Nighttime Breathing Issues Bad for Heart

Sleep apnea among the elderly increases risk from heart problems

(RxWiki News) Those scary moments when sleep apnea stops your breathing apparently does more than keep the oxygen from your brain, especially in the elderly.

A recently published study found that severe obstructive sleep apnea is linked with an increased risk of death among the elderly from cardiovascular problems.

"Can't sleep? - See a doctor."

The study, led by Miguel Angel Martinez-Garcia, MD, of La Fe University and Polytechnical Hospital in Valencia, Spain, aimed to find whether obstructive sleep apnea causes cardiovascular death.

In OSA, the airway is blocked during sleep, often from tissue in the back of the throat.

Researchers also sought to see if treating elderly patients with continuous positive airway pressure (CPAP) changes that risk.

In the study, researchers observed 939 patients ages 65 or older an average of six years. Each patient was assigned to a sleep study following Spain's guidelines: full standard polysomnography, or respiratory polygraphy.

The first sleep study looks at the heart and chest movements, and measures nasal airflow and the amount of oxygen in the blood.

In the second sleep study, researchers record the flow and pressure of air from the nose and mouth, and look at heart rate and chest movements.

Those patients who had the airway pressure treatment done before or had central sleep apnea syndrome were not included in the study.

Researchers looked at patients' age, gender, body mass index, history of cardiovascular issues, and other factors that may affect heart health, including smoking, alcohol, hypertension, glucose levels, and certain medications.

Those with mild-to-moderate sleep apnea scored between 15-29 on the apnea-hypopnea index, and patients with index scores greater than 30 were among the severe sleep apnea group.

Patients were either given the airway treatment for four or more hours each day or not treated at all.

After the follow-up period, patients with OSA were reviewed every three months during the first year and annually after that.

The researchers found that the risk of dying from cardiovascular problems was 2.25 times as often for those patients who went untreated.

For patients who received the airway pressure treatment, that risk was .93 times as often.

And among patients with untreated mild-to-moderate sleep apnea, that risk was 1.38 times more often.

In total, 190 deaths occurred in the group. A little more than half of these at about 53 percent were because of cardiovascular problems, including stroke and heart failure.

Having the airway treatment reduced the risk of dying from cardiovascular problems "to levels similar to those of patients without OSA or with untreated, mild-moderate OSA," the authors said in their review.

"In our study…, severe OSA not treated with CPAP was associated with an increased risk of cardiovascular mortality especially from stroke and heart failure, and CPAP treatment reduced this excess of cardiovascular mortality to levels similar to those seen in patients without OSA," Dr. Martinez-Garcia said.

The authors note a few limitations with the study, including that it was not randomized, and a respiratory polygraph was used to diagnose patients with sleep apnea.

The study was published online Sept. 13 in the American Journal of Respiratory and Critical Care Medicine.

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Review Date: 
September 14, 2012