Understanding lab testing: what blood work can & cannot tell you (AMA 91 sneak peek)

1. 0:00 – 0:11

   Intro

   1. PAPeter Attia0:00

      [upbeat music] Hey everyone, welcome to "The Drive Podcast." I'm your host, Peter Attia. [upbeat music]

2. 0:11 – 3:58

   Why lab testing is insufficient to answer the question “Am I healthy?”

   1. SPSpeaker0:11

      Peter, welcome to another AMA. How you doing?

   2. PAPeter Attia0:14

      Very well, thanks.

   3. SPSpeaker0:15

      Awesome. So today's AMA, we're gonna focus on lab testing. And if you compile all the questions people send us, the vast majority of them will touch this topic at some level. Meaning someone says, "Hey, I just got blood work done, and the result of X was Y. What should I do?" So I think it's not only a topic that is interesting and a lot of people care about, but it also seems like this is where people really focus on, you know, a report card of their health in a way. And so I think what'd be helpful is when we start is for you, when you work with patients, you're obviously reviewing labs with them often. And when you do it for the first time, you know, what do you hear from them? What do you hear that patients typically are hoping that these labs will tell them when you're going through that review?

   4. PAPeter Attia1:00

      Well, I mean, I think people rarely say explicitly, "Hey, I just wanna know if I'm healthy or not." I mean, I think more broadly there's a, a belief, um, and, and over the years in anticipation of that, I've sort of preemptively addressed this on every first lab call. Uh, but the belief is that, "Hey, by the time we're done this exercise today, I'm going to know everything I need to know about my health." Um, and, and obviously, you know, a subset of that or at least subservient to that question is, "I will know if I'm healthy," right? Um, and again, it's a very understandable, um, assumption to come in to a, to a, a lab assessment with because for the most part, when you've interacted with the healthcare system, the only routine maintenance things that, uh, tend to get done are lab testing. Now, of course, there's more than that, but we don't-- We tend to think of imaging in a separate category, so obviously a, a woman who gets her mammogram every year would also consider that a part of her routine, routine health maintenance. But for most people, um, when we interact with our doctors, we're doing so around lab tests. Um, [lip smack] and again, um, they're, they're objective, they're numerical, they have these reference ranges. I mean, all, all of these things about them make them feel like they should be, uh, complete. Um, [lip smack] and I think there's another thing, which is that, um, the... You know, if, if you don't fall outside of a reference range, and therefore nothing is getting flagged, I think people sort of assume, "Hey, all systems are go." Um, you know, the check engine light isn't coming on, so everything is, is, is okay. Um, and I would say that that view has probably been amplified over the past few years because there is really no shortage of direct-to-consumer testing products out there. Um, and that's kind of, I think, doubled down on that belief system, um, which is, "Hey, this is, this is the thing you need to know. And if you, if you buy our D2C product that will check your labs and frankly, um, uh, even, even test lots of labs, um, we're gonna, we're gonna have the solution to every, to every problem." Um, [lip smack] and so I usually just kind of ex- start by explaining, um, where I think the labs are valuable, um, but also where their blind spots are. And I, I think that's a, that's, that's a, that's an important discussion to have so that at the end of the lab discussion, um, I usually end up saying something to the effect of, "Look, uh, we will know roughly a third of what we care to know about you. Maybe, maybe, maybe a bit less, maybe twenty-five percent." Um, and that's a very important twenty-five percent. But we have a lot of work to do to really kind of get under the hood of truly understanding risk across

3. 3:58 – 8:31

   Defining health through the lenses of lifespan, health span, and fundamental organ systems, and how labs can come up short

   1. PAPeter Attia3:58

      everything that we care about.

   2. SPSpeaker3:59

      That's something we're gonna dive into much more detail here today's AMA. But I think what may be helpful is kinda stepping back. You asked the question, you know, are you healthy, right? And that's ultimately what people care about and want to know. And so when you're trying to understand the answer to that question for your patients, you know, how do you go about that? What are you, what are you looking at, and what are you truly trying to understand around that core question of am I healthy?

   3. PAPeter Attia4:26

      I mean, look, I think you have to start with defining what that means. And, um, I think there are different ways to define that. Um, if, if you're talking to a patient who, um, has just finished chemotherapy for cancer, um, then the definition really probably should center around that, right? It should be, am I NED? Uh, NED means no evidence of disease. So has the chemotherapy worked? Is the cancer, for all intents and purposes, gone? Um, are my blood counts back to normal? Because chemotherapy often wreaks havoc on the hematopoietic system. Um, and that frankly might be all you care about, right? Am I not anemic? Have my white cells come back? And am I free of cancer? And, and that, that would constitute the definition of am I healthy at the moment. Um, and so I-- in our context, in our practice, which I actually think reflects what many people are hoping to achieve when they, when they think through this question, um, we, we are really trying to think about it through the lens of what are the threats to longevity. And again, longevity has this very, um, at least in our view, pretty clear definition that's, that's pretty straightforward, right? Which is it's the, it's the product of both lifespan and healthspan. And, um, therefore, if you're, if you're in pursuit of better longevity, what that's saying is, "I want to live longer," or, "I want to live as long as possible in as high a state of health as possible." Um- And, and y- not having one of those things is insufficient. So living a long time in poor health, that's, that's not optimal, and having a short life in high health is also not optimal. So we, we want both of those things, and we frame it through the lens of what are the impediments to those things? And it's actually a relatively finite number of things. Um, so on the lifespan side of things, the impediments are the things that will shorten your life. So that, that is cardiovascular disease, cancer, uh, neurodegenerative and dementing diseases, metabolic disease, accidental deaths. Those are really the big ones. Now, of course, there are also organ-specific diseases and things like that that can fit in there, and we would always address those when relevant. So, you know, a person can also die from, uh, chronic obstructive pulmonary disease if they have a long-standing history of smoking, uh, kidney disease, liver disease that is unrelated to metabolic disease, et cetera. So, so there, there are other things in there, but you're capturing most of it, um, through what we just described. [lip smack] And then on the healthspan side of things, we're really talking about physical health. Um, and so that's, you know, freedom from pain, strength, endurance, uh, s- you know, excellent mobility. Basically, the ability to do anything you want physically. Um, [lip smack] and different people will have a different threshold, of course. So some people will have very high aspirations there, and others will have modest aspirations, and therefore they'll have a different standard for what constitutes healthy. Um, then there's a cognitive component to that, um, which is the ability to, um, to engage with your, with your brain, right? So this is everything from processing speed and short-term memory and long-term memory, uh, executive function, all of those things. And then there's an emotional component, um, which is, um, again, made up of many things, but it includes sense of purpose, happiness, uh, strength of relationships, emotional resilience, high distress tolerance, all of those things. Um, and as we go through this exercise, we feel that health constitutes everything I just talked about, and then we talk about how does the lab, uh, result help those things? Is it informing those things? Um, and if so, great, and if not, then do we have another way that we can look at those things?

4. 8:31 – 16:07

   The importance of longitudinal data, and the strengths and blind spots of labs for assessing cardiovascular disease risk

   1. SPSpeaker8:31

      And so before we kinda dive into labs as it relates to each of those kind of major diseases and categories you laid out, I think from a high level, how do you think about like a single snapshot of someone's lab? So if you're meeting with a patient for the first time and you have their labs from the week prior, right? How informative is that compared to if you have the labs from a week prior, as well as like a longer history of all the random times that they went to the doctor?

   2. PAPeter Attia9:00

      Well, I think there are a couple of things embedded within that. Um, the first is reliability of a lab. So if you only have a snapshot, if I only saw your labs, Nick, from today or last week, and I ne- I had, I had no access to anything else, it would be really difficult to make a decision, even in the context of something that was abnormal. Because I truly don't know if it is abnormal and, um, or if it's just actually, uh, a laboratory error. So you always have to have that in the back of your mind, and that's much easier to evaluate when you have longitudinal data. [lip smack] Furthermore, even if I know that it is a bear-- uh, pardon me, not aberrant, right? If I know that, hey, that, that result is actually what it says it is, I don't necessarily know how long it's been abnormal. And in some cases, that might matter. So I'll give you an example. Um, [lip smack] if I see that your C-reactive protein is three, um, and this is, if this is a highly sensitive C-reactive protein, that would be quite elevated. Um, and then let's assume I just immediately repeated the test, and lo and behold, it was three, not a lab error. Okay. But is it just three this week? I mean, maybe you're sick. Uh, maybe you were vaccinated two weeks ago, and this is still some lingering level, and it's coming back down, but it was, you know, 42 weeks ago. Uh, but your baseline is, you know, 0.5. Um, I, I can't figure out if this is sort of chronic inflammation or if it's reactive, if it's going up, if it's going down. So it would be difficult for me to sort of weigh in and say that, um, we're gonna y- you know, implement this playbook that we typically implement for people that have high inflammation. Um, the same I think would be true for something like ApoB, uh, or LDL cholesterol. So if your LDL cholesterol is, let's say it's 160 milligrams per deciliter, that's, that's, that's very, very high, right? That would put you above the 80th percentile. Um, if that's just that high because you've gone on a diet in the past, you know, three months that has you mainlining saturated fat and your ApoB and LDL-C have gone up, you know, that's kind of a different situation than if it's been that high your whole life, which might actually suggest you have a genetic condition that's driving that. So, um, I think longitudinal data are valuable, um, but you also have to work with what you have. There are some people who come in with, um, very little longitudinal data, and you s- you know, you still have to make decisions based on the information you have. Obviously, there are certain things that you don't need to check more than once: Lp (a) , ApoE, or any other genetic test, a- assuming that the, uh, answer you got is correct and the lab was, was done. Um, but, um, yeah, so I don't know. Hopefully, that answers your question, that, that, um, it's, it's a bit of both. No, for sure. And I think it will be helpful now to kind of go through the major chronic diseases one by one that you laid out earlier and just talk about, okay, where are labs helpful and where do they kind of leave a picture still unpainted? So let's start with the biggest killer, cardiovascular disease. So what do labs tell us, and how helpful are they in understanding someone's risk of this disease? Thank you for viewing this sneak peek of an Ask Me Anything episode of The Drive. As a premium member, you'll get immediate access to the full AMA episode you just watched a sneak peek for, our entire back catalog of AMA episodes, and all future AMA episodes. You'll get longevity-focused premium articles packed with actionable insights. You'll get unrivaled show notes for each and every episode of The Drive and much more. 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Episode duration: 16:07