Are all metabolic syndrome components responsible for penile hemodynamics impairment in patients with erectile dysfunction? The role of body fat mass assessment

Introduction. Erectile dysfunction (ED) is a common disease that is mostly vasculogenic in nature. ED correlates with cardiovascular risk factors, with endothelial dysfunction being the common link. Hypertension (HTA) and insulin resistance are the most important determinants of arteriogenic ED, and are also components of the metabolic syndrome (MetS), which supports a strong association between MetS and ED. However, MetS and, specifically, obesity interference on penile hemodynamics is still controversial. Aim. To evaluate the impact of independent MetS criteria and obesity on penile duplex Doppler ultrasound (PDDU) parameters in men with ED. Methods. Consecutive patients (n=212) referred to a unit of PDDU were evaluated for cardiovascular risk factors and MetS (ATP III criteria). Body mass index and body fat percentage (BF%) were calculated. Each patient underwent a PDDU by the same investigator. Data are expressed as mean±standard deviation, and statistical significance was considered at P level<0.05. Statistical analysis of clinical, laboratory, and PDDU parameters was performed with SPSS® software. Main Outcome Measures. To evaluate the individual power of MetS clusters and obesity as predictive factors for penile hemodynamic changes namely mean peak systolic velocity (mPSV). Results. MetS was present in 24.8% of men, and 80.8% of them presented penile hemodynamics alterations, with mPSV significantly lower comparatively to no MetS patients (29.0 vs. 35.4cm/s, P=0.004). Multivariate analysis demonstrated that, considering all MetS parameters, only HTA was significantly associated with diminished mPSV. However, after further adjustment for all cardiovascular risk factors, BF% remained the sole independent clinical factor for penile hemodynamics impairment. Conclusions. There is a strong association between MetS and ED, but within MetS criteria, only HTA was independently associated with the deterioration of penile hemodynamics parameters. Although the classical methods of evaluating obesity in MetS were not individually associated with PDDU impairment, BF% represented by itself an excellent predictor of vascular ED.