POSTPRANDIAL TRIGLYCERIDES AND ADIPOSE TISSUE STORAGE OF DIETARY FATTY ACIDS: IMPACT OF MENOPAUSE AND ESTRADIOL

OBJECTIVE: Postprandial lipemia worsens after menopause, but the mechanism remains unknown. We hypothesized menopause-related postprandial lipemia would be: 1) associated with reduced storage of dietary fatty acids (FA) as triglyceride (TG) in subcutaneous adipose tissue (SAT); and 2) improved by short-term estradiol (E(2)). DESIGN AND METHODS: We studied 23 pre- (mean±SD; 42±4yr) and 22 postmenopausal (55±4yr) women with similar total adiposity. A subset of postmenopausal women (n=12) were studied following 2 weeks of E(2) (0.15mg) and matching placebo in a random, cross-over design. A liquid meal containing (14)C-oleic acid traced appearance of dietary FA in: serum (postprandial TG), breath (oxidation), and abdominal and femoral SAT (TG storage). RESULTS: Compared to premenopausal, healthy lean postmenopausal women had increased postprandial glucose and insulin and trend for higher TG, but similar dietary FA oxidation and storage. Adipocytes were larger in post- compared to premenopausal women, particularly in femoral SAT. Short-term E(2) reduced postprandial TG and insulin, but had no effect on oxidation or storage of dietary FA. E(2) increased the proportion of small adipocytes in femoral (but not abdominal) SAT. CONCLUSIONS: Short-term E(2) attenuated menopause-related increases in postprandial TG and increased femoral adipocyte hyperplasia, but not through increased net storage of dietary FA.