Cumulative average glucose–lipid metabolic obesity index associates with benign prostatic hyperplasia incidence in Chinese middle-aged and older men

Composite metabolic indices such as CMI and TyG-BMI are used for cardiometabolic-risk prediction, yet evidence linking integrated glucose–lipid-obesity burden to benign prostatic hyperplasia (BPH) remains limited. This study constructed the novel glucose–lipid metabolic obesity index (GLMOI) and examined the association between its cumulative average and BPH incidence among Chinese middle-aged and older men. Based on the CHARLS database, 2413 men aged ≥ 45 years with complete 2011–2015 laboratory data were included. Cox proportional-hazards models were used to evaluate the association between quartiled cumulative average GLMOI and incident BPH. Multivariable adjustment, dose-response, trajectory, subgroup and sensitivity analyses (including propensity-score matching) were performed. During 4-year follow-up, 248 new BPH cases occurred. After full adjustment, higher cumulative average GLMOI was related to elevated BPH risk ( P for trend = 0.031; Q4 vs Q1: HR = 1.437, 95% CI 0.960–2.152). Per 1-SD GLMOI increment yielded a 15.2% higher BPH risk (HR = 1.152, 95% CI 1.013–1.310), indicating a dose-response relationship. GLMOI-fluctuating groups showed significantly higher BPH risk, while persistently high GLMOI only conferred marginal risk elevation. No significant subgroup-interaction was detected, though nominally stronger associations were seen in urban residents and participants without hypertension or diabetes. Cumulative average GLMOI combining glucose–lipid and obesity indicators is independently associated with incident BPH in Chinese middle-aged and older men. Metabolic fluctuation, rather than sustained high GLMOI, may increase BPH risk. GLMOI could serve as a low-cost marker for population-level BPH risk stratification.