Obese men who undergo gastric bypass surgery not only lose weight but their sex lives also improve. While obesity in men has been linked to low testosterone levels, high levels of oestrogen, impaired fertility, and worse sexual quality of life, there is little information on what happens to the men's sex hormones and sexual function if they lose weight. Therefore, researchers from America investigated 62 obese men in, which 22 had gastric bypass surgery and 42 controls, to find out the effects of gastric bypass surgery on reproductive hormones and sexual function in obese men. Weight, BMI, percent body fat and reproductive hormones were measured in all the subjects. The sexual quality of life was also assessed. At the study's outset, participants weighed 330 pounds, on an average, while the average BMI for the group was 46. At 2 years of follow up, it was found that the men who had weight loss surgery had dropped an average of nearly 17 points from their BMI. Their oestrogen levels had fallen significantly, while their testosterone levels had gone up. And all showed improvements on each of the four measures of sexual quality of life: they were less likely to avoid sexual encounters, have difficulty with sexual performance, have little sexual desire, or report not enjoying sex. The heavier the men were, the lower their testosterone, and the more likely they were to report dissatisfaction with their sex lives-especially avoiding sexual encounters and having difficulty performing sexually. There were no significant changes in measures of sexual quality of life or hormone levels in the group of men who didn't have the surgery. Both biological and psychological factors involved in obesity could affect sexual health and hormone levels. Further investigation is required to determine whether there is a casual relationship between hormone changes and sexual quality of life.
Journal of Clinical Endocrinology and Metabolism
April 2009