Serum leptin correlates in fertile and idiopathic infertile Yemeni males: a comparative cross-sectional study.

This comparative cross-sectional study aimed to evaluate the relationship between serum leptin and testosterone, FSH, LH, PRL and semen quality in fertile and idiopathic infertile Yemeni men. A total of 30 infertile males with unknown causes and 30 age-matched healthy fertile males were enrolled in this study. The body mass index (BMI) and waist circumference (WC) were measured. Semen samples were analyzed according to the WHO manual for semen analysis. Serum samples were tested for hormones. Subjects were then divided into subgroups and compared based on their main seminal findings. The WC, serum leptin, PRL, FSH and LH levels were significantly higher (p < 0.05) in the infertile subjects than in the fertile group. Serum leptin demonstrated a significant positive correlation (p < 0.01) with body weight, BMI and WC in fertile males and a significant negative correlation (p < 0.01) with testosterone in fertile and infertile males. Similarly, a significant positive correlation was found between serum leptin and FSH (p < 0.01) and LH (p < 0.05) levels in the infertile subjects. The findings showed that non-obstructive azoospermic (NOA) patients have significant (p < 0.05) high levels of serum leptin, FSH, and LH. These findings may support the possibility of a direct peripheral negative effect of leptin on testicular steroidogenesis independent of the suggested indirect effect, and it could directly impact spermatogenesis without inhibiting testosterone production. This effect was accompanied by increasing serum PRL levels. Furthermore, serum leptin and gonadotropins were found to be increased in the idiopathic NOA group. The present study provided valuable insights into the fertile and idiopathic infertile Yemeni males and could establish an important foundation for future andrological-related studies such as investigating the relationship between leptin and other hormones; and infertility-related genetic and epigenetic factors.

Impact of Metabolic Syndrome Factors on Testosterone and SHBG in Type 2 Diabetes Mellitus and Metabolic Syndrome.

OBJECTIVE: Several studies have often reported low testosterone and SHBG to be associated with type 2 DM and the metabolic syndrome (MetS). Our objective was to determine the impact of metabolic syndrome and diabetic parameters on testosterone and SHBG in both MetS subjects and type 2 DM patients. METHODS: In this study, 120 Yemeni male aged 30-70 years old were enrolled, 30 of whom were healthy subjects with BMI < 25 kg/m2 that served as control, 30 MetS, 30 type 2 DM without MetS, and 30 type 2 DM with MetS according to IDF criteria. RESULTS: Testosterone (free and total) and SHBG were significantly lower in MetS subjects and modestly reduced in type 2 DM with and without MetS. Stepwise linear regression showed free and total testosterone to be negatively affected by waist circumference, and univariate analysis shows this significant difference to disappear when adjusted for waist circumference. On the other hand, stepwise linear regression showed SHBG to be positively affected by testosterone and age and negatively affected by FBG and TG. Univariate analysis shows this observed significant difference to disappear when adjusted for testosterone. CONCLUSION: Abdominal obesity is a major determinant of low testosterone levels irrespective of diabetes status. Thus, supporting evidence suggesting that the causative relationship between the often low testosterone and type 2 DM might be bidirectional or even multidirectional and interrelated with obesity, MetS, and IR.