Weight gain in women at midlife: Unique issues in management and the role of menopausal hormone therapy

Weight gain is a common concern among aging women. Nearly two-thirds of women ages 40 to 59 years and about three-fourths of women older than 60 years are overweight (body mass index greater than 25 kg/m2) in the United States.

Ekta Kapoor, M.B.B.S., a consultant with the Women's Health Clinic; General Internal Medicine; and Endocrinology, Diabetes, Metabolism, and Nutrition at Mayo Clinic's campus in Rochester, Minnesota, says: "Midlife women may gain up to 0.7 kg per year and demonstrate a change in body fat distribution, from the premenopausal gynoid pattern (greater lower-body fat) to the postmenopausal android pattern (greater upper-body fat).

"Weight gain and body fat distribution changes are responsible, at least in part, for the greater risk of cardiovascular disease in postmenopausal women, in comparison with younger women with intact ovarian function. Cardiovascular disease is the leading cause of mortality in postmenopausal women, and the importance of risk factor modification cannot be overemphasized."

However, when women ask specifically about the impact of hormone therapy on weight gain during menopause, the answer is much more complicated because of the complex interactions of their symptoms with age-related changes.

There has been a debate about the relative contribution of aging versus menopause to weight gain in midlife women. Stephanie S. Faubion, M.D., of the Women's Health Clinic and General Internal Medicine at Mayo Clinic in Rochester, Minnesota, comments: "The current literature supports the aging theory, and that menopause, per se, after adjustment for aging, does not result in significant weight gain. However, menopause does result in body fat distribution changes, with a preferential deposition of body fat centrally, and an increase in abdominal obesity. This tendency persists despite adjustment for aging, total body fat and reduced physical activity level, all of which independently increase visceral fat deposition."

Aging-related weight gain is universal, occurs in both sexes, and is mainly ascribed to the decrease in lean body mass and physical activity level (which may be subtle). These changes result in a fall in both the resting- and activity-related energy expenditure. Therefore, unless there are compensatory changes in dietary habits and physical activity, aging results in weight gain.

Alice Y. Chang, M.D., a consultant with Endocrinology, Diabetes, Metabolism, and Nutrition at Mayo Clinic in Rochester, Minnesota, notes: "Midlife women during the menopausal transition might experience unique symptoms that facilitate weight gain, including vasomotor symptoms, mood disorders, sleep disturbances and musculoskeletal complaints.

"Perimenopausal women often underestimate the impact of vasomotor symptoms on so many aspects of their lives. For example, women with severe vasomotor symptoms, especially at night, might not realize how severe fatigue compromises their ability to remain active. Women are more prone to mood disorders in the perimenopausal period, and that can also interfere with their motivation to make lifestyle changes often required to prevent weight gain.

"On the other hand, women who are overweight or obese tend to have worse hot flashes than their normal-weight counterparts, and weight loss improves vasomotor symptoms. Resistance exercise training, which can prevent the muscle loss and decrease in energy expenditure related to aging in general, not only is shown to be as effective in perimenopausal women but can also help preserve bone mass during a period of accelerated bone loss and improve musculoskeletal symptoms."

Dr. Faubion adds: "Menopausal hormone therapy (MHT) is the most effective treatment for menopausal vasomotor symptoms. It should be strongly considered in recently postmenopausal (less than 10 years since last menstrual period) women with moderate to severe vasomotor symptoms in the absence of any contraindication to systemic estrogen use.

"In the young, recently postmenopausal women without pre-existent cardiovascular disease, low-dose transdermal estradiol does not increase the risk of cardiovascular disease, and may even be protective. Similarly, the risk of breast cancer does not seem to be increased with estrogen monotherapy, but may be higher in regimens using estrogen with synthetic progestogens. However, the current MHT regimens most commonly use micronized progesterone, which does not seem to be associated with the same risk of breast cancer. In addition to alleviation of vasomotor symptoms, MHT also improves sleep and mood for most women, although it is not recommended as primary therapy for sleep or mood disturbances."

While MHT does not cause any changes in weight by itself, it does result in favorable distribution of body fat. Dr. Kapoor explains: "Women on MHT tend to have redistribution of the central fat to the peripheral sites. However, MHT use is not recommended for prevention or management of weight gain. Women who are on MHT for management of vasomotor symptoms can, nonetheless, be counseled regarding its beneficial effects on body fat distribution.

"In addition to standard recommendations regarding a hypocaloric diet (500-750 kcal deficit per day), increased intake of whole grains, fruits and vegetables, use of meal replacements, and regular exercise (150-175 minutes per week), patients should be offered psychological support geared toward identification of barriers to change, monitoring behaviors, problem-solving, strategizing and reinforcement. This support can be provided by a psychologist in individual or group settings depending upon the patient's needs and preferences."

Dr. Kapoor continues: "Weight-loss medications should be discussed in appropriate situations (BMI > 30 kg/m2 or > 27 kg/m2 with complications). However, it is important to recognize potential challenges with medication use, including cost, side effects, modest efficacy (5-10 percent weight loss) and potential for weight regain despite continued use.

"Finally, bariatric surgery (for BMI greater than 40 kg/m2 or greater than 35 kg/m2 with complications) and endoscopic bariatric therapy (for BMI between 30 and 40 kg/m2) should be considered when appropriate. Endoscopic bariatric therapies comprise the fastest growing treatment for obesity, and offer promise to bridge medical and surgical therapy. However, the procedures continue to evolve and are not routinely covered by insurance. There also is the potential for weight regain after procedures such as intragastric balloon placement."

So when women ask about the impact of MHT on their weight maintenance and weight-loss goals, MHT cannot be recommended as a therapy to assist in weight loss. However, an individualized assessment should determine whether MHT could have a significant impact on symptoms during the menopausal transition and contribute to overall health.

Dr. Kapoor concludes: "Weight management in midlife women requires a thorough understanding of the menopausal changes, symptoms or both in order to recognize and address potential barriers to implementation of a behavioral program for weight loss. An ideal program follows a multidisciplinary approach, which involves several experts, including medical providers, behavioral psychologists, dietitians, exercise specialists and lifestyle coaches. In addition to recommending lifestyle changes, these providers should carefully screen patients for the presence of menopausal symptoms, including hot flashes, sleeping difficulties and mood problems, and appropriately treat for the conditions. This screening helps improve compliance with behavioral interventions for weight loss."