Abstract-Evidence suggests that obesity may raise blood pressure (BP) through oxidative stress-sensitive mechanisms and that the Dietary Approaches to Stop Hypertension combination diet (DASH-CD) may decrease BP by enhancing antioxidant capacity. To address this question, 12 obese patients with high-normal-to-stage 1 hypertension (hypertensives) and 12 lean normotensives were studied on their usual diets and after following the DASH-CD and a low-antioxidant diet in random sequence for 4 weeks each. Acute oxidative stress was induced by a 4-hour infusion of intralipid and heparin. Ferric-reducing activity of plasma (FRAP) and plasma F 2 -isoprostanes were measured as biomarkers of antioxidant capacity and oxidative stress, respectively. BP was lower in obese hypertensives on the DASH-CD than on the usual and low-antioxidant diets (Ϫ8.1Ϯ1.5/Ϫ7.4Ϯ1.6 mm Hg, PϽ0.05). BP did not change significantly in lean normotensives after 4 weeks on the DASH-CD but tended to rise on the low-antioxidant diet. FRAP on usual diets was higher in lean subjects than in obese subjects. FRAP increased in obese but not lean volunteers on the DASH-CD compared with usual diet, and the group difference disappeared. F 2 -isoprostanes increased from baseline during intralipid and heparin in both groups on the low-antioxidant diet but not in obese hypertensives on the DASH-CD. Among free-living obese hypertensives, the DASH-CD raises antioxidant capacity, lowers BP, and reduces oxidative stress induced by acute hyperlipidemia. The findings are consistent with evidence that elevated BP in obese subjects may reflect an imbalance between antioxidant capacity and oxidative stress that is improved by the DASH-CD. Key Words: obesity Ⅲ insulin resistance Ⅲ fatty acids Ⅲ F 2 -isoprostanes Ⅲ oxidative stress Ⅲ antioxidants P atients with high-normal blood pressure (BP) and hypertension are more obese and insulin resistant than are normotensives. Reduced antioxidant capacity and oxidative stress represent a potential mechanism linking obesity with insulin resistance, elevated BP, and cardiovascular disease. 1-10 For example, acutely raising lipids with a short-term infusion of intralipid and heparin, which mimics and/or exacerbates the dyslipidemia seen with insulin resistance, increases BP and raises F 2 -isoprostanes, a biomarker of oxidative stress. 11,12 Moreover, in experimental models, increasing oxidative stress with a long-term low-dose infusion of angiotensin and reducing antioxidant capacity by depletion of glutathione produce severe hypertension. 2,13 In these models, BP declines when antioxidant defenses are augmented by providing either superoxide dismutase 13,14 or vitamins C and E. 13 Vitamin C also lowers BP in humans, which implicates a role for antioxidant capacity in human hypertension. 15 In the Dietary Approaches to Stop Hypertension (DASH) Study, a diet rich in fruits and vegetables, either with or without low-fat dairy products, reduced BP significantly more in hypertensives than in normotensives. 16 Both diets are rich in a varie...

Both metabolic syndrome (MetS) and chronic kidney disease (CKD) are increasing in incidence and lead to significant cardiovascular morbidity and mortality. The relationship between these two entities is complex. Individual components of the MetS are known risk factors for incident kidney disease, but it is not clear how the clustering of these components is linked to the development and progression of kidney disease. Cross-sectional studies show an association of the MetS and prevalent CKD; however, one cannot draw conclusions as to which came first – the MetS or the kidney disease. Observational studies suggest a relationship between MetS and incident CKD, but they also demonstrate the development of MetS in patients with established CKD. These observations suggest a bidirectional relationship. A better understanding of the relationship between components of the MetS and whether and how these components contribute to progression of CKD and incident cardiovascular disease could inform more effective prevention strategies.

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