Joint effects of waist circumference trajectories and aging with risk of heart disease.

BACKGROUND: While waist circumference (WC) is a known risk factor for heart disease, the joint effects of its longitudinal trajectories and aging on disease risk remain unclear. METHODS: Our study involved 11,760 participants from the China Health and Retirement Longitudinal Study (CHARLS). Heart disease was defined as a self-reported physician diagnosis. We employed latent class growth modeling (LCGM) to identify waist growth trajectories within national male and female cohorts. Multivariate models were utilized to analyze waist-heart disease associations, including interaction effects with age. RESULTS: During the 5-year follow-up, 637 participants (5.42%) developed heart disease. Participants with a persistently high WC had the greatest risk of heart disease. This risk was significantly elevated compared to those with a stable, moderate WC in both males (OR 1.81, 95% CI: 1.34–2.45) and females (OR 1.39, 95% CI: 1.09–1.77). Furthermore, the combination of a persistently high WC and age 55 or older was associated with an additional, synergistic increase in risk in both sexes, as indicated by significant additive interaction measures (all RERI and AP > 0). In contrast, no such synergistic effect with age was found for participants whose high WC decreased over time. CONCLUSIONS: Elevated WC is significantly linked to heart disease risk, particularly in individuals aged ≥ 55 years, where high WC is associated with an additional risk. But in high-moderate and age ≥ 55 group, we did not observed this excess risk. However, the risk in this group remained elevated relative to those with a persistently moderate WC. BRIEF STATEMENT: The outcome (“heart disease”) is self-reported, representing a major limitation.