ECE2013 Poster Presentations Obesity (65 abstracts)
1Endocrinology Unit, Medical Department, Azienda Usl Bologna Maggiore-Bellaria Hospital, Bologna, Italy; 2Sexual Medicine and Andrology Unit, Department of Clinical Physiopathology, University of Florence, Florence, Italy; 3Diabetes Section Geriatric Unit, Department of Critical Care, University of Florence, Florence, Italy; 4Endocrinology Unit, Department of Clinical Physiopathology, University of Florence, Florence, Italy; 5Bariatric and Metabolic Surgery Unit, University of Florence, Florence, Florence, Italy; 6Bayer Schering Pharma AG, Berlin, Italy.
Introduction: Few randomised clinical studies have evaluated the impact of diet and physical activity on testosterone levels in obese men with conflicting results. Conversely, studies on bariatric surgery in men generally showed an increase in testosterone levels. The aim of the present study is to perform a systematic review and meta-analysis of available trials on the effect of body weight loss on sex hormones levels.
Methods: An extensive Medline search was performed including the following words testosterone, diet, weight loss and bariatric surgery and males. The search was restricted to data from January 1, 1969 up to August 31, 2012.
Results: Out of 266 retrieved articles, 24 were included in the study. Of the latter, 22 evaluated the effect of diet or of bariatric surgery, whereas two compared diet and bariatric surgery. Overall both low calorie diet and bariatric surgery are associated with a significant (P<0.0001) increase plasma sex hormone binding globulin bound and unbound testosterone levels (TT), bariatric surgery being more effective in comparison with low calorie diet (TT increase =8.73 (6.5110.95) vs 2.87 (1.684.07) for bariatric surgery and low calorie diet, respectively; both P<0.0001 vs baseline). Androgen rise is greater in those patients that lose more weight as well as in younger, non-diabetic subjects with a greater degree of obesity. Body weight loss is also associated with and decrease in estradiol and increase in gonadotropins levels. Multiple regression analysis shows that the degree of body weight loss is the best determinant of TT rise (B=2.50±0.98; P=0.029).
Conclusions: Present data show that weight loss is associated with an increase of both bound and unbound testosterone levels. The normalization of sex hormones induced by body weight loss is a possible mechanism contributing to the beneficial effects of surgery in morbid obesity.