Comparison of glucose and insulin metabolism in hypothyroid patients with thyrotropin level less and greater than 10 IU/L

Abstract

Insulin resistance is the lack of a proper biological response to the normal level of insulin in the blood,which includes the different biological effects of insulin on different tissues in the bodi. In practice, insulin resistance is defined by higher levels than normal glucose in response to insulin,leading to damage various organs. The prevalence of thyroid disease in type 2 diabetes is significantly higher than in the general population And insulin resistance is hallmark of type 2 diabetes. Association between insulin resistance and overt hypothyroidism were established in several studies, but it was controversy in subclinical hypothyroidism. In this study we evaluated the association between TSH and insulin resistance in subclinical and overt hypothyroidism. Method: This study was conducted as comparative cross-sectional on referred outpatients to clinics of Tabriz university. Regarding to inclusion and exclusion criteria, 120 subjects were chosen and devided in 3 age, gender and BMI matched groups, consisted of euthyroid subjects, hypothyroid subjects with 4.5<TSH<10 and TSH > 10. We evaluated insulin resistance with HOMA-IR (homeostasis model of assessment), then analyzed TSH and HOMA-IR in 3 groups. Results: the mean age and BMI(body mass index) in the group with TSH above 10 were higher than the other two groups. HOMA-IR in 20% of subjects in control group were greater than 1.7 and it was similar (58% of subjects) in two other groups (TSH > 4.5), this difference was statistically significant. HOMA-IR was not statistically significant in subjects with TSH 4.5-10 and greater than 10. In linear regression analysis there were direct relations between TSH and HOMA-IR in two groups with TSH more than 4.5. There were similar relations between ANTI TPO and HOMA-IR in these two groups, as ANTI TPO increased, HOMA-IR numbers have increased.