Menopause, central body fatness, and insulin resistance: effects of hormone-replacement therapy

In addition to being associated with termination of reproductive life in wo men, the menopause coincides with an increase in several comorbidities incl uding cardiovascular disease, This increase in the prevalence of cardiovasc ular disease in the postmenopausal years has been partially attributed to a dverse effects of estrogen deficiency on plasma lipid-lipoprotein levels an d on the cardiovascular system, although other factors are contributing. Ce ntral body fatness and insulin resistance are components of a cluster of me tabolic abnormalities which also increases the risk of cardiovascular disea se. This review summarizes studies that have examined the effects of the me nopause transition and of estrogen-replacement therapy on central body fatn ess and insulin resistance. Review of cross-sectional studies suggests that the menopause transition is associated with an increase in abdominal and v isceral adipose tissue accumulation, as measured either with dual X-ray abs orptiometry or computed tomography. These results appear to be independent of the aging process and total body fatness, In general, cross-sectional st udies using circumference measurements did not find any significant effect of the menopause, Longitudinal studies also support that accumulation of ce ntral body fatness accelerates with menopause. The effects of the menopause on insulin resistance appear to be moderate, if any, although available st udies are clearly insufficient to draw firm conclusions, The majority of in terventional studies support the notion that hormone-replacement therapy at tenuates the accumulation of central fat in postmenopausal women, compared with control or placebo-treated women, Retrospective comparisons of hormone users and nonusers also support a protective effect of hormone replacement on fat distribution, Moderate effects of estrogen therapy were found on in sulin resistance in postmenopausal women, although long-term, controlled tr ials using accurate measurements of insulin sensitivity are lacking, Treatm ent with progestins exerts moderate deleterious effects on insulin sensitiv ity, which may be attributable to the partial androgenicity of progestins u sed. It is concluded that part of the increased incidence of cardiovascular disease in postmenopausal women may be attributable to increased central b ody fatness. Therapies aiming at preventing these changes in fat distributi on such as hormone-replacement therapy, diet or exercise are likely to prov ide long-term cardiovascular and metabolic benefits for women's health. Cor onary Artery Dis 9:503-511 (C) 1998 Lippincott Williams & Wilkins.