Link between apnea and hypertension
Studies have established a direct link between sleep apnea and diseases such as hypertension, high blood pressure, stroke and coronary heart disease.
Records of the breathing of more than 1,400 people as they slept have disproved theories that people with high blood pressure are more likely to snore.
Victor Hoffstein of St Michael's Hospital in Toronto wrote in the British medical journal The Lancet that apnea, a temporary stoppage of breathing during sleep, may be a sign of hypertension.
Hoffstein noted previous studies have shown a direct link between snoring and high blood pressure or coronary heart disease, but said they were based on subjective reports from bed partners about whether the people tested snored.
He said his tests involved a microphone connected to a sound meter to record people at a sleep disorder clinic during the night. As soon as they woke up, their blood pressure was tested.
"Once the confounding effects of age and obesity were taken into account, snoring was eliminated as an independent variable affecting blood pressure," he reported. He said that when tests were done on snorers with hypertension, many were found to have sleep apnea. This raised "a possibility that it is sleep apnea, and not snoring, which is an independent predictor of raised blood pressure," he wrote.
Men, people over 65, and especially the seriously overweight are particularly prone to apnea. Apnea prevents restful sleep (by robbing you of restorative REM sleep), thus leading to daytime drowsiness, irritability, faulty memory, and lack of ability to concentrate.
One study found that, because of daytime drowsiness, those with apnea are seven times more likely than average to be in traffic crashes. Apnea may also increase the risk of hypertension, stroke, heart attack, and other cardiovascular hazards.
Studies have shown that sleep apnea, a condition in which the sleeper repeatedly stops breathing, is linked to coronary heart disease. Now researchers have found that coronary-disease patients who have sleep apnea are worse off than other coronary patients: They're at greater risk of having dangerously clogged arteries, heart attack, and stroke.
Researchers at the Mid-America Heart Institute in Kansas City, monitored the sleep of 141 heart patients. The 24 who showed signs of apnea were more likely to have had angioplasty to open blocked arteries (71 vs. 55 percent), a heart attack (75 vs. 56 percent), or a stroke (13 vs. 5 percent).