ANTITHYROID THERAPY IMPROVES GLYCEMIC CONTROL IN HYPERTHYROID TYPE 1 DIABETES MELLITUS PATIENTS

Abstract

Background and aims. Thyroid disorders are more frequently met in patients with diabetes mellitus than in general population. Thyroid hormones increase glycemia by several mechanisms, but the effect of antithyroid treatment on glucose control in type 1 diabetes mellitus (T1DM) cases is not well studied. The aim of our work was to analyze the evolution of glycemic control of T1DM patients submitted to specific therapy when hyperthyroidism was diagnosed. Material and method. The study group comprised by 37 patients, 35 women (94.6%) and 2 men (5.4%), known as having T1DM and diagnosed with hyperthyroidism during a 10-years interval. They were treated with antithyroid medication and reassessed after 6 months regarding thyroid function and glycemic control. Results. In the whole group, there was a significant decrease in mean HbA1c level (with 0.41%) and a significant increase in the percentage of patients being in the glycemic target (from 10.8% to 35.1%). The better glycemic control was obtained with a lower mean insulin dose. Patients who became euthyroid had a better evolution regarding glucose control in comparison to those who remained hyperthyroid. Changes in other cardiovascular risk factors were noted: systolic blood pressure decreased; diastolic blood pressure, HDL cholesterol, LDL cholesterol, non-HDL cholesterol, triglycerides and body weight increased. TSH and HbA1c values were inversely correlated. Conclusions. The therapeutic control of excessive thyroid function significantly contributes to the improvement of glycemic control in patients with T1DM and induces changes in the cardiovascular risk factors profile.