The effect of obesity on testicular function by insulin-like factor 3, inhibin B, and leptin concentrations in obese adolescents according to pubertal stages.

OBJECTIVES: The aim of the present study is to investigate the effect of obesity on testicular function by evaluating reproductive hormones, inhibinB, insulin-like 3(INSL3), and leptin, in obese and non-obese adolescents according to pubertal Tanner stages. DESIGN AND METHODS: Eighty adolescent boys were grouped (n=20) as; Group1: obese-Tanner2, Group2: non-obese-Tanner2, Group3: obese-Tanner4, Group4: non-obese-Tanner4. Serum INSL3, luteinizing hormone, follicle-stimulating hormone, total testosterone, free testosterone, estradiol, sex hormone binding globulin, inhibin B and leptin levels were assessed in all groups.
RESULTS: INSL3 levels were significantly lower in obese adolescents compared to non-obese boys (p=0.003, Tanner2) and (p=0.031, Tanner4). There was a negative correlation between INSL3 and leptin (r=-0.468, p=0.001). The negative correlation between INSL3 and BMISDS indicates that pubertal obesity leads to Leydig cell impairment.
CONCLUSIONS: This study demonstrated for the first time in the literature that obesity effects testicular Leydig cell function starting from Tanner stage 2.