Fat mass changes during menopause: a meta-analysis


Background: Fat mass has been shown to increase in ageing women, however, the extent to which menopausal status mediates these changes remains unclear.
Objectives: To determine (i) how fat mass differs in quantity and distribution between premenopausal and postmenopausal women, (ii) whether and how age and/or menopausal status moderates any observed differences and (iii) which type of fat mass measure is best suited to detecting differences in fat mass between groups.
Study Design: This review with meta-analysis is reported according to MOOSE guidelines.
Data sources and populations: Studies (published up to May 2018) were identified via PubMed to provide fat mass measures in premenopausal and postmenopausal women. 201 cross-sectional studies were included in the meta-analysis, which provided a combined sample size of 1 049 919 individuals consisting of 478 734 premenopausal women and 571 185 postmenopausal women. 11 longitudinal studies were included in the meta-analyses, which provided a combined sample size of 2 472 women who were premenopausal at baseline and postmenopausal at follow up.
Results: The main findings of this review were that fat mass significantly increased between premenopausal and postmenopausal women across most measures, including body mass index (1.14 kg/m2, 95 % confidence interval 0.95 to 1.32), body weight (1 kg, 0.44 to 1.57), body fat percentage (2.88 %, 2.13 to 3.63), waist circumference (4.63 cm, 3.90 to 5.35), hip circumference (2.01 cm, 1.36 to 2.65), waist to hip ratio (0.04, 0.03 to 0.05), visceral fat (26.90 cm2, 13.12 to 40.68) and trunk fat percentage (5.49 %, 3.91 to 7.06), with the exception of total leg fat percentage, which significantly decreased (-3.19 %, -5.98 to -0.41). No interactive effects were observed between menopausal status and age across all fat mass measures.
Conclusions: The change in fat mass quantity between premenopausal and postmenopausal women was predominantly attributable to increasing age with menopause having no significant additional influence. However, the decrease in total leg fat percentage and increase in measures of central fat are indicative of a possible change in fat mass distribution after menopause. These changes are likely to, at least in part, be due to hormonal shifts that occur during midlife with women having a higher androgen (i.e. testosterone) to estradiol ratio after menopause, which has been linked to enhanced central adiposity deposition. Evidently, these findings suggest attention should be paid to the accumulation of central fat after menopause, whereas increases in total fat mass should be monitored consistently across the lifespan.

Ambikairajah, A., Walsh, E., Tabatabaei-Jafari, H., & Cherbuin, N. (2019). Fat mass changes during menopause: a meta-analysis. American Journal of Obstetrics & Gynecology, 221(5), 393-409.e50. doi:10.1016/j.ajog.2019.04.023