Association between thyroid hormones and renal function in patients with chronic kidney disease: A hospital-based cross-sectional study among Nigerians

Background: A seemingly exciting link has been reported to exist between thyroid state and renal function, thus establishing a thyroid–renal axis. However, findings from studies aimed at evaluating this axis have not been consistent. Therefore, we hypothesized that estimated glomerular filtration rate (eGFR), a surrogate of incident chronic kidney disease (CKD), could be independently predicted by thyroid-stimulating hormone (TSH), free thyroxin (fT4), and free triiodothyronine (fT3). Materials and Methods: We compared the serum concentrations of TSH, fT4, and fT3 in patients with CKD after classifying them into stage III, stage IV, or end-stage renal disease based on the National Kidney Foundation Classification Criteria. Results: Our results showed that the concentrations of TSH, fT4, and fT3 were comparable across the different stages of CKD. Findings from the study also indicated that thyroid hormones were not associated with CKD, nor were they predictors of CKD development. Conclusion: The present study demonstrates that TSH, fT4, and fT3 are not effective risk factors that are independently associated with declined eGFR in patients with CKD. Our findings also revealed that these hormones are not useful tools in the early detection of CKD.