For years, the story of prediabetes has followed a familiar path. Blood sugar begins to rise, doctors sound the alarm, and patients are urged toward healthier habits. Walk more. Eat better. Lose weight. These changes matter, everyone agrees. They improve well-being, confidence, and overall health. But beneath this reassuring narrative, a more troubling question has lingered. Do these changes actually protect the heart.
A new study published today in The Lancet Diabetes & Endocrinology suggests that the answer may not be what medicine has long assumed. Drawing on decades of data from two of the world’s most influential diabetes prevention studies, researchers have found that the real turning point is not lifestyle change alone, but something more precise and measurable. Bringing blood glucose back to normal levels, effectively reversing prediabetes, appears to cut the risk of serious heart problems by more than half.
It is a finding that reshapes how scientists understand risk, prevention, and the hidden timeline of heart disease.
Following People Across a Lifetime
The research was led by Dr. Andreas Birkenfeld of King’s College London and University Hospital Tübingen. Instead of launching a new trial, his team returned to two landmark studies that have quietly followed people with prediabetes for decades.
One was the US Diabetes Prevention Program Outcomes Study, known as DPPOS. The other was the Chinese DaQing Diabetes Prevention Outcomes Study, or DaQingDPOS. Both studies tracked participants who began with prediabetes and were encouraged to adopt lifestyle changes such as increased exercise and healthier diets. Over time, researchers recorded who developed diabetes, who avoided it, and who went on to experience heart attacks, heart failure, strokes, or death.
By reanalyzing this long-term data, the team could ask a different question than before. Not whether people delayed diabetes, but whether they truly returned to normal blood sugar levels, a state known as prediabetes remission. And then, crucially, what happened to their hearts afterward.
When Blood Sugar Returns to Normal
The answer emerged with striking clarity. People who achieved remission from prediabetes experienced a 58% lower risk of dying from cardiovascular disease or being hospitalized for heart failure. This was not a short-term benefit. The protective effect persisted for decades after blood glucose levels normalized, suggesting that the body remembers this metabolic reset long into the future.
The findings did not stop there. The risk of heart attack, stroke, and other major adverse cardiovascular events was reduced by 42% among those who entered remission. Whether the data came from the United States or China, the pattern was the same.
Lower blood sugar, it seemed, was doing something deeper than previously understood. It was altering the trajectory of heart disease itself.
Challenging a Deeply Held Assumption
These results carry particular weight because of what earlier analyses of the same studies had shown. Despite improvements in exercise and diet, combined lifestyle interventions alone did not reduce cardiovascular disease in people with prediabetes. Delaying the onset of type 2 diabetes did not automatically translate into protection from heart attacks or early death.
Dr. Birkenfeld addressed this tension directly.
“This study challenges one of the biggest assumptions in modern preventative medicine. For years, people with prediabetes have been told that losing weight, exercising more and eating healthier will protect them from heart attacks and early death. While these lifestyle changes are unquestionably valuable, the evidence does not support that they reduce heart attacks or mortality in people with prediabetes.
“Instead, we show that remission of prediabetes is associated with a clear reduction in fatal cardiac events, heart failure, and all-cause mortality,”
His words do not dismiss the value of healthy living. Instead, they draw a sharper line between feeling healthier and changing the underlying processes that drive cardiovascular damage.
The Hidden Burden of Prediabetes
Prediabetes occupies an uneasy space in medicine. Blood glucose levels are elevated, but not enough to qualify as type 2 diabetes. Many people feel no symptoms at all. Yet beneath this quiet surface, risk is accumulating.
The condition often progresses to type 2 diabetes, but it also carries its own danger. Cardiovascular disease remains one of the leading causes of death globally, and prediabetes contributes to that burden in ways that are easy to underestimate.
The scale of the issue is enormous. In the United Kingdom, around one in five adults has diabetes or prediabetes. In the United States, it is more than one in three. In China, four in ten adults are affected. Worldwide, more than one billion people are estimated to have prediabetes.
Against this backdrop, even a modest reduction in heart disease risk would matter. A reduction of more than half changes the conversation entirely.
A Metabolic Turning Point
One of the most striking aspects of the findings is their durability. The benefits of prediabetes remission did not fade with time. Decades after blood glucose levels returned to normal, the reduced risk of heart failure and cardiovascular death remained.
This suggests that something fundamental changes when glucose regulation is restored. The body may enter a different metabolic state, one that stabilizes systems linked to the heart and blood vessels. Delaying diabetes without achieving remission, by contrast, may leave these harmful processes quietly active.
The consistency of the results across two very different populations strengthens this conclusion. Different cultures, different healthcare systems, different lifestyles, yet the same pattern appeared. Normalize blood sugar, and the heart is protected.
Rethinking Prevention
The findings point toward a shift in how clinicians may think about prevention. Traditionally, primary prevention of heart disease has focused on lowering blood pressure, reducing cholesterol, and stopping smoking. Prediabetes management has often sat alongside these goals, but not within the same category of proven life-saving interventions.
Dr. Birkenfeld believes that may soon change.
“The study findings mean that prediabetes remission could establish itself—alongside lowering blood pressure, cutting cholesterol and stopping smoking—as a fourth major primary prevention tool that truly prevents heart attacks and deaths,”
This is not a call to abandon lifestyle advice, but to refine the target. Lifestyle changes may still be the path, but remission becomes the destination, not merely effort or intention.
Why This Research Matters
This study matters because it redraws the map of risk for a condition affecting more than a billion people worldwide. It suggests that the heart does not respond simply to good intentions or partial improvements, but to a clear biological shift. Prediabetes remission appears to mark that shift.
For patients, the message is both sobering and empowering. Not all improvements carry the same weight, but one specific outcome, normal blood glucose levels, may offer lasting protection against some of the most feared cardiovascular events.
For clinicians, the findings open a new chapter in prevention, one that aligns prediabetes treatment with the most effective strategies for saving lives.
And for public health, the implications ripple outward. If reversing prediabetes can halve the risk of heart failure and cardiovascular death, then identifying, supporting, and sustaining remission becomes a powerful tool in confronting one of the world’s leading causes of mortality.
In the quiet numbers of long-term data, a new story has emerged. One that suggests the heart remembers when blood sugar finds its way back to balance, and rewards that return with years, even decades, of protection.
More information: “Prediabetes Remission and Cardiovascular Morbidity and Mortality: A post-hoc analyses from DPPOS and DaQingDPOS,” The Lancet Diabetes & Endocrinology (2025). DOI: 10.1016/S2213-8587(25)00295-5
