Glycosylated serum protein may improve our ability to predict endothelial and erectile dysfunction in nonorganic patients

Abstract

Introduction: Early prediction of erectile dysfunction (ED) is critical in the treatment of impotence. Underlying pathogenesis may be the reason for ED without organic causes in young men.

Aim: We evaluated the early predictive value of glycosylated serum protein (GSP) in young patients whose ED was diagnosed as "nonorganic" in origin according to general criteria.

Methods: A total of 150 young men with ED and 27 healthy men without ED were evaluated, including International Index of Erectile Function-5 (IIEF-5), causes of ED, influential or risk factors for ED, vascular parameters, and serum biochemical markers. Fifty-two ED patients aged 20-40 years without known etiology and 22 age-matched normal subjects were enrolled. The further assessment of two groups focused on vascular endothelial function and glycometabolic state.

Main outcome measures: Relationships among the IIEF-5 scores, flow-mediated dilation (FMD), and GSP were analyzed in cases vs. controls, using Pearson's correlation and multiple linear regression analysis.

Results: No significant differences in baseline characteristics, cardiovascular risks, and conventional biomarkers were found between testing and control groups, except fasting blood glucose level (4.69 ± 0.50 vs. 4.29 ± 0.48, P = 0.003). FMD values were significantly reduced in cases compared with controls and correlated positively with IIEF-5 scores (r = 0.629, P < 0.001). GSP levels were significantly increased in the ED cases compared with controls and correlated negatively with IIEF-5 scores (r = -0.504, P < 0.001) and FMD values (r = -0.469, P < 0.001). These parameters independently predicted ED presence. The positive predictive value of FMD > 11.55% for excluding ED and of GSP > 210.50 mg/L for diagnosing ED were 86.4% (area under the curve [AUC]: 0.942, specificity: 88.4%) and 84.5% (AUC: 0.864, specificity: 72.7%), respectively.

Conclusions: Underlying glycometabolic disorder and subclinical endothelial dysfunction may be served as early markers for organic ED in young ED patients without well-known related risk factors. GSP level may improve our ability to predict endothelial dysfunction and erectile dysfunction.