Thyroid status and kidney transplantation outcomes

Introduction: It is known that end-stage renal disease patients can display abnormal thyroid gland function, which may cause autoimmune hypothyroidism or subclinical alterations. The impact of thyroid function on graft outcomes is not completely clear among renal transplant patients. The aim of this study was to evaluate thyroid function among a cohort of 136 consecutive renal recipients in correlation with clinical parameters of graft function. Materials and methods: We performed a cross-sectional study on 136 subjects including 84 males and 52 females of overall mean age of 49.71 ± 10.98 years who underwent renal transplantations between 2005 and 2009 and had a mean follow-up of 28.3 ± 15.7 months. All patients were treated with a calcineurin inhibitor, steroids, and mycophenolate mofetil. The exclusion criteria were age below 18 years, multiorgan transplantation, graft failure in the first 6 months, or presence of a thyroid neoplasm. We evaluated levels of serum FT3, FT4, and thyroid-stimulating hormone (TSH) in relation to the following parameters: body mass index (BMI), serum creatinine, estimated glomerular filtration rate estimated glomerular filtration rate (eGFR) by Modification of Diet in Renal Disease (MDRD) formula, proteinuria/24 hours, serum sodium, potassium, calcium, phosphorus, cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, and hemoglobin (Hb). Results: Only 6.4% of our transplant recipients were treated with levothyroxine sodium. The patients showed an average FT3 of 3.24 ± 0.5 mg/dL; average FT4 of 0.84 ± 0.1 mg/dL, and mean TSH of 1.29 ± 0.8 mg/dL. The study showed no relationship between thyroid hormones and age of the transplant, while there was a significant difference in FT3 levels between men and women. We also observed a significant correlation between FT3 and serum creatinine, eGFR, serum sodium, BMI, and Hb; whereas there was no correlation with other variables. The correlations between FT4 and TSH and all examined variables were not significant. Conclusions: The interactions between the thyroid and the kidney have been incompletely studied among patients with renal transplants. Our data showed that the presence of low serum FT3 levels correlated with worse graft function, anemia, BMI, and serum sodium. Thus low FT3 levels could be predictive of graft function, especially in the 5 years posttransplantation. © 2011 by Elsevier Inc. All rights reserved.