Objective: We performed this meta-analysis to assess the association between metabolic syndrome (MetS) and benign prostatic hyperplasia (BPH). Method: We conducted extensive searches on the PubMed, Science and Cochrane Library to identify all articles. Outcomes including annual prostate growth rate, prostate volume (PV), International Prostate Symptom Score (IPSS), IPSS sub-scores (voiding and storage), prostatespecific antigen (PSA), maximum urine flow rate (Qmax), post-void residual urine volume (PVR) and quality of life (QoL) were assessed. Results: 21 studies with 15,317 patients were included. Patients with MetS had higher annual prostate growth rate [weighted mean difference (WMD) ¼ 0.79; p < .001], larger PV (WMD ¼ 2.62; p < .001), lower Qmax (WMD ¼ À0.48; p ¼ .001) and more PVR (WMD ¼ 8.28; p < .001). However, no significant differences were found between two groups in IPSS (WMD ¼ 0.20; p ¼ .37), IPSS-voiding (WMD ¼ À0.05; p ¼ .78), IPSS-storage (WMD ¼ À0.22; p ¼ .26), PSA (WMD ¼ 0.04; p ¼ .43), and QoL (WMD ¼ À0.01; p ¼ .70).
Conclusions:The study suggested that MetS may be one of the risk factors for the clinical progress of BPH. However, further study is warranted to support these results.