Type 2 diabetes is one of the fastest-growing health problems in the world. Hundreds of millions of people live with the condition, and many need daily medication to keep their blood sugar under control.
Good blood sugar control is essential because high blood sugar can slowly damage blood vessels, nerves, the kidneys, the eyes, and many other organs.
People with diabetes also have a much higher risk of developing heart disease and stroke, which are among the leading causes of death worldwide.
Type 2 diabetes develops when the body can no longer use insulin effectively.
Insulin is a hormone that moves sugar from the bloodstream into the body’s cells, where it is used for energy. When the body becomes resistant to insulin or cannot produce enough of it, sugar builds up in the blood instead of entering the cells.
Over many years, this excess sugar can damage tissues throughout the body and increase the risk of serious complications.
For most people who are newly diagnosed with type 2 diabetes, doctors usually prescribe metformin as the first treatment.
Metformin helps the body respond better to insulin and lowers the amount of sugar released by the liver. It has been used safely for decades and remains one of the most common and affordable diabetes medicines.
However, type 2 diabetes often becomes more difficult to manage over time.
As the disease progresses, many patients need a second medicine because metformin alone is no longer enough to keep blood sugar within a healthy range. For many years, two of the most common second-line treatments have been sulfonylureas and basal insulin.
Sulfonylureas work by encouraging the pancreas to release more insulin. Basal insulin, also called long-acting insulin, provides a steady supply of insulin throughout the day and night to help control blood sugar levels.
Both treatments are effective at lowering blood sugar and have been widely used because they are generally less expensive than many newer diabetes medicines.
A major new study, however, suggests these older medicines may carry higher risks for the heart than some newer treatment options.
The research was led by scientists at Northwestern University, headed by Dr. Matthew O’Brien. The team wanted to understand how different second-line diabetes medicines affect heart health in everyday medical practice rather than only in carefully controlled clinical trials.
To answer this question, the researchers analyzed the medical records of more than 132,000 adults with type 2 diabetes. Every participant had already been taking metformin and needed to begin a second diabetes medication because their blood sugar was no longer adequately controlled.
The researchers compared several commonly used medicines and looked at how often patients developed major cardiovascular problems. These included heart attacks, strokes, and heart failure.
The results showed important differences between the treatments. Patients who started taking sulfonylureas were 36 percent more likely to experience a major cardiovascular event than those who received a newer group of medicines called DPP-4 inhibitors.
The risk was even greater among people treated with basal insulin. According to the study, patients using basal insulin were about twice as likely to develop serious cardiovascular problems as those taking DPP-4 inhibitors.
The researchers also estimated how frequently these complications occurred. Among people taking basal insulin, one major cardiovascular event occurred for every 37 patients during approximately two years of follow-up. Among those taking sulfonylureas, one event occurred for every 103 patients over the same period.
Although these numbers may appear modest, they become much more important when applied to the millions of people living with type 2 diabetes. Even a small increase in cardiovascular risk could lead to thousands of additional heart attacks, strokes, or cases of heart failure.
Heart disease is already the leading cause of death in people with diabetes. High blood sugar damages blood vessels and encourages the buildup of fatty deposits inside arteries, increasing the risk of blocked blood flow to the heart and brain. Because of this, doctors now aim to choose diabetes treatments that not only lower blood sugar but also protect the cardiovascular system whenever possible.
In recent years, several newer diabetes medicines have become available, including DPP-4 inhibitors, GLP-1 receptor agonists, and SGLT-2 inhibitors. Previous research has shown that some of these newer medicines can reduce the risk of heart disease while also improving blood sugar control. However, they are often more expensive than older treatments, meaning cost remains an important factor for many patients and healthcare systems.
The researchers say their findings highlight the need to carefully balance medication costs with long-term health outcomes. Although newer medicines may cost more initially, preventing heart attacks, strokes, and heart failure could improve patients’ quality of life and reduce healthcare costs over time.
The study does not suggest that people should stop taking their current diabetes medicine on their own. Every patient has different medical needs, and the most appropriate treatment depends on age, other health conditions, kidney function, cost, and many other factors. Anyone with questions about their medication should discuss them with their doctor before making any changes.
Overall, the findings suggest that controlling blood sugar is only one part of diabetes treatment. Protecting the heart is equally important, and future treatment decisions may increasingly focus on medicines that can achieve both goals.
The research was led by Dr. Matthew O’Brien and his colleagues at Northwestern University and was published in the medical journal JAMA Network Open.
If you care about heart health, please read studies about the best time to take vitamins to prevent heart disease, and calcium supplements could harm your heart health.
For more health information, please see recent studies that blackcurrants can reduce blood sugar after meal and results showing how drinking milk affects risks of heart disease and cancer.
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