Question 140 of 433
How do I test for insulin resistance?
The short answer
For most people, begin with clinical risk assessment and established glucose tests. Routine fasting insulin and HOMA-IR screening are not recommended by the ADA/AACC laboratory guideline.
HbA1c, fasting plasma glucose, and a two-hour oral glucose tolerance test identify prediabetes or diabetes. Waist size, blood pressure, lipids, family history, prior gestational diabetes, medications, and liver health add context. A normal HbA1c does not rule out every early metabolic change; it also does not mean a large hormone panel is needed.
HOMA-IR is a research estimate calculated from fasting insulin and glucose. With glucose in mg/dL, the traditional formula is glucose multiplied by insulin in µU/mL, divided by 405. Different assays and populations give different distributions. A cutoff near 2 is not a universal diagnostic boundary, and low single-digit insulin values are not a validated treatment goal for everyone.
I may consider insulin measurements in selected unresolved situations, but that is a clinical choice, not proof that routine screening improves health. Before ordering one, ask how the result would change care beyond what the history and established tests already support.
“This book is for education. It is not medical advice, and reading it does not make you my patient or create a doctor-patient relationship.” From the book’s medical disclaimer. Full disclaimer
GUIDELINE — At-risk adults: established glucose testing; routine insulin screening and universal HOMA-IR cutoffs are unsupported.Evidence grade (draft mapping)GGuideline-based / consensusPart 11, Q140 · Sources: R1
Sources cited
- R1 Sacks DB et al. Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus. Diabetes Care. 2023;46:e151–e199. doi:10.2337/dci23-0036. PubMed 37471273DOI 10.2337/dci23-0036✓ Verified
From Longevity Unmasked by Afshine Ash Emrani, MD, FACC. Medical disclaimer. This book is for education. It is not medical advice, and reading it does not make you my patient or create a doctor-patient relationship. Nothing here is meant to diagnose, treat, cure, or prevent any disease. Medicine is personal: a test, drug, supplement, or exercise plan that helps one person can harm another. Do not start, stop, or change any medication or treatment because of something you read in these pages. Talk with a licensed clinician who knows your history first. If you think you are having a medical emergency, call 911. The author disclaims responsibility for any loss or harm arising from use of the information in this book.