Introduction and Objectives
Few studies have investigated the role of insulin or insulin resistance in prostate cancer. Several mechanisms could explain the association of obesity and metabolic syndrome with prostate cancer risk, including insulin and IGF signaling, and inflammation pathways
Material and Methods
We selected 153 patients who are divided in 2 groups: group A, 107 patients with metabolic syndrom without prostate cancer (MS-PC), and group B, 46 patients with metabolic syndrom and prostate cancer (MS+PC). IR (insulin resistance) was determinated used Homeostasis model assessment (HOMA-IR). The diagnosis for MS was made according to International Diabetes Federation. Body weight, waist circumference, hip circumference, blood pressure were determined. Body mass index (BMI) was calculated. Biochemical analyses including fasting plasma glucose, HbA1c, total cholesterol, triglycerides, high-density lipoprotein (HDL-C), fasting plasma insulin, adiponectin, leptin, TNF alpha, IL-6 and prostate-specific antigen (PSA) were performed. The prostate gland volume was measured using transrectal ultrasound. All patient with PSA > 3 ng/ml underwent prostate biopsy.
The average age was 66.23±12.72 in group A and 68.27±12.9 years in group B. HOMA-IR (2.35± 4.3 vs 3.45±6.4), adiponectin (10.89±4.96 vs 7.3±4.5 ng/ml), TNF alpha (4.4±4.1 vs 5.3±3.8 pg/ml), IL-6 (4.1±3.6 vs 5.9±6.8 pg/ml) was significantly higher in MS+PC patients (all p <0.05). By multiple linear regression, we found that among independent predictors of HOMA-IR were the body mass index, PSA level, and the serum levels of leptin, TNF alpha, IL-6 (positive correlation) and adiponectin (negative correlation). TNF alpha and IL-6 levels was correlated with the extent of histological injury (p = 0.001).
The mechanisms by which adipocytokines promote insulin resistance are complex, and our understanding incomplete. Several pathogenic mechanisms may be involved in the effect of insulin resistance in prostate cancer and adipocitokines and inflamatory citokines has a statisticaly significant role at least in our study. Further investigations are needed.
© 2009 European Association of Urology. Published by Elsevier Inc. All rights reserved.