March 2004

Study links snoring to heart failure

A landmark trial undertaken at the Alfred Hospital has proven conclusively the link between snoring and heart failure.

The CATNAP trial, the largest of its kind ever undertaken in the world, has shown that treating sleep apnoea—a major cause of snoring—results in significant improvement in heart function, a drop in stress hormone levels and an improvement in quality of life.

The study has been recently published in the American Journal of Respiratory Critical Care Medicine.

The study looked at the effects of treating sleep apnoea in 55 people for three months each.

All patients in the study snored regularly and had congestive heart failure that had not been effectively controlled with drug treatment.

After enrolling in the trial they were randomly selected either to undergo treatment for snoring known as CPAP (continuous positive airway pressure) for a period of three months or to a control group.

At the end of the period those patients who received treatment showed significant improvement in their heart function and a lowering of stress hormone levels.

The treated patients also reported feeling better and more awake and were enjoying a better quality of life.

Chief investigator in the study and head of the Alfred’s Sleep Disorders Centre Associate Professor Matthew Naughton said doctors previously knew that around one third of heart failure patients also suffered from sleep apnoea.

‘We set out to find out if treating that sleep apnoea could help treat the heart failure.’

Associate Professor Naughton said snoring is often not taken seriously by people but could be as serious as smoking or diabetes in terms of heart disease.

‘Not all snoring is harmful but if you snore often, are regularly tired, drop off to sleep during the day or notice that your sleep is very interrupted, you could actually be suffering from sleep apnoea which means you’re at higher risk,’ Associate Professor Naughton said.

‘Not only are you at higher risk of heart disease but being tired all the time means you’re at higher risk of vehicle or work place accidents.

‘It also means you don’t enjoy your life or time with your family as much. Treating sleep apnoea can be relatively easy.’

Associate Professor Naughton said further studies were required to determine if there was a benefit in terms of increased survival with sleep apnoea treatment for patients with heart disease.