Amador Norma, Guizar Juan-Manuel, Malacara Juan-Manuel, Pérez-Luque Elva, Paniagua Ramón
Unidad de Investigación en Epidemiología, Instituto Mexicano del Seguro Social (IMSS), León, Guanajuato, Mexico.
Arch Med Res. 2004 Jan-Feb;35(1):54-8. doi: 10.1016/j.arcmed.2003.08.010.
Angiotensinogen has been proposed as a possible link between obesity and hypertension because the adipocyte produces angiotensinogen and contains the enzymes required for its conversion. Moreover, sympathetic overactivity has been reported in obese subjects. The aim of this study was to compare heart sympathetic activation and serum angiotensinogen levels in obese and non-obese normotensive subjects, their relationship, and the effect of a drug that modifies the renin-angiotensin system.
Serum angiotensinogen, leptin, lipids, glucose, and insulin levels were measured and 24-h electrocardiograph monitoring was carried out in 41 (20 non-obese and 21 obese) volunteers before and after administration of 5 mg enalapril twice/day for 7 days.
Obese subjects had higher values than non-obese subjects for % body fat (35.1+/-4.6 vs. 30.5+/-5.2; p=0.005), triglycerides (1.93+/-0.9 vs. 1.25+/-0.7 g/L, p=0.002), insulin (114.8+/-82.5 vs. 45.9+/-22.2 pmol/L), leptin (31.4+/-20.4 vs. 14.1+/-11.2 ng/mL, p=0.002), and LF/HFn index (4.3+/-2.9 vs. 2.2+/-1.3, p<0.005). Enalapril increased angiotensinogen levels only in the non-obese group (4.2+/-3.9 vs. 9.7+/-5.4 ng/mL, p=0.001) and diminished the LF/HFn index (4.3+/-2.9 vs. 3.0+/-1.4, p=0.007) in the group of obese subjects. There was no association between angiotensinogen levels and sympathetic activity.
Higher level of sympathetic activity was found in normotensive obese as compared with non-obese subjects. Enalapril treatment reduced heart sympathetic activity in obese subjects but did not change angiotensinogen levels.
血管紧张素原被认为是肥胖与高血压之间可能的联系纽带，因为脂肪细胞可产生血管紧张素原并含有其转化所需的酶。此外，据报道肥胖受试者存在交感神经过度活跃的情况。本研究旨在比较肥胖与非肥胖正常血压受试者的心脏交感神经激活及血清血管紧张素原水平、它们之间的关系，以及一种可调节肾素 - 血管紧张素系统的药物的作用。
在41名（20名非肥胖和21名肥胖）志愿者中，于每日两次给予5毫克依那普利，共7天之前及之后，测量血清血管紧张素原、瘦素、血脂、血糖和胰岛素水平，并进行24小时心电图监测。
肥胖受试者的体脂百分比（35.1±4.6对30.5±5.2；p = 0.005）、甘油三酯（1.93±0.9对1.25±0.7克/升，p = 0.002）、胰岛素（114.8±82.5对45.9±22.2皮摩尔/升）、瘦素（31.4±20.4对14.1±11.2纳克/毫升，p = 0.002）和低频/高频比值指数（4.3±2.9对2.2±1.3，p < 0.005）均高于非肥胖受试者。依那普利仅使非肥胖组的血管紧张素原水平升高（4.2±3.9对9.7±5.4纳克/毫升，p = 0.001），并使肥胖受试者组的低频/高频比值指数降低（4.3±2.9对3.0±1.4，p = 0.007）。血管紧张素原水平与交感神经活动之间无关联。
与非肥胖受试者相比，正常血压肥胖者的交感神经活动水平更高。依那普利治疗可降低肥胖受试者的心脏交感神经活动，但未改变血管紧张素原水平。
