ABSTRACT

Thyroid dysfunction is known to cause significant changes in glomerular filtration rate. The present cross sectional study was performed to evaluate the changes in biochemical markers of renal function in hypothyroid subjects before and after treatment. Thyroid function tests (T3, T4 and TSH levels) were assayed in 385 subjects. Based on TSH levels, subjects were classified as euthyroid (n=198), sub clinical hypothyroid (n=98; TSH 6.1 to 19.9 µIU/ml) and overt hypothyroid (n=89; TSH ≥20 μIU/ml, abnormally low T4 levels). Forty-eight hypothyroid patients were re-evaluated after 3 months of thyroxine replacement therapy. Renal function tests were carried out in all subjects and statistically analyzed. Serum creatinine was significantly increased in sub-clinical and overt hypothyroid groups as compared to euthyroid subjects. Serum creatinine showed a significant negative correlation with T3 and T4 levels in overt group(r = -0.372, and r = - 0.371), whereas a positive correlation was observed with TSH (r=0.283). Uric acid levels were significantly increased in overt group as compared to euthyroid subjects. Uric acid levels showed a significant negative correlation with T3 levels in overt group (r= -0.298). After 3 months of thyroxine replacement therapy, creatinine and uric acids levels decreased significantly and were comparable to euthyroid levels. Hypothyroidism leads to reversible changes in renal function.

KEY WORDS: Renal functions; Thyroid functions; Biochemical markers