To investigate the role of heme oxygenase (HO) system in moderate to severe benign prostatic hyperplasia and lower urinary tract symptom patients and the influence of metabolic syndrome (MetS) components on HO-1 or HO-2 prostatic levels.

One hundred thirty-two consecutive patients who underwent transurethral resection of the prostate were prospectively enrolled. MetS was defined by the International Diabetes Federation. Patients were divided in 2 groups: group A (high-density lipoprotein–cholesterol [HDL-C] ≥40 mg/dL and triglycerides <150 mg/dL) and group B (HDL-C <40 mg/dL and triglycerides ≥150 mg/dL). Surgical specimens were collected for HO level determination. HO-1 levels were determined by enzyme-linked immunosorbent assay and HO-1 levels by Western blotting.

Patients with MetS showed lower levels of HO-1 (5.29 vs 6.28 ng/mL; P = .04), HO-2 (1.01 vs 1.83 ng/mL; P = .04), phosphorylated activated protein kinase (pAMPK; 0.62 vs 1.11 AUI; P <.01), and HO-activity (61.43 vs 70.22 AUI; P <.01) with respect to normal. The Pearson correlation analysis showed that HO-1, HO-2, and HO activity were negatively associated with waist circumference (P <.05), body mass index (P <.05), triglycerides (P <.05) and positively with HDL-C (P <.05). Group B showed lower levels of HO-1 (4.7 vs 6.6 ng/mL; P <.05), HO-2 (1.4 vs 0.4 ng/mL; P = .03), HO-activity (69.63 vs 58.42 AUI; P = .04), and higher International Prostate Symptoms Score (21.4 vs 25.0; P <.05) with respect to group A. The enzyme-linked immunosorbent assay showed that HO-1 and HO activity levels were significantly lower in group B compared with group A. Reduced HDL-C and elevated triglyceride levels decreased HO-1 expression in the prostate tissue. Western blot analysis of tissue samples showed significant differences in basal protein expression levels of HO-2 and pAMPK in group B compared with group A.

Alteration of serum triglycerides and HDL-C significantly impairs HO-1 and HO-2 levels in benign prostatic hyperplasia patients.