Prostate health and metabolic function have long been suspected to intersect, but the specific pathway connecting insulin resistance to benign prostatic hyperplasia has remained poorly characterized. This cross-national analysis adds meaningful granularity to that relationship, suggesting that a widely underused insulin sensitivity proxy — the estimated glucose disposal rate — may serve as a practical risk indicator for a condition affecting a majority of men over 60.
Drawing on nearly 7,900 older men from two large, nationally representative datasets — the U.S. National Health and Nutrition Examination Survey (NHANES) and China's Health and Retirement Longitudinal Study (CHARLS) — the analysis found a consistent inverse association between eGDR and benign prostatic hyperplasia (BPH) risk. The eGDR, derived from waist circumference, hypertension status, and HbA1c, functions as a surrogate for whole-body insulin sensitivity without requiring laboratory glucose clamps. Restricted cubic spline modeling confirmed the relationship was linear rather than threshold-dependent across both cohorts, and subgroup analyses revealed the association held regardless of age stratum, BMI category, or comorbidity profile. A mediation analysis within the NHANES sample further identified monocyte count as a partial mediator, accounting for approximately 15% of the eGDR–BPH association — implicating low-grade systemic inflammation as one mechanistic bridge.
This finding is noteworthy for several reasons. Insulin resistance promotes androgenic signaling, smooth muscle proliferation, and pro-inflammatory cytokine release, all of which are plausible drivers of prostatic enlargement. The monocyte mediation result aligns with growing evidence that innate immune activation is embedded in the metabolic-to-urological disease continuum. That said, both source datasets are observational and cross-sectional in design, precluding causal inference. BPH ascertainment methods may also differ between Chinese and American survey instruments, introducing classification heterogeneity. This is best characterized as a confirmatory, hypothesis-generating finding rather than a practice-changing one — but it reinforces metabolic health as a meaningful, modifiable factor in prostate health trajectories.