title: Combination of estrogen replacement and exercise protects against HDL oxidation in post-menopausal women.
abstract: The incidence of atherosclerosis and cardiovascular disease (CVD) in women increases following menopause and has been associated with a reduction in circulating estrogen. Increased CVD risk is also perpetuated by sedentary lifestyle. Growing evidence indicates that oxidation of lipoproteins leads to a powerful immune response, disruption of normal lipoprotein function, and deposition of atherosclerotic plaques. For example, once high-density lipoproteins (HDL) are oxidized, they lose the ability to a) participate in reverse transport of cholesterol to the liver, and b) protect low-density lipoproteins (LDL) against oxidation. The purpose of this study was to determine the effects of combining estrogen replacement and exercise upon lipid peroxidation of the HDL fraction (HDL-ox). Blood samples were drawn from 34 post-menopausal women from four groups: women who were not receiving estrogen replacement and who were sedentary (NSD) (n = 9); women who were not receiving estrogen replacement and who were participating in regular exercise (NEX) (n = 8); women who were receiving estrogen replacement and who were sedentary (ESD) (n = 8); and women who were receiving estrogen replacement and who were participating in regular exercise (EEX) (n = 9). Total-HDL cholesterol was significantly higher (p<0.05) in EEX when compared with NEX, NSD, and ESD. HDL-ox was assessed via malondialdehyde (MDA). Mean (+/- SEM) values for HDL MDA expressed in nM are as follows: NSD = 903.3 +/- 118.4; NEX = 1226.7 +/- 247.7; ESD = 876.7 +/- 116.3; EEX = 537.4 +/- 74.8. EEX lipid peroxidation was significantly (p = 0.02) lower than NEX. Lipid peroxidation tended to be lower in EEX than in NSD and ESD (p = 0.07). These data indicate that the combination of estrogen replacement and regular exercise in post-menopausal women may be most effective in reducing oxidation of HDL in vivo.
authors.affiliation: Redox Biology and Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, 77843-4243, USA. jml2621@neo.tamu.edu
authors.forename: J M
authors.initials: JM
authors.lastname: Lawler
authors.forename: Z
authors.initials: Z
authors.lastname: Hu
authors.forename: J S
authors.initials: JS
authors.lastname: Green
authors.forename: S F
authors.initials: SF
authors.lastname: Crouse
authors.forename: P W
authors.initials: PW
authors.lastname: Grandjean
authors.forename: R G
authors.initials: RG
authors.lastname: Bounds
mesh_terms: D000704:Analysis of Variance; D001161:Arteriosclerosis / Q000097:blood / Q000517:prevention & control; D002318:Cardiovascular Diseases / Q000097:blood / Q000517:prevention & control; D008078:Cholesterol, LDL / Q000097:blood*; D002149:Energy Intake; D015914:Estrogen Replacement Therapy; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D008875:Middle Aged; D017698:Postmenopause / Q000502:physiology*
chemical_list: D008078:Cholesterol, LDL