Endocrine Abstracts

Aim: Hyperinsulinaemia is frequent finding in patients with hyperprolactinemia and has associations with thyroid volume. In this study, we evaluated the association between thrombotic markers, insulin resistance, CIMT, and thyroid volume in female patients with prolactinoma.

Material and methods: 38 women with prolactinoma and 24 healthy women were included to the study. We evaluated anthropometric, biochemical, hematologic and hormonal parameters as well as thyroid volume (TV) and CIMT in prolactinoma patients (before treatment) and controls. Insulin resistance was calculated using the HOMA-IR.

Results: Mean age, BMI, TSH, mean platelet volume (MPV) and platelet distribution width (PDW) levels were similar between groups (P>0.05). HOMA-IR, platelet counts, prolactin, insülin levels, CIMT and tiroid volume was were significantly higher in prolactinoma group (P<0.05). While there was positive correlation between prolactin levels and insulin levels, platelet counts, CIMT and triglyceride levels (P=0.04, r=0.23; P=0.01, r=0.32; P=0.02, r=0.28; P=0.01, r=0.31, respectively), there was no significant correlation between prolactin levels and TV, MPV, PDW, and HOMA-IR (P>0.05). There was statistically significant positive correlation between TV and HOMA-IR, insulin levels, platelet counts and CIMT (P=0.00, r=0.45; P=0.00, r=0.43, P=0.00, r=0.35, respectively).

Conclusion: Hyperprolactinemia has been implicated in the pathogenesis of obesity and glucose intolerance and is reportedly associated with an impaired metabolic profile. Additionally, elevated PRL levels may increase the risk of developing atherothrombotic events via the activation of platelets. Thyroid volume has been found to be associated with age, anthropometry, smoking, iodine status and hyperinsulinaemia. Additonally, growth hormone and growth factors have been shown to affect TV. In our study, we determined relationship between TV and insulin resistance, platelet count, and CIMT in patients with prolactinoma. So we think that, insulin resistance and thrombotic factors may be responsible for change in thyroid volume in patients with prolactinomas.