title: Increment of body mass index is positively correlated with worsening of endothelium-dependent and independent changes in forearm blood flow.
abstract: Obesity is associated with the impairment of endothelial function leading to the initiation of the atherosclerotic process. As obesity is a multiple grade disease, we have hypothesized that an increasing impairment of endothelial and vascular smooth muscle cell functions occurs from lean subjects to severe obese ones, creating a window of opportunities for preventive measures. Thus, the present study was carried out to investigate the grade of obesity in which endothelial dysfunction can be detected and if there is an increasing impairment of endothelial and vascular smooth muscle cell functions as body mass index increases. According to body mass index, subjects were allocated into five groups: Lean controls (n = 9); Overweight (n = 11); Obese class I (n = 26); Obese class II (n = 15); Obese class III (n = 19). Endothelial and vascular smooth muscle cell functions were evaluated measuring forearm blood flow responses to increasing intra-arterial infusions of acetylcholine and sodium nitroprusside using venous occlusion plethysmography. We observed that forearm blood flow was progressively impaired from lean controls to severe obese and found no significant differences between Lean controls and Overweight groups. Known determinants of endothelial dysfunction, such as inflammatory response, insulin resistance, and diagnosis of metabolic syndrome, did not correlate with forearm blood flow response to vasodilators. Moreover, several risk factors for atherosclerosis were excluded as independent predictors after confounder-adjusted analysis. Our data suggests that obesity per se could be sufficient to promote impairment of vascular reactivity, that obesity class I is the first grade of obesity in which endothelial dysfunction can be detected, and that body mass index positively correlates with the worsening of endothelium-dependent and independent changes in forearm blood flow.
authors.affiliation: Endocrinology, Obesity Unit, Policlínica Piquet Carneiro, Department of Internal Medicine, Faculty of Medical Sciences, Rio de Janeiro State UniversityRio de Janeiro, Brazil; Laboratory for Clinical and Experimental Research in Vascular Biology - BioVasc, Biomedical Center, Rio de Janeiro State UniversityRio de Janeiro, Brazil.
authors.forename: Luiz G
authors.initials: LG
authors.lastname: Kraemer-Aguiar
authors.affiliation: Laboratory for Clinical and Experimental Research in Vascular Biology - BioVasc, Biomedical Center, Rio de Janeiro State UniversityRio de Janeiro, Brazil; Critical Care, Department of Internal Medicine, Faculty of Medical Sciences, Rio de Janeiro State UniversityRio de Janeiro, Brazil.
authors.forename: Marcos L
authors.initials: ML
authors.lastname: de Miranda
authors.affiliation: Laboratory for Clinical and Experimental Research in Vascular Biology - BioVasc, Biomedical Center, Rio de Janeiro State University Rio de Janeiro, Brazil.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Bottino
authors.affiliation: Department of Anesthesiology, National Cancer Institute Hospital Rio de Janeiro, Brazil.
authors.forename: Ronald de A
authors.initials: Rde A
authors.lastname: Lima
authors.affiliation: Laboratory for Clinical and Experimental Research in Vascular Biology - BioVasc, Biomedical Center, Rio de Janeiro State University Rio de Janeiro, Brazil.
authors.forename: Maria das Graças C
authors.initials: Md
authors.lastname: de Souza
authors.affiliation: Department of Internal Medicine, Andarai Federal Hospital Rio de Janeiro, Brazil.
authors.forename: Michelle de Moura
authors.initials: Mde M
authors.lastname: Balarini
authors.affiliation: Laboratory for Clinical and Experimental Research in Vascular Biology - BioVasc, Biomedical Center, Rio de Janeiro State UniversityRio de Janeiro, Brazil; Anesthesiology, Department of Surgery, Faculty of Medical Sciences, Rio de Janeiro State UniversityRio de Janeiro, Brazil.
authors.forename: Nivaldo R
authors.initials: NR
authors.lastname: Villela
authors.affiliation: Laboratory for Clinical and Experimental Research in Vascular Biology - BioVasc, Biomedical Center, Rio de Janeiro State University Rio de Janeiro, Brazil.
authors.forename: Eliete
authors.initials: E
authors.lastname: Bouskela
keywords: endothelial function; forearm blood flow; obesity; overweight; vascular reactivity; venous occlusion plethysmography