S. Lacroix

The role of oxidative stress in postprandial endothelial dysfunction

Endothelial dysfunction is a turning point in the initiation and development of atherosclerosis and its complications and is predictive of future cardiovascular events. Ingestion of high-carbohydrate or high-fat meals often results in postprandial hyperglycaemia and/or hypertriacylglycerolaemia that may lead to a transient impairment in endothelial function. The present review will discuss human studies evaluating the impact of high-carbohydrate and high-fat challenges on postprandial endothelial function as well as the potential role of oxidative stress in such postprandial metabolic alterations. Moreover, the present review will differentiate the postprandial endothelial and oxidative impact of meals rich in varying fatty acid types.

Provocative Issues in Heart Disease Prevention

In this article, new areas of cardiovascular (CV) prevention and rehabilitation research are discussed: high-intensity interval training (HIIT) and new concepts in nutrition. HIIT consists of brief periods of high-intensity exercise interspersed by periods of low-intensity exercise or rest. The optimal mode according our work (15-second exercise intervals at peak power with passive recovery intervals of the same duration) is associated with longer total exercise time, similar time spent near peak oxygen uptake (VO2 peak) VO2 peak, and lesser perceived exertion relative to other protocols that use longer intervals and active recovery periods. Evidence also suggests that compared with moderate-intensity continuous exercise training, HIIT has superior effects on cardiorespiratory function and on the attenuation of multiple cardiac and peripheral abnormalities. With respect to nutrition, a growing body of evidence suggests that the gut microbiota is influenced by lifestyle choices and might play a pivotal role in modulating CV disease development. For example, recent evidence linking processed (but not unprocessed) meats to increased CV risk pointed to the gut microbial metabolite trimethylamine N-oxide as axa0potential culprit. In addition, altered gutxa0microbiota could also mediate the proinflammatory and cardiometabolic abnormalities associated with excess added free sugar consumption, and in particular high-fructose corn syrup. Substantially more research is required, however, to fully understand how and which alterations in gut flora can prevent or lead to CV disease and other chronic illnesses. We conclude with thoughts about the appropriate role for HIIT in CV training and future research in the role of gut flora-directed interventions in CV prevention.

Are Drastic Caloric Restrictions and Moderate-Intensity Physical Activity Still Relevant Lifestyle Interventions for Obese Patients With Type 2 Diabetes?

The Look AHEAD (Action for Health in Diabetes) trial published recently in the New England Journal of Medicine reported that intensive lifestyle intervention focusing on weight loss did not reduce morbidity and mortality in patients with obese type 2 diabetes over a 9.6-year follow-up period. However, after the first year, body mass, waist circumference, and glycated hemoglobin levels again increased and physical fitness decreased, suggesting a lack of long-term adherence to interventions. First, the requirement of replacing some meals (2-3 meals/ day for 0-6 months and 1 meal/day thereafter) with liquid shakes and bars is questionable because it is not natural and is a behaviour that is hardly sustainable over time. We believe that this, plus the fact that drastic caloric restrictions lower resting metabolic rate and increase appetite, must have contributed to decreasing long-term compliance to nutritional intervention and favoured weight regain. We believe that nutritional intervention that is reduced in calories but also aims at improving nutritional quality and satiety and preserving palatability, such as the (low-carbohydrate) Mediterranean diet, would have resulted in more sustainable clinical benefits. Such a diet was in fact shown to improve long-term weight loss and maintenance and to reduce cardiovascular events in patients with high cardiovascular risk. Second, the prescribed physical activity in the Look AHEAD study cannot be considered intense, because of its high volume ( 175 min/wk) and moderate-intensity nature. Such a design is not optimal in promoting compliance and could have contributed to decreasing adherence to the exercise requirements (adherence to exercise intervention was not reported), thus providing insufficient training stimulus and accounting in part for the lack of major clinical benefits. Lower volume but more vigorous exercise, such as high-intensity interval training (HIIT),

A Single Mediterranean-Type Meal Leads to Postprandial Enrichment in Omega-3 Pufas and Does Not Impair Flow-Mediated Dilatation in Comparison to a High-Saturated Fat Meal in Healthy Men With High-Normal Fasting Triglyceridemia

s S357 679 ADIPONECTIN LIMITS MICROPARTICLE-INDUCED ENDOTHELIAL DYSFUNCTION M Ehsan, F Lovren, A Quan, Y Pan, K Singh, A Ramadan, M Wheatcroft, H Teoh, S Verma

015 Reliability of Near-Infrared Spectroscopy in the Evaluation of Forearm Microvascular Function

BACKGROUND: The assessment of microvascular reactivity by near-infrared spectroscopy (NIRS) was shown to be associated with cardiovascular status and the number of cardiovascular risk factors and could be of interest in cardiac or high-risk patients. However, the reliability of NIRS parameters measured at the arm has never been studied and should be known before they could be used in research and clinical settings. The aim of this study was to measure the absolute and relative reliability of the most commonly used NIRS parameters during post-occlusive hyperaemia in healthy young men. METHODS: 18 healthy men (33.56 7.88 years), without any cardiovascular risk factors (dyslipidemia, hypertension, abdominal obesity, diabetes and smoking) or cardiac symptoms had their fasting microvascular function evaluated twice, on two mornings separated by at least 7 days. Briefly, NIRS optodes were placed on the brachio-radialis muscle and a pressure cuff was installed on the upper-arm of subjects and inflated at 80mm Hg over the systolic blood pressure. NIRS parameters were registered continuously for 2 minutes at rest, 5 minutes during occlusion and 5 minutes post-occlusion. NIRS parameters listed in the table below were then analyzed. RESULTS: