Follicular phase hypothalamic-pituitary-gonadal axis function in women with fibromyalgia and chronic fatigue syndrome

Objective. Fibromyalgia (FM) and chronic fatigue syndrome (CFS) are clinica lly overlapping stress associated disorders. Neuroendocrine perturbations h ave been noted in both syndromes, and they are more common in women, sugges ting abnomalities of gonadal steroid hormones. We tested the hypothesis tha t women with FM and CFS manifest abnormalities of the hypothalamic-pituitar y-gonadal (HPG) hormonal axis. Methods. We examined the secretory characteristics of estradiol, progestero ne, follicle stimulating hormone (FSH), and luteinizing hormone (LH), inclu ding a detailed analysis of LH in premenopausal women with FM (n = 9) or CF S (n = 8) during the follicular phase of the menstrual cycle compared to ma tched healthy controls. Blood was collected from an indwelling intravenous catheter every 10 min over a 12 h period. LH was assayed from every sample; pulses of LH were identified by a pulse-detection program. FSH and progest erone were assayed from a pool of hourly samples for the 12 h period and es tradiol from samples pooled over four 3 h time periods. Results, There were no significant differences in FSH, progesterone, or est radiol levels in patients versus controls. There were no significant differ ences in pulsatile secretion of LH. Conclusion. There is no indication of abnormal gonadotropin secretion or go nadal steroid levels in this small, but systematic, study of HPG axis funct ion in patients with FM and CFS.