THYROID HORMONES IN NON-INSULIN-DEPENDENT DIABETES BEFORE AND AFTER THERAPY

Twenty patients of non-insulin-dependent diabetes mellitus (NIDDM) (15 males and 5 females) who developed secondary failure to oral hypoglycaemic drugs, were evaluated for thyroid hormone abnormalities before and after control of diabetic state with insulin. Blood glucose (mean ± SEM mg/dL) fasting and post prandial levels were 260±16 and 370±20 respectively before therapy. After 15 days of intensive insulin therapy these levels fell to 110±14 and 130±12 respectively (p < 0.005). Glycosylated haemoglobin percent (GHb%) (mean ± SEM) was 10±0.4 before therapy and after therapy it fell to 9.2±0.3 (p < 0.05). Serum tri-iodothyronine levels (mean ± SEM ng/mL) were 0.55±0.03 which was significantly lower (p < 0.05) as compared controls. After therapy it significantly (p < 0.05) rose to 1.22±0.08). Serum thyroxine (T4) (mean ± SEM mcg/dL) was 8.5±0.6 before therapy and it did not change significantly after therapy. Serum reverse tri-iodothyronine (rT3) values of (mean ± SEM ng/dl) 0.24±0.05 were higher before therapy and decreased to 0.20±0.82 after therapy. However thyrotropin (TSH) values before and after therapy remained same. There was no significant change in TSH response to thyrotropin releasing hormone (TRH) before and after control of diabetic state. It was concluded that peripheral changes in T3, T4 and rT3 (low T3, high rT3 and low or normal T4) occurred in uncontrolled diabetic state. However, pituitary thyrotroph function in NIDDM with ideal body weight was not significantly affected.