Women who have lived through economic hardship as a child or adult are likely to start perimenopause (the period leading up to menopause) earlier than affluent women, suggests research in the November issue of the Journal of Epidemiology and Community Health.
Researchers from Harvard School of Public Health (SPH) and Brown University School of Medicine analyzed self-reported data on menstrual cycle patterns and financial histories for more than 600 premenopausal U.S. women between ages 36 and 45. At the start of the study, women who were current users of oral contraceptives or who had menstrual cycle irregularity were excluded. Over the next three years, women were monitored every six months for the occurrence of self-reported perimenopausal symptoms.
The World Health Organization defines perimenopause as the phase during which hormonal, biological, and clinical changes begin. Early signs include cycle length variability, changes in blood flow, and midcycle spotting; later signs include missed periods or extended time between periods. Studies have shown that up to 90 percent of women may experience perimenopausal changes, beginning as early as age 36.
Women who said they had lived through periods of financial hardship both as children and as adults were 80 percent more likely to experience perimenopausal symptoms over the follow-up period after controlling for age, age at menarche, childbearing, years of oral contraceptive use, and family history of early menopause. Although weaker, the association was still evident after accounting for smoking, body weight, and depression. Similar associations were observed for most, but not all, measures of educational level and occupation. Current measures of household income were not associated with risk of perimenopause.
Pathways by which economic hardship could lead to early onset of perimenopause are by reducing the fetal egg store (and thus the number of eggs an infant girl has at birth) or by accelerating the rate at which eggs are depleted over the life course, given that perimenopause is in part triggered by egg depletion. Other research has shown that stressful life events and exposure to toxins such as tobacco and lead are associated with earlier menopause, with the effects likely to be cumulative.
Lauren Wise, a doctoral student in the Department of Epidemiology at SPH and lead author of the study, said: “Our findings suggest that lifetime socioeconomic position may influence ovarian function more strongly than either childhood or adult socioeconomic position alone. Although some studies have investigated the role of socioeconomic position in relation to early menopause, most have measured it at a single point in time. Additional research is needed to investigate whether our findings can be replicated in other populations, including those with greater racial/ethnic and socioeconomic heterogeneity.”