A new research article published in the Journal of American Heart Association sheds light on the potential link between insomnia and early-onset atrial fibrillation. This study, led by Allison E. Gaffey, PhD, clinical psychologist (cardiovascular medicine), examined electronic health records from over one million young veterans followed across more than 15 years. The authors found that patients with insomnia, a common type of chronic sleep disturbance, were more likely to develop atrial fibrillation compared to patients without insomnia. Characterized by an abnormal heart rhythm, atrial fibrillation is a cardiovascular condition that typically affects older adults. Patients with the condition can experience irregular heartbeats, palpitations, and lightheadedness. Treatment for atrial fibrillation may consist of medications to control the heart rate, such as beta blockers, and/or blood thinners to reduce the increased risk for stroke. "Chronic cardiovascular conditions like atrial fibrillation are usually diagnosed later in life but are likely rooted in earlier health behaviors and concerns,” Gaffey said. Recently, the American Heart Association and other major medical organizations have placed increased importance on understanding how sleep affects heart health. Sleep disturbances are common among both men and women who are veterans and the general public. Understanding how these conditions might relate to atrial fibrillation could result in earlier opportunities for prevention and diagnosis. "There has been growing attention to the role of sleep disturbances and disorders in risk for cardiac and vascular diseases," Gaffey said. “This investigation was born from a desire to better understand the role of sleep in these downstream health conditions.” Previous research has demonstrated an association between atrial fibrillation and risk for obstructive sleep apnea, a common disorder that involves difficulty breathing during sleep, and which is more common among adults who are overweight and obese. However, little was known about the role of insomnia as a risk factor for atrial fibrillation prior to this study. To tackle this question, the researchers relied on data from the U.S. Department of Defense’s Manpower Data Center, including information from 1,177,204 patients who received care at Veterans Affairs (VA) medical centers between October 1, 2001 and December 31, 2017. This large dataset consisted of several factors related to healthcare use including hospitalizations, outpatient visits, pharmacy prescriptions, and more. The dataset also included details about other medical diagnoses held by patients aside from insomnia and atrial fibrillation, along with patient demographics, such as age, sex, and race. The study revealed a significant association between insomnia and atrial fibrillation risk: there was a 32% increase in risk for the condition among patients with an insomnia diagnosis compared to those without an insomnia diagnosis. To ensure that this effect truly arose from insomnia rather than other reasons, the authors adjusted their analysis to control for possible confounding factors, including obstructive sleep apnea. Even after accounting for confounders, they still found that serious sleep disturbances independently led to an increased risk for atrial fibrillation. “We wanted to know if the initial effect of insomnia would remain if we accounted for other factors known to influence not only having insomnia, but also risk for cardiovascular diseases such as atrial fibrillation,” Gaffey said. “We adjusted for demographics, lifestyle factors such as a history of alcohol or substance use, and other clinical conditions, including whether or not anyone had a previous diagnosis of sleep apnea or psychiatric disorders like depression, anxiety, or PTSD." Although the study demonstrated a strong association between insomnia and atrial fibrillation, there are still limitations to the research. Importantly, the authors used data from younger adults with an average age of 28 years across all patients, and only 14% of the patients were women. As a result, the study findings may not necessarily apply to the general public beyond younger, male patients. Additionally, the authors identified insomnia diagnoses based on the VA electronic health record, but patients are likely underdiagnosed with insomnia at the VA and in other healthcare settings. Notably, the study has practical implications for healthcare providers and patients. The research highlights the importance of recognizing sleep disturbances early given their potential long-term consequences. The authors call attention to sleep as a risk factor that can be modified, asserting that sleep may be an important focus for atrial fibrillation prevention. They additionally suggest that future research should investigate if insomnia treatment, either through medication or cognitive behavioral therapy, could change the risk for atrial fibrillation. This study of younger adults shows that a history of insomnia is independently related to a greater risk for developing atrial fibrillation. Through this critical work, the authors contribute to our growing knowledge of the relationship between sleep health and heart health, offering hope for improving clinical care for young patients affected by sleep disturbances. To learn more, read the article: “Insomnia and Early Incident Atrial Fibrillation: A 16-Year Cohort Study of Younger Men and Women Veterans.”The Department of Internal Medicine at Yale is among the nation's premier departments, bringing together an elite cadre of clinicians, investigators, educators, and staff in one of the world's top medical schools. To learn more, visit Internal Medicine.