Metabolic syndrome and benign prostatic enlargement: a systematic review and meta-analysis.

OBJECTIVE: To summarise and meta-analyse current literature on metabolic syndrome (MetS) and benign prostatic enlargement (BPE), focusing on all the components of MetS and their relationship with prostate volume, transitional zone volume, prostate-specific antigen and urinary symptoms, as evidence suggests an association between MetS and lower urinary tract symptoms (LUTS) due to BPE. METHODS: An extensive PubMed and Scopus search was performed including the following keywords: 'metabolic syndrome', 'diabetes', 'hypertension', 'obesity' and 'dyslipidaemia' combined with 'lower urinary tract symptoms', 'benign prostatic enlargement', 'benign prostatic hyperplasia' and 'prostate'. RESULTS: Of the retrieved articles, 82 were selected for detailed evaluation, and eight were included in this review. The eight studies enrolled 5403 patients, of which 1426 (26.4%) had MetS defined according to current classification. Patients with MetS had significantly higher total prostate volume when compared with those without MetS (+1.8 mL, 95% confidence interval [CI] 0.74-2.87; P < 0.001). Conversely, there were no differences between patients with or without MetS for International Prostate Symptom Score total or LUTS subdomain scores. Meta-regression analysis showed that differences in total prostate volume were significantly higher in older (adjusted r = 0.09; P = 0.02), obese patients (adjusted r = 0.26; P < 0.005) and low serum high-density lipoprotein cholesterol concentrations (adjusted r = -0.33; P < 0.001). CONCLUSIONS: Our results underline the exacerbating role of MetS-induced metabolic derangements in the development of BPE. Obese, dyslipidaemic, and aged men have a higher risk of having MetS as a determinant of their prostate enlargement.