MON-150 - Endocrine Determinants of Adult Prostate Growth: Evidence from A Population-Based MRI Analysis of 30,000 Men

Background: Adult prostate growth is influenced by aging, somatic growth, and endocrine signaling, yet large-scale population data integrating circulating hormones with imaging-based phenotypes remain limited. In particular, the relative contributions of androgens and the insulin-like growth factor-I (IGF-I) axis across adult aging are incompletely defined.

Methods: We studied 30,616 adult men with automated deep-learning–derived prostate volume from standardized abdominal MRI. Participants with prior prostate cancer or prostate surgery were excluded. Circulating bioavailable testosterone (BAT) and IGF-1 were measured at baseline. Multivariable linear regression models assessed associations between prostate volume (ccm) and age, BMI, height, BAT, and IGF-1. Age-dependent effects were evaluated using interaction terms and age-stratified analyses (45–55, 55–65, 65–75, ≥75 years). Sensitivity analyses accounted for the time interval between hormone measurement and imaging and excluded men using medications affecting androgen action or prostate growth.

Results: Prostate volume increased markedly with age, with the prevalence of volumes >40, >50, and >60 ccm rising from 23%, 4%, and 1% at ages 45–55 to 68%, 40%, and 22% at ≥75 years. In fully adjusted models, age, BMI, height, BAT, and IGF-1 were each independently associated with larger prostate volume (all p< 0.001). Effect estimates were 0.68 ccm/year of age (95% CI 0.66–0.70), 0.26 ccm per BMI unit (0.22–0.30), 0.37 ccm per cm height (0.35–0.39), 0.52 ccm per nmol/L BAT (0.42–0.63), and 0.11 ccm per nmol/L IGF-1 (0.08–0.14) (all p < 0.001). Age-interaction analyses demonstrated that associations of height and BAT with prostate volume strengthened with advancing age, whereas BMI and IGF-1 showed stable effects across age strata. Results were robust in all sensitivity analyses.

Conclusion: In a large population-based MRI study, higher circulating BAT and IGF-1 were independently associated with greater adult prostate volume, beyond effects of age and body size. These findings support sustained roles for androgen bioavailability and the IGF axis in adult male tissue growth, with androgen-related associations becoming more pronounced later in life.

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