[Features of true gynecomastia in adult males].

Background: In recent years, the incidence of gynecomastia in adult men has increased significantly. It is of interest to study the specific features of the disease in these patients.

Aim: To identify the main characteristics of acute gynecomastia in adult men.

Materials and methods: A continuous one-stage study including 160 adult males with acute onset gynecomastia, who were he was treated in Endocrinology Research Centre, Moscow. Total bilirubin, hepatic transaminases, creatinine, urea, luteinizing hormone, prolactin, sex hormone binding globulin, estradiol, total testosterone, alpha-fetoprotein, chorionic gonadotropin and mammary gland condition were evaluated in all patients. Baseline significance threshold level of p<0.05.

Results: The incidence of gynecomastia increased from 5,4% in 2020 to 14,4% in 2024. Tumor forms of gynecomastia were rare, with 1,2% (95% CI 0,0; 3,0) of cases. In 30% (95% CI 22,9; 37,1) of men, gynecomastia was due to the intake of anabolic steroids for athletic stimulation. In 11,2% (95% CI 6,4; 16,1) of patients, gynecomastia was hepatogenic. In 7,5% (95% CI 3,4; 11,6), it was due to elevated sex hormone binding globulin. 47,5% (95% CI 39,8; 55,2) were endocrine non-tumorigenic form of gynecomastia due to excess body weight with formation of changes in sex hormone levels. The patients who took anabolic steroids were characterized by young age, as well as decreased luteinizing hormone levels and increased testosterone levels. The group of patients with elevated sex hormone binding globulin had no clinically significant features. Men from the group of hepatogenic gynecomastia were characterized by hyperestrogenism. Patients in the group with altered sex hormone levels were characterized by high body mass index and either increased estradiol or decreased testosterone or a combination of both.

Conclusion: The number of adult male patients with acute gynecomastia is progressively increasing. In the examined sample of patients, the main causes of gynecomastia were patients taking anabolic steroids, liver dysfunction and weight gain with the formation of changes in sex hormone levels. Patients taking anabolic steroids were characterized by a drug--induced increase in testosterone and estradiol levels, which was accompanied by suppression of pituitary gonadotropic function. Estradiol elevation was also characteristic of patients with hepatogenic form of gynecomastia and men with excess body weight with formation of changes in sex hormone levels.