The largest ever sleep apnoea study has found that CPAP treatments can significantly improve quality of life and mood.

But the common therapy does not reduce recurrent strokes and heart attacks in people with cardiovascular disease.

Researchers spent more than four years studying 2,700 people with obstructive sleep apnoea (OSA) and cardiovascular disease from seven countries who used Continuous Positive Airway Pressure (CPAP) machines to manage their OSA.

“We were surprised not to find a reduction in cardiovascular events from CPAP usage,” said researcher Dr Doug McEvoy from Flinders University.

“However patients who used the machines for a minimum of three hours a night reported significant improvements in their wellbeing from their snoring, mood, quality of life and the amount of time they needed to take off work due to sickness.”

Seventeen per cent of participants receiving CPAP treatment and routine care went onto develop serious cardiovascular events such as stroke and heart attack, compared to 15.4 per cent of those who received routine care alone.

The researchers also found that CPAP treatment produced a 20 per cent improvement in severe depression, a two thirds reduction in severe sleepiness, and a 20 per cent drop in days lost from work.

Co-author Professor Craig Anderson said CPAP machines clearly improved the lives of people with sleep disordered breathing, but the big risks still remained.

“We have shown that CPAP can help improve the lives of people with CPAP, which is significant, and of real benefit to people who suffer from sleep disordered breathing,” he said.

“More research is now needed on how to reduce the significant risk of suffering a heart attack or stroke for those who suffer from sleep apnoea.”

The full study is accessible here.