Role of surrogate markers in assessment of insulin resistance in females with thyroid disorders

IntroductionThyroid status is known to affect insulin sensitivity although conflicting data have been reported regarding hypothyroid and hyperthyroid states. Assessment of insulin resistance is difficult, therefore we compared homeostasis model assessment (HOMA), glucose to insulin (G:I) ratio, glucose to C-peptide (G:C) ratio and ferritin of hypothyroid and hyperthyroid subjects with euthyroid, euglycemic subjects.MethodsThe study group comprised of 40 hypothyroid, 25 hyperthyroid female subjects and 40 euthyroid controls. Serum samples of all the patients were assayed for thyroid profile, glucose, Insulin, C-peptide and ferritin. Homeostasis model of assessment (HOMA-IR), (G:I), (G:C) and ferritin were employed as surrogate measures to assess the level of insulin resistance. The area under the curves for the surrogate markers was determined from the receiver operating characteristics (ROC) curves for the hypothyroid and hyperthyroid patients.ResultsPatients with hypothyroidism demonstrated insulin resistance as observed by the higher HOMA-IR and G:I ratio as compared to the controls whereas insulin resistance was not detected in the hyperthyroid patients in our study.ConclusionThyroid dysfunction attributes to deranged glucose metabolism. Assessment of the surrogate markers might prove to be beneficial in detecting insulin resistance at the incipient stages and subsequent management.