Differences in Adipose Tissue Metabolism between Postmenopausal and Perimenopausal Women

Abstract

Changes in adipose tissue metabolism may contribute to the changes in body fat distribution seen during the menopause transition. We compared in vitro abdominal and gluteal sc adipose tissue metabolism [basal and stimulated lipolysis and activity of adipose tissue lipoprotein lipase (AT-LPL)] in postmenopausal and perimenopausal women (n = 12/group), matched for race, body mass index (29.5 ± 3.8 kg/m2; mean ± sd), and percentage body fat (42 ± 6%). The postmenopausal women were older (54 ± 3 vs. 48 ± 3 yr; P < 0.01) and had higher FSH (55.5 ± 26.4 vs. 16.6 ± 22.5 IU/ml; P < 0.01) and lower estradiol (33.8 ± 14.9 vs. 97.4 ± 61.7 pmol/liter; P < 0.05) concentrations than the perimenopausal women. Despite similar fat cell size and β-adrenergic receptor and postreceptor (dibutyryl-cAMP)-stimulated lipolysis, basal lipolysis was 77% lower in gluteal adipose cells from postmenopausal compared with perimenopausal women (P < 0.05). Within each group, AT-LPL activity in the gluteal region was significantly higher than in the abdominal region (P < 0.05). In addition, AT-LPL activity was significantly higher in the postmenopausal compared with perimenopausal women in both gluteal (4.9 ± 3.6 vs. 2.0 ± 1.4 nmol free fatty acid/g·min; P < 0.05) and abdominal (3.2 ± 2.6 vs. 1.3 ± 0.9 nmol free fatty acid/g·min; P < 0.05) adipose cells. The results of this study suggest that menopause status is associated with differences in adipose tissue metabolism in both the abdominal and gluteal fat depots. The lower lipolysis and higher AT-LPL activity in postmenopausal women may predispose them to gain body fat after menopause.