Association between Lipid Accumulation Product 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 longitudinal association between LAP and cardiometabolic multimorbidity (CMM) and to assess its value in risk prediction. METHODS: Data were analyzed from 3,348 individuals (mean age = 64 years; 54.9% female) enrolled in the English Longitudinal Study of Ageing who had no prior history of hypertension, coronary heart disease, diabetes, or 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 operationally defined as the coexistence of two or more of the following cardiometabolic disorders by wave 10 (2021-2023): hypertension, cardiovascular disease, diabetes, or stroke. Odds ratios (ORs) with 95% confidence intervals (CIs) were derived using logistic regression models with multivariable adjustment, and model performance was evaluated using discrimination metrics. RESULTS: During follow-up spanning 12-15 years, 197 cases of CMM were recorded. Analysis using restricted cubic splines demonstrated a linear trend between LAP and CMM risk, with no evidence of nonlinearity (p = 0.23). Each one standard deviation rise in LAP was significantly associated with elevated odds of developing 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). Trends were similar across LAP tertiles. Incorporating LAP into a model with conventional risk factors modestly improved discrimination (ΔC-index = 0.0064; p = 0.32), but significantly improved model fit (-2 log likelihood test, p < 0.001). CONCLUSION: Higher LAP was linearly and independently 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.