Definition: Insulin resistance is a condition in which the body does not respond to insulin the way it should. NIDDK says it can lead to higher blood sugar and weight gain, and that over time the pancreas may not make enough insulin to move the extra glucose into cells.
NIDDK says researchers do not fully understand what causes insulin resistance and prediabetes. Risk factors it lists include overweight, obesity or a large waist size, and being 35 or older.
NIDDK says the test for insulin resistance is mainly used only in research. In practice, the tests are for prediabetes:
| Test | Prediabetes range |
|---|---|
| A1C | 5.7% to 6.4% |
| Fasting plasma glucose | 100 to 125 mg/dL |
| Oral glucose tolerance test (2 hours) | 140 to 199 mg/dL |
In words: an A1C of 5.7% to 6.4%, a fasting glucose of 100 to 125 mg/dL, or a 2-hour glucose tolerance result of 140 to 199 mg/dL is in the prediabetes range. NIDDK says the glucose tolerance test is less convenient and costs more than the other two. It adds that cholesterol and triglyceride tests may also be recommended. See HbA1c, fasting insulin and lipid panel.
Since NIDDK says the insulin resistance test is mainly for research, the numbers most people see are the prediabetes tests above. Logging lab results with their dates, next to your weight and medicines, shows the trend your prescriber looks for.
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