Hypothalamic amenorrhea with normal body weight: ACTH, allopregnanolone and cortisol responses to corticotropin-releasing hormone test.
OBJECTIVE
Hypothalamic amenorrhea (HA) is a functional disorder caused by disturbances in gonadotropin-releasing hormone (GnRH) pulsatility. The mechanism by which stress alters GnRH release is not well known. Recently, the role of corticotropin-releasing hormone (CRH) and neurosteroids in the pathophysiology of HA has been considered. The aim of the present study was to explore further the role of the hypothalamic-pituitary-adrenal axis in HA.


METHODS
We included 8 patients (aged 23.16+/-1.72 years) suffering from hypothalamic stress-related amenorrhea with normal body weight and 8 age-matched healthy controls in the follicular phase of the menstrual cycle.


METHODS
We measured basal serum levels of FSH, LH, and estradiol and evaluated ACTH, allopregnanolone and cortisol responses to CRH test in both HA patients and healthy women.


RESULTS
Serum basal levels of FSH, LH, and estradiol as well as basal levels of allopregnanolone were significantly lower in HA patients than in controls (P<0.001) while basal ACTH and cortisol levels were significantly higher in amenorrheic patients with respect to controls (P<0.001). The response (area under the curve) of ACTH, allopregnanolone and cortisol to CRH was significantly lower in amenorrheic women compared with controls (P<0.001, P<0.05, P<0.05 respectively).


CONCLUSIONS
In conclusion, women with HA, despite the high ACTH and cortisol levels and, therefore, hypothalamus-pituitary-adrenal axis hyperactivity, are characterized by low allopregnanolone basal levels, deriving from an impairment of both adrenal and ovarian synthesis. The blunted ACTH, allopregnanolone and cortisol responses to CRH indicate that, in hypothalamic amenorrhea, there is a reduced sensitivity and expression of CRH receptor. These results open new perspectives on the role of neurosteroids in the pathogenesis of hypothalamic amenorrhea.
Meczekalski
B
B
Department of Reproductive Medicine and Child Development, Section of Gynecology and Obstetrics, University of Pisa, Pisa, Italy.
Tonetti
A
A
Monteleone
P
P
Bernardi
F
F
Luisi
S
S
Stomati
M
M
Luisi
M
M
Petraglia
F
F
Genazzani
A R
AR
D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D000568:Amenorrhea / Q000097:blood / Q000209:etiology* / Q000378:metabolism*; D001835:Body Weight; D016022:Case-Control Studies; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D005498:Follicular Phase / Q000097:blood; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000097:blood; D010913:Pituitary-Adrenal System / Q000378:metabolism; D011280:Pregnanolone / Q000097:blood*; D013997:Time Factors
D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D000324:Adrenocorticotropic Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D011280:Pregnanolone; D006854:Hydrocortisone