Obesity/insulin resistance is associated with endothelial dysfunction. Implications for the syndrome of insulin resistance.

Abstract

To test the hypothesis that obesity/insulin resistance impairs both endothelium-dependent vasodilation and insulinmediated augmentation of endothelium-dependent vasodilation, we studied leg blood flow (LBF) responses to graded intrafemoral artery infusions of methacholine chloride (MCh) or sodium nitroprusside (SNP) during saline infusion and euglycemic hyperinsulinemia in lean insulin-sensitive controls (C), in obese insulin-resistant subjects (OB), and in subjects with non-insulin-dependent diabetes mellitus (NIDDM). MCh induced increments in LBF were ‫ف‬ 40% and 55% lower in OB and NIDDM, respectively, as compared with C ( P Ͻ 0.05).

Abdominal Obesity Associated with Elevated Serum Butyrylcholinesterase Activity, Insulin Resistance and Reduced High Density Lipoprotein-Cholesterol Levels

“…p values are given for comparisons between groups tested with non-parametric, t test and Chi square tests cardiovascular dysfunction occurred in both at arterial and at cardiac myocyte levels as an independent risk factor of obesity. However, all animal and clinical studies examining vascular function in obesity have shown some degree of vascular abnormalities that occur at both endothelial and smooth muscle levels [18][19][20]. The correlation of lipid abnormalities with obesity, diabetes as well as with the MetS may also implicate involvement of BChE.…”

Differential blood pressure effects of oral glucose and intravenous L-arginine in healthy lean normotensive and obese hypertensive subjects

“…[21][22][23] Interestingly, endo- thelial dysfunction favours vasoconstriction and BP elevations during glucose and insulin infusions. [10][11][12][13][14]23 Endothelial dysfunction has been observed in hypertensives, obese and type-2 diabetics; conditions characterised by the presence of insulin resistance, compensatory hyperinsulinaemia and glucose intolerance. [12][13][14] Consequently, both hyperinsulinaemia and hyperglycaemia may play a role in the hypertension of obesity.…”

“…[10][11][12][13][14] It is thus possible, that the small increase in glucose and insulin induced by oral glucose in lean normotensives produced a small, but significant BP reduction. In fact, insulin-induces vasodilation in normal subjects [8][9][10][11][12][13][14] and glucose induces minimal BP changes in healthy animals'. 23 The failure to observe BP lowering in obese hypertensives is most likely due to hyperglycaemia and hyperinsulinaemia in the presence of insulin resistance and to possible endothelial dysfunction.…”

“…[1][2][3][4][5][6][7] In healthy subjects, insulin induces vasorelaxation and increases tissue blood flow; 8,9 these effects are diminished or lost in the subjects with endothelial dysfunction and/or insulin resistance. [10][11][12][13] Insulin resistance with compensatory hyperinsulinaemia has been observed in lean hypertensives, obese normotensives and hypertensives and in patients with type 2 diabetes mellitus. 2,[14][15][16][17][18] Infusions of insulin have been shown to increase blood pressure (BP) in rats.…”

Endothelial dysfunction and arterial abnormalities in childhood obesity

“…Considering the key role that the vascular endothelium plays in atherogenesis, it is not surprising that major cardiovascular risk factors such as hypercholesterolaemia, 8 type 2 diabetes, 21 hypertension, 22 ageing, male gender and smoking, 23 are all accompanied by vascular endothelial dysfunction.…”