Try This: Optimal Metabolic Health Lab Panel

Hi ,

I hope you’re having a fantastic summer!

While the team and I are away for travel, I wanted to re-share one of our most popular newsletters to date, Try This: Optimal Metabolic Health Labs.

Since this community has grown so much since I last shared it, I thought it’d make an excellent refresher and reference for long-time and new members.

I hope you enjoy it, and we’ll be back next week with another newsletter.Here's to you metabolic health,Dhru PurohitP.S. Even if you've seen this newsletter before, be sure to take advantage of the special $50 discount Levels Health is offering our community. More details below! Offer expires on August 1st, 2023.

Many people go to their doctor for an annual checkup and get comprehensive blood work, but very few stop to look at the actual results, especially when we’re told, “Great job, everything is normal!” 

And yet, less than 7 percent of Americans are metabolically healthy.

How can this be? How can our numbers be “normal” one minute, and the next thing we know, we’re on the fast track toward chronic diseases like obesity, diabetes, and heart disease?

This week, I’m re-sharing my optimal metabolic health labs newsletter with optimal reference ranges to help you catch signs of chronic illness before it’s full blown. 

That way, you can feel empowered knowing what’s going on beneath the surface with your metabolic health so you don’t have to sit back and wait for your numbers to fall out of range to begin to intervene with diet and lifestyle interventions. 

We must shift away from this “wait and see” approach and focus on preventive medicine, which requires looking at the bigger picture—what’s impacting these markers and why—so we can make healthy lifestyle changes earlier. 

Before we dive into the lab markers, let’s first address the limitations of routine lab tests. 

Limitations of Routine Lab Tests

1. Routine blood work is typically only done once a year, making it difficult to see when biomarkers change and what’s causing them to change.  Although blood sugar is just one area of health, it does have an impact on many other facets, like energy, hormone balance, and inflammation. That’s why I love wearing my continuous glucose monitor (CGM) paired with the Levels app. It allows me to see how my blood glucose changes in real time so that I don’t have to wait to make changes to my diet. See below for more information on Levels and a special deal to try out their CGM kits. 

2. Reference ranges are determined based on the average population, but 93 percent of Americans are metabolically unhealthy. This means “normal” is far from optimal. Metabolic dysfunction is likely already present if you’re on the borderline of being out of a reference range. (Note: I wrote about standard reference ranges and the problems that come with them in a previous newsletter.)

3. Lab tests that detect early signs of metabolic dysfunction aren’t on standard lab panels. Fasting insulin, for example, is the best test for detecting early signs of insulin resistance, yet many doctors are unaware of its usefulness and therefore don’t test for it. 

In this podcast interview, I sit down with my dear friend and cofounder of Levels, Dr. Casey Means, to discuss the importance of metabolic lab tests and how to get the most out of them. 

Like I said above, connecting my CGM with Levels has been super helpful for giving me insight into my blood sugar on a daily basis. In addition to food, I can also see how my blood sugar is impacted by working out, sleeping, traveling, and stress and use the Levels app to take notes and document times for reference.

Want to Try Levels? Get It for $50 Off with My Code DHRU50

I was able to talk to my friends at Levels and work out a special deal for anyone who wants to experiment with a CGM. But first, I have to say that I am an investor of Levels because I stand by their mission to make CGMs more widely accessible to the public. 

For new users, use this link and use the code DHRU50 to get $50 off your first order, which includes their annual membership and a one-month CGM kit.

Levels is also changing the game for routine metabolic lab testing for its members. With Levels’ Metabolic Health Panel, you can get blood work done from the comfort of your home. It’s super easy, convenient, and it includes fasting insulin — the best marker for detecting early signs of insulin resistance (read on to learn more about fasting insulin and why it’s not typically included on standard lab tests). 

If you’re not a member, you can use this link to sign up and get $50 off, and you can sign up for their membership metabolic lab testing program.Quick Note: The offer from Levels expires August 1st, 2023, so be sure to take advantage of this discount while you can.

Next, I’m unpacking the top metabolic lab tests, their optimal ranges, and their limitation from this Levels blog that borrowed reference ranges from their expert team of advisors that includes Dr. Mark Hyman, Dr. Ben Bikman, Dr. Sarah Gottfried, Dr. Rob Lustig, and Dr. Molly Maloof.

Fasting Glucose

What is it? A measure of your blood glucose levels unaffected by a recent meal.

Why it’s important: It tells us how well our insulin and glucose pathways function without the influence of food. High fasting blood glucose is associated with a greater risk of heart disease, metabolic dysfunction, diabetes, and all-cause mortality. If your fasting blood glucose levels are in the prediabetes or diabetes range, it’s a sign that insulin resistance has been going on for some time, which is one limitation. Unlike fasting insulin, fasting glucose tests can’t detect insulin resistance early on.

Standard Reference Ranges: 

• Normal: <100 mg/dL 

• Prediabetes: 100–125 mg/dL

• Diabetes: 126 mg/dL

Optimal Reference Range: 72–85 mg/dL

Fasting Insulin

What is it? A measure of your insulin unaffected by a recent meal. Our pancreas produces insulin, which binds to glucose in our bloodstream and delivers it to our cells. 

Why it's important: Fasting insulin indicates how well your body can regulate blood glucose levels. It is the best test for detecting insulin resistance before it’s full-blown. The best part is it’s super affordable at around $15. You just have to ask your doctor for it since they don’t routinely test it. Fasting insulin is such a powerful biomarker that we wrote an entire newsletter about it! 

If you want to learn more information, you can read up on it here: Try This: The #1 Lab Test for Optimal Metabolic Health.

Standard Reference Range: <25 mIU/L

Optimal Reference Ranges: 2–5 mIU/mL

• >10 mIU/mL is concerning

• >15 mIU/mL is significantly elevated

Hemoglobin A1C (HbA1c)

What is it? Your hemoglobin A1C (HbA1c) is the percentage of blood hemoglobin with glucose attached.

Why it's important: HbA1c measures blood glucose levels over three months. This test is more accurate than fasting glucose because it measures your average blood glucose over time. It helps detect prediabetes and diabetes because a high HbA1c indicates high blood sugar and insulin resistance.

HbA1c has limitations because it doesn’t account for the daily blood glucose variability from stress, diet, exercise, hormonal changes, etc. Additionally, it has a sensitivity of 60 percent and doesn’t consider the biological variability between ethnic groups.

For more on HbA1c and how it relates to longevity, read this newsletter on the top causes of high levels and how to lower yours using simple diet and lifestyle strategies.

Standard Reference Ranges: 

• Normal: <5.7% 

• Prediabetes: 5.7%–6.4% 

• Diabetes: >6.5%

Optimal Reference Range: <5.5%, but <5% is ideal

LDL Cholesterol

What is it? Known as the “bad cholesterol,” low-density lipoprotein (LDL) carries and delivers cholesterol to our tissues. 

Why it's important: High LDL is linked to an increased risk of coronary artery disease, heart attack, and stroke because LDL cholesterol can get stuck in our arteries' endothelial lining, leading to inflammation, plaque buildup, and reduced blood flow. 

However, new research challenges this idea and suggests that it's not your LDL cholesterol levels but the size of your LDL cholesterol particles associated with heart disease.

For this reason, experts recommend getting an NMR test instead, which tells you the size and number of your cholesterol particles (see “Bonus Tests” for further explanation) to understand your cardiometabolic risk. 

As Dr. Molly Maloof says, “LDL IS A GARBAGE TEST.” 

High LDL cholesterol is associated with a 30 percent greater risk of heart disease, whereas high triglycerides are associated with an 80 percent risk. Your triglyceride-to-HDL ratio is a much better indicator of heart disease risk, followed by your total cholesterol-to-HDL ratio. 

My cardiologist, Dr. Michael Twyman, joined me for a deep dive into the critical role of endothelial dysfunction and high cholesterol in determining our susceptibility to heart disease.In this article, you’ll find his top tips for safeguarding your endothelial cells and becoming what he calls “heart attack proof.” 

Standard Reference Ranges:

• <70 mg/dL for those with heart or vascular disease

• <100 mg/dL for those at high risk 

Optimal Reference Range:

<100 mg/dL. Some experts consider <70 mg/dL optimal, but an NMR test can give you a comprehensive look at how problematic your LDL is. 

HDL Cholesterol

What is it? Known as “good cholesterol,” high-density lipoprotein (HDL) cholesterol carries cholesterol away from the arteries and tissues to the liver to be redistributed, metabolized, or excreted. 

Why it's important: You want your HDL cholesterol to be high. Some experts say the standard reference ranges are too low to be cardioprotective. For example, if somebody has low HDL cholesterol (say 45 mg/dL) and borderline high triglycerides (say 148 mg/dL), they may be told they’re in good shape but still be at increased risk for metabolic disease. 

HDL tends to be lower if you are insulin resistant and have high triglycerides. Dr. Means recommends calculating your triglycerides-to-HDL ratio to understand your metabolic health better (see below for more on the TG-to-HDL ratio). 

Standard Reference Range: >45 mg/dL

Optimal Reference Range: >60 mg/dL is good, but >90 mg/dL is optimal

Total Cholesterol

What is it? The sum of all the cholesterol in your blood (HDL and LDL). 

Why it's important: This test doesn’t say much when viewed in a silo. You can have an in-range total cholesterol score and still be at risk for chronic disease. What matters is your HDL levels and how much of it makes up your total cholesterol. This is why the total-cholesterol-to-HDL-cholesterol ratio is a better predictor of cardiometabolic health than total cholesterol alone (see below). 

Standard Reference Ranges:

• 20 years old or younger: 75–169 mg/dL

• 21 years old and older: 100–199 mg/dL

Optimal Reference Range:

• <180 mg/dL

Total-Cholesterol-to-HDL-Cholesterol Ratio (TC:HDL)

Why it's important: Together, these numbers tell you more about your risk for heart disease than either one on its own. The lab tests your doctor orders do not calculate this, but you can easily do it by dividing your total cholesterol by your HDL cholesterol. 

TC:HDL = Total Cholesterol ➗ HDL 

The higher your ratio, the greater your risk for chronic diseases like obesity, type 2 diabetes, and heart disease. 

Standard Reference Ranges:

• Most healthcare providers prefer a ratio of 5:1 or less

• 3.5:1 is considered very good

Optimal Reference Ranges:

• <3.5:1 is good

• <2:1 is ideal

Triglycerides

What is it? When excess calories go unused, they are converted into triglycerides and circulate in the blood or are stored as fat.

Why it’s important: Triglyceride levels are a significant indicator of the overall quality of a person’s diet. Consuming concentrated sources of sugar from ultra-processed foods or fructose (think soda and high fructose corn syrup) activates our liver’s fat-storage switch and produces triglycerides.

To learn more about this metabolic switch and how fructose activates it:

• Try This: How To Turn Off Your Fat Storage Switch

• The Latest Science on How to Turn Your Body’s Fat Storage Switch Off (interview with Dr. Richard Johnson)

The good thing about triglycerides is that it only takes about a month for changes to your diet to have a positive impact on them. 

Standard Reference Range: <150 mg/dL

Optimal Reference Range: <100 mg/dL, although some experts say <80 mg/dL or <50 mg/dL

Triglycerides-to-HDL Ratio (TG:HDL)

Why it's important: If your doctor can’t order a fasting insulin test, your triglycerides-to-HDL ratio is the next best thing. This ratio will tell you about your insulin sensitivity. If your ratio is low, it means you are insulin sensitive. If the ratio is high, there’s likely insulin resistance present. 

Your TG:HDL ratio can also tell you more about your LDL cholesterol if you can’t get an NMR test. If your ratio of triglycerides to HDL is high, there’s a good chance that your LDL cholesterol is small and dense—the dangerous kind that damages your endothelial lining. Like TC:HDL, you can calculate this ratio by dividing your triglycerides by your HDL. 

TG:HDL = Triglycerides ➗ HDL 

Experts agree that this is one of the most powerful markers to predict your risk of heart disease. One study found that people with the highest TG:HDL ratio had a 600 percent increased risk for heart disease. 

Optimal Reference Range: <1

Note: >2.5:1 in Caucasians and >1.5:1 in African Americans indicates metabolic syndrome.

High-Sensitivity C-Reactive Protein (hsCRP)

What is it? A marker of inflammation.Why it’s important: It tells us how much inflammation is present inside the body and is high in individuals with metabolic dysfunction and chronic disease. If you’re stressed, sick, or have an infection, hsCRP can also come back high, making it hard to identify the root cause.

Standard Reference Range: <2.0 mg/L 

Optimal Reference Range: <1.0 mg/L, although some experts say <0.5 mg/L

Bonus Tests

NMR: The NMR test tells you what percentage of your LDL cholesterol is small and dense (atherogenic) or light and fluffy (less dangerous) by measuring the makeup of your LDL particle sizes.

Why it's important: Small, dense LDL cholesterol is the most dangerous because it damages the endothelial lining. It’s also a sign of insulin resistance. Contrarily, very low-density LDL cholesterol (VLDL) particles are light, fluffy, and less likely to cause damage. Someone can have a low LDL level and still be at risk for heart disease if it’s the small, dense type. And someone can have a high LDL level and be at low risk if it’s mostly the VLDL type. 

Traditional medicine emphasizes LDL cholesterol because we have drugs that effectively lower it. But if our LDL and HDL are high and our triglycerides are low, the person is probably in good cardiometabolic health.Not to mention, if small, dense LDL is high due to insulin resistance, statins won’t resolve that issue. Additionally, doctors tend to advise patients to go on a low-fat diet to lower LDL, which, in turn, encourages people to eat more carbs. The result? Small, dense LDL cholesterol remains the same or increases even more.

Apolipoprotein B: ApoB is found on the surface of lipoproteins, mainly LDL, which carries 90 percent of apoB particles. 

Why it's important: ApoB is a proxy for your levels of small, dense LDL cholesterol, making it a good indicator of cardiovascular disease risk.

Further Reading: Peter Attia on apoB

Final Thoughts

Routine lab work can help us understand the bigger picture of what’s going on with our metabolic health, but it does have limitations. If we know our blood glucose and cholesterol levels and the optimal reference ranges to strive for, we can become the CEO of our health and make changes if our levels fall out of range. Get my Try This: Optimal Metabolic Health Labs cheatsheet.⚠️ These newsletters are for educational purposes only and are meant to help you ask questions and work with your medical provider to design a plan that’s best for you and your long-term health.