Adeyemi E O, Desai K D, Towsey M, Ghista D
Department of Medicine, FMHS, UAE University, Al Ain, United Arab Emirates.
Am J Gastroenterol. 1999 Mar;94(3):816-23. doi: 10.1111/j.1572-0241.1999.00861.x.
Our aim was to characterize autonomic dysfunction in patients with irritable bowel syndrome (IBS) using heart rate variability (HRV) studies.
EKG signals were obtained from 35 patients (mean age, 39.1 +/- 9.5 yr, M:F ratio = 2.9:1) and 18 healthy controls (mean age, 38.2 +/- 6.5 yr, M:F ratio = 2:1) in supine, standing, and deep-breathing modes. Fast Fourier transformation and autoregressive techniques were used to analyze the HRV power spectra in very low (VLF, 0.0078-0.04 Hz), low (LF, 0.04-0.14 Hz), and high (HF, 0.14-0.4 Hz) frequency bands.
In the supine position, the VLF power spectral density (PSD) in IBS was significantly higher than normal (3 vs 1.3 beats per minute [bpm]2/Hz, p < 0.01). On changing from the supine to standing position, the normals (NC) had raised median PSDs in the VLF (1.3 vs 12.8 bpm2/Hz, p < 0.01) and LF (1.6 vs 6.1 bpm2/Hz, p < 0.01) bands, as a sign of increased sympathetic tone, whereas the median HF PSDs (parasympathetic tone) remained unchanged (1.8 bpm2/Hz each, p = 0.8). Similarly, the IBS patients had increased VLF (3.04 vs 14.93 bpm2/Hz, p < 0.01) and LF (2.8 vs 8.7 bpm2/Hz, p < 0.01) PSDs on standing up, but the HF PSD was also raised (from 2.4 to 5.7 bpm2/Hz, p = 0.04). On changing from standing to the deep-breathing mode, the normals had a significant increase in the HF (from 1.8 to 10.3 bpm2/Hz, p < 0.001) and a significant reduction of the VLF (from 12.8 to 2.2 bpm2/Hz, p < 0.01) PSDs. The reduction of the LF PSD was not significant (from 6.1 to 5.6 bpm2/Hz, p = 0.6). In IBS, HF PSD remained constant (5.7 bpm2/Hz each, p = 0.6), whereas the LF PSD increased from 8.7 to 24.2 bpm2/Hz (p < 0.0001). The VLF PSD was reduced (from 14.9 to 4.1 bpm2/Hz, p < 0.0001). In IBS, the median sympathovagal outflow ratio was significantly lower in the standing position (1.4 vs 2.8, p < 0.02) and higher in the deep-breathing mode (7.33 vs 0.42, p < 0.0001) than normal.
IBS patients have reduced sympathetic influence on the heart period in response to orthostatic stress and diminished parasympathetic modulation during deep breathing.
我们的目的是通过心率变异性（HRV）研究来描述肠易激综合征（IBS）患者的自主神经功能障碍。
从35例患者（平均年龄39.1±9.5岁，男:女比例=2.9:1）和18名健康对照者（平均年龄38.2±6.5岁，男:女比例=2:1）获取仰卧位、站立位和深呼吸模式下的心电图信号。采用快速傅里叶变换和自回归技术分析极低频（VLF，0.0078 - 0.04Hz）、低频（LF，0.04 - 0.14Hz）和高频（HF，0.14 - 0.4Hz）频段的HRV功率谱。
在仰卧位时，IBS患者的VLF功率谱密度（PSD）显著高于正常水平（3 vs 1.3次/分钟[bpm]²/Hz，p < 0.01）。从仰卧位变为站立位时，正常对照者（NC）的VLF（1.3 vs 12.8 bpm²/Hz，p < 0.01）和LF（1.6 vs 6.1 bpm²/Hz，p < 0.01）频段的中位数PSD升高，这是交感神经张力增加的表现，而HF频段的中位数PSD（副交感神经张力）保持不变（均为1.8 bpm²/Hz，p = 0.8）。同样，IBS患者站立时VLF（3.04 vs 14.93 bpm²/Hz，p < 0.01）和LF（2.8 vs 8.7 bpm²/Hz，p < 0.01）的PSD增加，但HF的PSD也升高（从2.4到5.7 bpm²/Hz，p = 0.04）。从站立位变为深呼吸模式时，正常对照者HF（从1.8到10.3 bpm²/Hz，p < 0.001）显著增加，VLF（从12.8到2.2 bpm²/Hz，p < 0.01）的PSD显著降低。LF的PSD降低不显著（从6.1到5.6 bpm²/Hz，p = 0.6）。在IBS患者中，HF的PSD保持不变（均为5.7 bpm²/Hz，p = 0.6），而LF的PSD从8.7增加到24.2 bpm²/Hz（p < 0.0001）。VLF的PSD降低（从1
