Systemic delivery of estradiol, but not testosterone or progesterone, alters very low density lipoprotein-triglyceride kinetics in postmenopausal women.
BACKGROUND
Sexual dimorphism in plasma triglyceride (TG) metabolism is well established but it is unclear to what extent it is driven by differences in the sex hormone milieu. RESULTS from previous studies evaluating the effects of sex steroids on plasma TG homeostasis are inconclusive because they relied on orally administered synthetic hormone preparations or evaluated only plasma lipid concentrations but not kinetics.


OBJECTIVE
The purpose of this study was to evaluate the effects of systemically delivered 17β-estradiol, progesterone, and T on very low density lipoprotein-triglyceride (VLDL-TG) concentration and kinetics in postmenopausal women.


METHODS
VLDL-TG concentration and kinetics were evaluated by using stable isotope-labeled tracer techniques in four groups of postmenopausal women (n = 27 total) who were studied before and after treatment with either 17β-estradiol (0.1 mg/d via continuous delivery skin patch), progesterone (100 mg/d via vaginal insert) and T (12.5 mg/d via skin gel), or no intervention (control group).


RESULTS
VLDL-TG concentration and kinetics were unchanged in the control group and not altered by T and progesterone administration. Estradiol treatment, in contrast, reduced VLDL-TG concentration by approximately 30% due to accelerated VLDL-TG plasma clearance (25.1 ± 2.5 vs. 17.4 ± 2.7 mL/min; P < .01).


CONCLUSIONS
Estradiol, but not progesterone or T, is a major regulator of VLDL-TG metabolism.
Washington University School of Medicine, St Louis, Missouri 63110.
Gordon I
GI
Smith
Dominic N
DN
Reeds
Adewole L
AL
Okunade
Bruce W
BW
Patterson
Bettina
B
Mittendorfer
D000279:Administration, Cutaneous; D000282:Administration, Intravaginal; D001682:Biological Availability; D004958:Estradiol / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007700:Kinetics; D050356:Lipid Metabolism / Q000187:drug effects*; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D008875:Middle Aged; D017698:Postmenopause / Q000187:drug effects / Q000378:metabolism; D011374:Progesterone / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D013739:Testosterone / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D014280:Triglycerides / Q000378:metabolism*
D007328:Insulin; D008079:Lipoproteins, VLDL; D014280:Triglycerides; C030106:very low density lipoprotein triglyceride; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol