The hearts of women who snore appear to become damaged more quickly than those of men who "saw lumber" at night, a new study suggests.
Evaluating nearly 4 500 British adults who underwent cardiac imaging, researchers also learned that obstructive sleep apnoea (OSA) may be vastly underdiagnosed among snorers.
This finding surprised study author Dr Adrian Curta, who heads cardiac imaging at Munich University Hospital in Germany.
Serious health conditions
"A further surprise was the different manifestation of disease according to gender," Curta said. "Females show different alterations in cardiac [measures]. A possible reason for this could be that women with OSA are more vulnerable to cardiac alterations."
Loud snoring is a hallmark of obstructive sleep apnoea, which affects between 3 and 7% of adults in the United States, according to the US National Institutes of Health. Also characterised by brief periods where breathing stops, often followed by gasping for air, sleep apnoea is becoming recognised as a contributor to serious health conditions, such as high blood pressure, heart disease and poor blood sugar metabolism.
Sleep apnoea treatment depends on the cause. Treatments include surgery to open narrowed upper airways or using a CPAP (continuous positive airway pressure) machine while sleeping.
Curta and his colleagues evaluated data from the UK Biobank, which follows the health and well-being of 500 000 volunteers. The researchers looked at data from nearly 4 500 participants who underwent cardiac imaging. These study volunteers were split into three groups: 38 with obstructive sleep apnoea; 1 919 who reported snoring; and 2 536 without OSA or snoring.
In both men and women, those with sleep apnoea and snoring tended to have larger left ventricles of the heart, meaning the walls were enlarged and the heart was working harder to pump, Curta said.
But when the snoring group was compared to the unaffected group, a more significant difference was found in the size of the left ventricle among women compared to men. These cardiac changes in self-reported snorers suggest earlier heart impairment in women and could point to undiagnosed sleep apnoea, he said.
Better prevention needed
The findings suggest the transition from snoring to obstructive sleep apnoea is an evolving process linked to a potentially dangerous enlargement of the left ventricle. But the research did not prove that sleep apnoea causes heart changes, only that an association exists between the two.
Curta noted that researchers are still uncertain why snoring would remodel women's hearts more quickly than men's. More research needs to be done to understand this process, he said.
"The most important clinical implication is that we need better prevention for OSA, such as a broader information programme," Curta said. "Individuals with snoring should ask someone to observe them during sleep if they show periods of breathing cessation."
Those who do stop breathing while sleeping should undergo a sleep study to determine how advanced their sleep apnoea is and the proper treatment, Curta said.
Underreported and underdiagnosed
Dr Tetyana Kendzerska is a sleep physician at Ottawa Hospital Sleep Center in Canada, and wasn't involved in the new research. Since obesity is a known contributor to snoring and sleep apnoea, Kendzerska said losing excess weight is encouraged for those with snoring or sleep apnoea.
"We know that men and women report different symptoms for OSA, and as a result, obstructive sleep apnoea is seriously underreported and underdiagnosed in women," she said.
"Given that potential cardiovascular risk associated with sleep apnoea may be greater in women than in men, first we need to identify women with sleep apnoea [by] increasing awareness among health care professionals," Kendzerska added.
The research was to be presented at the annual meeting of the Radiological Society of North America, in Chicago. Research presented at meetings typically hasn't been peer-reviewed or published, and results are considered preliminary.
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