Prediabetes
Blood sugar elevated above normal but not yet at the diabetes threshold. Reversible in most patients with structured lifestyle change.
What it is
Prediabetes is the metabolic intermediate where blood glucose handling is impaired but hasn't crossed the diabetes diagnostic threshold. The CDC estimates 96 million U.S. adults — over one in three — have prediabetes, and 80% don't know it. Untreated, roughly 5–10% progress to type 2 diabetes each year. The key insight from the Diabetes Prevention Program trial: a 7% weight loss plus 150 minutes/week of moderate exercise cuts progression risk by 58%, beating metformin head-to-head.
Key lab markers
- HbA1c 5.7–6.4% — the most widely-used diagnostic anchor.
- Fasting glucose 100–125 mg/dL — impaired fasting glucose.
- 2-hour OGTT 140–199 mg/dL — impaired glucose tolerance.
- Triglycerides and HDL — central markers of the metabolic-syndrome phenotype often paired with prediabetes.
Symptoms
Prediabetes is usually asymptomatic — it's caught by routine screening, not symptoms. Some patients notice mild fatigue, more frequent thirst, or skin changes (acanthosis nigricans). Waiting for symptoms misses the window where lifestyle reverses the trajectory.
When to discuss with a doctor
An HbA1c in the 5.7–6.4% range warrants an honest conversation with your primary-care doctor: weight, diet, activity level, family history. The Diabetes Prevention Program is the most-validated lifestyle protocol — a 16-week structured course covered by many insurers. Annual repeat HbA1c is the minimum monitoring cadence.