A new large U.S. study reveals that people with prediabetes—blood sugar levels above normal but not yet diabetes—face significantly higher risks of heart disease, kidney problems, heart failure, and death over decades, even if they never develop full-blown diabetes.
This landmark research, following more than 10,000 adults over nearly 30 years, underscores the importance of early screening and prevention strategies for millions with prediabetes. It challenges the common assumption that only people who progress to diabetes are at risk for serious complications.
What Is Prediabetes?
Prediabetes is a warning sign, where blood sugar is elevated but not high enough to be diabetes. Often defined by a blood test called HbA1c between 5.7% and 6.4%, or fasting blood sugar between 5.6 and 6.9 mmol/L, prediabetes affects over one in three adults in the United States today.
Many people with prediabetes go on to develop type 2 diabetes, a condition known to increase risk for cardiovascular disease, kidney failure, and early death. But until now, it was unclear if prediabetes itself was risky separate from diabetes progression.
Study Overview
Researchers from Johns Hopkins and other institutions analyzed data from the Atherosclerosis Risk in Communities (ARIC) study, encompassing 10,310 adults aged 46 to 70 years old without diabetes at the start. About 60% had prediabetes based on blood sugar levels.
Participants were monitored for around 30 years for major health outcomes including:
- Atherosclerotic cardiovascular disease (ASCVD, such as heart attacks and strokes)
- Heart failure
- Chronic kidney disease
- Overall mortality
The researchers used statistical models that accounted for people who progressed from prediabetes to diabetes during follow-up, thereby isolating risks associated specifically with prediabetes.
Key Findings
- Nearly 30% of those with prediabetes progressed to diabetes after a median of 7 years.
- Over about 30 years, people with prediabetes had:
- A 21% higher risk of any major complication (heart disease, kidney disease, heart failure, or death) than those with normal blood sugar.
- When accounting for progression to diabetes, 85% of this increased risk still remained.
- Prediabetes was linked to increases in:
- Atherosclerotic cardiovascular disease by 38%
- Heart failure by 37%
- Chronic kidney disease by 25%
- All-cause mortality by 23%
These associations held even after adjusting for age, sex, race, and other health factors.
What This Means for You
The study’s findings highlight that prediabetes is not a benign condition. Individuals with prediabetes should be considered at increased risk for serious health problems, regardless of whether they develop diabetes.
Health care providers should prioritize early detection, lifestyle changes such as diet and exercise, and management of other cardiovascular risk factors like blood pressure and cholesterol in people with prediabetes.
New medications originally used for diabetes, like SGLT2 inhibitors and GLP-1 receptor agonists, also show promise in preventing complications in people with prediabetes.
Table 1: Prediabetes vs. Normal Blood Sugar – 30-Year Risks
| Outcome | Normal Blood Sugar Risk (%) | Prediabetes Risk (%) | Increased Risk (Hazard Ratio) |
|---|---|---|---|
| Any major complication (ASCVD, etc.) | 68 | 77 | 1.21 (21% higher) |
| Atherosclerotic Cardiovascular Disease (ASCVD) | 18 | 23 | 1.38 (38% higher) |
| Heart Failure | 18 | 25 | 1.37 (37% higher) |
| Chronic Kidney Disease (CKD) | 32 | 36 | 1.25 (25% higher) |
| All-cause mortality | 43 | 56 | 1.23 (23% higher) |
Table 2: Excess Risk in Prediabetes Explained vs. Not Explained by Progression to Diabetes
| Outcome | Total Excess Risk in Prediabetes | Excess Risk Remaining After Accounting for Diabetes | Percentage of Excess Risk Remaining |
|---|---|---|---|
| Any major complication | 21% | 18% | 85% |
| Atherosclerotic CVD | 38% | 31% | 81% |
| Heart Failure | 37% | 28% | 76% |
| Chronic Kidney Disease | 25% | 20% | 80% |
| All-cause mortality | 23% | 18% | 78% |
Why Early Intervention Matters
Prediabetes is an important opportunity for prevention. Randomized trials show lifestyle interventions—such as weight loss, healthy diet, and regular physical activity—and in some cases medications like metformin, substantially reduce progression to diabetes.
But this study shows that managing blood sugar alone is not enough; comprehensive cardiovascular and kidney risk reduction strategies are also needed in this group.
Reference: here