Microvascular function in younger adults with obesity and metabolic syndrome: role of oxidative stress. Am J Physiol Heart Circ Physiol 2013 Oct 15;305(8):H1230-7
Date
08/13/2013Pubmed ID
23934859Pubmed Central ID
PMC3798789DOI
10.1152/ajpheart.00291.2013Scopus ID
2-s2.0-84885608137 (requires institutional sign-in at Scopus site) 33 CitationsAbstract
Older adults with cardiovascular disease exhibit microvascular dysfunction and increased levels of reactive oxygen species (ROS). We hypothesized that microvascular impairments begin early in the disease process and can be improved by scavenging ROS. Forearm blood flow (Doppler ultrasound) was measured in 45 young (32 ± 2 yr old) adults (n = 15/group) classified as lean, obese, and metabolic syndrome (MetSyn). Vasodilation in response to endothelial (ACh) and vascular smooth muscle [nitroprusside (NTP) and epoprostenol (Epo)] agonists was tested before and after intra-arterial infusion of ascorbic acid to scavenge ROS. Vasodilation was assessed as a rise in relative vascular conductance (ml·min(-1)·dl(-1)·100 mmHg(-1)). ACh and NTP responses were preserved (P = 0.825 and P = 0.924, respectively), whereas Epo responses were lower in obese and MetSyn adults (P < 0.05) than in lean controls. Scavenging of ROS via infusion of ascorbic acid resulted in an increase in ACh-mediated (P < 0.001) and NTP-mediated (P < 0.001) relative vascular conductance across all groups, suggesting that oxidative stress influences vascular responsiveness in adults with and without overt cardiovascular disease risk. Ascorbic acid had no effect on Epo-mediated vasodilation (P = 0.267). These results suggest that obese and MetSyn adults exhibit preserved endothelium-dependent vasodilation with reduced dependence on prostacyclin and are consistent with an upregulation of compensatory vascular control mechanisms.
Author List
Limberg JK, Harrell JW, Johansson RE, Eldridge MW, Proctor LT, Sebranek JJ, Schrage WGMESH terms used to index this publication - Major topics in bold
AcetylcholineAdult
Antioxidants
Ascorbic Acid
Case-Control Studies
Endothelium, Vascular
Epoprostenol
Humans
Infusions, Intra-Arterial
Metabolic Syndrome
Microvessels
Muscle, Skeletal
Muscle, Smooth, Vascular
Nitroprusside
Obesity
Oxidative Stress
Regional Blood Flow
Ultrasonography, Doppler
Vasodilation
Vasodilator Agents
