Abstract

Introduction: Leptin is a 16 KD protein which is mainly secreted from the adipose tissue and is known to be involved in the satiety process. Accordingly, the hormone also seems to play a role in the hypothalamo-hypophyseal-gonadal axis in order to modulate reproductive system. In our prospective study, we aimed to compare the mean serum leptin concentrations in infertile and fertile males and to investigate the relationship between serum leptin levels with the sperm density, serum FSH, LH, testosterone levels and the volumes of testis in infertile males.

Materials and Methods: A total of 38 infertile males as a study group and 28 healthy men who had been proved to be fertile in last 1 year as a control group, were included in the study. Mean body mass index (BMI) and serum leptin levels of fertile and infertile males were evaluated. In addition, the volumes of testes, sperm densities and serum FSH, LH, testosterone levels were obtained from all patients in the study group. Patients having sperm concentrations between 1 million and 20 millions per milliliter of ejaculate were involved in the study. Patients with unilateral varicocele or bilateral varicoceles, urinary tract infection, congenital penil contracture, sexual dysfunction and retrograde ejaculation were excluded from the study. Statistically, the variations were compared with their relevant mean and standard deviation values. Student t-test was used as a parametric test and Mann Whitney U test was used as a non-parametric test. The correlation values were calculated by using Pearson correlation test.

Results: Mean age for the study and the control groups were 33±5.1 (range 24-44) and 32±2.5 (range 27-36) respectively. Mean BMI value for fertile group was 24.9±2.4 kg/m2 and 24.8±2 kg/m2 for the control group (p>0.05). There were no statistically significant differences between the mean serum leptin concentrations of the fertile and the infertile group. Mean serum leptin concentration was 5.7±6.5 ng/ ml for the study and 3.9±2.4 ng/ ml for the control group. Mean leptin concentration was higher in infertile group than the mean values reported in the literature (5±0.4 ng/ml for fertile group). However, mean serum leptin concentration for the fertile group was lower than this value. In addition, in infertile males, no correlations were found between serum leptin levels and testis volume, sperm density, serum FSH, LH, testosterone levels.

Conclusion: Our data suggest that although serum leptin concentrations tend to increase with the decrease in seminal sperm concentration, there were no statistically significant differences between the mean serum leptin levels of oligozoospermiac and fertile men. So, determination of serum leptin levels in oligozoospermiac males might not be used as diagnostic and prognostic criteria. However, it can be used as an additional parameter to predict the degree of testicular dysfunction in infertile males.