Abstract
BACKGROUND: Diastolic dysfunction (DD) represents an early indicator of cardiac impairment and is strongly linked to adverse cardiovascular outcomes. While obesity-related indices have been associated with DD, the role of Body Roundness Index (BRI)-a novel adiposity measure reflecting body shape-remains unclear. This study aimed to evaluate the association between BRI and diastolic function in a community-based cohort. METHODS: This cross-sectional analysis included 1,466 participants from the Longitudinal Investigation of Osteoarthritis and Cardiovascular Health Status cohort. BRI was calculated using a validated formula, and DD was assessed via echocardiographic parameters. BRI's optimal cutoff was derived via 1000-iteration bootstrap ROC analysis. Multivariable regression models were used to evaluate associations, adjusting for age, sex, blood pressure, lipid profile, and cardiovascular comorbidities. RESULTS: Higher BRI was significantly associated with increased odds of DD. In fully adjusted logistic regression, each 1-unit increase in BRI was associated with 14.4% higher odds of DD (OR = 1.144, 95% CI: 1.046-1.251, P = 0.003). High BRI (≥4.2) was linked to 41.7% higher odds of DD (OR = 1.417, 95% CI: 1.114-1.804, P = 0.004). Robust regression confirmed BRI was inversely associated with septal e' (β = -0.164, P = 8.10 × 10(-4)) and lateral e' velocities (β=-0.167, P = 5.59 × 10(-3)), and marginally positively associated with E/e' ratio (β=0.121, P = 0.053). Restricted cubic spline models showed a nonlinear association between BRI and DD probability (P < 0.001 for overall association, P = 0.006 for linearity). Interaction analyses indicated BRI's effect on DD was not modulated by blood pressure and lipid profiles. Subgroup analyses indicated a consistent trend of association between BRI and DD. CONCLUSIONS: BRI is nonlinearly and independently associated with impaired diastolic function in middle-aged and older adults, with modest diagnostic performance. These findings provided evidence on the link between body shape metrics and DD.