Evaluation of interaction between serum zinc levels and pubertal gynecomastia

The aim of this study was to investigation association between serum zinc levels and pubertal gynecomastia. The study was conducted as a cross-sectional and case control study between the January 2017 and October 2017 in the Division of Adolescent Medicine, Department of Pediatrics, Hacettepe University İhsan Doğramacı Children's Hospital. One hundred and nine adolescents between the ages of 10 and 20 years were included. The serum zinc levels of the cases were compared. Estrogen, total testosterone, DHEAS, β-HCG, FSH, LH, SHBG, prolactin levels, renal and liver function tests, and thyroid function tests were measured in all cases to differentiate pubertal gynecomastia from pathological gynecomastia. Serum zinc levels were measured by the atomic absorption spectrophotometry method. A total of 109 patients, comprising 54 patients with pubertal gynecomastia and 55 healthy adolescents, were included in the study. The mean age of adolescents in the pubertal gynecomastia group was 14,2±1,7 (min-max: 9,8-17,8) years and the mean age of the control group was 15.8±1.4 (min - max: 13.3 - 20) years (p <0.001). Beta-HCG levels were found to be lower than 2 mIU/ml in all patients. FSH, LH, estradiol, testosterone, DHEAS, SHBG, prolactin, TSH, fT4 levels were within the normal limits. The mean zinc level in the pubertal gynecomastia group was found as 99,42±19,35 (42-143,00) μg/dl in the gynecomastia group and 108,94±21,33 (71,19 - 167,20) μg/dl in the control group (p=0.016). A positive correlation was found between the testosterone level and the serum zinc levels (r=0.321, p=0.22). There was a correlation between prolactin and serum zinc level on the negative side (r=0,291, p=0,04). In the light of our results, serum zinc level seems to be lower in cases with pubertal gynecomastia compared to the control group. As the zinc level increases, testosterone level increases and prolactin level decreases. In our study, there was a positive correlation between serum zinc level and testosterone level. In 2 cases in which zinc deficiency was detected, after zinc therapy, gynecomastia regression was observed. From this point of view, zinc replacement should be considered in the management of pubertal gynecomastia when zinc level is low. Key words: gynecomastia; zinc; testosterone; puberty; prolactin