The impact of body mass index on reproductive hormones, testosterone/estradiol ratio and semen parameters

INTRODUCTION: The aim of this study was to evaluate the relationship between body mass index (BMI) and sperm parameters and reproductive hormone levels in patients with no known risk factors for infertility. MATERIAL AND METHODS: Four hundred patients who met the study’s inclusion criteria were divided into three groups according to their BMI values as normal weight (BMI: 18.5–24.9 kg/m(2)), overweight (BMI 25–29.9 kg/m(2)), and obese (BMI ≥30 kg/m(2)). Semen parameters, reproductive hormone levels and testosterone/estradiol ratio were compared retrospectively between the groups. RESULTS: There was no significant difference between the groups in terms of age and infertility period. The mean BMI of all the patients was 26.6 ±4.08, and the BMI in the normal, overweight and obese groups were 22.6 ±1.7, 27.4 ±1.3, and 33.4 ±2.9, respectively (p <0.001). There was no significant difference between the groups in terms of serum follicle stimulating hormone, luteinizing hormone, estradiol, prolactin, semen volume, sperm concentration, total sperm count, and progressive and total motility. Serum testosterone (T) level and testosterone/estradiol (T/E2) ratio were significantly higher in the normal BMI group (p <0.001). CONCLUSIONS: Adipose tissue increase was not significantly correlated with change in the semen parameters and it was negatively correlated with T levels and T/E2 ratio.