编者按:大量研究发现,提高心肺适能可以带来更多健康获益。美国心脏协会(AHA)2015科学年会上,有多项心肺适能相关讲题,涉及心血管疾病(CVD)危险因素评估、肥胖悖论等话题。关于这些问题,《国际循环》记者在会议现场采访了Carl Lavie教授。Lavie教授为美国昆士兰大学医学院奥克斯纳临床学院新奥尔良约翰奥克斯纳心脏和血管研究所教授、心脏康复和预防心脏病部门主任,其研究领域包括心脏康复和预防、血脂、高血压、肥胖和运动,以及非侵入性检查包括超声心动图、运动试验和心脏核医学。
International Circulation: Dr. Lavie, one session involved in this AHA meeting has the title of “Cardiorespiratory Fitness as a Component of Cardiovascular Disease Risk Assessment”. What is your assessment on this view? Which aspects does cardiorespiratory fitness show its significance with CVD beyond traditional risk factors?
《国际循环》:本届AHA大会上有一个会议的议题为“心肺适能是心血管疾病风险评估的一部分”。您对此作何评论?您认为,除了影响传统危险因素外,心肺适对心血管疾病的重要性体现在哪些方面?
Dr. Carl Lavie: In fact I think that the data that we reviewed at our symposium really shows that cardiorespiratory fitness not only is a significant risk factor, it is perhaps the strongest of our cardiovascular disease risk factors. I often tell people that a lot of times people will call me to get the results of a stress test and all they want to know is whether the stress test was positive or negative. Was it ischemic or non ischemic and actually the data on the exercise capacity of fitness is even more important than whether the test was ischemic or non ischemic. In fact a person who has an ischemic stress test, a positive stress test, but a high level of fitness, they are at lower risk than the person who has a non ischemic or negative stress test but at a low level of fitness, and that is because fitness is so important for predicting cardiovascular risk. Another way to say this is that if we look at patients who have certain diseases like hypertension, like obesity, like diabetes, that a lot of times the people who have those disorders but who are fit, they are actually at lower risk than the persons who don’t have those disorders but are unfit. That is because fitness is such an important predictor.
Carl Lavie教授:实际上,我认为该研讨会上所回顾的数据显示,心肺适能不仅是心血管疾病的危险因素,也许还是最强的心血管疾病危险因素。很多时候,人们让我看他们的负荷试验结果是阳性还是阴性、是否存在缺血,我通常会告诉他们这一信息。其实,就心血管疾病风险评估而言,与试验结果显示是否存在缺血相比,运动耐量数据更重要。实际上,负荷试验阳性提示存在缺血但适能水平较高的患者,心血管疾病发生风险低于负荷试验阴性不存在缺血但心肺适能水平较低者。这是因为,心肺适能对心血管疾病风险预测而言非常重要。另一个例子是,很多心肺适能较好的伴有高血压、肥胖、糖尿病等疾病的患者,其心血管疾病发生风险要低于那些虽无上述疾病但心肺适能较差者。这都归因于心肺适能是心血管疾病非常重要的预测因素。
International Circulation: Studies have revealed several obesity paradoxes in the field of cardiovascular diseases. You reported at this meeting that the obesity paradox is not about obesity, it is about cardiorespiratory fitness. Could you please explain the reasons?
《国际循环》:研究发现心血管疾病存在多种肥胖悖论。您在本次会议上报告指出,肥胖悖论无关肥胖,而是与心肺适能有关。请您解释一下原因。
Dr. Carl Lavie: I actually reviewed a lot of data and a lot of this is actually reviewed a state of the art paper that I published in JACC last year. We also reviewed data from 10 studies published by Vaughn Barry that was a meta analysis of 10 studies and it looked at fitness and fatness. They show that if you are not fit, you have 2 times higher the mortality and it does not really matter what you weight whereas if you are fit, meaning at least relatively fit, you have a good prognosis and your prognosis doesn’t matter whether you are normal weight, overweight, or obese. In our cardiovascular patients, we have published many papers and many other people have meta analysis on the obesity paradox. But we showed in 2 big papers that in coronary disease and a study of 10,000 people that if you were not in the lower tri-sectional of fitness, so if you were at least relatively fit, you had a good prognosis and it did not matter what your BMI was, your waist circumference was, or your percent body fat was. But if you had a poor fitness there was an obesity paradox, you did worse in both total mortality and cardiovascular mortality but if you are unfit, those who did particularly the worst were those in the lowest amounts of body mass index, waist circumference, and percent body fat so that is where the obesity paradox is. That was in a study of 10,000 people with coronary disease and I showed the same thing in 2,060 patients with heart failure again, the obesity paradox was particularly present in the unfit individuals.
Carl Lavie教授:我查阅了大量数据,并于去年在JACC上发表了一篇综述文章。我们对Vaughn Barry发表的心肺适能与肥胖相关的10项研究数据进行了回顾和荟萃分析。其结果显示,心肺适能不好者的死亡率是适能较好者的2倍以上。实际上,若适能较好,体重对死亡率的影响较小。也就是说,如果适能相对较好,则不论体重正常、超重还是肥胖,预后均较好。我们发表了很多有关心血管疾病患者的文章,其他研究者也就肥胖悖论做过荟萃分析。我们开展了2项有关心血管疾病患者中肥胖悖论的大规模研究,并发表了相关文章,其中1项涉及10 000例冠状动脉疾病患者。结果发现,若患者的心肺适能相对较好,则不论其BMI、腰围及体脂百分比如何,预后均较好。相反,若患者的心肺适能相对较差,则总死亡率及心血管死亡率更高,尤以在BMI、腰围及体脂百分比较低者中更显著。这就是所谓的肥胖悖论。另外,我们对2060例心力衰竭患者的研究也得到了类似结果,即心肺适能不好的心力衰竭患者中也存在肥胖悖论。
International Circulation: When we are talking about cardiorespiratory fitness. How to implement cardiorespiratory fitness measurement in clinical practice?
《国际循环》:就心肺适能而言,临床实践中应如何推广应用心肺适能检测?
Dr. Carl Lavie: Certainly I think the best way would be if clinicians actually measured fitness and if they did a stress test on every one. That is not going to happen, there is not going to be a way that all patients in the world are going to get a full stress test. One way that that can be done is that clinicians can be emphasizing physical activity. The main component of fitness is physical activity. There is an inherited form of fitness that is not physical activity or exercise related, but the majority of fitness that we see in adults is coming from higher physical activity, so if we at least ask all patients about their physical activity and document that in the medical record, and then recommend physical activity for those who are getting low amounts of physical activity, that would go a long way to improving the fitness of our patients. The other thing that can easily be done, and we discussed this at the symposium, there are non exercise assessments of fitness that you can assess fitness by some simple things like age, gender, smoking status, BMI or waist circumference status, and a simple measure of physical activity and then that can be used to estimate fitness and has been shown in several studies that that correlates very well with measured fitness.
Carl Lavie教授:我认为最好的方法是让临床医生对每例患者行负荷试验并测定其心肺适能。但是,这是不可能的,因为不可能世界上的所有患者都能进行负荷试验。我们可以做的就是,让临床医生强调体力活动。适能的重要组成部分就是体力活动。虽然有1种适能与遗传有关,与体力活动及运动无关;但成年人群中大多数的良好适能源于积极的体力活动。因此,如果我们询问所有患者进行体力活动并在病历中做相应记录,推荐体力活动量较低者积极进行体力活动,则能改善这些患者的适能。另外有一点很容易做到的就是,我们这次研讨会上提到的可采用年龄、性别、吸烟状态、BMI、腰围等简单评估体力活动情况进而对适能进行非运动适能评估。目前,已有数项研究显示,采用上述方法评估的非运动试验与实际测量的适能具有较好的相关性。
International Circulation: I am so glad you mentioned that measurement before I ask you, but I still would like to ask you considering cardiorespiratory fitness is so important, you mentioned several factors to measure. What can we do in general to improve the patient’s cardiovascular fitness and health?
《国际循环》:非常高兴在我还没问您之前,您介绍了心肺适能的检测方法,但我仍想知道,既然心肺适能如此重要,对于心血管疾病患者,提高心肺适能有哪些方法呢?
Dr. Carl Lavie: The way to improve the fitness is obviously some people are naturally fitter. Some people will have an inherited component of fitness but most people the way they get their fitness is to increase their physical activity. If we can get people to achieve the federal fitness activity guidelines, which are basically doing about 150 minutes a week of moderate physical activity or doing about 75 minutes per week of vigorous activity. Moderate physical activity is a brisk walk. Vigorous physical activity would be a jog or doing a fast bicycle ride. If we could get people to do that amount of physical activity, we would get most people to be having pretty good levels of cardiorespiratory fitness so that I think is the biggest thing. We need to document it in the medical record and we need to get our patients at least to get the recommendation from their clinician to increase their physical activity if their physical activity is low.
Carl Lavie教授:显然,改善心肺适能的重要办法是能够更加自然地健康。有些人可能更容易做到,这些人天生适能就较好。但是,大部分人的适能改善是需要通过积极的体力活动来实现。要想改善适能,则需要让让人们达到美国指南所推荐的体力活动量,即最基本的每周要进行约150分钟的中等强度活动或75分钟的剧烈活动。快步行走是一种中等强度活动,而慢跑或快速骑自行车则属于剧烈活动。如果人们能做到以上活动量,则大多数人会具有相对较好的心肺适能。我认为,鼓励心血管疾病患者积极进行体力活动是提高心肺适能的最好方法。临床实践中,我们需要评估门诊中每例患者的体力活动情况并将其记录在病历中,鼓励体力活动水平较低者至少达到医生推荐的体力活动量。
International Circulation: Do you want to add more comments?
《国际循环》:最后,您还有什么要补充的?
Dr. Carl Lavie: I think that in conclusion I would say that we really have to emphasize physical activity and fitness. Low fitness, you do not have to be super fit, but if you are low fit and if you are in the lowest 20% or 30% of fitness based on age and gender, you have a high risk of cardiovascular disease and cardiovascular morbidity and mortality. We need to get people out of the low fitness category at least into the next lower or the middle levels of fitness. If we do that we have a tremendous chance of reducing cardiovascular disease morbidity and mortality.
Carl Lavie教授:最后,我想说的是,我们真的需要强调体力活动及适能。若一个人适能处于同年龄及性别人群适能水平的下20%或30%,则其心血管疾病风险较高,心血管疾病发病率及死亡率也更高。我们需要积极提高心肺适能较差者的适能水平,这将有助于降低心血管疾病发病率及死亡率。