Diagnostic value of the LH-releasing hormone stimulation test in functional amenorrhea.

LH-releasing hormone (25 mug, iv.) was administered to 37 women with functional amenorrhea. In addition to the clinical classification, these patients were divided into three groups according to the basal level of serum LH. A significant correlation was found between the base-line levels of LH and the serum concentration of oestradiol plus oestrone. The absolute increment of LH after the injection of LH-RH was found to be dependent only on the base-line level of LH. Except for the patients with anorexia nervoxa, the base-line levels and the response pattern of FSH were almost the same for all three groups. From the results of this study, it was concluded that: 1. The circulating levels of oestradiol and oestrone, where derived from ovarian secretion, actually depend on the gonadotrophic stimulus. In patients with functional amenorrhea, the oestrogens do not make an independent contribution to the pituitary response to LH-RH. 2. Dysregulation of releasing hormones, whether located at the hypothalamic or suprahypothalamic level, necessarily influences the secretory capacity of the pituitary gland; long-standing deficiency of LH-RH, may finally lead to a state of pituitary "functional" unresponsiveness to releasing hormones. 3. In view of the excellent correlation between base-line levels of LH and the absolute increment of LH following stimulation with LH-RH, this test only accentuates the existing pituitary secretroy capacity, which can be roughly estimated from circulating levels of LH and FSH. 4. This test may be useful in distinguishing the milder cases of psychogenic amenorrhea from extreme gonadotrophic dysfunction in patients with anorexia nervosa.