Serum Free T4/Free T3 Ratio as a Predictor of Subclinical Hypothyroidism in Non- Hemodialysis Dependent Chronic Kidney Disease Patients

Abstract

Background: Chronic kidney disease (CKD) is an increasingly prevalent condition, recognized as a public health priority, affecting 10–12% of the population. Subclinical Hypothyroidism is a clinical condition with minimal symptoms or no symptoms of hypothyroidism. Early detection and management decrease the cardiovascular and metabolic complications in CKD patients. Objective:
The study was conducted to evaluate serum FT4 / FT3 Ratio, as a Predictor of Subclinical Hypothyroidism in Patients with CKD. Patients and methods: The study was conducted at Tanta University hospitals, Internal Medicine outpatient clinics, inpatient wards of Nephrology and Endocrinology Units and clinical pathology department. From September 2021 to September 2022.100 subjects were included; 50 normal healthy volunteers as controls and 50 patients suffering from CKD of varying etiology have been considered for the study after fulfilling the inclusion criteria. Data were collected including demographic, clinical, and laboratory data. Statistical analysis was carried out for all collected data using IBM, SPSS version 21. Statistical significance was determined at a P level ≤ 0.05. Results: TSH, and free T4 / free T3 ratio were significantly higher in CKD group compared to control group (P value <0.001). Free T3 was significantly lower in CKD group compared to control group (P value <0.001). Free T4 was insignificantly different between both groups. Free T4 / Free T3 ratio can significantly predict incidence of subclinical hypothyroidism with AUC=0.879 and P value <0.001. Free T3 can significantly predict incidence of subclinical hypothyroidism with AUC= 0.071 and P value<0.001.TSH can significantly predict incidence of subclinical hypothyroidism with AUC= 0.643 and P value=0.014. Free T4 was an insignificant predictor of incidence of subclinical
hypothyroidism. Conclusion: free T4 / free T3 ratio can significantly predict incidence of subclinical hypothyroidism with AUC= 0.879 and P value <0.001. Free T3 can significantly predict incidence of subclinical hypothyroidism with AUC= 0.071 and P value<0.001. Free T4 was an insignificant predictor of incidence of subclinical hypothyroidism.