Normal inhibin B levels suggest partial preservation of gonadal function in adult male patients with anorexia nervosa.

Introduction: The impact of undernutrition on endocrine and exocrine gonadatrope function is poorly known in male anorexia nervosa (AN) patients.

Aim: The aim of this study was to compare the pituitary-gonadal function of male AN subjects with that of healthy controls, Kallmann syndrome (KS) patients, and female AN subjects.

Methods: Observational monocentric cross-sectional study performed in 31 male and 25 female subjects with restrictive-type AN, 22 male and 20 female controls, and nine male KS patients.

Main Outcome Measures: Hormonal parameters are as follows: follicule stimulating hormone (FSH), luteinizing hormone (LH), sex hormone binding globulin, estradiol, testosterone, inhibin B, thyroid hormones, growth hormone (GH), insulin-like growth factor 1 (IGF-1), cortisol, adrenocorticotropic hormone (ACTH), dehydroepiandrosterone sulfate, and leptin.

Results: Similar abnormalities of free T3, GH, IGF-I, cortisol, and leptin were found in men as in AN women with equivalent undernutrition status when compared with corresponding controls. Low levels of LH, FSH were found in both male and female AN patients. In male AN, total testosterone was found lower than in controls but higher than in KS, while a lack of estradiol was noticed in AN women. Sex hormones variations were directly related to weight gain only in AN men. No relationship was found between sex hormones and leptin variation for both sexes. In AN men, inhibin B levels were similar to that of controls and did not correlate with testosterone levels.

Conclusions: Significant differences of undernutrition impact on gonadal status were noticed between male and female AN subjects, including partial preservation of testosterone release and probable preservation of exocrine function, according to the normal inhibin B levels.