What Is Prediabetes and Why Reversing It Matters

A Silent Epidemic With a Misleading Name

The word "prediabetes" can sound almost harmless — a warning sign, a grey zone, a condition you can worry about later. That framing has proven costly. According to the U.S. Centers for Disease Control and Prevention, roughly 80% of people with prediabetes don't know they have it. Globally, an estimated 635 million adults — about 12% of the world's adult population — live with the condition, according to updated figures published in Diabetes Care.

That number is rising. And new research shows the stakes are far higher than a future diabetes diagnosis alone.

What Prediabetes Actually Is

Prediabetes is defined as blood glucose levels that are higher than normal but not yet high enough to meet the diagnostic threshold for type 2 diabetes. It is typically identified by one of two measurements:

• Fasting blood glucose between 100 and 125 mg/dL (5.6–6.9 mmol/L)
• HbA1c (a measure of average blood sugar over three months) between 5.7% and 6.4%

At its root, prediabetes is a disorder of insulin resistance. Insulin is the hormone that allows glucose to move from the bloodstream into cells, where it is used for energy. When cells in the muscles, liver, and fat tissue stop responding efficiently to insulin — a state called insulin resistance — the pancreas compensates by producing more of it. Over time, the pancreas cannot keep pace, blood sugar climbs, and prediabetes takes hold. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) describes insulin resistance as the almost universal precursor to the condition.

Most people with prediabetes have no symptoms at all, which is precisely why it so often goes undetected for years.

The Risks Beyond Diabetes

The conventional concern about prediabetes is that it progresses to type 2 diabetes. Without intervention, roughly 15–30% of people with prediabetes will develop full diabetes within five years. But prediabetes carries independent risks that extend well beyond blood sugar.

Elevated glucose and insulin resistance silently damage blood vessels and drive inflammation, raising the risk of heart attack, stroke, and kidney disease — even before diabetes is diagnosed. Research has consistently shown that the cardiovascular clock starts ticking long before the diabetes threshold is crossed.

New Evidence: Remission Halves Heart Risk

A landmark study published in The Lancet Diabetes & Endocrinology analyzed data from two major long-term prevention trials — the U.S. Diabetes Prevention Program Outcomes Study and China's DaQing Diabetes Prevention Outcomes Study — following participants for up to 20 years.

The findings were striking: people who achieved prediabetes remission (returning blood sugar to normal levels) saw their risk of cardiovascular death or heart failure hospitalization fall by 58%. The risk of heart attack and stroke dropped by 42%. All-cause mortality fell significantly as well.

Crucially, these benefits persisted across different ages, ethnicities, and body weights. Researchers also identified a simple clinical marker: a fasting blood glucose of 97 mg/dL or lower was associated with lasting protection — a threshold actionable in any primary care setting worldwide.

How Prediabetes Can Be Reversed

The evidence for reversibility through lifestyle change is robust. A systematic review published in PMC found that lifestyle modification interventions made people 18% more likely to return to normal glucose levels compared to control groups. The key levers are well-established:

• Weight loss: Losing just 5–7% of body weight — roughly 10–14 pounds for a 200-pound person — cuts the risk of progressing to type 2 diabetes by 58%, according to the original Diabetes Prevention Program trial.
• Physical activity: At least 150 minutes of moderate exercise per week (brisk walking counts) significantly improves insulin sensitivity.
• Dietary quality: Reducing refined carbohydrates and added sugars, increasing fiber, and eating more vegetables all improve blood glucose control.

Metformin, an inexpensive generic drug, is also used in some cases — particularly for younger adults with higher-risk profiles — but lifestyle change remains the first-line recommendation endorsed by the Cleveland Clinic and major diabetes organizations worldwide.

Why It Matters Now

With prediabetes prevalence projected to keep rising — especially in low- and middle-income countries — the case for treating the condition as a serious cardiovascular risk factor, not merely a diabetes precursor, has never been stronger. Simple screening with a fasting blood test costs almost nothing. The consequences of inaction, the new Lancet data makes clear, can be measured in years of life.