The Effect of Low FT3 Level on Kidney Disease Progression and Potassium Levels in Euthyroid Adult Patients with Solitary Kidney

OBJECTIVE: The aim of this study was to investigate the effect of low FT3 levels on CKD progression and hyperkalemia in euthyroid patients with solitary kidney.

MATERIAL and METHODS: Seventy-six solitary kidney outpatients were enrolled in the study. Patients with a preexisting thyroid disease were excluded. The baseline and final laboratory parameters were evaluated. Serum Thyroid hormones (TSH, FT3 and FT4) were measured at baseline.

RESULTS: The mean age of the patients was 50.4 ± 13.8 years and mean follow-up was 43 ± 29 months. Of the patients, 24% had progressive CKD and 19.7% developed hyperkalemia. Patients with a progressive course had lower FT3 levels (2.71 ± 0.34 vs. 3.17±0.47; p <0.001). Similarly hyperkalemic patients had lower FT3 values (2.77 ± 0.34 vs. 3.13 ± 0.49; p = 0.011). FT3 levels were negatively correlated with, age, history of hypertension and serum potassium level and positively correlated with serum albumin and eGFR levels. In multivariate regression analysis, FT3 levels were independently associated with progression of CKD. Low eGFR and RAS-blocker use was independently associated with the development of hyperkalemia.

CONCLUSION: In patients with solitary kidney, low FT3 level is associated with the progression of CKD. In addition, development of hyperkalemia is common in CKD patients with low FT3 levels.