After menopause, an estimated one in four women may develop irregular heart rhythms—known as atrial fibrillation—in their lifetime, with insomnia being a major contributing factor, followed by stressful life events, according to new research published in the Journal of the American Heart Association.
Atrial fibrillation may lead to blood clots, stroke, heart failure, or other cardiovascular complications. It primarily affects older adults, and more than 12 million people in the United States are expected to develop atrial fibrillation by 2030, according to the American Heart Association.
“In my general cardiology practice, I see many postmenopausal women with picture-perfect physical health who struggle with poor sleep and negative psychological emotional feelings or experience, which we now know may put them at risk for developing atrial fibrillation,” says lead study author Susan X. Zhao, MD, a cardiologist at Santa Clara Valley Medical Center, in a release. “I strongly believe that in addition to age, genetic, and other heart-health related risk factors, psychosocial factors are the missing piece to the puzzle of the genesis of atrial fibrillation.”
Researchers reviewed data from more than 83,000 questionnaires by women ages 50-79 from the Women’s Health Initiative, a major US study. Participants were asked a series of questions in key categories: insomnia, stressful life events, their sense of optimism, and social support.
Questions about sleeping habits focused on if participants had trouble falling asleep, wake up several times during the night, and overall sleep quality, for example. Questions about stressful life events addressed topics such as loss of a loved one, illness, divorce, financial pressure, and domestic, verbal, physical, or sexual abuse. Questions about participants’ outlook on life and social supports addressed having friends to talk with during and about difficult or stressful situations, a sense of optimism such as believing good things are on the horizon, and having help with daily chores.
During approximately a decade of follow-up, the study found:
- About 25% or 23,954 women developed atrial fibrillation
- A two-cluster system (the stress cluster and the strain cluster)
- For each additional point on the insomnia scale, there is a 4% higher likelihood of developing atrial fibrillation. Similarly, for each additional point on the stressful life event scale, there is a 2% higher likelihood of having atrial fibrillation.
“The heart and brain connection has been long established in many conditions,” Zhao says in the release. “Atrial fibrillation is a disease of the electrical conduction system and is prone to hormonal changes stemming from stress and poor sleep. These common pathways likely underpin the association between stress and insomnia with atrial fibrillation.”
Researchers note that poor sleep, stressful life events, and feelings, such as depression, anxiety, or feeling overwhelmed by one’s circumstances, are often interrelated. It’s difficult to know whether these factors accumulate gradually over the years to increase the risk of atrial fibrillation as women age.
Chronic stress has not been consistently associated with atrial fibrillation, and the researchers note that a limitation of their study is that it relied on patient questionnaires utilized at the start of the study. Stressful life events, however, though significant and traumatic, may not be long-lasting, Zhao notes. Further research is needed to confirm these associations and evaluate whether customized stress-relieving interventions may modify atrial fibrillation risk.