Thyroid Hormone Influencing The Renal Function Of Chronic Kidney Disease Patients With Subclinical Hypothyroidism

Background Subclinical hypothyroidism is a common complication inchronic kidney disease, but the use of thyroid hormone to treat subclinicalhypothyroidism is an issue of debate.Objective This study was undertaken to investigate the impact ofthyroid hormone therapy on the changes in estimated glomerular filtrationrate (eGFR) in subclinical hypothyroidism patients with stage2-4chronickidney disease.Methods A total of197patients were included in the final analysis.The patients were divided into TH treatment group (n=120) and non-THtreatment group (n=77). The treated patients were initially administeredL-thyroxine with25μg/d, serum TSH concentration was remeasuredevery month. When TSH concentration was reduced to the normalreference range, serum TSH concentration was remeasured every threemonths. The changes in eGFR over time were compared betweenpatients with and without thyroid hormone replacement therapy using alinear mixed model. Kaplan-Meier curves were constructed to determinethe effect of thyroid hormone on renal outcome, a reduction of eGFR by50%, or end-stage renal disease. The independent prognostic value ofsubclinical hypothyroidism treatment for renal outcome was ascertained by multivariate Cox regression analysis.Results Among the197patients,120(60.9％)took thyroid hormone,whereas77(39.1%)did not. During the mean follow-up duration of34.8±24.3months, the overall rate of decline in eGFR was significantlygreater in the non-TH treatment group compared to the TH treatmentgroup (-5.93±1.65vs.-2.11±1.12ml/min/yr/1.73m2; P=0.040).Moreover,a linear mixed model revealed that there was a significant difference inthe rates of eGFR decline over time between the two groups (P<0.01).Kaplan-Meier analysis also showed that event-cumulative survival wassignificantly lower in non-TH treatment group (P=0.002). In multivariateCox regression analysis, thyroid hormone replacement therapy wasfound to be an independent predictor of chronic kidney disease outcome(hazard ratio,0.28;95%CI,0.12–0.68; P=0.013).Conclusion Thyroid hormone therapy not only preserved renalfunction better, but was also an independent predictor of renal outcome inchronic kidney disease patients with subclinical hypothyroidism.