title: Sequentially combined estradiol valerate plus levonorgestrel therapy decreases 18:1 trans-fatty acid content of plasma lipids in healthy postmenopausal women.
abstract: Trans-fatty acids (TFA) have been classified as atherogenic dietary constituents but the effect of hormone replacement therapy (HRT) on their concentrations is not known. We used a washout protocol to study the effect of long-term estrogen and combined estrogen-progestin HRT on plasma elaidate (18:1t), which is the trans isomer of oleate and the major TFA in the diet. The study group comprised 15 women receiving estradiol valerate HRT and 15 women receiving combined HRT with estradiol valerate and levonorgestrel. The concentrations of elaidate in plasma phospholipids, cholesteryl esters and triglycerides were determined by gas chromatography. At baseline, the total plasma elaidate concentration was lower in the combined HRT group than in the estradiol valerate HRT group (p < 0.01). In the combined HRT group, the concentration of elaidate increased significantly after withdrawal of HRT (p < 0.001) and decreased again to the baseline level after restart of therapy (p < 0.001). These changes were due to decreases in the concentrations of phospholipids and triglycerides; in phospholipids there was also a proportional decrease of elaidate. There were no changes in elaidate in women receiving estradiol valerate alone. Our results suggest that long-term combined HRT treatment decreases plasma TFA, which is not achieved by estrogen alone.
authors.affiliation: Department of Clinical Chemistry, Laboratory of Atherosclerosis Genetics, Tampere University Hospital and University of Tampere Medical School, Tampere, Finland.
authors.forename: Hannu
authors.initials: H
authors.lastname: Jokela
authors.forename: Anne
authors.initials: A
authors.lastname: Kalela
authors.forename: Mari
authors.initials: M
authors.lastname: Lilja
authors.forename: Mia
authors.initials: M
authors.lastname: Salmi
authors.forename: Terho
authors.initials: T
authors.lastname: Lehtimäki
authors.forename: Tarja
authors.initials: T
authors.lastname: Kunnas
authors.forename: Klaus
authors.initials: K
authors.lastname: Teisala
authors.forename: Reijo
authors.initials: R
authors.lastname: Punnonen
authors.forename: Seppo T
authors.initials: ST
authors.lastname: Nikkari
mesh_terms: D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D006801:Humans; D016912:Levonorgestrel / Q000494:pharmacology*; D008055:Lipids / Q000097:blood; D008875:Middle Aged; D019301:Oleic Acid / Q000097:blood; D009829:Oleic Acids; D017698:Postmenopause; D044242:Trans Fatty Acids / Q000097:blood*
chemical_list: D004967:Estrogens; D008055:Lipids; D009829:Oleic Acids; D044242:Trans Fatty Acids; D019301:Oleic Acid; C011459:elaidic acid; D004958:Estradiol; D016912:Levonorgestrel