Can You Have Insulin Resistance with a Normal A1C? What a Nurse Wants You to Know

“Your Labs Are Normal” Doesn’t Mean You’re Fine

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You leave your doctor’s appointment with the same answer you’ve gotten for the last five years.
“Everything looks good. Labs are normal.”

And you sit in your car and think… then why do I feel like this?
Why am I exhausted by 2pm every day? Why can’t I lose weight no matter what I do? Why does my brain feel like it’s running through fog? Why am I doing everything “right” and nothing is changing?

You’ve heard “your labs are normal” so many times that you’ve started to believe the problem must be you. Your discipline. Your effort. Your willpower.

It’s not you. And I need you to hear that.

Your labs might technically be within range. But “within range” and “optimal” are not the same thing. And the test that would actually tell you whether you have insulin resistance? There’s a very good chance your doctor never ordered it.

What Is a Fasting Insulin Test and Why Don’t Most Doctors Order It?

When you go in for your annual physical or routine bloodwork, your doctor typically checks two things related to blood sugar: your fasting glucose and your A1C (hemoglobin A1C).

Fasting glucose is a snapshot. It tells you what your blood sugar is right now, after you haven’t eaten for 8 to 12 hours. A result under 100 mg/dL is considered normal. Between 100 and 125 is prediabetes. Over 126 is diabetes.

A1C is a wider view. It measures your average blood sugar over the last 2 to 3 months by looking at how much sugar has attached to your red blood cells. Under 5.7% is normal. 5.7 to 6.4% is prediabetes. Over 6.5% is diabetes.

Both of these tests measure the same thing… glucose. They just measure it differently.

And here’s the problem: neither one tells you how hard your body is working to keep that glucose number “normal.”

Think of it this way. Imagine two women sitting in the same doctor’s office on the same day. Both have a fasting glucose of 94 mg/dL. Both A1Cs come back at 5.4%. Both get told their labs are normal.

But behind the scenes, the first woman’s pancreas is producing 5 units of insulin to maintain that glucose level. Easy. No sweat. Her metabolic system is cruising.

The second woman’s pancreas is grinding out 18 units of insulin just to hold the line at 94. Her body is working triple shifts to keep that number where it is. She’s exhausted, gaining weight she can’t explain, brain fog is constant, and she can’t stop thinking about food.

On paper, they look identical. Metabolically, they’re in completely different places.

The only way to see the difference? A fasting insulin test. And most routine bloodwork panels do not include it.

That’s not an oversight by your specific doctor. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) states plainly that doctors use blood tests to find out if someone has prediabetes, but they don’t usually test for insulin resistance. It’s just not part of the standard protocol. Which means millions of women are walking around with insulin resistance that nobody is looking for… because nobody is ordering the test that would find it.

What Is HOMA-IR and How Do You Calculate It?

A fasting insulin test measures how much insulin your pancreas is producing after you haven’t eaten. That number alone is helpful. But when you combine it with your fasting glucose, you can calculate something even more useful… your HOMA-IR score (Homeostatic Model Assessment of Insulin Resistance). This is essentially a number that tells you how insulin-resistant your body is.

The math is simple: (fasting glucose x fasting insulin) / 405.

Both values must come from the same fasting blood draw.

Here’s how to read your HOMA-IR score:
Under 1.0 — Optimal insulin sensitivity. Your body is using insulin efficiently.
1.0 to 2.5 — Moderate range. Worth watching, especially if you have other risk factors like PCOS, family history of diabetes, or unexplained weight gain.
Over 2.5 — Insulin resistance is likely present. Your pancreas is working harder than it should to keep your blood sugar in range.
Over 3.0 — Significant insulin resistance. This level may already be driving symptoms… fatigue, weight gain, brain fog, food noise… even if your glucose and A1C still look completely normal on paper.

So why doesn’t your HOMA-IR show up on your standard bloodwork? A few reasons. Most standard metabolic panels are built around glucose, not insulin. Time constraints in a 15-minute appointment don’t leave room for expanded testing. And many providers follow a “wait and see” approach to borderline results… meaning they don’t dig deeper until your numbers actually cross into prediabetes or diabetes territory.

By then, the damage has been building for years.

Can You Have Insulin Resistance with Normal Blood Sugar and a Normal A1C?

Yes. And this is the part that makes me want to flip a table.

Your fasting glucose can be perfect. Your A1C can be textbook. And insulin resistance can still be building behind the scenes for years because your pancreas is compensating… producing more and more insulin to keep your blood sugar in range.

According to the Cleveland Clinic, as long as your pancreas can make enough insulin to overcome the resistance, your blood sugar levels will stay in a healthy range and you won’t have any symptoms. But over time, the cells that make insulin can wear out. That’s when blood sugar finally rises. That’s when you get the prediabetes or diabetes diagnosis. But the insulin resistance? That started long before the numbers changed.

Research from a peer-reviewed study published in a PMC journal found that elevated insulin levels in the absence of impaired glucose tolerance and normal A1C may actually be a much earlier indicator of metabolic disease risk than glucose or A1C alone. In other words… insulin was waving a red flag the whole time. Nobody was watching for it.

How Many People Have Undiagnosed Insulin Resistance and Prediabetes?

According to the CDC’s most recent National Diabetes Statistics Report (January 2026), over 115 million American adults have prediabetes. And 8 in 10 of them don’t know it.

Let that sink in for a second. 80% of people with prediabetes are walking around right now being told their labs are normal.

On top of that, research published in Diabetes Care found that using A1C alone to screen for prediabetes missed about 75% of at-risk individuals. The study specifically noted that A1C was less sensitive for detecting at-risk individuals compared to fasting glucose and glucose tolerance testing… and none of those tests even measure insulin.

Meanwhile, a growing body of research shows that elevated insulin levels can appear years… and according to some researchers, potentially even decades… before blood sugar ever crosses into an abnormal range. Your pancreas is working overtime to keep your glucose normal, and nobody’s checking to see how hard it’s working.

Why Insulin Resistance Testing Matters Even More If You Have PCOS

If you have polycystic ovary syndrome, this isn’t just relevant. It may be the entire missing piece of your health puzzle.

Research estimates that insulin resistance affects between 50 and 80% of women with PCOS… including women who are not overweight. That’s not a small subset. That’s the majority. And many of those women have never had their insulin levels checked.

Insulin resistance in PCOS doesn’t just affect blood sugar. It directly drives excess androgen (testosterone) production, which can cause irregular periods, acne, hair loss, excess body hair, and difficulty getting pregnant. The cycle looks like this: insulin resistance leads to higher insulin levels, which triggers increased androgen production, which disrupts ovulation, which worsens PCOS symptoms. It feeds itself.

And the whole time, your fasting glucose and A1C may look completely normal because your pancreas is compensating.

One peer-reviewed study in the Journal of Clinical Medicine proposed that the medical community needs to shift from a “glucose-centric” approach to an “insulin-centric” model when managing PCOS… because by the time glucose rises, the metabolic damage has already been happening for years. The study emphasized that early identification of insulin resistance would enable timely intervention and could reduce the risk of long-term metabolic and reproductive complications.

If you’ve been told your labs look fine but you’re still gaining weight, still exhausted, still struggling with PCOS symptoms that nobody can explain… this may be why. The right labs were never ordered.

What Blood Tests Should You Ask Your Doctor For?

  1. Ask for a fasting insulin test at your next appointment.
    • It’s a simple blood draw done at the same time as your regular fasting labs.
    • You may need to specifically request it… many providers won’t think to order it unless you ask.
    • If your provider pushes back, you can explain that you’d like to assess insulin resistance beyond what glucose and A1C alone can show.
    • The NIDDK confirms that providers don’t usually test for insulin resistance as part of standard screening.
    • That doesn’t mean the test isn’t available or valuable. It means you may need to advocate for yourself.
  2. Know your HOMA-IR score.
    • Once you have your fasting insulin and fasting glucose from the same blood draw, you can calculate it yourself:
      • (fasting glucose x fasting insulin) / 405.
        • Under 1.0 is optimal.
        • Over 2.5 starts to suggest insulin resistance.
        • Over 3.0 is significant.
    • There are also free HOMA-IR calculators online if math isn’t your thing.
  3. Ask about a full hormone panel if you have PCOS or suspect it.
    • Fasting insulin
    • HOMA-IR
    • testosterone (total and free)
    • DHEA-S
    • LH
    • FSH
    • lipid panel
      • These give a much more complete picture of what’s happening metabolically and hormonally than glucose and A1C alone.
  4. Know the difference between “normal range” and “optimal.”
    • Lab reference ranges are based on population averages… they tell you where most people fall, not where you should be for your best health.
    • A fasting glucose of 98 is technically “normal” but it’s not optimal.
    • An A1C of 5.6 is technically “normal” but it’s one decimal point from a prediabetes diagnosis.
    • Don’t let “in range” make you stop asking questions.
  5. Trust your body.
    • If you feel like something is off, something probably is.
    • You are not imagining it.
    • You are not lazy.
    • You are not failing.
    • You may just be missing data.

If you’re currently on a GLP-1 or considering one, I put together a free checklist that walks you through what to track between appointments… the stuff most people don’t think to monitor.

GRAB IT HERE FOR FREE

The Part I Take Personally

I was the woman in the car. I had PCOS. I had high blood pressure, high cholesterol, and sleep apnea. I was labeled pre-diabetic for about eight months in 2006… and then my A1C came back down and everybody moved on. Normal. Case closed.

Except my white blood cell count kept showing chronic inflammation. Nobody connected those dots. Nobody said “hey, your A1C looks better but let’s dig deeper into WHY your body is still inflamed, WHY you can’t lose weight, WHY none of this is adding up.”

I never got the right tests. I still haven’t. What I got was a doctor who finally looked at me and said… something isn’t adding up. The calories in versus calories out math wasn’t mathing. My body wasn’t responding the way it should have been. And instead of handing me another pamphlet, he prescribed a GLP-1.

That changed everything. But I think about how many years I spent blaming myself for something that had a physiological explanation nobody bothered to look for. How many times I white-knuckled a diet and watched the scale not move and thought it was ME.

I’m a NICU nurse. I believe in evidence. I believe in labs. But I also believe that the wrong labs… or the incomplete ones… can leave you blaming yourself for something that was never your fault.

If your doctor says your labs are normal but your body is screaming that something is wrong… believe your body. Then go get the right labs. The ones I’m telling you about in this post? I wish someone had told me about them ten years ago.

Frequently Asked Questions About Insulin Resistance and Lab Testing

Can you have insulin resistance with a normal A1C?

Yes. Insulin resistance can develop years before your A1C ever moves out of the normal range. Your pancreas compensates by producing more insulin to keep blood sugar stable. As long as it can keep up, your glucose and A1C may look fine on paper while insulin resistance builds underneath. A fasting insulin test or HOMA-IR calculation can reveal what glucose-based tests miss.

What is HOMA-IR and how do I get tested?

HOMA-IR stands for Homeostatic Model Assessment of Insulin Resistance. It’s not a separate blood test… it’s a calculation using two values from a single fasting blood draw: your fasting glucose and your fasting insulin. The formula is (fasting glucose x fasting insulin) / 405. A score under 1.0 is considered optimal. Over 2.5 suggests insulin resistance. Over 3.0 is significant. You’ll need to ask your doctor to order a fasting insulin level since it’s not included in standard metabolic panels.

Does a normal fasting glucose mean I don’t have insulin resistance?

Not necessarily. Your fasting glucose measures what your blood sugar is at one moment in time. It doesn’t tell you how much insulin your body needed to get it there. Two people can have the exact same fasting glucose but very different insulin levels… and very different levels of metabolic stress happening behind the scenes.

Why doesn’t my doctor test for insulin resistance?

Most standard bloodwork panels focus on glucose, not insulin. The NIDDK notes that providers don’t usually test for insulin resistance as part of routine screening. It’s not that the test doesn’t exist or isn’t valuable. It’s that the current standard of care doesn’t include it unless you specifically ask or your provider is thinking beyond the basics.

What blood tests should I ask for if I have PCOS?

For a more complete metabolic and hormonal picture, consider asking about: fasting insulin, fasting glucose (to calculate HOMA-IR), A1C, testosterone (total and free), DHEA-S, LH, FSH, and a full lipid panel. These tests together can reveal insulin resistance, hormonal imbalances, and metabolic risk factors that glucose and A1C alone would miss.

Is it too late to test for insulin resistance in my 40s?

No. Research shows that lifestyle and medical interventions can reduce the risk of progressing from insulin resistance to type 2 diabetes significantly… even in midlife. The earlier you identify insulin resistance, the more options you have. But “earlier” doesn’t mean it has to be your 20s. It means earlier than waiting for a diabetes diagnosis.

Not sure where to start? My free Wellness Strategy Quiz can help you figure out what to focus on first based on where you are right now

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Click here to view my sources:
  • CDC National Diabetes Statistics Report (January 2026) — cdc.gov/diabetes/php/data-research
  • CDC Prediabetes Statistics — cdc.gov/diabetes/communication-resources/prediabetes-statistics
  • NIDDK — Insulin Resistance & Prediabetes — niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance
  • Lorenzo C, et al. “A1C Between 5.7 and 6.4% as a Marker for Identifying Pre-Diabetes, Insulin Sensitivity and Secretion, and Cardiovascular Risk Factors.” Diabetes Care. 2010;33(9):2104-2109.
  • Parker J. “Recognizing the Role of Insulin Resistance in Polycystic Ovary Syndrome: A Paradigm Shift from a Glucose-Centric Approach to an Insulin-Centric Model.” Journal of Clinical Medicine. 2025;14(12):4021.
  • “Hyperinsulinemia: An Early Biomarker of Metabolic Dysfunction.” PMC. 2023. pmc.ncbi.nlm.nih.gov/articles/PMC10186728
  • Cleveland Clinic — Insulin Resistance: What It Is, Causes, Symptoms & Treatment — my.clevelandclinic.org/health/diseases/22206-insulin-resistance
  • “Markers of Insulin Resistance in Polycystic Ovary Syndrome Women: An Update.” World Journal of Diabetes. 2022. pmc.ncbi.nlm.nih.gov/articles/PMC8984569
  • “Insulin Resistance, Metabolic Syndrome and Polycystic Ovaries: An Intriguing Conundrum.” Frontiers in Endocrinology. 2025.
  • Ezeh U, et al. “Detecting Insulin Resistance in Polycystic Ovary Syndrome: Purposes and Pitfalls.” PubMed. 2004.

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I’m a registered nurse and health coach who shares real, BS-free information about metabolic health, PCOS, perimenopause, and weight loss, because y’all deserve better than vague wellness fluff. But here’s what I need you to know: I am not YOUR nurse. Everything I share here is for educational purposes only. It is not medical advice, it’s not a diagnosis, and it doesn’t create a provider-patient relationship between us. Nothing on this site replaces the care of a licensed provider who actually knows your full health history. The opinions and content here are my own and do not reflect the views of my employer or the hospital where I work.

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