What insulin resistance looks like before diabetes
Glucose is the measurement everyone knows and it is a late one. Insulin rises first, for years, keeping glucose in range by working harder.
The compensating phase
Insulin resistance means the tissues respond less to insulin, so the pancreas produces more of it to achieve the same effect. For a long time that works. Glucose stays normal, hemoglobin A1c stays normal, and an annual panel comes back reassuring — while insulin levels are well above where they started.
A fasting glucose of 92 mg/dL tells you the system is still compensating. It does not tell you how much effort that is taking, and only measuring insulin does.
Why this phase is not harmless
Nerve injury associated with impaired glucose tolerance and the metabolic syndrome begins during it. That injury preferentially affects the small unmyelinated fibers, and nerve conduction studies are relatively insensitive to it — which is why skin biopsy measuring intraepidermal nerve fiber density has traditionally been used to confirm the diagnosis, and why sudomotor testing is useful non-invasively.
Vascular consequences appear during the same phase. Endothelial function is tightly coupled to insulin signaling in the vessel wall, which is why endothelial markers behave as insulin-resistance markers, and why they sit alongside prothrombotic and pro-inflammatory measures. Arterial stiffness and endothelial function.
How rare metabolic health actually is
Analysis of the National Health and Nutrition Examination Survey for 2009 to 2016 defined optimal metabolic health as optimal waist circumference, glucose and hemoglobin A1c, blood pressure, triglycerides and HDL cholesterol, with no medication for any of them. By that definition, 12.2% of American adults met a full definition of optimal metabolic health in the National Health and Nutrition Examination Survey for 2009 to 2016 — so roughly 88% of US adults did not. Fewer than one in three normal-weight adults met it; the figure fell to 8.0% among overweight adults and 0.5% among adults with obesity.
In the Padda Institute patient population the picture is starker still: fewer than 3% of patients overall, and fewer than 1% of chronic pain patients, meet the same definition of metabolic health. Those are practice-reported figures from our own population, not trial outcomes, and individual results vary.
What to measure
- Fasting insulin alongside glucose and hemoglobin A1c — the single highest-yield addition to a standard panel.
- C-peptide and fructosamine, which describe the same process from different angles.
- Triglycerides and HDL cholesterol, and lipid particle analysis rather than total cholesterol alone.
- Waist circumference, which is part of the definition and takes ten seconds.
- Body composition, because normal weight with low muscle mass is a distinct and common pattern.
- Sudomotor and vascular measurements, because the consequences appear before the diagnosis does.
The genuinely encouraging part
Every component of that metabolic health definition responds to changes in what people eat, how they move and how they sleep. Not equally, not in everyone, and not overnight — but triglycerides and fasting glucose move within weeks to months, and being able to watch them move is itself part of what makes a change stick.
References
- Araújo J, Cai J, Stevens J. Prevalence of Optimal Metabolic Health in American Adults: National Health and Nutrition Examination Survey 2009–2016. Metabolic Syndrome and Related Disorders. 2019;17(1):46–52. doi:10.1089/met.2018.0105
- Cortez M, Singleton JR, Smith AG. Glucose intolerance, metabolic syndrome, and neuropathy. Handbook of Clinical Neurology. 2014;126:109–122. doi:10.1016/B978-0-444-53480-4.00009-6
Related reading
Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP, medical director of Measura. Last reviewed .