Effects of Ketoacidosis and Puberty on Basal and TRH-Stimulated Thyroid Hormones and TSH in Children with Diabetes Mellitus

Summary

Basal and TRH-stimulated thyroid hormones and TSH were evaluated in two groups of prepubertal and pubertal diabetics: group B-45 children without ketoacidosis; group C - 16 children with ketoacidosis. The diabetic patients showed no signs of diabetic microangiopathy. Fifty-three healthy subjects served as controls (group A). T₄, T₃, FT₄ and FT₃ serum levels were reduced in diabetics, particularly in ketotic ones; T₄ and T₃ values were lower in pubertal than in prepubertal non-ketotic diabetics and in pubertal than in prepubertal controls, while no significant difference was observed between pubertal and prepubertal ketotic patients. Moreover, no difference in rT₃ serum concentrations was found between group A, B and C, but non-ketotic and ketotic pubertals showed a significant rT₃ reduction if compared with non-ketotic and ketotic prepubertals and with healthy pubertals. TBG was lower in group B and group C diabetics than in controls. After TRH stimulus, T₃ levels showed a significant increase both in controls and in non-ketotic diabetics, while no variation was observed in ketotic children; furthermore, at 120 minutes T₃ values were lower in diabetic than in healthy children, particularly in ketotic ones. Basal TSH serum concentrations were reduced in ketotic diabetics, while no difference was found between nonketotic and control subjects. After TRH stimulus, TSH peak was higher in pubertal non-ketotic diabetics than in pubertal controls, while no difference was found between prepubertal and pubertal diabetics, both in non-ketotic and in ketotic status.

The data clearly show that metabolic control affects thyroid function and hypothalamic-pituitary-thyroid axis in insulin-dependent diabetic children and adolescents; during diabetic ketoacidosis the derangement of thyroid hormones is impressive. Puberty modifies peripheral thyroid metabolism both in diabetics and in normal children.

Key-Words

Thyroid Hormones - Insulin-Dependent Diabetes Mellitus - Puberty - Ketoacidosis