Nutritional Epidemiology Research Unit-UMR U557 INSERM, U1125 INRA, CNAM, CRNH-IdF, France.
J Hypertens. 2010 Feb;28(2):325-32. doi: 10.1097/HJH.0b013e328333d1fc.
Obesity is associated with increased cardiovascular morbidity. The skin is a unique site allowing simple, noninvasive assessment of capillary density and endothelial function. In the present study, we measured skin capillary density and endothelial function in a group of normotensive overweight/obese nondiabetic individuals and healthy lean controls.
We examined 120 relatively insulin-sensitive overweight individuals (BMI 27.9 +/- 2.7 kg/m, mean +/- SD) with normal blood pressure and fasting plasma glucose and 130 lean (BMI 22.4 +/- 1.7 kg/m) controls. We used video microscopy to measure skin capillary density in the resting state and during venous occlusion. Laser Doppler flowmetry, combined with iontophoresis of acetylcholine (endothelial-dependent vasodilation) and following skin heating (endothelial-independent dilation), was performed. Resting capillary density was negatively correlated with BMI (r = -0.130, P < 0.05). Resting capillary density (mean +/- SE) was lower, however nonsignificantly, in overweight as compared with the lean individuals (88.6 +/- 1.5 vs. 91.8 +/- 1.4, P = 0.117). Capillary recruitment, defined as the percentage increase in capillary density during venous congestion, was higher in overweight (9.5 +/- 1.0%) than in controls (5.4 +/- 0.9%, P = 0.003), which remained significant after adjustment for age, sex, mean arterial pressure and fasting glucose. As a consequence, capillary density during venous occlusion was similar between the groups. Endothelial-dependent and independent cutaneous vasodilation was also similar between groups. No correlations were found between capillary density and plasma markers of adiposity, inflammation or endothelial dysfunction.
BMI was inversely correlated with resting capillary density. This suggests a lower baseline tissue perfusion associated with higher vasomotor tone. Despite this, capillary recruitment was higher in overweight as compared with lean individuals, resulting in similar capillary density during venous congestion. Our results suggest that skin microcirculation abnormalities, in the absence of endothelial dysfunction, may be one of the earliest detectable alterations in vascular function in overweight individuals.
肥胖与心血管发病率增加有关。皮肤是一个独特的部位，可以简单、无创地评估毛细血管密度和内皮功能。在本研究中，我们测量了一组血压正常、超重/肥胖、非糖尿病个体和健康瘦对照者的皮肤毛细血管密度和内皮功能。
我们检查了 120 名相对胰岛素敏感的超重者（BMI 27.9 +/- 2.7 kg/m，平均值 +/- SD），血压和空腹血糖正常，以及 130 名瘦（BMI 22.4 +/- 1.7 kg/m）对照者。我们使用视频显微镜在静息状态和静脉闭塞期间测量皮肤毛细血管密度。激光多普勒流量测量仪与乙酰胆碱的离子电渗疗法（内皮依赖性血管舒张）相结合，并在皮肤加热后（内皮非依赖性扩张）进行。静息毛细血管密度与 BMI 呈负相关（r = -0.130，P < 0.05）。然而，超重者的静息毛细血管密度（平均值 +/- SE）较低，但无统计学意义（88.6 +/- 1.5 与 91.8 +/- 1.4，P = 0.117）。毛细血管募集，定义为静脉充血期间毛细血管密度的百分比增加，在超重者中较高（9.5 +/- 1.0%），而在对照组中较低（5.4 +/- 0.9%，P = 0.003），调整年龄、性别、平均动脉压和空腹血糖后仍有统计学意义。因此，两组之间静脉闭塞期间的毛细血管密度相似。内皮依赖性和非依赖性皮肤血管舒张在两组之间也相似。未发现毛细血管密度与血浆肥胖标志物、炎症标志物或内皮功能障碍标志物之间存在相关性。
BMI 与静息毛细血管密度呈负相关。这表明与较高的血管紧张度相关的基线组织灌注较低。尽管如此，超重者的毛细血管募集较高，与瘦者相比，静脉充血期间的毛细血管密度相似。我们的结果表明，在超重者中，皮肤微循环异常，而无内皮功能障碍，可能是血管功能最早可检测到的改变之一。
