Association of cumulative average NHHR with benign prostatic hyperplasia incidence in middle-aged and older adults: a prospective nationwide cohort study in China

Background Recent studies have demonstrated that metabolic syndrome is a significant factor influencing the incidence and progression of Benign Prostatic Hyperplasia (BPH). The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) serves as a novel lipid index for predicting metabolic syndrome. The primary objective of this research is to investigate whether the cumulative average NHHR correlates with the incidence of BPH. Methods This study leveraged data from the China Health and Retirement Longitudinal Study (CHARLS), ultimately incorporating a sample of 2,505 participants. Cumulative average NHHR was computed using repeated measurement data from the first and third national surveys to assess its relationship with the outcome variable of BPH incidence. The analysis employed multiple Cox regression analyses, restricted cubic splines (RCS), subgroup analyses, and sensitivity analyses. Results Within a cohort of 2,505 participants, 210 (8.38%) developed BPH during the 4-year follow-up period (2011–2015). After implementing multiple logistic regression with full adjustments made, the findings revealed that elevated levels of cumulative average NHHR were significantly positively associated with the likelihood of developing BPH, reflected by an odds ratio (OR) of 1.15 (95% CI: 1.10–2.35, P = 0.002). The RCS analyses indicated a positive linear correlation between cumulative average NHHR and BPH incidence (P for overall = 0.012, P for nonlinear = 0.348). Subgroup analysis and interaction tests (all P for interaction > 0.05) showed that age, BMI, residence, education, marital status, alcohol consumption, smoking status, hypertension, and diabetes did not significantly modify the positive relationship. Sensitivity analyses further confirmed the robustness of this association. Conclusion Our study has identified a significant association between cumulative average NHHR and the incidence of BPH, NHHR has the potential to be a valuable marker in the management and prevention of benign prostatic hyperplasia.