Insulin Resistance Test: Labs Your Annual Physical Skips

Many people in their 40s, 50s, and 60s leave an annual physical with a reassuring note: glucose normal, A1c fine. Yet the weight keeps settling around the middle, energy dips after meals, and something feels off. One common reason is insulin resistance, a metabolic shift that can build quietly for years before standard screening labs catch it.

This guide explains what insulin resistance is, why routine tests can miss it, which labs give a clearer picture, how the menopause transition and falling testosterone play a role, and what the evidence says actually helps.

What is insulin resistance?

Insulin resistance is a condition in which the body does not respond to insulin the way it should, so the pancreas makes more insulin to keep blood sugar in range. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) notes that people with insulin resistance and prediabetes usually have no symptoms.

Over time, if the pancreas cannot keep up, blood sugar climbs into the prediabetes and then type 2 diabetes range. The scale of the problem is large: the CDC National Diabetes Statistics Report estimates that 40.1 million Americans have diabetes (12.0% of the population), and about 27.6% of adults with diabetes are undiagnosed.

Why can A1c and fasting glucose look normal while insulin rises?

Glucose and A1c measure the result, not the effort. When cells resist insulin, the pancreas often compensates by producing more of it, which keeps glucose normal until that compensation begins to fail.

Standard diagnostic thresholds, summarized by the NIDDK, are shown below. A person can sit comfortably in the normal column for years while their fasting insulin is climbing.

Test	Normal	Prediabetes	Diabetes
A1c	Below 5.7%	5.7% to 6.4%	6.5% or above
Fasting plasma glucose	99 mg/dL or below	100 to 125 mg/dL	126 mg/dL or above
2-hour oral glucose tolerance test	139 mg/dL or below	140 to 199 mg/dL	200 mg/dL or above

These cutoffs are designed to diagnose prediabetes and diabetes, not to detect the earlier stage when insulin is working overtime. The NIDDK also notes that health care professionals may not test for insulin resistance at all, which is one reason the earliest shifts often go unnoticed on a routine panel.

Which insulin resistance labs should you ask about?

The most useful insulin resistance workup combines fasting insulin with glucose, lipids, inflammation, and liver markers, so your provider sees the pattern rather than a single number. No one lab diagnoses insulin resistance on its own.

• Fasting insulin. A direct look at how hard the pancreas is working. Reference ranges differ between laboratories and are often broad, so your provider interprets the number alongside your other results and watches the trend over time.
• A1c and fasting glucose. Still essential for screening and diagnosis, even though they may lag behind insulin changes.
• Lipid panel, including the triglyceride-to-HDL pattern. High triglycerides with low HDL can hint at insulin resistance. It is a helpful clue but not a diagnosis.
• ApoB. A count of atherogenic lipoprotein particles, often useful when insulin resistance changes the lipid profile even if standard cholesterol numbers look acceptable.
• hs-CRP. A marker of low-grade inflammation that frequently travels with metabolic dysfunction.
• Liver markers (such as ALT and AST). Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely tied to insulin resistance. An analysis of national US survey data found MASLD in about 32.5% of US adults and 61.4% of adults with diabetes in 2021 to 2023 (Bril et al., Journal of the Endocrine Society, 2025).

You may also see HOMA-IR mentioned online; it is a calculation used mainly in research and is not routinely ordered in clinical care.

How does menopause affect insulin resistance?

Insulin resistance tends to accelerate during the menopause transition itself. In the Study of Women’s Health Across the Nation (SWAN), insulin resistance rose about 8.7% per year during the transition, roughly twice the rate seen after menopause (Shieh et al., 2022).

That timing matters. Changes in body fat distribution, sleep disruption, and shifting hormones can all cluster in the same years, which is why metabolic labs belong in a thoughtful perimenopause evaluation.

Hormone therapy has been studied here, carefully. The 2022 hormone therapy position statement of The North American Menopause Society (now The Menopause Society) states that hormone therapy significantly reduces new-onset type 2 diabetes but is not government approved for that purpose. It also notes that hormone therapy is not contraindicated in otherwise healthy women with type 2 diabetes and may help glycemic control when used for menopause symptoms (Menopause Society 2022 position statement summary). Hormone therapy decisions are made on symptoms and an individual risk-benefit review, not as a diabetes treatment.

Do falling testosterone levels affect insulin resistance in men?

Yes. Low testosterone and insulin resistance are closely linked in men, and the relationship appears to run in both directions: excess visceral fat can lower testosterone, and low testosterone can worsen body composition and insulin sensitivity.

In the T4DM trial of 1,007 Australian men at high risk who were all enrolled in a lifestyle program, adding testosterone reduced the proportion with type 2 diabetes at two years by 40% compared with placebo. Erythrocytosis (a high red blood cell count) occurred in 22% of men on testosterone, and the investigators emphasized careful risk assessment and holistic care over routine prescribing (Wittert et al., Journal of Endocrinology, 2023). Testosterone therapy is not FDA-approved for diabetes prevention. Men who want a full evaluation can learn more about men’s health care at Amsara and testosterone therapy in Arizona.

What are the symptoms of insulin resistance in women over 40?

Insulin resistance often has no symptoms, so the most reliable signs are measurements and lab patterns rather than how you feel. That said, some physical clues are worth noting.

• Waist circumference. The National Heart, Lung, and Blood Institute states that a waist of more than 35 inches for women or more than 40 inches for men increases risk for heart disease and type 2 diabetes.
• Acanthosis nigricans. Darker, velvety skin on the back of the neck, underarms, or groin can signal high insulin levels.
• Skin tags, especially around the neck and underarms.
• Midsection weight gain that resists changes that used to work, energy crashes or strong cravings after carbohydrate-heavy meals.
• Lab patterns such as rising triglycerides, low HDL, elevated liver enzymes, or an A1c creeping toward 5.7%.

What helps reverse insulin resistance?

Consistent lifestyle change remains the strongest evidence-based tool. According to the CDC National Diabetes Prevention Program, people with prediabetes who join a structured lifestyle change program focused on healthy eating and physical activity can cut their risk of developing type 2 diabetes by 58%, and by 71% for people over 60.

• Resistance training. A 2023 meta-analysis of 27 studies in adults with overweight or obesity who did not have diabetes found that resistance training lowered fasting insulin and improved insulin resistance, and the authors concluded it plays an independent role (Boyer et al., Obesity Research and Clinical Practice, 2023).
• Adequate protein and fiber. Protein supports muscle, the body’s largest glucose sink, and fiber slows glucose absorption.
• Sleep. Short or fragmented sleep, common in midlife, is associated with worse glucose control, so sleep is part of the metabolic plan.
• Medications when appropriate. Metformin and GLP-1 medications may be considered for some adults, based on their health history and goals. Your provider will determine whether any medication is right for you. Compounded GLP-1 products are not FDA-approved. Read more about GLP-1 weight loss in Arizona.

How common is prediabetes in Arizona?

Prediabetes is very common in Arizona. The Arizona Department of Health Services reports that nearly 2 million Arizonans have prediabetes and that close to 90% of them are unaware of it.

The American Diabetes Association estimates that approximately 615,200 Arizona adults, or 10.6% of the adult population, have diagnosed diabetes, with about 34,400 new adult diagnoses each year. For residents of Scottsdale, Phoenix, Tucson, and beyond, that makes metabolic testing in midlife a practical step rather than an extra.

How does Amsara Health approach insulin resistance testing in Arizona?

Amsara Health is a concierge integrative telehealth practice based in Scottsdale, serving adults across Arizona. We look beyond the basic panel to understand how your metabolism is actually functioning, then build a plan around the results.

Your first visit is a consultation and full history. If appropriate for you, your provider then orders labs through Sonora Quest or Quest, which may include fasting insulin, fasting glucose, A1c, a lipid panel, ApoB, hs-CRP, and liver markers. At your follow-up, your provider reviews the results with you and builds an integrative plan that may combine strength and nutrition guidance, sleep support, and, when appropriate, medication such as metformin or a GLP-1, or hormone therapy. Progress on weight, symptoms, and mood is tracked between visits. Some patients also add biological age testing to track change over time. No specific treatment or result is guaranteed.

Learn more about our advanced lab testing, see visit and membership pricing, or read about GLP-1 weight loss care in Arizona.

Frequently asked questions

Metabolic change often shows up alongside other midlife shifts in sleep, mood, and cycles. If that sounds familiar, our perimenopause symptoms guide is a helpful next read.

Sources

• Centers for Disease Control and Prevention. National Diabetes Statistics Report. CDC, 2026.
• Centers for Disease Control and Prevention. Prediabetes Statistics. CDC, 2026.
• Centers for Disease Control and Prevention. About the National Diabetes Prevention Program. CDC, 2024.
• National Institute of Diabetes and Digestive and Kidney Diseases. Insulin Resistance and Prediabetes. NIH, 2025.
• National Institute of Diabetes and Digestive and Kidney Diseases. Diabetes Tests and Diagnosis. NIH, 2022.
• Bril F, Bolla S, Huynh K, Bobba N. Prevalence of MASLD in People With Diabetes Has Decreased in the US, but Rates of Liver Fibrosis Are Still on the Rise. Journal of the Endocrine Society, 2025.
• Shieh A, et al. Longitudinal associations of insulin resistance with change in bone mineral density in midlife women (SWAN). JCI Insight, 2022.
• The North American Menopause Society. The 2022 hormone therapy position statement of The North American Menopause Society (guideline summary). Menopause, 2022.
• Wittert G, et al. Testosterone and type 2 diabetes prevention: translational lessons from the T4DM study. Journal of Endocrinology, 2023.
• Boyer W, Toth L, Brenton M, Auge R, Churilla J, Fitzhugh E. The role of resistance training in influencing insulin resistance among adults living with obesity/overweight without diabetes: a systematic review and meta-analysis. Obesity Research and Clinical Practice, 2023.
• National Heart, Lung, and Blood Institute. Aim for a Healthy Weight. NIH, 2025.
• Arizona Department of Health Services. Taking Action Against Diabetes: The 2025 Arizona Diabetes Action Plan and Report. ADHS, 2025.
• American Diabetes Association. The Burden of Diabetes in Arizona. ADA, 2024.
• U.S. Food and Drug Administration. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. FDA, 2024.

This article is for educational purposes and is not a substitute for individual medical advice. Talk with a licensed provider about your specific situation.

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