Relationship Between Hyperthyroidism And Glucose Metabolism And Serum Growth Hormone

Objective:To investigate the relationship between hyperthyroidism and glucose metabolism ,study the effects of hyperthyroidism on glucose tolerance, insulin secretion, and insulin sensitivity. At the same time,examine serum growth hormone level in the patients with hyperthyroidism and its relation to thyroid hormones·Methods:In this study 56 cases of hyperthyroidism patients, 30 cases of euthyroid control with matching age and body mass index were involved. Fasting insulin(FIns),2 hrs postprandial insulin (2h INS),fasting plasma glucose(FPG),oral glucose tolerance test 2-h plasma glucose (OGTT 2hPG), hemoglobin A1c (HbA1c)and fasting serum growth hormone(GH)were assayed. At the same time, homeostasis model assessment-insulin resistance (HOMA-IR), insulin sensitivity index (ISI) and homeostasis model assessment of insulin sensitivity (HOMA–IS) were measured.Results:OGTT 2h PG, 2h INS ,HbA1c ,HOMA–IR and GH of the patients were significantly higher than those of the euthyroid controls ,ISI of the patients were significantly lower than those of the euthyroid controls . FPG and FIns were higher than those of the euthyroid controls ,HOMA–IS of the patients were lower than those of the euthyroid controls ,but these were no significant. FPG was correlated with FT3,FT4,FIns and BMI; OGTT 2hPG was correlated with BMI.Conclusion: This study has confirmed the impact of hyperthyroidism on glucose metabolism ,glucose metabolism abnormality is common in hyperthyroidism. Both impaired insulin secretion and decreased peripheral insulin sensitivity are the factors contributing to the development of abnormal glucose tolerance in the hyperthyroid state. Among the total,GH may play an important role in glucose metabolism abnormality of hyperthyroidism.