Women's Midlife Health: Why the Midlife Matters.

With the launch of Women’s Midlife Health, we seek to stimulate increased scientific and clinical focus on the midlife and its relevance to health and healthy aging. Over the past two decades, several cohort studies have advanced scientific understanding of the natural history of ovarian aging and begun to elucidate the interrelationship between ovarian aging and, for example, bone, cardiovascular, cognitive, and musculoskeletal health. Notably, these studies have also shed light on age-related changes that occur in midlife independent of ovarian aging. Critical insights include observations that bone loss, osteoarthritis, adverse changes in lipid profiles, diabetes, metabolic syndrome, and sleep disturbances frequently begin and/or accelerate during the midlife period – in some cases accelerated by the endocrine changes associated with the menopause and in others simply coincident with them. It is apparent that healthy behaviors in midlife, such as maintenance of physical activity and healthy body weight may moderate these changes. Furthermore, it is increasingly recognized that healthy lifestyles and control of vascular risk factors in midlife may be beneficial for cognitive health in later years. Thus, the evidence strongly suggests that the midlife represents a critical window for preventing chronic disease and optimizing health and functioning. In addition to symptoms that are the hall mark of menopause, i.e. vasomotor symptoms or “hotflashes”, several health conditions peak or are exacerbated during the midlife, including fibroids and consequent hysterectomies, migraine and systemic lupus erythematosus. Thus the midlife also warrants attention as a vulnerable window for an important subset of gynecologic and hormone-sensitive conditions. We define the midlife as beginning at about age 35–40 years and extending to about age 60–65 years. This age range encompasses the late reproductive to late postmenopausal stages of reproductive aging [1–4]. Thus, for women, it includes the menopausal transition and post-menopause up through the age where, presumably, ovarian senescence is no longer actively influencing the aging process. Studies of aging have typically focused on and enrolled participants aged 60 or 65 and older, an age when the window of opportunity for primary prevention may well have been missed. While prevention and healthy lifestyles are important at all ages, it is increasingly apparent that health in midlife is an important determinant of a healthy and fully functional life in the following decades. For example, the mid-life appears to be a vulnerable window for onset of functional limitations and the transition to disability. Up to one quarter of recently menopausal women report having substantial functional limitations. Mobility-based disabilities are highly prevalent, with one midlife cohort reporting that 39 % of women reported moderate to extreme difficulty in mobility as measured by the World Health Organization Disability Assessment Schedule [5]. Declines in functioning during this life-stage may be related to the acceleration of other adverse changes in the midlife including the onset of metabolic syndrome and diabetes, adverse changes in lipid profiles, hearing and vision, and body composition changes but may also be a direct result of the onset of osteoarthritis. In one of few prospective studies that included midlife women, two-thirds had evidence of osteoarthritis, the leading cause of pain and adult disability in the United States, in the early postmenopause (mean age 57 years) [6]. Risk of osteoporosis and, concomitantly, fracture increases with aging and it has long been understood that bone loss is associated with menopause. The midlife cohort studies have now documented that bone loss begins prior to the final menstrual period with an accelerated period of loss in bone mineral density and bone strength beginning 1–2 years before menopause until 2–5 years * Correspondence: harlow@umich.edu Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA Full list of author information is available at the end of the article