Effect of menopausal status on lipolysis: comparison of plasma glycerol levels in middle-aged, premenopausal and early, postmenopausal women.
To determine whether menopausal status affects systemic lipolysis, we measured plasma glycerol concentrations following an overnight fast and during euglycemic hyperinsulinemic conditions (40 mU x m(-2) x min(-1)) in 43 middle-aged, premenopausal women (mean +/- SE; 47 +/- 0.4 years) and 26 early, postmenopausal (51 +/- 0.8 years) women. In addition, body composition was measured by dual-energy x-ray absorptiometry and abdominal fat distribution by computed tomography (CT). Postmenopausal women had greater amounts of whole body (fat mass, 22.8 +/- 1.4 v 17.4 +/- 1.2 kg; percent fat, 34.7 +/- 1.2 v 29.1 +/- 1.4; both P <.01) and intra-abdominal fat (89.0 +/- 6.5 v 55.9 +/- 4.4 cm2; P <.01) compared with premenopausal women. Despite greater adiposity, plasma glycerol concentrations were similar between pre- and postmenopausal women following an overnight fast (142.7 +/- 9.7 v 136.1 +/- 6.4 micromol/L) and at 30 minutes (112.7 +/- 5.5 v 108.4 +/- 4.5 micromol/L ) and 120 minutes (92.7 +/- 4.5 v 97.5 +/- 5.9 micromol/L ) into the euglycemic hyperinsulinemic clamp. Plasma glycerol levels remained similar after statistical adjustment for fat mass, percent fat, and intra-abdominal fat. Moreover, no differences in plasma glycerol were observed in pre- and postmenopausal women matched (+/- 5%) for fat mass (n = 22/group) or intra-abdominal fat (n = 15/group). In premenopausal women, plasma glycerol levels at 30 and 120 minutes of hyperinsulinemia were positively related to adiposity measures (range, r =.314 to r =.493; P <.05 to P <.01), although no relationships were found in postmenopausal women. Our results suggest no effect of menopausal status on plasma glycerol levels under postabsorptive or hyperinsulinemic conditions.
Toth
Michael J
MJ
Division of Clinical Pharmacology, Department of Medicine, University of Vermont, Burlington, VT 05405, USA.
Sites
Cynthia K
CK
Poehlman
Eric T
ET
Tchernof
Andre
A
D000005:Abdomen; D000273:Adipose Tissue / Q000033:anatomy & histology; D000375:Aging; D001823:Body Composition; D005215:Fasting / Q000097:blood; D005260:Female; D005990:Glycerol / Q000097:blood; D006801:Humans; D006946:Hyperinsulinism / Q000097:blood; D008066:Lipolysis; D008593:Menopause / Q000502:physiology*; D008875:Middle Aged; D017698:Postmenopause / Q000502:physiology; D017697:Premenopause / Q000502:physiology
D005990:Glycerol