Ask for a fasting insulin today.

At your next labs, ask your clinician for a fasting insulin along with fasting glucose (not glucose or A1C alone). Do not change meds or invent a cutpoint from this tip. The lie I taught in medical school: if fasting glucose and A1C look fine, metabolic risk is covered. Insulin can already be running high while glucose still looks normal. Dankner R, Chetrit A, Shanik MH, Raz I, Roth J. Basal-state hyperinsulinemia in healthy normoglycemic adults is predictive of type 2 diabetes over a 24-year follow-up: a preliminary report. Diabetes Care. 2009;32(8):1464-1466. Prospective follow-up of 515 adults who were normoglycemic at baseline (fasting plasma glucose 110 mg/dL or less and 2-h OGTT under 140 mg/dL by 1980 criteria). Restudied after 24 years (mean age at follow-up 70.4). Outcomes: 50.3% stayed normal glucose tolerance; 11.1% IFG; 9.9% IGT; 4.5% IFG+IGT; 24.3% type 2 diabetes. Hyperinsulinemia = baseline fasting insulin in the upper quintile (Q5) of this sample. Adjusted ordered logistic regression: fasting insulin Q5 vs Q1 to Q4 OR 1.98 (95% CI 1.13-3.48) for progression to type 2 diabetes; OR 1.67 (0.94-2.95) for IFG/IGT. Authors report basal hyperinsulinemia was the most significant predictor of progression to type 2 diabetes in that model. Fasting glucose Q5 was the strongest predictor for IFG/IGT (OR 1.99, 1.10-3.61). DOI 10.2337/dc09-0153 PMID 19541790. Observational follow-up, not a trial. Ordering insulin does not by itself prevent diabetes. Single baseline insulin; no time-to-onset detail; survival bias may attenuate links. The upper-quintile cut was sample-specific to this Israeli multi-ethnic cohort, not a universal lab optimal number. Assays and reference ranges differ by lab. Educational tip only. Not medical advice. Ask a clinician whether fasting insulin fits your situation and how to interpret it. Related: The Blood Test Your Doctor Doesn't Order https://www.youtube.com/watch?v=ylkO3ETjEIE