Insulin Resistance
Insulin resistance is a state where cells respond poorly to insulin, prompting the body to produce more of it; it often precedes prediabetes and type 2 diabetes, per the American Diabetes Association (ADA) 2026 Standards of Care.
Symptoms
Often no symptoms at all in early stages; some people develop skin changes (acanthosis nigricans -- dark, velvety patches, often on the neck or underarms), fatigue after meals, or difficulty losing weight.
Causes and risk
Excess body weight (particularly abdominal fat), physical inactivity, genetics, and PCOS all raise risk; normal fasting glucose and A1c do not rule out insulin resistance, since fasting insulin often rises before glucose does.
How it is evaluated
HOMA-IR (calculated from fasting glucose and insulin) is a commonly used research and clinical marker, though the exact cutoff varies by lab and population; fasting glucose and A1c remain the standard tests for tracking progression toward diabetes.
Treatment
Lifestyle intervention -- a 5-7% weight loss target through diet and activity change -- reduced progression to diabetes by roughly 58% in the Diabetes Prevention Program and remains first-line, per ADA 2026 Standards of Care. Metformin is considered for higher-risk individuals (BMI 35+, under 60, or with a history of gestational diabetes) but is not FDA-approved specifically for "insulin resistance" as a standalone diagnosis -- its evidence base is in diabetes prevention and treatment.
When to seek care
Symptoms of very high blood sugar -- excessive thirst, frequent urination, blurred vision, or confusion -- warrant prompt medical evaluation.