UNDERSTANDING WEIGHT GAIN AT MENOPAUSE

Key issues  For women aged 55–65 years, weight gain is one of their major health concerns  Is weight gain at midlife due to menopause or aging?  What other factors influence weight gain at midlife?  Does being overweight/obese affect the menopause transition?  Does hormone therapy cause weight gain?  What can women do to prevent weight gain/lose weight?

Consequences of obesity in women at midlife  Increased risk of cardiovascular disease including coronary artery disease, hypertension and stroke  Increased risk of dementia  Increased risk of breast, uterine and colon cancer  Increased likelihood of depression  Greater likelihood of sexual dysfunction

Weight gain does not appear to be affected by the hormonal changes of the menopause  BMI does not differ between premenopausal and postmenopausal women, after adjusting for age and other covariants (Matthews et al Int J Obes Relat Metab Disord 2001)  The steady weight gain in women (approx 0.5 kg/year) is due to age rather than the menopause (Sternfeld et al Am J Epidemiol 2004;160:912–22)

In animal models  Ovariectomized mice/estrogen receptor (ER) knockout mice/aromatase gene knockout mice have reduced energy expenditure, adipocyte hypertrophy and fatty liver  Estradiol treatment of ovariectomized/ER knockout/aromatase knockout mice protects against fatty liver and insulin resistance

The perimenopause and body composition (1)  A more rapid increase in fat mass  Redistribution of fat to the abdomen  Transition from a gynoid to an android pattern of fat distribution and an increase in total body fat

The perimenopause and body composition (2)  A high waist circumference, indicating accumulation of excessive central abdominal fat, is an independent predictor of metabolic disease risk in postmenopausal women  These changes occur across all ethnic groups

 Obesity in women is associated with poorer education, urbanization, inactivity, parity, family history of obesity and marriage at earlier age  There is a bi-directional relationship between obesity and depression  Many psychoactive medications are associated with weight gain  Chemotherapy is associated with an increase in total body fat and abdominal and visceral adiposity Other factors influencing weight gain in midlife Other factors influencing weight gain in midlife

Obesity and the menopause transition  Greater adult weight has been associated with an older age of natural menopause (Akahoshi et al J Obes Relat Metab Disord 2002)  Obese women tend to experience more severe vasomotor symptoms  Obese women tend to lose bone at a lower rate across menopause than non-obese women  Higher BMI is a risk factor for urinary incontinence and sexual dysfunction  Reductions in weight, BMI and abdominal circumference have been associated with a reduction in vasomotor symptoms in overweight and obese women

Hormone therapy and weight  Estrogen-only therapy and estrogen–progestin therapy (EPT) do not increase body weight or BMI (Norman RJ et al Cochrane Review 2000)  Improved insulin sensitivity has been observed with oral EPT, and both oral estrogen-alone and EPT may reduce the incidence of type 2 diabetes (Bonds DE et al Diabetologia 2006)

Strategies to prevent/manage weight excess  Physical activity is important to prevent weight gain, achieve weight loss, prevent loss of muscle mass with increasing age and to protect against bone loss  A reduction in total calories eaten each day is needed to achieve weight loss. No single diet has been consistently shown to be better than any other for weight loss. Ideally, any weight loss diet should be a healthy one that can be continued long term  Anti-obesity medications have been associated with a 5–10% loss in weight but this is rarely sustained when the medication is stopped  Bariatric surgery is a clinical and cost-effective intervention for moderate to severely obese people compared to other non-surgical interventions  Yoga, acupuncture and some traditional Chinese herbal medicines have been shown to aid weight loss in some studies (Sui Y et al Obes Rev 2012)