Table 2. Available meta-analyses evaluating the effects of bariatric surgery on testosterone levels.

Study	No. of trial	No. of patient	Main inclusion criteria
Corona et al (2013) [23]	11	262	Studies comparing testosterone levels before and after bariatric surgery
Corona et al (2015) [11]	15	398	Studies comparing testosterone levels before and after bariatric surgery
Escobar-Morreale et al (2017) [46]	7	382	Studies showing data on prevalence of obesity-associated secondary hypogonadism among patients undergoing to bariatric surgery
Wen et al (2018) [47]	23	654	Studies reporting sexual function and at least one sex hormone level with a follow-up time of at least 6 months
Lee et al (2019) [48]	28	1,022	Studies evaluating the effect of bariatric surgery on sex hormones or sperm parameters