HORMONAL FLUCTUATIONS AND MYALGIC ENCEPHALOMYELITIS/CHRONIC FATIGUE SYNDROME IN WOMEN: THE ROLE OF MENSTRUAL CYCLE AND MENOPAUSE

Abstract

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disabling multisystem disease, predominantly affecting women as compared to men and showing extreme symptom variability across reproductive life stages. The aim of this research was to determine the effects of hormonal changes, menopause status, and symptom severity in individuals with ME/CFS. This was a prospective observational cohort study conducted at JPMC, Karachi from January 2024 to June 2025. Final recruitment was of 150 women with ME/CFS (90 were in the premenopausal, 30 in the perimenopausal and 30 in the postmenopausal strata). Baseline demographic and clinical profiling, laboratory hormonal assays (estradiol, progesterone, LH, FSH), symptom daily profiles and monthly activity data, and objective autonomic probe reflex testing (tilt-table studies) were obtained. The findings revealed a clear hormonal gradient across the groups (ANOVA p < 0.001), with estradiol and progesterone levels becoming lower and gonadotropins higher with older reproductive age. Symptom trajectories varied according to for premenopausal women: fatigue and pain peaked pre menstrually (CFQ p = 0.01, VAS p = 0.02) and cognitive impairment was lowest at ovulation (p = 0.04). When comparing across menopause groups, symptom burden was greater in the perimenopausal and postmenopausal participants and the perimenopausal and postmenopausal participants had lower SF-36 quality-of-life component scores (physical functioning 0.01, mental health 0.04). Tilt-table findings from the cohort suggest age-related differences in autonomic dysfunction with postmenopausal women more likely to exhibit orthostatic hypotension (36.7%) and premenopausal women more likely to express POTS (38.9%). The correlation analysis revealed that low levels of estradiol and progesterone were significantly correlated with higher levels of fatigue and pain, whereas the opposite association was found for LH and FSH, the latter two being positively correlated with fatigue and orthostatic symptoms. These findings provide the first quantifiable evidence for reproductive hormonal dynamics substantially modulating the clinical expression of ME/CFS in women and the need for hormone-sensitive management approaches.