Before the A1c moves — reading insulin resistance early

Your annual labs come back and the glucose is 94. The A1c is 5.4. Your doctor says everything looks great, and on paper it does. But you are hungry again not long after breakfast, you lose the thread of a meeting in the mid-afternoon, and you have gained weight around the middle that did not used to be there. The waistband changed before anything on the lab report did.

This is one of the most common versions of the question we hear: “Why are my blood tests normal but I don’t feel normal?” With blood sugar, the answer is usually mechanical rather than mysterious. The two markers most people get measured — fasting glucose and hemoglobin A1c — are the last things to change in the sequence. They report on a system that has already failed to compensate. We would rather see the compensation while it is still happening.

Why glucose and A1c are late markers

Blood glucose is tightly defended. The body treats a stable circulating sugar level the way it treats pH and core temperature — as something worth spending resources on. The main resource it spends is insulin. When cells respond less readily to insulin, the pancreas does not let glucose rise; it secretes more insulin to get the same job done. Glucose stays in range because the beta cells are working harder, not because the system is healthy.

Fasting glucose only starts to drift upward when that compensation begins to fall short — when the beta cells can no longer produce enough extra insulin to override the resistance, or when the liver’s overnight glucose output stops being adequately suppressed. A1c is later still. It reflects how much glucose has become chemically attached to hemoglobin over the lifespan of a red blood cell, which means it is an average of an average. It also gets distorted by things that have nothing to do with sugar: iron deficiency and anemia can shift it, as can any condition that changes how long red cells survive in circulation. We have seen A1c read deceptively low in a patient with meaningful iron deficiency and deceptively high in someone whose red cells were simply long-lived.

Compensatory hyperinsulinemia, in plain terms

Insulin is not only a sugar hormone. It is a storage signal. When insulin is elevated, the body is being told, continuously, to store fat and not to release it. Lipolysis is suppressed. The liver is pushed to package excess carbohydrate into triglycerides, which it exports as VLDL particles. Sodium retention goes up at the kidney. Uric acid clearance goes down. Ovarian theca cells, in women who are predisposed, read high insulin as a signal to make more androgens.

So the downstream fingerprints of high insulin show up in lipids, in uric acid, in liver enzymes, in blood pressure, in skin tags and the velvety darkening at the back of the neck, and in menstrual pattern — often well before fasting glucose moves a single point. Those fingerprints are what we read first.

What we look at before glucose changes

• Fasting insulin. The single most useful early marker, and the one almost never ordered. It tells us how much insulin the body is spending to keep glucose where it is. A low-normal glucose achieved with a high insulin is a very different metabolic situation from the same glucose achieved with a low one.
• HOMA-IR. A simple calculation — fasting insulin multiplied by fasting glucose, divided by 405 — that combines the two into an index of insulin resistance. It is not a diagnosis. It is a way of reading glucose and insulin together instead of separately.
• Triglyceride-to-HDL ratio. A cheap and durable proxy. When the liver is handling an insulin load it cannot keep up with, triglycerides rise and HDL falls. The ratio often drifts before either number individually looks abnormal on a standard panel.
• Uric acid. Insulin reduces renal uric acid excretion, and fructose metabolism in the liver generates uric acid directly. A uric acid creeping toward the top of the reference range, in someone with no gout history, is worth asking about.
• ALT. When the liver stores fat it should not be storing, ALT often rises quietly — still “normal” by lab standards, but higher than it was on the panel from a few years ago. Fatty liver is, for many people, the first organ-level consequence of chronic hyperinsulinemia.
• Fasting glucose trend, not value. A glucose that reads 83, then 88, then 93 over successive annual panels is telling us something, even though every one of those results was filed as normal.
• Waist measurement and the symptom pattern. Central adiposity, afternoon energy collapse, needing to eat to stay functional, waking at night with a racing mind, carbohydrate cravings in the evening. These are data too.

Normal range, functional range, and the gray area

Laboratory reference ranges are built from the population that uses the lab. They describe what is common, not what is optimal. In a population where metabolic dysfunction is widespread, the range widens to accommodate it. Fasting insulin is the clearest example: the upper end of many reference ranges sits well above the level at which we would already consider a person meaningfully insulin resistant.

The functional range is narrower and tighter — the band in which the system appears to be doing its job without strain. The space between the two is the gray area, and it is where most of the people who come to us are living. Not diseased. Not well. Flagged by nothing. We have written about this more broadly in why your normal labs may be hiding the real story; blood sugar is where the gap is widest and the consequences are most reversible.

Glucose is the last number to change. Insulin is the first — and almost nobody is measuring it.

What this feels like before it shows up anywhere

The lived version is specific. Energy that falls off a cliff after a carbohydrate-heavy lunch. Shakiness or irritability if a meal is delayed — reactive hypoglycemia, which is often an early sign of an oversized insulin response rather than a sign that you need to eat more often. Waking in the small hours as cortisol and adrenaline rise to correct a dipping glucose. Brain fog that tracks with meals rather than with sleep; we go through the other causes of that in what we look for underneath brain fog.

In women, insulin resistance frequently announces itself through the cycle before it announces itself through weight — irregular periods, acne along the jawline, unwanted hair growth, or a perimenopausal transition that is markedly rougher than expected. Falling estrogen reduces insulin sensitivity on its own, which is why metabolic symptoms often surface in the perimenopausal decade in women whose labs had always been unremarkable.

The levers that actually change insulin signaling

Insulin sensitivity is unusually responsive to behavior, which is the good news in all of this. The levers are not exotic.

Muscle is the largest glucose sink in the body. Skeletal muscle takes up glucose through a contraction-activated pathway that does not require insulin at all. Resistance training builds the tank; walking after meals opens the valve. Both lower the amount of insulin needed to clear the same meal.

Meal composition changes the insulin curve more than meal size. Protein and fiber first, carbohydrate not naked, and a real gap between eating occasions so insulin can fall. Liquid sugar and fructose deserve particular attention because of the liver’s role in both triglyceride and uric acid production.

Sleep debt produces measurable insulin resistance in healthy people. This is one of the most reliable findings in metabolic physiology. Short or fragmented sleep reduces glucose disposal the next day, independent of diet.

Cortisol raises glucose by design. Chronic stress keeps hepatic glucose output elevated, which keeps insulin elevated. When the pattern points that way, we look at the cortisol curve rather than guessing. Acupuncture has a legitimate role here in downshifting sympathetic tone — not as a blood sugar treatment, but because a nervous system stuck in output mode is a metabolic problem.

Targeted nutrients — magnesium status, omega-3s, and others depending on what testing shows — can support insulin signaling, but they work as adjuncts to the structural levers, not as replacements for them. And nothing here is a reason to change a prescribed medication; if you are on anything that affects glucose, that conversation belongs with your prescribing doctor.

How we approach it

We start by ordering the markers that are usually missing — fasting insulin alongside glucose, a full lipid panel we can calculate a ratio from, uric acid, liver enzymes, ferritin and iron studies so we can interpret the A1c honestly. Then we put those next to your history, your meal pattern, your sleep, and what the afternoon actually feels like. That is collecting all the pieces of the puzzle. We don’t mask symptoms — we look to address the underlying issues that cause symptoms and dis-ease.

From there the plan is specific to what the numbers show and what you can realistically sustain, and we re-measure rather than assume. If this describes your labs and your afternoons, a functional medicine consultation is the place to start — reach out and we will tell you what we would want to see.

The journal is written by Dr. Nazzar from the practice. Articles reflect clinical observation and current research, not personalized medical advice. To explore your own case, schedule a consultation.