I spend more time than might be usual thinking about heart arrhythmias—because almost all of the older people I know have recently been diagnosed with atrial fibrillation, or Afib. More than 12 million people in the U.S. will have the condition in 2030, according to government statistics, and those whom I know often wonder what causes it. There are a variety of risk factors, including advancing age, high blood pressure, obesity, smoking, and—perhaps less well-known—diabetes.

By some estimates, people who have Type 2 diabetes are 34% more likely to develop Afib than people without diabetes. In a new piece for TIME, contributor Markham Heid explains the cause-and-effect relationship between the two. One hypothesis is that elevated blood sugar—a hallmark of diabetes—causes damage to the heart that may result in arrhythmias. Yet another possibility is that diabetes-related inflammation contributes to the development of an arrhythmia.

According to figures from the U.S. Centers for Disease Control and Prevention (CDC), about one out of every seven strokes is caused by Afib. Fortunately, there's good evidence that people who have well-controlled diabetes are much less likely to develop Afib or other types of arrhythmias than people who have poorly controlled diabetes. Plus, there are some newer types of diabetes drugs that may help lower a person’s odds of developing an arrhythmia. Experts suggest asking your doctor about medications that have been shown to reduce heart-related complications—it might be time to reassess your regimen.