Abnormal cortisol secretion and responses to corticotropin-releasing hormone in women with hypothalamic amenorrhea.

Hypothalamic amenorrhea (HA) is a common disorder associated with hypoestrogenemia and has adverse effects. The mechanism of GnRH deficiency in these women is not yet known. To investigate the role of the hypothalamic-pituitary-adrenal axis in HA, we studied 10 women [mean age, 29 +/- 7 (+/- SD) yr] with 0.5-13 yr of amenorrhea (mean, 4.3 +/- 3.7 yr) related to simple weight loss or psychological stress. We investigated cortisol and ACTH responses to a bolus of ovine CRH, 24-h plasma cortisol levels obtained every 10 min, and urinary free cortisol levels in these patients. Results were compared with those obtained in normal women during all phases of the menstrual cycle. We found that mean basal concentrations of cortisol were significantly higher (P = 0.03) in the HA patients (mean, 210 +/- 130 nmol/L) than in the normal women (100 +/- 30 nmol/L). The delta (peak - basal) cortisol was significantly lower (P = 0.004) in the HA patients than in the normal women (320 +/- 100 vs. 440 +/- 90 nmol/L, respectively). ACTH responses to CRH did not differ between HA patients and normal women. The 24-h mean cortisol was significantly higher (P = 0.006) in the HA patients than in the normal controls (280 +/- 50 and 220 +/- 50 nmol/L, respectively), due to higher cortisol levels at night. The urinary free cortisol level was significantly higher (P = 0.005) in the HA patients (230 +/- 70 nmol/day) than in normal women (150 +/- 40 nmol/day). We conclude that women with HA have a blunted cortisol response to CRH administration. In addition, they have hypercortisolism, as demonstrated by elevated 24-h mean serum cortisol levels and urinary free cortisol values. This hypothalamic-pituitary-adrenal axis activation in patients with stress or weight loss may be a mechanism in the development of amenorrhea and may relate to other potential adverse effects of HA.