L M Title1, P M Cummings, K Giddens, B A Nassar. 1. Division of Cardiology, Laboratory Medicine at the Queen Elizabeth II Health Sciences Center, Halifax, Nova Scotia, Canada. ltitle@is.dal.ca
Abstract
OBJECTIVES: The goal of this study was to determine whether postprandial hyperglycemia, induced by oral glucose loading, attenuates endothelial function in healthy subjects without diabetes and whether coadministration of vitamins C and E could prevent these postprandial changes. BACKGROUND: Epidemiologic evidence suggests that postprandial hyperglycemia, below diabetic levels, is a risk factor for cardiovascular disease. Postprandial hyperglycemia may promote atherosclerosis through endothelial dysfunction and oxidative stress. METHODS: We evaluated the acute effects of oral glucose loading (75 g), alone and with vitamins C (2 g) and E (800 IU), on endothelium-dependent flow-mediated dilation (FMD) of the brachial artery, in a randomized, double-blind, placebo-controlled, crossover study of 10 healthy volunteers. Changes in the levels of markers of oxidative stress (plasma malondialdehyde and erythrocyte glutathione, glutathione peroxidase and superoxide dismutase) were also assessed. RESULTS: Increases in plasma glucose and insulin after glucose loading were unaffected by vitamin coadministration. With glucose loading alone, FMD fell from 6.5+/-2.2 at baseline to 5.4+/-1.7, 3.7+/-2.1*, 4.1+/-3.5* and 5.7+/-1.9% at 1, 2, 3 and 4 h (*p < 0.05 vs. 0 h). In contrast, FMD did not change significantly after glucose plus vitamins (6.4+/-1.3, 7.6+/-1.8, 7.9+/-2.7, 6.9+/-2.3, 6.9+/-1.9% at 0, 1, 2, 3 and 4 h). By two-way repeated measures analysis of variance we found a significant interaction between vitamin treatment and time (p = 0.0003), indicating that vitamins prevented the glucose-induced attenuation of FMD. Oxidative stress markers did not significantly change with glucose loading alone or with vitamins. CONCLUSIONS: Oral glucose loading causes an acute, transient decrease of FMD in healthy subjects without diabetes, which is prevented by vitamins C and E.
RCT Entities:
OBJECTIVES: The goal of this study was to determine whether postprandial hyperglycemia, induced by oral glucose loading, attenuates endothelial function in healthy subjects without diabetes and whether coadministration of vitamins C and E could prevent these postprandial changes. BACKGROUND: Epidemiologic evidence suggests that postprandial hyperglycemia, below diabetic levels, is a risk factor for cardiovascular disease. Postprandial hyperglycemia may promote atherosclerosis through endothelial dysfunction and oxidative stress. METHODS: We evaluated the acute effects of oral glucose loading (75 g), alone and with vitamins C (2 g) and E (800 IU), on endothelium-dependent flow-mediated dilation (FMD) of the brachial artery, in a randomized, double-blind, placebo-controlled, crossover study of 10 healthy volunteers. Changes in the levels of markers of oxidative stress (plasma malondialdehyde and erythrocyte glutathione, glutathione peroxidase and superoxide dismutase) were also assessed. RESULTS: Increases in plasma glucose and insulin after glucose loading were unaffected by vitamin coadministration. With glucose loading alone, FMD fell from 6.5+/-2.2 at baseline to 5.4+/-1.7, 3.7+/-2.1*, 4.1+/-3.5* and 5.7+/-1.9% at 1, 2, 3 and 4 h (*p < 0.05 vs. 0 h). In contrast, FMD did not change significantly after glucose plus vitamins (6.4+/-1.3, 7.6+/-1.8, 7.9+/-2.7, 6.9+/-2.3, 6.9+/-1.9% at 0, 1, 2, 3 and 4 h). By two-way repeated measures analysis of variance we found a significant interaction between vitamin treatment and time (p = 0.0003), indicating that vitamins prevented the glucose-induced attenuation of FMD. Oxidative stress markers did not significantly change with glucose loading alone or with vitamins. CONCLUSIONS: Oral glucose loading causes an acute, transient decrease of FMD in healthy subjects without diabetes, which is prevented by vitamins C and E.
Authors: Sietze Reitsma; Dick W Slaaf; Hans Vink; Marc A M J van Zandvoort; Mirjam G A oude Egbrink Journal: Pflugers Arch Date: 2007-01-26 Impact factor: 3.657
Authors: Sherman J Bigornia; Melanie M Mott; Donald T Hess; Caroline M Apovian; Marie E McDonnell; Mai-Ann Duess; Matthew A Kluge; Antonino J Fiscale; Joseph A Vita; Noyan Gokce Journal: Obesity (Silver Spring) Date: 2010-01-07 Impact factor: 5.002