应用心率变异性研究进食对自主神经活动的影响
发布时间：2018-05-16 17:42
本文选题：进食 + 自主神经 ； 参考：《南方医科大学》2014年硕士论文
【摘要】：目的和意义： 当前社会竞争激烈,亚健康状态日益增多。其中,胃肠功能紊乱被认为是亚健康的主要表现之一。胃肠功能紊乱是指临床检查未发现器质性改变,但机体出现饱胀、餐后不适、恶心呕吐、上腹痛、烧心感、便秘等临床表现的一种疾病。据文献报道,全球人群中有10%-20%的胃肠功能紊乱症状,女性多于男性。我国广东等地曾开展关于胃肠功能紊乱流行病学调查研究显示广州市2001年、广东省2004年的患病率分别为5.6%和5.62%[2]。同时陈e萚3]在对广东城镇居民进行问卷调查也显示功能性消化不良患病率为18.92%。现代医学认为,自主神经功能异常和胃肠功能紊乱关系密切[7]。但胃肠功能紊乱者自主神经的活动有何特点,其进食前后的变化有何异常,目前还没有确切的结果。原因之一是由于机体在正常状况下进食前后的自主神经活动还需进一步阐明。 1.心率变异性是目前反映自主神经活动的最为敏感且无创性的量化指标 很早人们就认识到自主神经对胃肠道调节和食物代谢起到重要的作用,如进食前后胃肠道蠕动的变化,食物的动力学效应,都与自主神经(即交感和副交感神经)的调节有关,但进食前后,交感和副交感神经是如何变化的,是直到心率变异性的应用,才有了较为客观具体的研究。 目前对人体自主神经功能的检测方法主要有体位性血压测试、皮肤交感反应、深呼吸心率变异、瓦氏动作反应指数等,但上述这些方法仅能单独反映交感神经或副交感神经的功能,灵敏度和特异度均较差[8]。而且在测试的过程中需要被试高度配合,故不益于广泛使用。心率变异性(Heart Rate Variability,HRV)被公认为是目前反映自主神经活动的最为敏感且无创性的量化指标。心率变异性是通过心搏间的微小差异来反映自主神经对心脏窦房结的调控。其中,频域分析法可将复杂的心率波动信号按不同频段来描述能量的分布情况,能对交感神经和副交感神经的活动水平进行量化。频域分析可获得多项指标,按频段对应的生理意义可分为以下几种：低频段(LF),频率在0.04-0.15Hz之间,能量主要来自包括动脉压的短期调整在内的相关机制,反映交感神经调制强度；高频段(HF),频率在0.15-0.4Hz之间,能量主要来自呼吸运动对心脏间期信号的影响,反映副交感神经调制强度；交感/副交感平衡比(LF/HF),是交感神经活性和副交感神经活性的比值,反映交感神经与副交感神经对心脏进行双重调节的平衡性。 2.餐前餐后自主神经功能波动变化研究争议 目前,已有研究采用HRV频谱分析的方法评价成年人餐前餐后的自主神经功能状态,但研究结果存在争议。Vaz M[32]等人认为HF值在进餐后有下降的趋势,即进餐后迷走神经活动减弱；Kaneko[38]等人则认为HF在餐后的5min内有细微的显著性升高。同时Lipsitz[39]等人在健康青年志愿者的餐后记录中发现伴随着心脏交感神经活动的增强心率变异性指标LF值有明显的升高。这些结果 不一致,直接影响到我们对正常情况下自主神经对胃肠道调节的规律的认识,也妨碍了我们进一步了解胃肠功能紊乱的自主神经活动状态,通过调节自主神经来对胃肠功能紊乱进行调节。 3.导致餐前餐后自主神经功能波动变化研究争议的原因分析 已有的研究存在的争议可能由以下因素导致：1.目前的研究只对餐前和餐后的数据进行了比较分析,没有设立严格的对照；2.HRV呈现波动性,即使在同样的清醒或者睡眠状态下HRV指标值均会有显著地波动变化；3.实验过程中,志愿者不自觉地进入睡眠状态会对研究结果有干扰。 4.本研究的目的和意义 因此,本研究拟在前人研究的基础之上,进一步探索正常人进食前后自主神经功能的变化。采用流行病学自身前后对照的实验设计,应用HRV频域指标动态平移的方法,比较进食对清醒状况下正常人自主神经活动的影响。旨在揭示由于进食对自主神经活动的影响,从而为进一步研究亚健康状态下胃肠功能紊乱的自主神经活动及对其自主神经功能进行有效调节提供理论依据。 方法： 1.样本人群的纳入标准在年龄在20-30岁的在校大学生中,选择健康无器质性疾病病史且2年内无明显胃肠功能紊乱表现的大学生作为被试。有以下胃肠功能紊乱表现的人群需要排除：临床表现主要在胃肠道,涉及进食和排泄等方面的不正常,也常伴有失眠、焦虑、注意力不集中、健忘、神经过敏、头痛等其他功能性症状[62-63]。最终选取其中22例健康大学生进行实验。 2.实验方案 本研究采用自身前后对照研究：每人进行三次进食实验,分别计入HC(高热量试验组)、LC(低热量试验组)和对照组。其中,高热量组给予470kca1(碳水化合物270kcal,脂肪104kcal,蛋白质54kcal,其他20kcal)热量的食物,低热量组给予160kcal(碳水化合物50kcal,脂肪90kcal,蛋白质30kcal,其余10kcal)热量的食物,对照组不给予食物。所有志愿者均要求在测试前禁食8小时或以上,试验在清晨7：30---9：30之间进行。 3.检测指标：心电检测；脑电检测 使用美国Bio-logic公司生产的PSG多导睡眠仪分别监测给予实验处理前后的脑电图(EEG)和心电图(ECG)。根据志愿者的EEG记录,截取实验处理前后同为清醒状态下的心电数据进行比较。使用MATLAB R2007a软件对获得的心电数据进行分析,将之转化为一系列有序的RR间期(RRI)。用Kubios HRV version2.0软件对RRI数据作进一步处理,获得研究所需的HRV指标。 4.分析指标 睡眠分期:NREM睡眠(即非快动眼睡眠sleep stage1,2,3,4)以及REM睡眠(快动眼睡眠)；HRV分析(LF、HF、LFnu、HFnu、LF/HF)。 5.统计方法 实验数据通过SPSS20.0软件进行统计分析。LF、HF、LFnu、HFnu、LF/HF等计量资料的描述采用均数±标准差(x±s)；进食对自主神经活动的影响采用配对样本t检验进行比较(Paired-Samples t-test)。检验水准α设为0.05。 结果： 1.基线情况 这22例健康自愿者中男性10例、女性12例。男女性别年龄均可比(t=0.823,p0.05)、BMI (t=0.946,p0.05)。本研究中,标准多导睡眠图以及心电图连续记录30min。实验期间所有实验对象至多进入到睡眠1-2期,大部分实验对象(19/22,86.3%)在平躺的状态下无意识进入睡眠状态。 2.睡眠状态对研究结果存在一定的干扰 在本研究中,标准多导睡眠图以及心电图连续记录30min,这个时间段一般实验对象至多能进入到睡眠1-2期。大部分实验对象(19/22,86.3%)在平躺的状态下无意识进入睡眠状态。由于睡眠一期的长度比较短,我们将禁食状态下实验对象1期跟清醒状态下的LF,HF以及LF/HF数据的值组合在一起与睡眠 2期状态下各指标的值进行比较。在清醒状态与睡眠2期状态下各指标的比较中,除了LF/HF其余各指标均有显著性差异(P0.05)。相比较睡眠2期状态,HR和LFnu值在清醒阶段明显较高；然而LF, HFnu值则在清醒阶段相对较低。这些结果表明在分析进食对于自主神经活动影响的时候,应考虑到实验对象自主神经的变化会随着睡眠状态的变化而变化。因此,本研究均选用清醒状态,对进食前后的自主神经活动进行比较。 3.HRV指标在相同睡眠状态下存在波动 本研究对22例实验对象均采取按顺序以5min为窗口地连续记录进行HRV频谱分析。结果观测到LF,HF and LF/HF指标值的波动。随机选取其中一人的数据为例,在图表3-1中发现在相同睡眠状态下LF,HF and LF/HF指标值均存在连续性地波动。 4.同热量的进食对自主神经波动的影响 4.1对HRV指标均值的影响 本实验中,分别对各组处理前后的指标进行配对t检验(Paired-sample t test)比较,,研究不进食、进食低热量及进食高热量是否会对HRV指标造成不一样的影响。结果显示：(1)对照组、低热量组中处理前后各指标的变异系数无明显差异。,(2)高热量组餐后的HR, LFnu以及LF/HF相较于餐前均有显著升高(P0.05),其余指标在三组间的比较均无显著差异。 4.2对HRV指标变异系数CV的影响 通过对对照组、低热量试验组以及高热量试验组的心率与HRV指标的变异系数进行分析,分析结果显示：(1)对照组、低热量组中处理前后各指标的变异系数无明显差异。(2)高热量组餐后HR, LF, HF, HFnu及LF/HF的变异系数较餐前均显著升高(P0.05),其余指标无显著差异。4.3进食对自主神经功能的影响在性别间的差异 对同为空腹状态下的HRV指标进行性别间的比较,结果显示,除男性志愿者的平均心率低于女性志愿者外(P0.05),其余指标LF、HF、LFnu、HFnu、 LF/HF等在男女间的差异没有统计学意义。(1)对男性志愿者中对照组、低热量组以及高热量组HRV指标均数的进行分析,结果显示,高热量组餐后的HR以及LF较餐前有显著性升高(P0.05),其余指标在三组间的比较无显著差异。(2)对女性志愿者中对照组、低热量组以及高热量组HRV指标均数进行分析,结果显示,高热量组餐后的HR以及LF/HF较餐前都有显著性升高(P0.05),其余指标在三组间的比较无显著差异。 结论： 1.采用流行病学自身前后对照的实验设计,相对于单纯地比较餐前和餐后HRV指标数据的差异,能更客观、准确和直接地表现由于进食所导致的HRV指标的波动变化。 2.志愿者在测试过程中很容易进入到非快动眼睡眠阶段,而睡眠状态对自主神经也会有一定的影响,因此,在分析进食对于HRV波动变化的影响时,要考虑睡眠状态的混杂。 3.在进食过程中,进食热量的不同会造成HRV指标值出现差异。摄入较低热量的食物并不会对HRV其他指标造成影响;摄入高热量(450kca1)的食物会造成餐后HR和LF/HF显著地升高。 4.在进食过程中,进食热量的不同会造成HRV指标的变异系数出现差异。研究结果显示高热量组餐后HF值的变异系数显著增大,说明高热量组HF的波动性较低热量组及对照组大,可以认定HF的这种变化极有可能也是受进食所导致。 5.进食对心率变异性的影响存在性别间的差异,女性的心率变异性受进食的影响较男性显著。
[Abstract]:Purpose and significance:
The current social competition is fierce and subhealth is increasing. Among them, gastrointestinal dysfunction is considered as one of the main manifestations of subhealth. Gastrointestinal dysfunction refers to a disease that has not found organic changes in clinical examination, but the body appears to be full, postprandial discomfort, nausea and vomiting, upper abdominal pain, heartburn, constipation and other clinical manifestations. In the global population, there were 10%-20% symptoms of gastrointestinal dysfunction and more women than men. The epidemiological investigation of gastrointestinal dysfunction in Guangdong and other places in China showed that in 2001 in Guangzhou, the prevalence rate in 2004 in Guangdong province was 5.6% and 5.62%[2]., respectively, and E? 3], in Guangdong urban residents, also showed the merit of the questionnaire. The prevalence of dyspepsia is 18.92%. modern medicine. It is considered that the dysfunction of autonomic nervous function and gastrointestinal dysfunction is closely related to [7]., but what is the characteristic of the autonomic nervous activity in the patients with gastrointestinal dysfunction, what is the abnormal changes before and after eating, and there is no definite result at present. One of the reasons is that the body is in normal condition before eating. The subsequent autonomic nerve activity needs to be further clarified.
1. heart rate variability is currently the most sensitive and noninvasive quantitative indicator of autonomic nervous activity.
Early people recognized that the autonomic nerve plays an important role in the gastrointestinal regulation and food metabolism, such as the changes in the gastrointestinal peristalsis before and after eating, the dynamic effects of food, and the regulation of the autonomic nerve (sympathic and parasympathetic nerve), but how the sympathetic and parasympathetic nerves change before and after eating, which is until the heart rate variation. There is a more objective and specific research on the application of sex.
At present, the methods of detecting autonomic nervous function mainly include body position blood pressure test, skin sympathetic response, deep breathing heart rate variation, and valson action response index, but these methods can only reflect the function of sympathetic or parasympathetic nervous system alone, the sensitivity and specificity are poor [8]. and need to be used in the process of testing. Heart Rate Variability (HRV) is recognized as the most sensitive and noninvasive quantitative indicator of autonomic nervous activity. Heart rate variability reflects the regulation of autonomic nerve to the sinoatrial node through a small difference between the heart beat. Complex heart rate fluctuation signals describe the distribution of energy according to different frequency bands and quantize the activity level of sympathetic and parasympathetic nerves. Frequency domain analysis can obtain a number of indicators. The physiological significance of the frequency domain can be divided into the following categories: low frequency (LF), frequency between 0.04-0.15Hz, energy mainly from arterial pressure The relative mechanism of short-term adjustment reflects the modulation intensity of sympathetic nerve; high frequency (HF), frequency between 0.15-0.4Hz, energy mainly comes from the influence of respiratory movement on interphase signals, reflecting the modulation intensity of parasympathetic nerve; sympathetic / parasympathetic balance ratio (LF/HF), the ratio of sympathetic and parasympathetic activity, and the ratio of sympathetic and parasympathetic nerve activity. The balance between sympathetic and parasympathetic nerves regulate the heart.
2. postprandial postprandial autonomic nervous function fluctuations
At present, the HRV spectrum analysis has been used to evaluate the autonomic nervous function status of adult postprandial postprandial neural function, but the results are controversial.Vaz M[32] and others believe that the HF value decreases after the meal, that is, the vagus nerve activity is weakened after the meal, and Kaneko[38] and others believe that HF has a slight significant rise in the 5min after the meal. Lipsitz[39] et al. Also found a significant increase in the LF value of the heart rate variability index associated with cardiac sympathetic activity in the postprandial records of healthy young volunteers.
The inconsistency directly affects our understanding of the regularities of the gastrointestinal regulation of the autonomic autonomic nerve under normal conditions, and also hinders us to further understand the autonomic nervous activity state of the gastrointestinal dysfunction, and regulates the gastrointestinal dysfunction by regulating the autonomic nerve.
3. causes of controversy on autonomic nervous function changes after prandial meal
The existing disputes may be caused by the following factors: 1. the current study is only a comparative analysis of pre - and post - meal data, without a strict control; 2.HRV is fluctuating, even in the same sober or sleep state, with significant fluctuations in the value of the HRV index; 3. in the course of the experiment, volunteers Unconscious sleep can interfere with research results.
4. purpose and significance of the study
Therefore, on the basis of previous studies, this study intends to further explore the changes in autonomic nervous function of normal people before and after eating. By using the experimental design before and after epidemiology, the effect of feeding on the autonomic nervous activity of normal people in sober condition is compared with the method of HRV frequency domain index dynamic translation. The effect of food on autonomic nervous activity provides a theoretical basis for further study of autonomic activity of gastrointestinal dysfunction and the effective regulation of autonomic nervous function in subhealth state.
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