Thyroid function and oxidative stress indices in type 2 diabetics

Abstract

Augusta C. Nsonwu-Anyanwu, Edmund R. Egbe, Sunday J. Offor, Chinyere A. O. Usoro, Chinonyerem V. Alago, Divinegift O. Ebiese

Objectives: This study assessed the levels of triiodothyronine (T3 ), thyroid stimulating hormone (TSH), total antioxidant capacity (TAC), total plasma peroxides (TPP) and oxidative stress index (OSI) in type 2 diabetics and in different states of metabolic control to determine the possible relationship between oxidative stress, thyroid function and poor metabolic control. Methods: Ninety consenting subjects aged 40 to 65 years comprising of 50 type 2 diabetics and 40 nondiabetic volunteers in Calabar, Nigeria were recruited into this case control study. Their fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), T3 , TSH, TPP, TAC and OSI were determined using colorimetric methods. Anthropometric indices and socio-demographic information were obtained by standard methods. Results: The body mass index, FPG, HbA1c, TPP, and OSI were found to be significantly higher and TAC lower in type 2 diabetics compared to the non-diabetic controls. The FPG, T3 , TSH, TPP, TAC and OSI of diabetics with poor glycemic control do not differ from those with good glycemic control. T3 correlated positively with the duration of diabetes while TAC negatively correlated with TPP and OSI in type 2 diabetics. Conclusion: Irrespective of the metabolic control state, type 2 diabetes seems to be associated with increased oxidative stress indices which may not be related with changes in T3 and TSH levels.