Lol. Here’s the discussion.
In our study population, lower free testosterone levels and diminished ratings for sexual quality of life were correlated with increased BMI. Among subjects losing weight through bariatric surgery, there was a reduction in estradiol levels, an increase in total and free testosterone levels, and an increase in ratings for sexual quality of life. Studies in the literature had convergent findings on the relation between weight loss, testosterone levels, and sexual function. Leenen et al. (11) did not find a correlation between body fat distribution and free or total testosterone.
Weight loss was not associated with change in free and total testosterone. Niskanen et al. (14) showed that abdominally obese men increased their free and testosterone levels after a very low-calorie diet; however, there was no change in estrogen levels. Kaukua et al. (13) showed that weight loss increases free and total testosterone; however, it did not change sexual function scores.
To the contrary, Esposito et al. (15) demonstrated that sexual function improves after a weight reduction program. Bastounis et al. (19) found an improvement in SHBG and total testosterone and a reduction in estradiol after gastric bypass surgery; however, the change in free testosterone was not significant. Globerman et al. (20) found an improvement in free and total testosterone in 16 obese men who underwent silastic ring gastroplasty.
In summary, prior individual studies agree with some of our findings, although there is concurrence when these studies are considered in aggregate. This may be in part due to our larger sample size, which confers greater power to detect changes, and in part to differing effects of different types and degrees of weight loss.
Our study has several strengths, including a detailed anthropometric evaluation, long follow-up period (2 yr), a relatively large number of participants, and presence of a control group. Weaknesses of this study include the exclusion of a number of men because of lack of follow-up and unavailable blood samples. However, the excluded men had similar anthropometric characteristics in comparison to the study sample.
We did not find an association between change in body fat and hormonal and sexual quality of life parameters, despite a correlation between these and change in weight; this may be due to the limitations of the bioelectric impedence when compared with other techniques such as dual-energy x-ray absorptiometry scans. The correlation between body weight, BMI, and SHBG is well established, yet it was not seen in our study population.
It is likely that this is attributable to the narrow range for BMI, with associated very depressed SHBG levels in our study population. Inclusion of less obese and normal weight subjects would likely reveal this known correlation. Our results highlight an association between sexual quality of life and hormonal measures independent from weight. Because this relationship is confounded by biopsychosocial aspects of obesity, further studies are required to demonstrate a cause and effect relationship.