Elevated insulin and reduced insulin like growth factor binding protein-3/prostate specific antigen ratio with increase in prostate size in Benign Prostatic Hyperplasia

Background: Insulin and insulin like growth factor-1 (IGF-1) have growth promoting effects, while insulin like growth factor binding protein-3 (IGFBP-3) has growth inhibitory effects. The present study was designed to assess the concentrations of insulin, IGF-1, IGFBP-3 and their association with prostate size in patients with BPH. Methods: Ninety 90 BPH cases and 90 controls were enrolled in the study. Insulin, IGF-1, IGFBP-3, PSA, testosterone and estradiol were estimated in both the groups. Results: Insulin, IGF-1 and estradiol were increased and IGFBP-3/PSA was decreased in BPH cases when compared with controls. Insulin (r = 0.64, p = 0.001) and IGF-1 (r = 0.22, p = 0.03) were positively correlated and IGFBP3/PSA (r = -0.316, p = 0.002) were negatively correlated with prostate size in BPH. Multivariate analysis showed that insulin (p = 0.001) and IGFBP-3/PSA (p = 0.004) predicts the prostate size in patients with BPH. Insulin was increased and IGFBP-3/PSA was reduced in BPH patients with increased prostate size. At a cutoff concentration of 527.52, IGFBP-3/PSA ratio was found to differentiate benign growth of prostate from normal prostate with 96% sensitivity and 96% specificity. Conclusion: Insulin is elevated and IGFBP-3/PSA is reduced with increase prostate size in BPH cases. (C) 2017 Elsevier B.V. All rights reserved.