Ribeiro M M, Trombetta I C, Batalha L T, Rondon M U, Forjaz C L, Barretto A C, Villares S M, Negrão C E
Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil.
Braz J Med Biol Res. 2001 Apr;34(4):475-8. doi: 10.1590/s0100-879x2001000400006.
To study the relationship between the sympathetic nerve activity and hemodynamic alterations in obesity, we simultaneously measured muscle sympathetic nerve activity (MSNA), blood pressure, and forearm blood flow (FBF) in obese and lean individuals. Fifteen normotensive obese women (BMI = 32.5 +/- 0.5 kg/m2) and 11 age-matched normotensive lean women (BMI = 22.7 +/- 1.0 kg/m2) were studied. MSNA was evaluated directly from the peroneal nerve by microneurography, FBF was measured by venous occlusion plethysmography, and blood pressure was measured noninvasively by an autonomic blood pressure cuff. MSNA was significantly increased in obese women when compared with lean control women. Forearm vascular resistance and blood pressure were significantly higher in obese women than in lean women. FBF was significantly lower in obese women. BMI was directly and significantly correlated with MSNA, blood pressure, and forearm vascular resistance levels, but inversely and significantly correlated with FBF levels. Obesity increases sympathetic nerve activity and muscle vascular resistance, and reduces muscle blood flow. These alterations, taken together, may explain the higher blood pressure levels in obese women when compared with lean age-matched women.
为研究肥胖状态下交感神经活动与血流动力学改变之间的关系，我们同时测量了肥胖个体和瘦个体的肌肉交感神经活动（MSNA）、血压及前臂血流量（FBF）。研究对象为15名血压正常的肥胖女性（BMI = 32.5±0.5kg/m²）和11名年龄匹配的血压正常的瘦女性（BMI = 22.7±1.0kg/m²）。通过微神经ography术直接从腓神经评估MSNA，采用静脉阻断体积描记法测量FBF，使用自主血压袖带无创测量血压。与瘦对照女性相比，肥胖女性的MSNA显著增加。肥胖女性的前臂血管阻力和血压显著高于瘦女性。肥胖女性的FBF显著降低。BMI与MSNA、血压及前臂血管阻力水平呈直接且显著的正相关，但与FBF水平呈反向且显著的负相关。肥胖会增加交感神经活动和肌肉血管阻力，并减少肌肉血流量。综合这些改变，可能解释了肥胖女性与年龄匹配的瘦女性相比血压水平更高的原因。
