Doctors specializing in sleep medicine have found a link to sleep disorders and heart disease in the past, but they didn’t know if losing sleep was causing heart attacks or purely coincidence. But study results, presented at EuroHeartCare, the annual meeting of the European Society of Cardiology, are said to be the first to examine how sleep disorders impact a person's risk for heart disease or stroke.

"Sleep is not a trivial issue,” professor Valery Gafarov said during the presentation, according to a statement. “In our study, it was associated with double the risk of a heart attack and up to four times the risk of stroke. Poor sleep should be considered a modifiable risk factor for cardiovascular disease along with smoking, lack of exercise, and poor diet. Guidelines should add sleep as a risk factor to recommendations for preventing cardiovascular disease."

The study was part of the World Health Organization’s program "MONICA" (Multinational Monitoring of Trends and Determinants in Cardiovascular Disease), which was designed to study the human heart on an international level. In 1994, researchers began studying the sleep quality of 657 Russian men between the ages of 25 and 64. None had a history of heart attack, stroke, or diabetes.

After following them for 14 years, nearly two-thirds of the participants who had a heart attack also had a sleep disorder. The highest rates were found in men with sleep disorders who were either widowed, divorced, had low levels of education, or had medium to heavy manual labor jobs.

Men with sleep disorders had up to a 2.6 times higher risk of myocardial infarction, which is a heart attack cause by the death of the heart muscle, and a 1.5 to 4 times higher risk of stroke. Heart disease kills 50 percent of the total population, and nearly 80 percent of deaths from heart disease are caused specifically from heart attacks and stroke, according to the research.

“It means that today we are talking about an epidemic of cardiovascular disease,” Gafarov said. “It is therefore necessary to engage in intensive prevention of risk factors leading to the development of cardiovascular diseases.”

Between 50 and 70 million Americans are affected by chronic sleep disorders. Obstructive sleep apnea, one of the most infamous of sleeping disorders, occurs in 50 percent of obese individuals, according to the Academy of Sleep Medicine. An apnea occurs when there's a 90 percent reduction in airflow. It may occur in as frequently as 50 to 100 times per hour, as a cycle ensues characterized by constant reawakening throughout the night. Cutting off the airway can put a severe strain on a person’s heart throughout the night, which in turns often leads to heart disease.

"For most people, good quality sleep is seven to eight hours of rest each night. People who are not sleeping well should speak to their doctor," Gafarov said. "Our previous research showed that sleeping disorders are very closely connected with depression, anxiety, and hostility, so speaking with a psychologist may also help."

Source: Gafarov V. Risk of an arterial hypertension and stroke in women with depression in Russia: MONICA-psychosocial epidemiological study. At The European Society of Cardiology's EuroHeartCare. 2015.