Elevated serum thyroglobulin levels as a marker of reversible hypothyroidism in patients with end-stage renal disease due to chronic glomerulonephritis

Difference in thyroid function depending on the etiology of end-stage renal disease (ESRD) was evaluated in 124 Japanese patients on haemodialysis (HD) due to either chronic glomerulonephritis (CGN, n = 82) or lifestyle related systemic disease (non-CGN, n = 42), such as diabetes mellitus (n = 30) or hypertension (n = 12). There was no significant difference in serum free thyroxine, free triiodothyronine and thyroid-stimulating hormone (TSH) level, but serum thyroglobulin (Tg) level was significantly higher in CGN (p = 0.0151). Prevalence of the patients with hypothyroidism (TSH > 4.83 mU/l) was 11 or 13.4% in CGN and 4 or 9.5% in non-CGN (p = 0.017). The most striking finding was the elevated Tg in 38 or 46.3% in CGN and in 11 or 26.2% in non-CGN (p = 0.034). Logistic regression analysis revealed elevated serum TSH level and higher thyroid volume were the significant factors associated with elevated Tg level. Extreme Tg elevation over 100 ng/ml was found only in CGN (12 or 14.6%), and 2 of the patients were overtly hypothyroid but became euthyroid after iodide restriction. Elevated Tg responding to elevated TSH mainly found in CGN suggested the relatively preserved thyroid tissue and reversible recovery of the thyroid function. *Corresponding author: Toru Sanai, The Division of Nephrology, Faculty of Medicine, Department of Internal Medicine, Saga University, Nabeshima 5-1-1, Saga-city, Saga 849-8501, Japan; The Division of Nephrology, Department of Internal Medicine, Fukumitsu Hospital, Kashiihama 4-10-1, Higashiku, Fukuoka-city, Fukuoka 813-0016, Japan; The Department of Nephrology, Abe Clinic, Taharashinmachi 2-3-8, Kokuraminani-ku, Kitakyushu-city, Fukuoka 800-0226, Japan E-mail: [email protected]