Will Reversing Prediabetes Save Your Heart and Kidneys?

The high blood sugar of diabetes is associated with damage to the heart and kidneys. Just how much does slightly elevated blood sugar, termed prediabetes, affect health? Doctors define prediabetes as fasting blood sugar between 100 and 125 mg/dl. (Various organizations and experts may have slightly different cut-off points, but they are all reasonably close.) This elevated blood sugar, though not yet considered diabetes, results in glycosylated hemoglobin (HbA1c) of 5.7 to 6.4 percent. This is a way of measuring blood sugar over a period of several weeks. Previous research showed that prediabetes puts the heart and kidneys at risk. Now we have evidence that reversing prediabetes can substantially reduce that risk.

How Does Elevated Blood Sugar Affect the Heart and Kidneys?

Scientists at the Centers for Disease Control and Prevention in Atlanta wondered whether prediabetes makes sense as a diagnostic term (Lancet Diabetes & Endocrinology, May 2018). How risky is this elevated blood sugar? To find out, the researchers tracked the health of roughly 28,000 adults for 25 years.

They used data from the National Health and Nutrition Examination Surveys to examine how prediabetes affects cardiovascular and kidney health. The survey periods included 1988-1994; 1999-2004; 2005-2010; and 2011-2014. Even slight elevations in blood sugar were associated with an increased risk of both heart and kidney disease.

Moreover, the researchers found that as the proportion of people with prediabetes rose, so did the prevalence of high blood pressure and elevated blood fats such as cholesterol. Over time, fewer people smoked but more had high blood pressure. People who had been diagnosed with diabetes were far more likely to be taking medication for their high blood pressure and high cholesterol.

Can You Protect Your Heart and Kidneys?

That is a critical question, and a recent study published in Lancet Diabetes & Endocrinology (Dec. 12, 2025) offers a lot of optimism. The investigators used data generated by two large diabetes prevention trials in different populations. The first enrolled 2,402 Americans with prediabetes into the Diabetes Prevention Program Outcomes Study. The other was conducted in China, involving 540 Chinese volunteers with prediabetes in the DaQing Diabetes Prevention Outcome Study. These individuals changed their dietary and exercise habits during the six-year long study. After 30 years, they were 33% less likely to have died from heart problems and 26% less likely to have died from any cause than those who were in the control group. The amount of time spent free of type 2 diabetes was closely linked to these cardiovascular benefits.

In contrast, people who participated in the US study, which targeted weight loss and exercise for at least 150 minutes a week, did not have significantly fewer cardiovascular complications 20 years later. The time during which volunteers were receiving active intervention was 2.8 years. The American Diabetes Association concluded that lifestyle intervention for prediabetes is unproven.

Following Up on Americans:

This new research has analyzed blood glucose levels and HbA1c. After all, if the problem with prediabetes is that it too often turns into diabetes, shouldn’t we know what the blood sugar was doing? Analyzing the risk of cardiovascular death or hospitalization for heart failure showed quite a difference among the American volunteers. Their rate for these unfortunate outcomes was 1.74 per 1,000 person-years for those who had reached remission of their prediabetes. (This was defined as fasting blood glucose below 100 mg/dL.) In contrast, those who had not reached remission during the study had complications at a rate of 4.17 per 1,000 person-years.

Tracking the Chinese:

The intervention period of the Chinese study lasted longer, and so did the follow-up, though there were fewer individuals in the study. The scientists found that among those who had reached remission of their prediabetes, the rate of cardiovascular death or hospitalization for heart filure was 9.5 per 1,000 person-years. For comparison, those who had not reached remission had a rate of 17 per 1,000 person-years. That’s quite a difference!

There are a lot more details in this study, but the bottom line is pretty straightforward.

According to the authors:

“…prediabetes remission–reached after 1 year of intervention in DPPOS or after 6 years in DaQingDPOS–is associated with a legacy effect on cardiovascular outcomes persisting two-to-three decades after the intervention concluded.”

We think that is a big deal, and it shows that reversing prediabetes is worth the very considerable effort it may take! While this new research looked only at cardiovascular complications rather than both heart and kidneys, it is very likely that protecting the heart can also help the kidneys.

Learn More:

If you would like guidance on both medications and natural approaches to blood sugar control, you may wish to read our Guide to Managing Diabetes. Although it was written primarily for people with type 2 diabetes, those with prediabetes can benefit from the suggestions as well. You might also want to listen to our interview with Dr. Matthew Longjohn of the YMCA, Dr. Karen Lawson of the University of Minnesota and Dr. Tieraona Low Dog, a founding member of the American Board of Integrative Medicine. It is Show 1036: How to Prevent Diabetes by Changing Your Life. Our most recent podcast on diabetes was with Dr. John Buse, the Verne S.. Caviness Distinguished Professor of Medicine at the University of North Carolina. It is Show 1445: From Lizard Spit to Ozempic: Rethinking How We Treat Diabetes. We think you will find it very informative.