Endocrine Abstracts

Aim: Isolated male hypogonadotropic hypogonadism can be congenital or acquired. Mean platelet volume (MPV), which is a determinant of platelet function, is an independent risk factor for cardiovascular disease. The aim of this study is to evaluate MPV values in untreated, normosmic, isolated, male, idiopatic hypogonadotropic hypogonadism (IHH) patients, and the relationships among MPV, low testosterone levels, metabolic syndrome, impaired fasting glucose (IFG) and cardiovascular risk in these patients

Materials and methods: Thirty-one patients with untreated, normosmic, isolated, male, idiopatic hypogonadotropic hypogonadism (mean age 22.0±4.9 years) and 30 healthy controls (mean age 22.5±7.5 years) who came to Erzurum Regional Education and Research Hospital, Outpatient Clinic of Endocrinology Department were included in the study. Patient group and the control group were matched for age and BMI. It was used the IDF criteria (2005) for diagnosis of metabolic syndrome, and the ADA criteria (2007) for diagnosis of impaired fasting glucose. All hormonal analyses were done by chemiluminesance assay. All the study subjects were evaluated by biochemical and platelet parameters. Hypogonadotropic hypogonadism was defined as total testosterone <229 ng/dl, absent or inadequate as pituitary gonadotropins. Homeostasis model assessment (HOMA–IR) was used as a measure of insulin sensitivity using the equation: Fasting insulin (mU/l) × fasting glucose (mmol/l)/22.5.

Result: The MPV levels in IHH patients were also significantly higher than controls (8.6±0.65 and 7.6±0.54 fl, respectively; P=0.0001). To assess the correlation with MPV, a Pearson correlation analysis was performed on each variable. MPV had a positive correlation between parameters of metabolic syndrome (r=0.444; P=0.0001), IFG (r=0.371; P=0.04), insulin (r=0.820; P=0.02), HOMA–IR (r=0.822; P=0.023), and BMI (r=0.373; P=0.012). MPV had a negative correlation between total testosterone (r=−0.586; P=0.0001), free testosterone (r=−0.634; P=0.0001), LH (r=−0.471; P=0.0001), FSH (r=−0.434; P=0.0001). Metabolic syndrome and IFG in IHH patients had significantly more often than controls (P=0.003 and P=0.0001, respectively). The multiple regression analysis between MPV and other risk factors was performed. The age, metabolic syndrome, IFG, BMI, insulin, CRP and HOMA–IR were independent predictive factors for high MPV levels.

Conclusion: These results suggest that subjects with male IHH are susceptible to increased platelet activation and increased MPV values which contribute to increased risk of cardiovascular complications. From this study it has been observed that hypogonadotropic hypogonadism with low testosterone may be a feature of the metabolic syndrome, impaired fasting glucose, increased MPV levels, and cardiovascular risk in young adult males. Thus, in IHH patient, testosterone replacement therapy may be useful protecting from the cardiovascular disease. In IHH patients, further study is needed to better understand low testosterone relationship between these three components for preventive from the cardiovascular risk.