Thyroid Gland and Chronic Kidney Disease in Children

Abstract

Introduction. Chronic kidney disease in children is accompanied by pronounced metabolic, hormonal, and inflammatory disturbances, among which alterations in thyroid status occupy an important place. As renal function declines, peripheral thyroid hormone metabolism becomes impaired, iodine clearance decreases, chronic inflammation intensifies, and the likelihood of developing a biochemical profile consistent with low T3 syndrome increases. Aim. To summarize current evidence on thyroid dysfunction in children with chronic kidney disease and to analyze the main pathogenetic mechanisms, laboratory abnormalities, and clinical significance of thyroid status alterations in this patient population. Materials and methods. This study was conducted as a narrative literature review. Recent publications on chronic kidney disease in children, thyroid profile abnormalities associated with reduced renal function, the pathogenetic mechanisms of low T3 syndrome, and the clinical significance of hormonal disturbances in this patient population were reviewed and analyzed. Results and discussion. Thyroid dysfunction in children with chronic kidney disease does not always reflect primary thyroid pathology, as it often develops secondary to uremic intoxication, impaired deiodinase activity, chronic inflammation with activation of proinflammatory cytokines, protein-energy deficiency, and metabolic disturbances. The most common hormonal abnormality is low T3 syndrome, which should be regarded as one of the markers of systemic metabolic maladaptation in chronic kidney disease. In childhood, these changes are of particular clinical importance because they may be associated with growth retardation, impaired nutritional status, abnormalities of bone metabolism, and reduced adaptive capacity. Conclusion. Thyroid dysfunction in children with chronic kidney disease is a clinically significant manifestation of systemic disorders and requires comprehensive assessment during follow-up, especially in patients with growth retardation, malnutrition, and a marked decline in renal function.