Testosterone Is Associated with Erectile Dysfunction: A Cross-Sectional Study in Chinese Men

Background: Testosterone is essential for the regulation of erectile physiology, but the relationship between low testosterone and erectile dysfunction (ED) has not been firmly established. Purpose: To examine the association between serum total, free and bio-available testosterone and ED in a population-based sample. Methods: A consecutive series of 1776 men aged 20–77 participated in the routine physical examination from September 2009 to December 2009 in Guangxi, China. ED was assessed using the five-item International Index of Erectile Function (IIEF-5) questionnaire. Total testosterone (TT), sex hormone binding globulin (SHBG) and other biochemical profiles were measured. Free testosterone (FT) and bio-available testosterone (BT) were calculated based on Vermeulen’s formula. Data were collected with regard to smoking, alcoholic drinking, physical activity and metabolic syndrome. Results: The prevalence of ED (IIEF-5,22) was 47.6%. Men with ED were significantly older, and more prone to smoke cigarettes ($20 cigarettes/day) or drink alcohol ($3 drinks/week), and more likely to have elevated blood pressur