MUNICH – Getting less than 6 hours of sleep nightly on a regular basis or waking up multiple times was independently associated with increased risk of subclinical atherosclerosis in the Spanish PESA study, Fernando Dominguez, MD, reported at the annual congress of the European Society of Cardiology.
Moreover, a graded response was evident in PESA (Progression of Early Subclinical Atherosclerosis): The more times an individual typically awoke per night, the greater the number of atherosclerotic carotid or femoral artery territories documented on three-dimensional vascular ultrasound, added Dr. Dominguez of the Spanish National Center for Cardiovascular Research in Madrid.
the cardiologist said.
The cross-sectional PESA study, whose principal investigator was Valentin Fuster, MD, PhD, included 3,974 middle-aged Madrid bank employees free of known heart disease or history of stroke who wore a waistband activity monitor for a week to record sleep quantity and quality. They also underwent three-dimensional vascular ultrasound and measurement of coronary artery calcium.
PESA was one of several large studies presented at the meeting that focused on deviations from normal sleep as a marker for increased risk of cardiovascular disease and/or mortality. Of note, however, PESA was the only one to use activity monitoring technology to track sleep.
“It was essential to use objectively measured sleep variables, because they showed huge disparity with patients’ self-reports on sleep questionnaires,” Dr. Dominguez explained.
Indeed, while 10.7% of PESA participants self-reported sleeping less than 6 hours per night on the Sleep Habits Questionnaire, actigraphy showed the true rate was 27.1%.
Based on actigraphic findings, subjects were divided into tertiles based upon average hours of sleep per night, ranging from less than 6 to more than 8. They were also grouped in quintiles based upon their extent of fragmented sleep.
Subjects with short sleep were significantly older and more likely to have high blood pressure, a higher body mass index, and metabolic syndrome than those who averaged 7-8 hours of sleep. Individuals in the top quintile for sleep awakening were older and had higher prevalences of smoking and hypertension than those in the lowest quintile.
In multivariate analyses adjusted for these differences as well as for physical activity, depression, obstructive sleep apnea, daily calorie consumption, alcohol intake, and other potential confounders, subjects who slept less than 6 hours per night had a 27% greater volume of noncoronary plaque than those who slept 7-8 hours. They also had 21% more vascular territories laden with subclinical atherosclerosis. The risk of subclinical noncoronary atherosclerosis was greater among women who averaged less than 6 hours of sleep per night, representing a 48% relative risk increase in plaque volume, versus 21% in men.
At the other extreme, women who slept more than 8 hours per night had an 83% increased plaque volume, while men who slept that much had no increase in risk, compared with men who slept for 7-8 hours.
Subjects in the top quintile for sleep fragmentation had 34% more vascular territories affected by atherosclerosis than those in the lowest quintile. Their noncoronary plaque burden was 23% greater as well.