Sleep disruption may be linked to the irregular, rapid heart rate known as atrial fibrillation (AF), which raises the risk of stroke, dementia, heart attack and death, making sleep quality a modifiable risk factor for those conditions.
In a study by researchers at UC San Francisco, the team found that having less REM sleep – the sleep that includes more dreaming – was linked to higher chances of developing AF.
The connection between sleep disruption and AF was found to be independent of obstructive sleep apnea, which previously had been established as a risk factor for AF and other cardiovascular diseases. AF can cause symptoms such as heart palpitations, fatigue and shortness of breath, and also is linked to kidney disease.
“Given the high prevalence of sleep problems and substantial negative impacts of atrial fibrillation, prospective and randomized clinical trials are needed to assess whether interventions that improve sleep quality can reduce the incidence of atrial fibrillation and recurrence among those who already have the disease,” said senior author Gregory Marcus, MD, MAS, a UCSF Health cardiologist and director of clinical research in the UCSF Division of Cardiology.
The study appeared June 26, 2018, in HeartRhythm, the journal of the Heart Rhythm Society.
In the study, Marcus and his colleagues analyzed participants in the UCSF Health eHeart Study from March 2013 to February 2016, with findings validated in the Cardiovascular Health Study (CHS), which followed 5,703 participants over an average of 11.6 years, including a subset who underwent polysomnography. To determine if the observed relationships readily translated to medical practice, the researchers also examined five years of data from 14.3 million participants in the California Healthcare Cost and Utilization Project (HCUP). Sleep quality was assessed with the Pittsburgh Sleep Quality Index.
The HeartRhythm study measured how long and well participants slept, the amount of time it took to fall asleep, and sleep patterns (i.e., time spent in REM sleep vs. non-REM sleep). They then analyzed the effect of sleep disruptions on AF, while controlling for other potential AF risk factors.
The study found that 11.6 percent of the 4,553 Health eHeart Study participants with AF exhibited more frequent nighttime awakening. This was supported by the CHS and HCUP, in which frequent nighttime awakening predicted a 33 percent and 36 percent greater risk of AF, respectively.
The researchers said possible explanations for the connection between REM sleep and AF could include sleep’s impact on the autonomic nervous system, which has an important role in controlling heart rate and blood pressure, or frequent waking that puts extra stress on the heart’s chambers.