Fewer than one in ten American adults is metabolically healthy. That’s what a large NHANES analysis found when it looked at blood sugar, triglycerides, HDL, blood pressure, and waist circumference across the population. I’ve written about that data before, but it’s worth repeating here because it’s one of the key reasons this newsletter exists. When your physician reviews your labs and tells you everything looks fine, the reference range they’re using might not be telling you everything you need to know.
Many ‘normal’ labs might be far from ‘normal’. Many lab reference ranges are set to catch disease, not the years of quiet, slow loss of metabolic health that precede it. A good example is Hemoglobin A1c. If it’s above 5.7, even if you’re told “you’re not diabetic yet,” you’re probably not in a good place either… and it often warrants closer attention, lifestyle changes, and perhaps medication.
I order a decently broad panel on myself twice a year. A few of the tests I order for myself and my family aren’t ordered on a standard panel. Not that the standard panel is bad, but I want to catch certain disease processes early so I can consider preventive measures and optimize my chances of staying healthy and fit.
Below, I’ve laid out the labs I think are worth knowing the results of, how I think about them clinically, and the standard reference range next to the range where the evidence may or may not suggest you probably want it.
Some of these markers have decades of large prospective studies and formal society guidelines behind their optimal ranges… I’ll tell you when that’s the case. Others are used widely in clinical practice but rest on thinner evidence, and I’ll mention that too. That’s but one difference between a physician with 30 years of experience and your typical online influencer.
It’s important to understand that I don't order 100s or thousands of biomarker tests for myself. Most humans die of very predictable causes. The tests I utilize address the most common causes of human demise.
I released my low back strengthening/hardening protocol last weekend. I’ve had back pain for 40+ years— these keep my pain at bay
The Boring stuff wins… a 6-minute short-form podcast I put out nearly every Thursday.
Disclaimer: This article describes the laboratory tests I choose to follow and the values I personally aim for based on my health, age, training, risk factors, and interpretation of the available evidence. These are my goals, not universal targets, and some differ from standard laboratory reference ranges or professional society guidelines. Your medical history, medications, genetics, symptoms, and individual risk factors may make entirely different tests or targets appropriate for you. This information is for educational purposes and should not be used to diagnose a condition, change a medication, start a supplement, or pursue a particular laboratory value on your own. Instead, use it to inform a conversation with your physician, who can interpret these results in the context of you.
Insulin resistance is the upstream driver behind a lot of what shows up in my office, and in cardiology offices, and in endocrinology offices, more than almost anything else. It also develops years before fasting glucose, or A1c, might cross a diagnostic threshold, and you’re told that you have a problem.
If you’re insulin resistant, then you’re at risk for type 2 diabetes. If you’re insulin resistant, you’re likely to have chronic systemic inflammation too. And as we have discussed here often, chronic systemic inflammation (CSI) drives heart disease, the risk of stroke, dementia, certain cancers, and even arthritis and tendon issues.
Insulin resistance and secondary CSI accelerate the diseases that are the most common causes of death and disability in humans. If you’re pursuing metabolic health… this is where we have to start.
This is one of the tests most people never have ordered. Normal fasting glucose with elevated fasting insulin means the pancreas is working overtime to keep glucose in the normal range. That’s the definition of insulin resistance.
Most labs report a “normal” fasting insulin as anything under 18-25 µIU/mL, a threshold so wide it misses the entire window where intervention probably matters most. This is when it is easiest to address the earliest of changes that might lead to type 2 diabetes nearly a decade down the road.
I target below 5 µIU/mL, which indicates excellent insulin sensitivity. Above 10, I would work hard to change my lifestyle and address any underlying issues. This is one of the key area-under-the-curve problems that lead to poor health. The longer these changes persist, the more severe the silent damage becomes and the harder it is to correct.
Once you have fasting insulin and fasting glucose (See CMP below), you can calculate HOMA-IR yourself: multiply fasting insulin (𝜇U/ml) by fasting glucose (mg/dL) and divide by 405.
A fasting glucose of 90 with a fasting insulin of 12 gives you a HOMA-IR of 2.7. Individually, both numbers would be considered normal using standard lab reference ranges. But a HOMA-IR score of 2.7 is NOT normal.
A HOMA-IR below 1.0 is optimal. Above 1.5 may indicate early insulin resistance. Above 2.0 is significant and nearly always indicates severe insulin resistance, regardless of how reassuring the individual glucose or insulin values look on their own.
Standard reference ranges define fasting glucose as normal up to 99 mg/dL and A1c as normal up to 5.7%. I want my patients closer to a fasting glucose under 90 and an A1c under 5.4%.
A glucose of 97 might not raise an eyebrow at a routine physical. But it should trigger a question. Sometimes fasting morning glucose is elevated, and it’s not abnormal. Stress, the dawn phenomenon, and more can cause a level to be higher than your fasting insulin, or HOMA-IR suggests. This is why we need to look at fasting insulin, HOMA-IR, and your fasting glucose in context. Sometimes we need an oral glucose tolerance test to clarify issues further.
One caveat I’ve written about at length: A1c can run falsely high in endurance athletes and anyone with altered red blood cell turnover, so if you train seriously and your A1c is elevated while your fasting insulin and HOMA-IR are both optimal, that mismatch is worth discussing with your physician before assuming it’s due to metabolic dysfunction.
My goals for my levels are as follows:
Fasting insulin optimal: below 7 µIU/mL (below 5 is excellent). Above 10 is a red flag.
HOMA-IR optimal: below 1.0. Above 2.0 is significant insulin resistance.
Fasting glucose optimal: below 90 mg/dL. 95 and trending up deserves attention even though it’s “normal.”
A1c optimal: below 5.5%. Standard flags at 5.7%.
For members, we’ll continue going well beyond the labs included at a typical annual physical. I’ll show you the markers I order for myself twice a year, why I follow them, and what I look for when I review the results. We’ll cover chronic systemic inflammation, cardiovascular risk beyond a standard cholesterol panel, thyroid function, vitamins and iron status, liver and kidney health, uric acid, hormones, and some tests I deliberately don’t order despite their popularity in wellness circles.
I’ll also share the ranges I pay attention to when strong evidence supports those targets, and when they reflect my own judgment. The goal isn't to turn you into your own doctor. It's to give you enough context to have a much better conversation with yours.
Comments
Nothing yet. Say the first thing.
Sign in to join the conversation.