Arora S, Smakowski P, Frykberg R G, Simeone L R, Freeman R, LoGerfo F W, Veves A
Deaconess-Joslin Foot Center, Boston, MA 02215, USA.
Diabetes Care. 1998 Aug;21(8):1339-44. doi: 10.2337/diacare.21.8.1339.
We have compared the hyperemic response to heat and the endothelium-dependent and endothelium-independent vasodilatation between the dorsum of the foot and the forearm in diabetic neuropathic and non-neuropathic patients and healthy control subjects.
We studied the cutaneous microcirculation in the forearm and foot in 15 diabetic patients with neuropathy, in 14 diabetic patients without neuropathy, and in 15 control subjects matched for age, sex, BMI, and in the case of diabetic patients, for the duration of diabetes. Patients with peripheral vascular disease and/or renal impairment were excluded. The cutaneous microcirculation of the dorsum of the foot and the flexor aspect of the forearm was tested in all subjects. Single-point laser Doppler was employed to measure the maximal hyperemic response to heating of the skin to 44 degrees C and laser Doppler imaging scanner was used to evaluate the response to iontophoresis of 1% acetylcholine chloride (Ach) (endothelium-dependent response) and 1% sodium nitroprusside (NaNP) (endothelium-independent response).
The transcutaneous oxygen tension was lower in the neuropathic group at both foot and forearm level, while the maximal hyperemic response to heat was similar at the foot and forearm level in all three groups. The endothelium-dependent vasodilation (percent increase over baseline) was lower in the foot compared to the forearm in the neuropathic group (23 +/- 4 vs. 55 +/- 10 [mean +/- SEM]; P < 0.01)], the non-neuropathic group (33 +/- 6 vs. 88 +/- 14; P < 0.01), and the control subjects (43 +/- 6 vs. 93 +/- 13; P < 0.001). Similar results were observed during the iontophoresis of NaNP (P < 0.05). No differences were found among the three groups when the ratio of the forearm:foot response was calculated for both the endothelium-dependent (neuropathic group, 2.25 +/- 0.24; non-neuropathic group, 2.55 +/- 0.35; and control subjects, 2.11 +/- 0.26; P = NS) and endothelium-independent vasodilation (neuropathic group, 1.54 +/- 0.27; non-neuropathic group, 2.08 +/- 0.33; and control subjects, 2.77 +/- 1.03; P = NS). The vasodilatory response, which is related to the C nociceptive fiber action, was reduced at the foot level during iontophoresis of Ach in the neuropathic group. In contrast, no difference was found during the iontophoresis of NaNP at the foot and forearm level and of Ach at the forearm level among all three groups.
In healthy subjects, the endothelial-dependent and endothelial-independent vasodilatation is lower at the foot level when compared to the forearm, and a generalized impairment of the microcirculation in diabetic patients with neuropathy preserves this forearm-foot gradient. These changes may be a contributing factor for the early involvement of the foot with neuropathy when compared to the forearm.
我们比较了糖尿病性神经病变患者、非神经病变患者以及健康对照者足部和前臂对热的充血反应以及内皮依赖性和非内皮依赖性血管舒张情况。
我们研究了15例患有神经病变的糖尿病患者、14例无神经病变的糖尿病患者以及15例在年龄、性别、体重指数方面匹配的对照者（对于糖尿病患者，还在糖尿病病程方面进行了匹配）的前臂和足部皮肤微循环。排除患有外周血管疾病和/或肾功能损害的患者。对所有受试者的足部背侧和前臂屈侧皮肤微循环进行检测。采用单点激光多普勒测量皮肤加热至44摄氏度时的最大充血反应，并用激光多普勒成像扫描仪评估对1%氯化乙酰胆碱（Ach）离子导入（内皮依赖性反应）和1%硝普钠（NaNP）离子导入（非内皮依赖性反应）的反应。
神经病变组足部和前臂水平的经皮氧分压均较低，而三组在足部和前臂水平对热的最大充血反应相似。神经病变组中，足部的内皮依赖性血管舒张（相对于基线的增加百分比）低于前臂（23±4对55±10[平均值±标准误]；P<0.01），非神经病变组（33±6对88±14；P<0.01）以及对照者（43±6对93±13；P<0.001）。在NaNP离子导入过程中也观察到了类似结果（P<0.05）。当计算前臂与足部反应的比值时，三组在内皮依赖性血管舒张（神经病变组，2.25±0.24；非神经病变组，2.55±0.35；对照者，2.11±0.26；P=无显著性差异）和非内皮依赖性血管舒张方面（神经病变组，1.54±0.27；非神经病变组，2.08±0.33；对照者，2.
