Thyroid function in type 2 diabetes mellitus and in diabetic nephropathy

Diabetic patients have higher prevalence of thyroid disorders than the general population which may have an influence on diabetic management. The present study compared the levels of thyroid hormones, serum creatinine, glycated haemoglobin and urine microalbumin between type 2 diabetics without any complications, type 2 diabetics with nephropathy and age and sex matched normal controls.

The mean serum T3 level in type 2 diabetics without any complications was 91.27 ± 14.56 ng/dl , in type 2 diabetics with nephropathy was 88.5320 ± 30.87 ng/dl and in controls was 134.98 ± 28.55 ng/dl. The mean serum T4 level in type 2 diabetics without any complications was 7.73 ± 1.42 μg/dl, in type 2 diabetics with nephropathy was 7.25 ± 2.72 μg/dl and in controls was 8.61 ± 1.73 μg/dl. The mean serum TSH level in type 2 diabetics without any complications was 3.99 ± 1.87 μIU/ml, in type 2 diabetics with nephropathy was 4.27 ± 1.62 μIU/ml and in controls was 2.07 ± 1.09 μIU/ml. Correlations between T3, T4, TSH with serum creatinine, glycated haemoglobin were not statistically significant in type 2 diabetes without any complications and diabetic nephropathy. We found a statistically significant correlation between T3 and urine microalbumin in patients with diabetic nephropathy.

Failure to recognize the presence of abnormal thyroid hormone levels may be a primary cause of poor management of diabetes mellitus type 2. Therefore there is a need for the routine assay of thyroid hormones in type 2 diabetics and diabetic nephropathy in order to improve the quality of life and reduce the morbidity.