Brachial artery ultrasound is commonly employed for noninvasive assessment of endothelial function. However, analysis is observer dependent and susceptible to errors. We describe studies on a computerized edge-detection and wall-tracking software program to allow more accurate and reproducible measurement. In study 1, three purpose-built Perspex phantom arteries, 3.00, 4.00, and 6.00 mm in diameter, were measured with the software. There was a mean bias of 11 microm (P < 0.001 at each level) between known and measured values; the mean resolving power of the software was estimated as 8.3 microm. In study 2, the mean intraobserver coefficient of variation of repeated measures of flow-mediated dilation (FMD) using the software (6.7%) was significantly lower than that for traditional manual measurements using the intima-lumen interfaces (24.8%, P < 0.05) and intima-media interfaces (32.5%, P < 0.05). In study 3, 24 healthy volunteers underwent repeat testing twice within 1 wk; the coefficients of variation for between-visit reproducibility of FMD and response to glyceryl trinitrate using the software were 14.7 and 17.6%, respectively. Assuming 80% power and an alpha of 0.05, eight subjects with matched controls would be required, in a parallel designed study, to detect an absolute 2.5% change in FMD. In summary, we have developed a semiautomated computerized vascular ultrasound analysis system that will improve the power of clinical intervention studies to detect small changes in arterial diameter.

Background: Regular consumption of nϪ3 fatty acids of marine origin can improve serum lipids and reduce cardiovascular risk. Objective: This study aimed to determine whether eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids have differential effects on serum lipids and lipoproteins, glucose, and insulin in humans. Design: In a double-blind, placebo-controlled trial of parallel design, 59 overweight, nonsmoking, mildly hyperlipidemic men were randomly assigned to receive 4 g purified EPA, DHA, or olive oil (placebo) daily while continuing their usual diets for 6 wk. Results: Fifty-six men aged 48.8 ± 1.1 y completed the study. Relative to those in the olive oil group, triacylglycerols fell by 0.45 ± 0.15 mmol/L (Ϸ20%; P = 0.003) in the DHA group and by 0.37 ± 0.14 mmol/L (Ϸ18%; P = 0.012) in the EPA group. Neither EPA nor DHA had any effect on total cholesterol. LDL, HDL, and HDL 2 cholesterol were not affected significantly by EPA, but HDL 3 cholesterol decreased significantly (6.7%; P = 0.032). Although HDL cholesterol was not significantly increased by DHA (3.1%), HDL 2 cholesterol increased by Ϸ29% (P = 0.004). DHA increased LDL cholesterol by 8% (P = 0.019). Adjusted LDL particle size increased by 0.25 ± 0.08 nm (P = 0.002) with DHA but not with EPA. EPA supplementation increased plasma and platelet phospholipid EPA but reduced DHA. DHA supplementation increased DHA and EPA in plasma and platelet phospholipids. Both EPA and DHA increased fasting insulin significantly. EPA, but not DHA, tended to increase fasting glucose, but not significantly so. Conclusions: EPA and DHA had differential effects on lipids, fatty acids, and glucose metabolism in overweight men with mild hyperlipidemia.Am J Clin Nutr 2000;71:1085-94. KEY WORDSEicosapentaenoic acid, docosahexaenoic acid, EPA, DHA, hyperlipidemia, fish oil, nϪ3 fatty acids, lipids, LDL particle size, glucose metabolism, insulin metabolism, men INTRODUCTIONThere is considerable evidence to support a protective effect of dietary nϪ3 polyunsaturated fatty acids against atherosclerotic heart disease (1). The 2 principal nϪ3 fatty acids in marine oils, eicosapentaenoic acid (EPA; 20:5nϪ3) and docosahexaenoic acid (DHA; 22:6nϪ3), have a wide range of biological effects (1-3). Those relevant to heart disease include influences on lipoprotein metabolism (4, 5), platelet and endothelial function, vascular reactivity, neutrophil and monocyte cytokine production, coagulation, fibrinolysis, and blood pressure (1-3, 6, 7). In addition, the effect of nϪ3 fatty acids may be dependent, to some extent, on the presence of underlying disorders such as dyslipidemia, hypertension, diabetes mellitus, and vascular disease.nϪ3 Fatty acid supplementation in animals and humans results in substantial increases in plasma and tissue EPA and DHA as well as variable incorporation in different phospholipid classes in different tissues (8-10). These differences may be important to the subsequent utilization and metabolism of EPA and DHA. Although both fatty acids are considered to ...

In light of the worldwide epidemic of obesity, and in recognition of hypertension as a major factor in the cardiovascular morbidity and mortality associated with obesity, The Obesity Society and The American Society of Hypertension agreed to jointly sponsor a position paper on obesity-related hypertension to be published jointly in the journals of each society. The purpose is to inform the members of both societies, as well as practicing clinicians, with a timely review of the association between obesity and high blood pressure, the risk that this association entails, and the options for rational, evidenced-based treatment. The position paper is divided into six sections plus a summary as follows: pathophysiology, epidemiology and cardiovascular risk, the metabolic syndrome, lifestyle management in prevention and treatment, pharmacologic treatment of hypertension in the obese, and the medical and surgical treatment of obesity in obese hypertensive patients. The United States is currently facing a very real obesity epidemic. The most recent National Health and Nutrition Examination Survey indicates that approximately two thirds of US adults are presently classified as overweight or obese (body mass index [BMI] !25) and one third as obese (BMI !30) (1,2). While the numbers alone are formidable, they leave unaddressed the medical costs associated with obesity and obesity-related comorbidities, not the least of which is obesity-related hypertension. Given the frequent concurrence of obesity and hypertension, it is no coincidence that as the rate of obesity continues to rise, so too does the rate of hypertension. It is estimated that at least 75% of the incidence of hypertension is related directly to obesity (1). It is essential, therefore, to develop treatment strategies for the management of obesity in order to reduce the development of obesity-related hypertension as well as to effectively manage high blood pressure (BP) in the obese.Recent publications have estimated that the annual medical burden of obesity and obesity-related diseases in the United States totaled roughly $147 billion in 2008 (1) and that projected obesity-related medical expenses will more than double by 2018, topping $344 billion, or about 21% of total healthcare spending (1). Although lifestyle changes aimed at prevention, especially in childhood, are the ultimate solution to the societal problem of obesity and its complications, the scope of illness caused by obesity demands immediate attention and therapeutic intervention in the obese population. Given the important role that obesity plays in the pathogenesis of hypertension, the leadership of both The Obesity Society and The American Society of Hypertension have commissioned this position paper for the purpose of providing the membership of both societies, as well as the community of clinicians in practice, with a current and timely summary on the relationship between weight and BP, on the cardiovascular (CV) risk imposed and on the management of obesity-related hypertension.

Abstract-Animal studies suggest that the 2 major 3 fatty acids found in fish, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may have differential effects on blood pressure (BP) and heart rate (HR). The aim of this study was to determine whether there were significant differences in the effects of purified EPA or DHA on ambulatory BP and HR in humans. In a double-blind, placebo-controlled trial of parallel design, 59 overweight, mildly hyperlipidemic men were randomized to 4 g/d of purified EPA, DHA, or olive oil (placebo) capsules and continued their usual diets for 6 weeks. Fifty-six subjects completed the study. Key Words: eicosapentaenoic acid Ⅲ docosahexaenoic acid Ⅲ fatty acids Ⅲ blood pressure Ⅲ heart rate C urrent evidence from epidemiological studies, clinical trials, and experimental animal studies suggests that 3 fatty acids of marine origin may be protective against cardiovascular disease. 1 Most studies that assessed the potential cardiovascular benefits of 3 fatty acids have focused largely on the importance of eicosapentaenoic acid (EPA), with little attention given to the relative effect of docosahexaenoic acid (DHA). This is probably attributable to the fact that the majority of commercial marine oil preparations as well as most, but not all, fish species contain more EPA than DHA. In addition, EPA, unlike DHA, is a substrate for the cyclooxygenase and lipoxygenase enzymes involved in eicosanoid metabolism.Fish oil supplementation in humans results in substantial increases in plasma and tissue 3 fatty acids, particularly EPA and DHA, but with variable incorporation in different phospholipid classes in different tissues. In vitro animal and human studies have shown that EPA and DHA are differentially incorporated into plasma, 2 platelet, 3,4 and tissue lipids. 4 These differences may play an important role in the utilization and metabolism of the 2 fatty acids. For example, EPA and DHA differ in their effects on membrane fluidity and the activities of membrane-bound enzymes 5 and on neutrophilmediated endothelial detachment. 6 Compelling evidence shows that in vitro DHA but not EPA decreased cytokine-induced expression of endothelial leukocyte adhesion molecules. 7 Recent reports have described differences in lipid metabolism 8,9 and platelet aggregation. 10 An antihypertensive effect of fish oils has been demonstrated in hypertensive patients, 11-14 although generally only when relatively large doses of fish oils have been used. We recently reported that daily fish meals that provide 3.65 g/d of 3 fatty acids significantly reduced blood pressure (BP) in overweight, treated hypertensives. 15 This study addresses the question of whether EPA and DHA have differential effects on BP and heart rate (HR) in humans. In support of a differential effect of EPA and DHA on BP control, McLennan et al 16 recently reported that DHA was more effective than EPA at retarding the development of hypertension in spontaneously hypertensive rats (SHR) but not in adult SHR with already established hyperten...