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Nightmares: An independent risk factor for heart disease?



Frequent nightmares are independently linked to an increased risk for cardiovascular disease (CVD), new research shows. In what researchers describe as “surprising” findings, results from a large study of relatively young military veterans showed those who had nightmares two or more times per week had significantly increased risks for hypertension, myocardial infarction, or other heart problems.

“A diagnosis of PTSD incorporates sleep disturbance as a symptom. Thus, we were surprised to find that nightmares continued to be associated with CVD after controlling not only for PTSD and demographic factors, but also smoking and depression diagnosis,” said Christi Ulmer, PhD, of the department of psychiatry and behavioral sciences, Duke University Medical Center, Durham, N.C.

The findings were presented at the virtual annual meeting of the Associated Professional Sleep Societies.

Unclear mechanism

The study included 3,468 veterans (77% male) with a mean age of 38 years who had served one or two tours of duty since Sept. 11, 2001. Nearly one-third (31%) met criteria for PTSD, and 33% self-reported having at least one cardiovascular condition, such as heart problems, hypertension, stroke, and MI.

Nightmare frequency and severity was assessed using the Davidson Trauma Scale. Nightmares were considered frequent if they occurred two or more times per week and moderate to severe if they were at least moderately distressing. About 31% of veterans reported having frequent nightmares, and 35% reported moderately distressing nightmares over the past week.

After adjusting for age, race, and sex, frequent nightmares were associated with hypertension (odds ratio, 1.51; 95% confidence interval, 1.28-1.78), heart problems (OR, 1.50; 95% CI, 1.11-2.02), and MI (OR, 2.32; 95% CI, 1.18-4.54).

Associations between frequent nightmares and hypertension (OR, 1.43; 95% CI, 1.17-1.73) and heart problems (OR, 1.43; 95% CI, 1.00-2.05) remained significant after further adjusting for smoking, depression, and PTSD.

“Our cross-sectional findings set the stage for future research examining the possibility that nightmares may confer cardiovascular disease risks beyond those conferred by PTSD diagnosis alone,” Dr. Ulmer said in a news release.

Dr. Ulmer also said that, because the study was based on self-reported data, the findings are “very preliminary.” Before doctors adjust clinical practices, it’s important that our findings be replicated using longitudinal studies, clinically diagnosed medical conditions, and objectively assessed sleep,” she said.

She added that more research is needed to uncover mechanisms explaining these associations and determine if reducing the frequency and severity of nightmares can lead to improved cardiovascular health.

Timely research

Reached for comment, Rajkumar (Raj) Dasgupta, MD, of the University of Southern California, Los Angeles, noted “the correlation between nightmares and heart disease is a timely topic right now with COVID-19 as more people may be having nightmares.”

“If a patient mentions nightmares, I do think it’s important not to just glaze over it, but to talk more about it and document it in the patient record, especially in patients with cardiovascular disease, atrial fibrillation, diabetes, and hypertension,” said Dr. Dasgupta, who wasn’t involved in the study.

The research was supported by the Veterans Integrated Service Network 6 Mental Illness Research, Education and Clinical Center and the Department of Veterans Affairs HSR&D ADAPT Center at the Durham VA Health Care System. Dr. Ulmer and Dr. Dasgupta have disclosed no relevant financial relationships.

A version of this article originally appeared on

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