Plasma cholesterol esterification and transfer, the menopause, and hormonereplacement therapy in women

With the onset of the menopause, plasma lipids and lipoprotein metabolism c hanges toward a more atherogenic profile that is improved by HRT. To determ ine whether cholesterol esterification rate (CER) and transfer of cholester yl esters from high density lipoproteins to apolipoprotein B-containing lip oproteins are affected by menopause and HRT, plasma newly synthesized chole steryl ester transfer (NCET) activity, CER and plasma lipids, lipoproteins, and apolipoprotein concentrations were measured in perimenopausal women (a ge range: 40-55 yr), including 49 premenopausal women and 32 postmenopausal women who were subsequently randomized to receive either placebo or 17-bet a estradiol/norethisterone for 6 months. Plasma NCET (P = 0.03) and CER (P = 0.008) were significantly higher in postmenopausal women. Plasma low dens ity lipoprotein cholesterol concentration, high density lipoprotein concent ration, and body mass index were independent predictors of plasma NCET in p remenopausal women, and plasma triglyceride and apolipoprotein B concentrat ions were corresponding predictors in postmenopausal women. When data were adjusted for plasma triglyceride, plasma NCET activity was no longer signif icantly different (P = 0.81) between premenopausal and postmenopausal women . Plasma NCET and CER did not change significantly in postmenopausal women during HRT. These data suggest that the determinants of plasma NCET activit y after menopause and increased levels of triglyceride-rich lipoprotein acc epters of cholesteryl esters may lead to increased plasma NCET that is not reduced by HRT in postmenopausal women.