Obstructive sleep apnoea (OSA) may raise the risk of cancer in women – but not men, according to research.
Greek scientists analysed data from 19,000 people to examine if there was a link between OSA and cancer.
They found cancer was more prevalent in women with sleep apnoea than those without. The trend did not exist in men, however.
The findings remained true when other cancer-causing factors, such as a high BMI, smoking status and alcohol consumption, were taken into account.
Millions of people around the world have OSA, which can cause snoring.
Experts said the findings should not alarm people who snore, and warned it is not the first time the link to cancer has been made.
Lifestyle changes can combat the condition, often caused by being overweight, smoking, or drinking too much alcohol.
Obstructive sleep apnoea, where the airways narrow during sleep and interrupts normal breathing, can have a big impact on quality of life.
It affects between four and ten per cent of people in the UK, and in the region of 22 million in the US, according to estimates.
The NHS states OSA could lead to high blood pressure, a stroke, heart attack, or developing type 2 diabetes.
Researchers from Aristotle University of Thessaloniki led the study, using data of 5,789 women and 13,767 men.
The study looked at how many times the volunteers experienced partial or complete airways closure per hour of sleep.
The experts also looked at how many times during the night the blood oxygen levels of participants dropped below 90 per cent.
The data showed that 388 people – two per cent – of the participants had been diagnosed with a serious cancer.
This included 160 women, 2.8 per cent of the total women, and 228 men, which is 1.7 per cent of all men in the group.
Scientists suggested a lower level of oxygen in the blood, caused by restricted breathing, could play a role in the development of cancer.
Dr Athanasia Pataka, co-author of the study, published in the European Respiratory Journal, said: ‘This area of research is very new.
‘And the effects of gender on the link between OSA and cancer have not been studied in detail before.
‘Our study of more than 19,000 people shows that severity of OSA is linked to a cancer diagnosis.
‘This link was especially strong in the women that we analysed, and less so in the men.’ She called for more trials to confirm the results.
The researchers also cautioned that the results not prove that OSA causes an increased risk of cancer.
Professor Anita Simonds, consultant in respiratory and sleep medicine at Royal Brompton and Harefield NHS Foundation Trust, was sceptical of the study.
She said: ‘In this study the overall cancer prevalence was low at just two per cent, therefore OSA patients should not be alarmed by this research.’
Men with OSA are more likely to be sleepy, snore, or stop breathing in the middle of the night.
Whereas women are more likely to feel fatigued, have insomnia, depression and morning headaches. (By VANESSA CHALMERS)