title: Associations between plasma antioxidants and hypertension in a community-based sample of 415 Australians aged 60-64.
abstract: It has been suggested that increased oxidative stress may be both a cause as well as a consequence of hypertension. In vivo oxidation of low-density lipoproteins by oxygen-free radicals may increase hypertension-related atherogenesis, and antioxidants may be beneficial in this regard. Previous findings concerning associations between serum measures of antioxidants and hypertension have however been inconsistent. Plasma levels of beta-carotene, Vitamin A, E, uric acid, homocysteine and total antioxidant capacity, as well as two markers of oxidative stress, malondialdehyde (MDA) and protein carbonyls, were measured in morning fasting blood samples provided by 415 Australians aged 60-64 years, selected randomly from the community. Participants also provided information on sociodemographic attributes, mental and physical health, and provided two measures of resting blood pressure, allowing a diagnosis of definite or borderline hypertension. Those with hypertension had lower levels of beta-carotene and higher levels of uric acid and MDA compared to normotensive participants. The last two of these associations persisted when the analyses controlled for lifestyle and health factors. The findings from this study offer limited support for the proposition that lower antioxidant status and higher oxidative stress are associated with hypertension, and suggest the need for longitudinal studies to examine causality and intervention studies to determine the benefit of antioxidants in this group.
authors.affiliation: Centre for Mental Health Research, Australian National University, Canberra, Australia. ruth.parslow@anu.edu.au
authors.forename: R A
authors.initials: RA
authors.lastname: Parslow
authors.forename: P
authors.initials: P
authors.lastname: Sachdev
authors.forename: C
authors.initials: C
authors.lastname: Salonikas
authors.forename: O
authors.initials: O
authors.lastname: Lux
authors.forename: A F
authors.initials: AF
authors.lastname: Jorm
authors.forename: D
authors.initials: D
authors.lastname: Naidoo
mesh_terms: D000367:Age Factors; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D018592:Cross-Over Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000453:epidemiology / Q000503:physiopathology; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D009517:New South Wales / Q000453:epidemiology; D018384:Oxidative Stress / Q000502:physiology; D012111:Residence Characteristics; D012189:Retrospective Studies; D012307:Risk Factors; D014505:Urban Population; D014527:Uric Acid / Q000097:blood; D014801:Vitamin A / Q000097:blood; D014810:Vitamin E / Q000097:blood; D019207:beta Carotene / Q000097:blood
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D019207:beta Carotene; D006710:Homocysteine; D014801:Vitamin A; D014810:Vitamin E; D014527:Uric Acid; D008315:Malondialdehyde