Microsoft Word - NEF357BF

Dr. med. Josef Evers, KfH Dialysezentrum, Dorotheenweg 3, D-53474 Bad Neuenahr (Germany) Dear Sir, Various alterations of thyroid hormones, mostly decreased levels of total thyroxine (T4) and triiodothyroxine (T3) in serum, and a blunted, delayed rise of thyroid-stimulating hormone (TSH) after administration of thyrotropin-releasing hormone (TRH) have been found in patients with renal failure [1]. However, decreased levels of TSH and no rise in response to exogenous TRH stimulation are unusual. Therefore, we want to report about 4 dialysis patients with subnormal TSH levels and a negative TRH test. Within 2 years of opening of a new dialysis center in an area with endemic goiter we detected 4 out of 30 patients with extremely low TSH levels which did not rise after intravenous injection of 0.400 μg TRH. Levels of basal and stimulated TSH (after administration of TRH), total and free thyroid hormones are given in table 1. Patient 1 (R.M.) is a 64-year-old anxious man with end-stage renal failure (ESRF) due to nephrosclerosis and regular hemodialysis treatment since August 1991. After transfer to our center he suffered from gradual loss of dry weight, hypokalemia, ventricular premature beats and repeated congestive failure. After subtotal thyroidectomy in December 1993 because of autonomy of the right thyroid lobe, TSH was normal at 2.09 μU/ml in March 1994, in response to TRH 4.89 μU/ ml, T4 was 7.0 μg/dl and T3 110 ng/dl. Histo-logical examination revealed only degenerative changes of the thyroid, no adenoma. Patient 2 (P.K.) is a 68-year-old man with acromegaly and ESRF with unknown primary disease with hypertension and atrial fibrillation. He started with regular dialysis treatment in August 1992. The left kidney had to be removed in November 1992 because of a hypernephroma. 99mTc scintillation scanning of the thyroid showed multinodular goiter with autonomy in two nodules. In April 1993, he suffered from a myocardial infarction with severe congestive heart failure, and in 20 months he lost weight from 67 to 58 kg. No antithyroid therapy has been given until now. Table 1. Dialysis patients with low TSH levels (normal levels in parentheses) Age/Sex Basal TSH (0.1-4.0) μU/ml Stimulated TSH (2.0-30.0)