Thyroid hormones and glycaemic indices in euthyroid, hyperthyroid, hypothyroid, all type 2 diabetics and non-diabetic subjects

Abstract

Abstract Background Abnormal thyroid hormone levels have been reported in type 2, but the relationship between thyroid hormone levels and glycaemic indices: fasting plasma glucose (FPG), C-peptide (C-pep) and glycated haemoglobin (HbAlc), used in the management of type 2 is not well defined. This cross-sectional study examined the relationship between thyroid hormones and glycaemic indices in type 2. Results Positive correlations were observed between FPG and HbAlc in hypothyroid (r = 0.382, P = 0.011) and hyperthyroid group (r = 0.295, P = 0.012). FPG correlated with C-pep in hyperthyroid diabetics (r = 0.481, P < 0.001). HbAlc and TSH correlated positively in hypothyroid diabetics (r = 0.330: P = 0.031). HbAlc also correlated with T4 in hypothyroid diabetics (r = 0.379: P = 0.012). C-peptide and TSH correlated positively in hyperthyroid diabetics only (r = 0.279; P = 0.042). C-peptide also correlated with T3 and T4 in euthyroid diabetics (r = 0.231, P = 0.020; r = 0.248, P = 0.045), respectively. Conclusion The presence of abnormal levels of thyroid hormones influenced glycaemic indices in type 2 population. This implies that thyroid hormones investigation can assist in proper diagnosis and management of diabetes mellitus.

Keywords

• Thyroid hormones
• Glycated haemoglobin
• Diabetes mellitus
• C-peptide