Supplementary Material for: Association between lipid accumulation products and cardiometabolic multimorbidity in adults aged 50 years and older: Findings from the English Longitudinal Study of Ageing

Introduction: The lipid accumulation product (LAP) is a sex-specific index that reflects visceral adiposity and lipid imbalance. This study aimed to investigate the prospective association between LAP and cardiometabolic multimorbidity (CMM), and to assess its value in risk prediction. Methods: We analyzed data from 3,348 participants (mean age: 64 years; 54.9% women) in the English Longitudinal Study of Ageing who were free of hypertension, coronary heart disease, diabetes, and stroke at baseline (wave 4: 2008–2009). LAP was calculated using waist circumference (cm) and fasting triglyceride levels (mmol/L) via standardized sex-specific formulas. CMM was defined as having two or more of the following conditions by wave 10 (2021–2023): hypertension, cardiovascular disease, diabetes, or stroke. Multivariable logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs), and model performance was evaluated using discrimination metrics. Results: During a 12-15 year follow-up period, 197 participants developed CMM. A restricted cubic spline analysis showed a linear association between LAP and CMM risk (p for nonlinearity = .23). Each 1 standard deviation increase in LAP was associated with higher odds of CMM (OR = 1.31; 95% CI: 1.16-1.49), which remained significant after adjusting for physical activity (OR = 1.30; 95% CI: 1.14-1.47). Similar trends were observed across LAP tertiles. Incorporating LAP into a model with conventional risk factors modestly improved discrimination (ΔC-index = 0.0064; p = .32), but significantly improved model fit (-2 log likelihood test, p < .001). Conclusion: High LAP was independently and linearly associated with increased risk of CMM in older adults. While the inclusion of LAP modestly improved model fit, its added value in enhancing risk discrimination beyond established cardiometabolic risk factors was limited in this cohort.