Skrapari Ioanna, Tentolouris Nicholas, Perrea Despoina, Bakoyiannis Christos, Papazafiropoulou Athanasia, Katsilambros Nicholas
First Department of Propaedeutic Medicine, Athens University Medical School, Laiko General Hospital, Greece.
Obesity (Silver Spring). 2007 Jul;15(7):1685-93. doi: 10.1038/oby.2007.201.
The aim of this study was to test the hypothesis that baroreflex sensitivity (BRS), assessed by indirect measurement of aortic pressure, is blunted in obesity. Additionally, the potential effect of cardiac autonomic nervous system (ANS) activity, aortic compliance, and metabolic parameters on BRS of obese subjects was investigated.
A group of 30 women with BMI>30 kg/m2 and a group of 30 controls with BMI<25 kg/m2 were examined. BRS was estimated by the sequence technique, cardiac ANS activity by short-term spectral analysis of heart rate variability (HRV), and aortic compliance by the method of applanation tonometry.
BRS was lower in obese women (9.18+/-3.77 vs. 19.63+/-9.16 ms/mm Hg, p<0.001). The median values (interquartile range) of the power of both the high-frequency and low-frequency components of the HRV were higher in the lean than in the obese participants [1079.2 (202.7 to 1716.9) vs. 224.1 (72.7 to 539.6) msec2, p=0.001 and 411.8 (199.3 to 798.0) vs. 235.8 (99.4 to 424.5) msec2, p=0.01 respectively]. Low-to-high-frequency ratio values were higher in the obese subjects [0.82 (0.47 to 2.1) vs. 0.57 (0.28 to 0.89), p=0.02]. Aortic augmentation values were not significantly different between lean and obese subjects. Multivariate analysis demonstrated a significant and independent association between BRS and age (p=0.003), BMI (p<0.001), and high-frequency power of HRV (p<0.001). These variables explained 72% of the variation of BRS values.
BRS is severely reduced in obese subjects. BMI, age, and the parasympathetic nervous system activity are the main determinants of BRS. Baroreflex behavior is of clinical relevance because an attenuated BRS represents a negative prognostic factor in cardiovascular diseases, which are common in obesity.
本研究旨在验证以下假设，即通过间接测量主动脉压力评估的压力反射敏感性（BRS）在肥胖人群中降低。此外，还研究了心脏自主神经系统（ANS）活动、主动脉顺应性和代谢参数对肥胖受试者BRS的潜在影响。
对一组30名体重指数（BMI）>30 kg/m² 的女性和一组30名BMI<25 kg/m² 的对照者进行检查。通过序列技术估算BRS，通过心率变异性（HRV）的短期频谱分析评估心脏ANS活动，并通过压平式眼压测量法测定主动脉顺应性。
肥胖女性的BRS较低（9.18±3.77对19.63±9.16 ms/mm Hg，p<0.001）。瘦者HRV高频和低频成分功率的中位数（四分位间距）高于肥胖参与者[1079.2（202.7至1716.9）对224.1（72.7至539.6）msec²，p=0.001；411.8（199.3至798.0）对235.8（99.4至424.5）msec²，p=0.01]。肥胖受试者的低频与高频比值更高[0.82（0.47至2.1）对0.57（0.28至0.89），p=0.02]。瘦者与肥胖受试者的主动脉增强值无显著差异。多变量分析显示BRS与年龄（p=0.003）、BMI（p<0.001）和HRV高频功率（p<0.001）之间存在显著且独立的关联。这些变量解释了BRS值变异的72%。
肥胖受试者的BRS严重降低。BMI、年龄和副交感神经系统活动是BRS的主要决定因素。压力反射行为具有临床相关性，因为减弱的BRS是心血管疾病的负面预后因素，而心血管疾病在肥胖人群中很常见。
