Background: Approximately 80% of reproductive age women experience physical or emotional symptoms before onset of menses. Of these women, ∼20% experience symptoms severe enough to interfere with social functioning and life activities, and meet clinical criteria for premenstrual syndrome (PMS). More than 100 different symptoms are associated with PMS. Symptom groupings tend to be stable within an individual, but vary distinctly between women. Potential differences in the etiology of symptoms suggest that PMS may have subtypes that represent distinct entities.
Methods: The goal of this study was to identify symptom patterns using factor analysis. We then used linear regression to evaluate relations between PMS risk factors with factor scores for the symptom patterns. Analysis included: (1) 414 healthy women aged 18-30 years; (2) the subgroup of these women meeting established criteria for PMS (n = 80). All participants provided information on the occurrence and severity of 26 premenstrual symptoms by validated questionnaire.
Results: Four distinct symptom patterns emerged, labeled Emotional, Psychological/Cognitive, Physical, and Consumption. We observed a linear relationship between body mass index and the Consumption pattern in both the total study population (p = 0.03) and the PMS subset (p = 0.04). Additionally, in the total population, physical activity was inversely associated with the Physical pattern (p = 0.04), but positively associated with the Consumption pattern (p = 0.03). Results from this study are consistent with previously identified patterns and suggest that distinct subtypes of PMS exist.
Conclusions: Future studies of behavioral factors should evaluate associations with symptom patterns in addition to PMS as an aggregate disorder.
Keywords: epidemiology; exercise; menstrual cycle; obesity.