 2.31-3.29), and the second strongest in CHNS (3.43, 2.67-4.31). Among obesity-originating edges, the same rank order (diabetes, hypertension, IHD and CVD) was observed across cohorts. Obesity showed the highest out-expected influence and the lowest in-expected influence. A positive hypertension-to-obesity association and bidirectional hypertension-diabetes associations were consistently observed. CONCLUSIONS: CMDs are highly interrelated, and obesity plays a central role in bridging CMDs in the longitudinal networks, highlighting its relevance to both individual CMDs and their clustering as cardiometabolic multimorbidity.