Hypothalamic-pituitary-thyroidal axis dysfunction and cortisol secretion in patients with nonclassical congenital adrenal hyperplasia

Objective-The purpose of this study was to evaluate thyroid function and TS H and cortisol (F) secretion in hyperandrogenemic women with nonclassical c ongenital adrenal hyperplasia (NC-CAH) due to 21-hydroxylase deficiency (Gr oup A) when compared with women with hyperandrogenemic symptoms (menstrual irregularities, hirsutism, acne, seborrhea and sterility) of other etiologi es (Group B). Methods-Seventy-two women were subjected to stimulation of th e adrenal cortex with i.v. ACTH administration in the early proliferative p hase of the menstrual cycle. Basal plasma TSH, T-3, T-4, and FTI as well as basal and ACTH-stimulated plasma F and 17-hydroxyprogesterone levels were determined. Results-According to internationally accepted criteria and HLA haplotyping, we diagnosed 28 NC-CAH patients as well as affected heterozygo tes of the disease. No significant difference was found in the plasma T3, T 4, or FTI or F concentrations between the women of the two groups. On the c ontrary, plasma TSH levels were significantly lower in patients with 21-hyd roxylase deficiency when compared to the women with hyperandrogenemic sympt oms of other etiologies. Conclusion-The results of this study support a dys function of the hypothalamic-pituitary-thyroidal axis due to altered ACTH s ecretion patterns.