Incidence of Subclinical Hypothyroidism in Renal Transplant Patients

Thyroid disorders are common in chronic kidney disease. THE AIM: The purpose of this study was to compare thyroid gland disorders among healthy participants and renal transplant patients and to assess the duration of dialysis on thyroid disorders before transplantation. MATERIAL AND METHODS: Prospective study during 12 months period included 80 participants divided into two groups. Study group of 40 patients with transplanted kidney was divided in two subgroups, according to the time spent on dialysis (i.e. under and over 72 months). The control group included 40 healthy participants. The exclusion criteria was represented by the previous thyroid disorders and systemic illnesses and treatment with drugs that interfere with thyroid function (amiodarone, propranolol, lithium). The blood samples were taken for standard laboratory analysis, total thyroid hormone levels. Serum level of free thyroxine (T4) and free triiodothyronine (T3) were assayed by RIA using commercially available kits. Subclinical hypothyroidism is defined by the finding of elevated thyroid-stimulating hormone (TSH) > 4.4 mmol/L and normal values of T3 and T4. RESULTS: The relative distribution of the functional thyroid disorders is statistically significantly higher in the experimental group: the low T3 syndrome in 12.5% (n = 5) patients (p = 0.017); low T4 syndrome in 7.5% (n = 3) patients (p = 0.072) and subclinical hypothyroidism in 17.5% (n = 7) patients (p = 0.021). There is statistically significant difference in the relative representation (percentage) between respondents to 72 months and respondents over 72 months duration of hemodialysis, namely: low T3 syndrome, which is a higher percentage was recorded in patients up to 72 months duration of dialysis (19.23%), then subclinical hypothyroidism where a greater percentage recorded in subjects over 72 months duration of dialysis (35.71%) before transplantation. CONCLUSION: Considering that we are found in kidney transplant patients a significant link of subclinical hypothyroidism with decreased level of T3 and higher incidence of low T3 syndrome, which are associated with increased cardiovascular mortality and morbidity, and act as markers of survival patients after transplantation, it is necessary to conduct a periodically measuring levels of T3, T4 and TSH in these patients in order to assess the relationship between thyroid dysfunction and mortality risk in this population.