title: Erectile dysfunction may be the first clinical sign of insulin resistance and endothelial dysfunction in young men.
abstract: OBJECTIVE
  The purpose of this study is to investigate the possible underlying pathogenesis of erectile dysfunction (ED) without well-known etiology in young men under the age of 40 years.
  
  
  METHODS
  192 patients and 33 normal controls were enrolled. ED was evaluated by using the International Index of Erectile Function-5 (IIEF-5) questionnaire. Traditional cardiovascular risk factors, hormone levels, and vascular parameters were measured. Insulin resistance (IR) was measured by homeostasis model assessment (HOMA).
  
  
  RESULTS
  Patients with ED had significantly higher levels of systolic blood pressure (SBP), high-sensitivity C-reactive protein (Hs-CRP), high Insulin resistance index (HOMA-IR) and carotid intima-media thickness (IMT), compared with controls. The brachial artery endothelium-dependent flow-mediated vasodilation (FMD) values were significantly lower in ED patients. By multivariate logistic regression analysis, FMD, SBP, Hs-CRP and HOMA-IR were significantly associated with ED. In receiver-operating characteristic (ROC) analysis, FMD was a significant predictor of ED (area under the curve (AUC) 0.933, p < 0.001). The cutoff value of FMD <10.4 % had sensitivity of 81.3 % and specificity of 100 %. HOMA-IR was also proven to be predictor of ED (AUC of HOMA-IR 0.759, p < 0.001).
  
  
  CONCLUSIONS
  ED may be the first clinical sign of endothelial dysfunction and a clinical marker of cardiovascular and metabolic diseases. Subclinical endothelial dysfunction and insulin resistance may be the underlying pathogenesis of ED in young patients without well-known etiology. Measurement of FMD, HOMA-IR can improve our ability to predict and treat ED, as well as subclinical cardiovascular disease early in young men.
authors.affiliation: Department of Ultrasound, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Fengjuan
authors.initials: F
authors.lastname: Yao
authors.forename: Lijuan
authors.initials: L
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yanping
authors.initials: Y
authors.lastname: Huang
authors.forename: Donghong
authors.initials: D
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
authors.forename: Yanqiu
authors.initials: Y
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Fan
authors.forename: Cuiling
authors.initials: C
authors.lastname: Li
authors.forename: Chunhua
authors.initials: C
authors.lastname: Deng
mesh_terms: D000328:Adult; D000367:Age Factors; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D001916:Brachial Artery / Q000503:physiopathology*; D002097:C-Reactive Protein / Q000032:analysis; D002318:Cardiovascular Diseases / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D059168:Carotid Intima-Media Thickness; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D007172:Erectile Dysfunction / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D006801:Humans; D015994:Incidence; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D012372:ROC Curve; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014664:Vasodilation; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D002097:C-Reactive Protein