A study published in January 2020 in Mayo Clinic Proceedings supports other data that show having diabetes can take a serious toll on the heart. Indeed, the CDC notes that those with diabetes are twice as likely to die of heart disease as those without diabetes. Even after ruling out risk factors like high body mass index (BMI) and high blood pressure, diabetes significantly increases the likelihood of future heart failure, the new study found. “We found a strong association between having diabetes and also developing heart failure,” says Michael D. Klajda, MD, an internist at Mayo Clinic in Rochester, Minnesota, and a coauthor of the research. “The study also expands on the current knowledge that even without any sort of significant structural disease of the heart, people with diabetes are still at risk for developing heart failure. These findings can be a great discussion point between a patient and their physician regarding how diabetes can adversely affect many different organs,” says Dr. Klajda. RELATED: 8 Ways to Manage Both Diabetes and Heart Health
Heart Failure Contributes to 1 in 8 Deaths
Heart failure describes a condition where the heart isn’t able to pump enough blood to meet the body’s requirements for oxygen and blood, according to the American Heart Association (AHA). When a person has heart failure, the heart tries to compensate in different ways, including enlarging, developing more muscle mass, and pumping blood faster. The rest of the body also tries to make up for the deficit by diverting blood from less-important tissues and organs, and the blood vessels narrow to keep blood pressure up, according to the AHA. About 6.5 million Americans have heart failure, and it contributes to 1 in 8 deaths overall, according to the CDC. Early diagnosis and treatment can help people live longer and feel better even after a heart failure diagnosis. RELATED: What Are the Complications of Type 2 Diabetes, and How Can You Avoid Them?
Increased Risk for Heart Failure Is Linked to the Presence of Diabetes
Investigators initially recruited 2,042 people older than 45 from the Rochester Epidemiology Project. Researchers identified participants with diabetes, and then matched each individual with two people who didn’t have diabetes but had an otherwise similar health profile — meaning they were of similar age and sex, with a similar status for hypertension, coronary artery disease, and diastolic dysfunction. According to the Harvard Health Letter, diastolic dysfunction occurs when your heart has difficulty relaxing between beats, which limits the amount of blood the ventricles can collect for the next heartbeat. The final group totaled 116 people with diabetes and 232 without diabetes. By matching participants in this way, investigators were able to take all the major associated risk factors out of the equation, to see if diabetes would still affect the way the heart was able to function, says Klajda. They determined the presence of heart failure by using the standard Framingham criteria. During the 10-year follow-up, 21 percent of the participants with diabetes developed heart failure, compared with 12 percent of the people without diabetes. Yet death due to a heart event, heart attack, and stroke were not statistically different in the two groups. RELATED: 5 Emerging Heart Disease Risk Factors
Limitations of the Study Include a Small Sample Size
These results are not unexpected, says Salim S. Virani, MD, PhD, a professor of cardiology at the Baylor College of Medicine and a staff cardiologist at Michael E. DeBakey VA Medical Center, both in Houston. Dr. Virani was not involved in the current study. “Similar trends have been seen in larger-scale studies; it’s established now that diabetes is independently associated with future risk of heart failure development for patients,” says Virani. As to why this increased risk in the group with diabetes didn’t lead to earlier death, heart attack, or stroke, Virani points to the small size of the study as a possible explanation. “This is a very, very small study in terms of the sample size, and it wasn’t designed to show a difference in mortality,” he says. A much larger sample size would be needed to do that, according to Virani. “We do know that diabetes itself is associated with an increased risk of mortality and less longevity.” The lack of difference in those outcomes could also be a reflection of advances in diabetes and cardiovascular care that improve outcomes in diabetic patients, says Horng H. Chen, MD, a cardiologist at the Mayo Clinic in Minnesota and the senior author of the study. “It could also be that the population needed to be followed for an extended time past 10 years to see a difference between the two groups,” says Dr. Chen. Why diabetes increases the risk for heart failure even after scientists control for coronary artery disease, high blood pressure, and obesity is still a focus of much research, says Klajda. “There are a lot of theories, but it’s thought to be mostly due to the impact of diabetes itself; it may have a negative impact factor on cardiac muscle cells.” Diabetes could be affecting the small muscles of the heart, and that would not be discovered in routine screenings, says Virani. “There could also be things happening at the molecular level whereby the metabolism of the heart muscles changes when somebody has diabetes and high sugars,” he says. Diabetes may also make the heart stiffer, which wouldn’t be detected by current imaging technology like echocardiography, he says. RELATED: What Is Hyperglycemia or High Blood Sugar?
Healthy Living and Current Medications Can Reduce Risk of Diabetes and Heart Failure
If you’re at risk for diabetes because of obesity or a family history, prevention of diabetes should be the number one priority, says Virani. “This disease is preventable through lifestyle changes,” he says. It’s critical to get the recommended amount of physical activity and consume a diet that is heart healthy and low in sugar, he says. For people who have already been diagnosed with diabetes, making lifestyle changes such as starting to exercise and keeping blood sugar stable can still make a big difference, says Virani. In addition to healthier habits, medications now used in diabetes treatment have been shown to reduce future risk of heart failure, Virani says. “SGLT2 inhibitors have shown a strong signal in the reduction in heart failure in the last three or four years,” he says.
