Endocrine Abstracts

Introduction and aim

Graves’ disease which is the most common cause of hyperthyroidism is an autoimmune disease presenting with goitre, orbitopathy and dermopathy. The disease is caused by stimulant type TSH receptor antibodies (TRAB). TSH receptor (TSHR) has been shown in different tissues other than thyroid. Testis is one of the extrathyroidal tissues with TSHR. The aim of this study was to investigate relationship between TRAB and inhibin-B, which is an indicator of spermatogenesis.

Materials and methods: After approval of the Clinical Ethics Committee of Bakırköy Dr. Sadi Konuk Training and Research Hospital, 53 male patients who were admitted to the outpatient clinics aged 18 to 65 with Graves disease positive for TRAB and 34 male controls with no infertility problems, autoimmun diseases and medications whic may affect Hypotalamo-pituitary-gonadal axis were included the study. Sociodemographic data form was applied to all patients included in the study and TSH, fT3, fT4, Anti-TPO, Anti-Tg, TRAB values were recorded. For inhibin B assay, 5 ml venous blood was collected in a plain bottle without anticoagulant between hours 08:00–11:00 and serum was separated by centrifugation. The serum aliquots were stored at -80 °C untill analysis. Inhibin-B studied with ELISA (E-EL-H0313 Detection Range: 7.81~500 pg/ml, Sensitivity: 4.69 pg/ml)

Results: Mean age was 39.5 ± 11.8 years in patient group and 40.17 ± 12.1 in control group. Mean duration of disease was 31 months. Mean TSH was 3.5 ± 13.8 this is because of high TSH values of hypothyroid men among patients and median TSH was 0.02 in patient group. Mean TSH was 1.3 ± 0.69 in control group. There were 35 hyperthyroid, 14 euthyroid, 4 hypothyroid men in patient group and all men in control group were euthyroid. Serum inhibin-B was negatively correlated with body mass index (BMI) (r = -0.217, P < 0.01) and positively correlated with existing of thyroid nodules (r = 0.255 P < 0.05) in patient group; on the other hand we did not observe relation between TRAB, TSH, Anti-TPO, Anti-Tg, fT4, fT3 and inhibin-B in patient group. Studies demonstrated that inhibin-B is lower in TRAB positive Graves patients than control group (P < 0.0001).

Conclusion: This study showed inhibin-B is significantly low in TRAB positive Graves patients but no significant relationship between TSH, fT3, fT4, TRAB, duration of disease and inhibin-B. Therefore, all patients with Graves disease should be consulted on their reproductive health.