Study Reveals Blood Sugar Control Halves Heart Disease Risk

A recent study has found that individuals with prediabetes who successfully manage their blood sugar levels may reduce their risk of death from heart disease or heart failure by as much as 50%. This research, published on December 12, 2023, in the journal Lancet Diabetes & Endocrinology, highlights the significant long-term benefits of achieving normal glucose levels.

Prediabetes affects an estimated 38% of adults in the United States, a condition characterized by elevated blood sugar levels that do not yet qualify as diabetes. The findings indicate that those who reach a state of “remission” from prediabetes can expect a substantially lower risk of cardiovascular-related deaths or hospitalizations two decades later, compared to those who do not achieve normal glucose levels.

Dr. Latha Palaniappan, associate dean for research at Stanford Medicine, noted the encouraging nature of the findings, stating, “That is an incredible finding and really gives people hope that what they do today will have an effect two decades from now.” Historically, there has been evidence linking Type 2 diabetes to an increased risk of heart attacks and heart failure. While some studies have suggested a connection between prediabetes and cardiovascular disease, the exact relationship remained unclear until now.

The urgency for patients and healthcare providers to address prediabetes is underscored by these results. Current guidelines emphasize weight loss and lifestyle changes to prevent progression to Type 2 diabetes, but they do not specifically recommend lowering blood glucose levels to a normal range.

To arrive at these conclusions, the research team conducted a follow-up analysis of data from two significant trials, including the US Diabetes Prevention Program, which ran from 1996 to 2001. This trial evaluated three interventions aimed at preventing the onset of Type 2 diabetes in individuals with prediabetes. These included an intensive lifestyle program focused on diet and exercise, the use of the drug metformin to lower blood glucose, and a placebo.

The trial revealed that the intensive lifestyle program reduced the incidence of Type 2 diabetes by 58% over three years compared to the placebo group, while metformin resulted in a 31% reduction. The new research revisited participants from this trial twenty years later and found that approximately 11% had achieved normal glucose levels within one year, irrespective of the intervention they received.

Among this subset, there was a 50% lower risk of cardiovascular death or hospitalization for heart failure compared to participants who did not reach normal glucose levels, even after adjusting for various characteristics, including the development of full-blown diabetes.

To validate these findings, researchers also analyzed data from a similar diabetes prevention trial conducted in China. In this study, around 13% of participants with elevated glucose levels attained normal levels after six years. Thirty years later, this group exhibited a 51% lower risk of death from heart disease or hospitalization compared to those who did not achieve normal glucose levels.

Dr. Andreas Birkenfeld, chair of the Department of Diabetology, Endocrinology, and Nephrology at University Hospital Tubingen and senior author of the new study, explained that normalizing glucose levels—whether or not accompanied by weight loss—can lead to reduced abdominal fat, decreased inflammation, and improved insulin sensitivity.

Despite these promising results, the study also highlighted challenges. Researchers did not ascertain which participants maintained lifestyle changes after the initial intervention period. Dr. Jonathan Newman, clinical research director at NYU Langone Heart, acknowledged that while they attempted to control for differences between those who achieved remission and those who did not, unmeasured variables could still influence outcomes.

Overall, achieving normal glucose levels proved difficult for participants in both the US and China trials, prompting questions about how to improve success rates. Judy Regensteiner, director of the Ludeman Family Center for Women’s Health Research at the University of Colorado Anschutz Medical Campus, emphasized the need for effective strategies, stating, “It’s a good proof of concept. But if these really well-done studies have low success rates in getting people to those numbers, what do we do differently?”

Experts have noted that the new GLP-1 drugs, which help control blood sugar and aid weight loss, were not available during the original trials conducted in the 1980s and 1990s. Dr. Selvin pointed out that while lifestyle interventions remain the first-line therapy, combining them with newer medications could be a potential path forward.

While managing blood glucose levels is a crucial aspect of reducing the risk of cardiovascular disease, it is not the only factor. Maintaining a healthy weight, adhering to a nutritious diet, and engaging in regular exercise are equally important. Dr. Newman remarked, “Prediabetes is the canary in the coal mine” and often indicates broader metabolic problems. Targeting blood glucose levels alone does not guarantee a reduction in cardiovascular disease risk, but it can serve as a significant marker for health outcomes.