Last update:
12-Nov-2004

OBJECTIVE Thyroid function abnormalities are common in chronic hemodialysis (HD) patients and their incidence increases with age. The signs and symptoms are rarely suggestive and are easily confused with those of end stage renal failure (ESRF) on dialysis. The aim of this study was to assess thyroid function in a selected group of symptomless, older, HD patients.

METHOD Thyroid function of 109 HD patients, 61 males and 48 females, with an age of 67.5±8.8 years (51–85) and on HD for 57.7±52 months (9–250) was assessed. No patient had a history of thyroid disease, had received any medication that could interfere with thyroid function or suffered from acute illness at the time of the study. Blood was drawn before the first dialysis of the week and FT₃, FT₄, TSH, anti-Tg and anti-TPO blood levels were measured using RIA methods.

RESULTS The results showed that (a) two male patients (1.83%) had subclinical hyperthyroidism as indicated by abnormally low TSH (<0.3 μIU/mL) and normal thyroid hormone levels (FT₃ 1.6–4.3 pg/mL, FT₄ 0.6–1.9 ng/dL), (b) two patients (1 male, 1 female, 1.83%) presented with overt hypothyroidism as indicated by high TSH (>4 μIU/mL) and low FT₃, FT₄, and (c) 10 patients (8 female, 2 male, 9.17%) had high TSH values with normal levels of thyroid hormones suggesting subclinical hypothyroidism. Anti-Tg antibodies were abnormally elevated (>100 IU/mL) in 8 (7.34%) and anti-TPO (>10 IU/mL) in 10 (9.17%) patients. The higher percentage of women with abnormally high TSH values (18.75% vs 4.92%, x²=5.24, P<0.05) was the only statistically significant difference between males and females.

CONCLUSIONS Thyroid function abnormalities, mostly mild hypothyroidism, were not unusual (12.83%) in the selected HD population of this study. This finding suggests that screening of the older HD population for thyroid function abnormalities is warranted.

Key words: Age, Hemodialysis patients, Thyroid function.