Serum Antioxidant Vitamins and Blood Pressure in the United States Population

Abstract

Abstract-Serum vitamin C has been inversely associated with blood pressure in several epidemiologic studies, but little is known about effect of other antioxidant vitamins. We examined the relation between serum vitamins A, C, and E, ␣-carotene, and ␤-carotene levels and blood pressure among 15 317 men and women Ն20 years of age who participated in the Third National Health and Nutrition Examination Survey. Blood pressure was characterized as the average of 6 measurements obtained over 2 visits by trained observers and hypertension was defined as blood pressure Ն140/ 90 mm Hg and/or taking antihypertensive medications. In multivariate models, a 1 SD difference in vitamin A (16.2 g/dL) and vitamin E (20.4 g/dL) was associated with a 43% (OR, 1.43; 95% CI, 1.34 to 1.53) and 18% (OR, 1.18; 95% CI, 1.09 to 1.27) higher odds of hypertension, respectively. A 1 SD difference in ␣-carotene (0.47 g/dL) and ␤-carotene (496 g/dL) was associated with a 16% (OR, 0.84; 95% CI, 0.76 to 0.94) and 11% (OR, 0.89; 95% CI, 0.82 to 0.97) lower odds of hypertension, respectively. In addition, serum vitamins A and E were positively and significantly associated with both systolic and diastolic blood pressure, whereas ␣-carotene and ␤-carotene were inversely and significantly associated with systolic and vitamin C associated with diastolic blood pressure in multivariate linear regression analyses.

Associations between plasma antioxidants and hypertension in a community-based sample of 415 Australians aged 60–64

“…We found no significant association between plasma levels of Vitamins A and E and hypertension status in comparison to the findings reported by Chen et al,14 in which these measures were strongly associated with having definite or probable hypertension, and diastolic and systolic BP. We have no adequate explanation for this discrepancy in the results, except for the fact that samples were quite different in ages, with our group being in the narrow age range of 60-64 years, whereas the NHANES III sample had a wide age range X20 years.…”

“…Our results offer some support for previously reported findings including those of Chen et al, 14 who found a significant association between b-carotene and hypertension in logistic regression analyses. In our study, we found b-carotene to be associated with both diastolic and systolic BP, findings that held for the multiple linear regression analyses although the amount of variation explained by b-carotene was relatively small.…”

“…12 Two reviews on this topic have concluded that such an association between intake of Vitamin C and hypertension exists, but could be the result of other confounding factors. 10,13 In this context, a recent study 14 drawing on cross-sectional data collected through the Third National Health and Nutrition Examination Survey (NHANES III) undertaken in the United States is noteworthy. The authors reported highly significant associations between hypertension and serum levels of Vitamins A and E, a-and b-carotene in participants, after controlling for sociodemographic, lifestyle and health factors, including age, sex, ethnicity, education, body mass index, alcohol consumption, history of diabetes, dietary intakes of sodium, potassium, saturated fat and total energy intake.…”

Reactive oxygen species and vascular biology: implications in human hypertension

“…159 Antioxidant vitamins reduced blood pressure and arterial stiffness in patients with diabetes or hypertension in small clinical studies, 160 but had no effect in postmenopausal women, in healthy subjects or in pregnant women at risk for hypertension/preeclampsia. [159][160][161][162] …”

“…161,162 However, findings are inconsistent and clinical trial data are inconclusive. [163][164][165] In general results of clinical studies investigating cardiovascular effects of antioxidants have been disappointing given the consistent and promising findings from experimental investigations.…”