Hogikyan R V, Galecki A T, Halter J B, Supiano M A
Department of Internal Medicine, and Institute of Gerontology, University of Michigan, Ann Arbor, USA.
Metabolism. 1999 Dec;48(12):1536-41. doi: 10.1016/s0026-0495(99)90242-1.
Adrenergic responsiveness (AR) appears to be increased in subjects with diabetes, but measurement of arterial AR in normotensive people with type 2 diabetes mellitus has not been previously reported. We sought to determine whether, compared with control subjects, there is increased arterial AR in type 2 diabetes mellitus and its relationship to the level of systemic sympathetic nervous system activity (SNSa). We studied 15 type 2 diabetic subjects aged 57 +/- 3 years without hypertension or clinical signs of autonomic neuropathy and 13 age-matched control subjects aged 55 +/- 2 years. We assessed vascular alpha-AR by measuring forearm blood flow (FABF) by venous occlusion plethysmography during intrabrachial artery norepinephrine (NE) and phentolamine infusions, as well as arterial plasma NE levels and the extravascular NE release rate (NE2) derived from 3H-NE kinetics, as estimates of systemic SNSa. The vasoconstricting effect of NE during intrabrachial artery NE infusion was greater in type 2 diabetes compared with control subjects (P = .02). The vasodilating effect of phentolamine was greater in type 2 diabetics compared with control subjects (P = .05), suggesting increased endogenous arterial alpha-adrenergic tone. Arterial plasma NE levels (control v type 2, 1.8 +/- 0.10 v 1.84 +/- 0.14 nmol/L, P = .86) and NE2 (control vtype 2, 11.8 +/- 1.54 v 13.3 +/- 0.89 nmol/min/m2, P = .39) were similar in the two groups. In summary, in type 2 diabetes compared with control subjects, (1) the vasoconstriction response to intraarterial NE is greater, (2) plasma NE and NE2 are similar, suggesting similar levels of systemic SNSa, and (3) arterial alpha-adrenergic tone is greater. We conclude that subjects with type 2 diabetes demonstrate inappropriately increased alpha-AR for their level of systemic SNSa.
糖尿病患者的肾上腺素能反应性（AR）似乎有所增加，但此前尚未有关于2型糖尿病血压正常者动脉AR测量的报道。我们试图确定，与对照受试者相比，2型糖尿病患者的动脉AR是否增加及其与全身交感神经系统活动水平（SNSa）的关系。我们研究了15名年龄在57±3岁、无高血压或自主神经病变临床体征的2型糖尿病受试者以及13名年龄匹配的对照受试者，年龄为55±2岁。我们通过静脉阻断体积描记法在肱动脉输注去甲肾上腺素（NE）和酚妥拉明期间测量前臂血流量（FABF）来评估血管α-AR，同时测量动脉血浆NE水平以及从3H-NE动力学得出的血管外NE释放率（NE2），作为全身SNSa的估计值。与对照受试者相比，2型糖尿病患者在肱动脉输注NE期间NE的血管收缩作用更大（P = 0.02）。与对照受试者相比，酚妥拉明在2型糖尿病患者中的血管舒张作用更大（P = 0.05），提示内源性动脉α-肾上腺素能张力增加。两组的动脉血浆NE水平（对照组对2型糖尿病组，1.8±0.10对1.84±0.14 nmol/L，P = 0.86）和NE2（对照组对2型糖尿病组，11.8±1.54对13.3±0.89 nmol/min/m2，P = 0.39）相似。总之，与对照受试者相比，2型糖尿病患者（1）对动脉内NE的血管收缩反应更大，（2）血浆NE和NE2相似，提示全身SNSa水平相似，（3）动脉α-肾上腺素能张力更大。我们得出结论，2型糖尿病患者表现出其全身SNSa水平下α-AR不适当增加。
