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 b-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 b-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.

Heme oxygenase-1 expression is down-regulated by angiotensin II and under hypertension in human neutrophils

“…Oxidative stress may result from an excessive production of ROS or a reduced antioxidant availability. In this light, it has been described that in hypertensive patients, the plasma levels of antioxidants, such as vitamins A and E, and total antioxidant capacity are decreased [3]. Alterations of normal endothelium function appear to play a central role in the pathogenesis of hypertension [4].…”

Circulating carotenoid concentrations and incident hypertension: the Coronary Artery Risk Development in Young Adults (CARDIA) study

“…However, the SU.VI.MAX trial found no reduction in incident BP after 6.5 years of supplementation with a combination of purified antioxidant vitamins and minerals,14 Thus, it is plausible that serum carotenoids, which might play an antioxidant role or be a marker of a generally healthy diet and lifestyle, relate inversely to future BP increase. However, only a few cross-sectional studies4,15,16 and one prospective study14 have reported an inverse relation between serum carotenoids and hypertension. Therefore, we conducted longitudinal analyses to clarify whether serum carotenoid concentrations measured at 3 different examinations predict incident hypertension in the Coronary Artery Risk Development in Young Adults (CARDIA) study.…”

Rb1 Protects Endothelial Cells from Hydrogen Peroxide-Induced Cell Senescence by Modulating Redox Status

“…14) MDA is a major and stable end product formed during the peroxidation of lipids and is regarded as marker of lipid peroxidation in tissues. 15) Here, we reported that Rb1 antagonizes H 2 O 2 -induced HUVECs senescence through upregulating endogenous antioxidants SOD and decreasing vascular lipid peroxidation. Cell Culture Primary HUVECs were prepared from newborn human umbilical cords within 6 h by 0.1% collagenase (Gibco) perfusion as described previously.…”