Estrogen/androgen balance in men with hyperestrogenism normalized by using letrozole of the aromatase inhibitor drug class

Introduction . Currently, virtually no data on comparative studies of efficacy and safety of drug class aromatase inhibitors vs. standard therapies used in patients with overweight and/or obesity with an initial testosterone deficiency and excessive estradiol are available. Aim : to study and evaluate the efficacy and safety of the use of the reversible aromatase inhibitor letrozole in adult men with overdeveloped adipose tissue and/or obesity with hyperestrogenism and testosterone deficiency. Materials and Methods . A randomized, open, interventional, comparative, single-centre clinical trial was conducted by enrolling 49 obese men. The patients were divided into 2 groups: Group 1 (n = 26) – patients received standard metformin therapy (1000 mg 2 times a day), along with letrozole (at a dose of 2.5 mg 2 times a week); Group 2 (n = 23) – patients received only standard metformin therapy. Patients were monitored for 8 weeks from the date of inclusion. Anthropometric parameters were monitored: body weight, body mass index, waist as well as hip circumference. Laboratory data were also evaluated: level of sex hormone binding globulin (SHBG), total testosterone, estradiol, glucose, uric acid, insulin. All subjects filled out questionnaires twice (before the start of the study and after its completion) – the aging symptoms questionnaire for men (Aging Males Symptoms, AMS) and IIEF (International Index of Erectile Function). Results . Total testosterone level significantly and reliably increased only in Group 1 from 10.6 to 22.2 nmol/L. In Group 2 testosterone level increased insignificantly from 9.28 to 11.02 nmol/L, and did not reach the physiological normal range. Estradiol changes also differed markedly and significantly: in Group 1, estradiol decreased from 51.4 to 24.3 pg/ml, i.e., by 2.1-fold reaching physiological range, whereas in Group 2 estradiol level decreased insignificantly from 45.1 to 44.4 pg/ml, and remained above the range of normal values. Significant changes in SHBG were observed only in Group 2. Insulin level in Group 1 significantly decreased from 10.6 to 6.6 μIU/ml, i.e., by 1.6-fold. In Group 2, insulin also decreased, but less pronounced, from 15.8 to 13.7, i.e., by 1.2-fold, which turned out to be statistically insignificant and according to the НОМА-IR index (Homeostasis Model Assessment of Insulin Resistance), it remained within the insulin resistance range. Glucose level did not change significantly in both groups. Uric acid, on the