Heme oxygenase levels and metaflammation in benign prostatic hyperplasia patients

To investigate the relationship between intra-prostatic levels of heme oxygenase (HO), metaflammation in benign prostatic hyperplasia (BPH) tissue in patients with MetS and moderate-severe lower urinary tract symptoms (LUTS).

Between January 2012 and June 2013, 132 consecutive patients, who underwent transurethral resection of the prostate for moderate-severe LUTS, secondary to clinical BPH, were enrolled. Prostate samples were investigated for the presence of an inflammatory infiltrate, according to the Irani score, and for HO-1 and HO-2 levels measurements. Patients were evaluated for the presence of metabolic syndrome (MetS) defined by the International Diabetes Federation.

We observed that subjects with MetS exhibited greater Irani score (3.0 vs. 2.0; p < 0.05), Irani grade (2.0 vs. 1.0; p < 0.05) and lower value of HO-1 (4.55 vs. 6.01; p < 0.05) and HO-2 (0.81 vs. 2.66; p < 0.05). HO-1 (3.91 vs. 5.67; p < 0.05) and HO-2 (1.06 vs. 1.37; p < 0.05) were significantly reduced in patients with high intra-prostatic inflammation (Irani score ≥4). At the multivariate logistic regression analysis, HO-1 reduction (OR 0.588; p < 0.01), waist circumference (OR 1.09; p < 0.01), triglycerides (OR 1.013; p < 0.05) and HDL (OR 0.750; p < 0.05) were independent predictors of high intra-prostatic inflammation. We also found that HO-1 reduction (OR 0.598; p < 0.01) and the presence of MetS (OR 34.846; p < 0.01) were associated with Irani score ≥4.

MetS-induced inflammation may play a key role in BPH. In detail, prostate metaflammation is inversely related to intra-prostatic HO-1 levels, serum HDL and positively with triglycerides.