This study aimed to gain insight into the underlying pathogenesis of erectile dysfunction in young men under the age of 40 years without widely-known risk factors. Compared with normal controls, patients with erectile dysfunction had increased carotid intima-media thickness, fasting levels of blood glucose and insulin, and homeostatic model assessment index, as well as lower flow-mediated vasodilation and testosterone levels (P < 0.05), though all of these values were within their respective normal range. Multivariate logistic regression analysis identified carotid intima-media thickness, flow-mediated vasodilation, insulin level, and homeostatic model assessment index as significant predictors of erectile dysfunction. Young men with flow-mediated vasodilation <10.65% were 11.645 times more likely to have erectile dysfunction, young men with carotid intima-media thickness >0.623 mm had a 4.16-fold, and young men with homeostatic model assessment index >1.614 had a 5.993-fold greater risk of having erectile dysfunction. In conclusions, in young men with normal results from general clinical screening, an increased carotid intima-media thickness and homeostatic model assessment index and reduced flow-mediated vasodilation were associated with a higher incidence of erectile dysfunction. Erectile dysfunction may appear before the detection of traditional cardiovascular risk factors and may be the earliest clinical sign of subclinical cardiovascular disease.
Keywords: endothelial dysfunction; erectile dysfunction; intima–media thickness; risk factors.