Condition
Prediabetes
Prediabetes describes blood glucose levels above normal but below the diabetes threshold. It is common, often silent, and represents an important window for intervention.
How it is defined
The American Diabetes Association criteria for prediabetes include any of:
- Fasting plasma glucose 100–125 mg/dL (impaired fasting glucose).
- 2-hour plasma glucose 140–199 mg/dL on a 75 g oral glucose tolerance test (impaired glucose tolerance).
- Hemoglobin A1C 5.7–6.4%.
Why it matters
Without intervention, a meaningful fraction of people with prediabetes progress to type 2 diabetes over 3–10 years. Cardiovascular risk is also elevated in prediabetes — not only after diabetes develops.
What helps
Landmark randomized trials, including the Diabetes Prevention Program, demonstrated that structured lifestyle programs (typically targeting 5–7% weight loss and ≥150 minutes of moderate activity per week) reduce the incidence of type 2 diabetes by approximately half over several years. Metformin reduces incidence as well, with the greatest benefit in younger adults with higher BMI.
Monitoring
Periodic re-testing (typically annually) is reasonable for people with prediabetes, alongside attention to blood pressure, lipids, and weight.