Early predictors of obstructive sleep apnoea have been found, which could mean earlier treatment, or even prevention.
Maternal asthma, frequent childhood lower respiratory tract infections and exposure to smoking, all before the age of seven, have been newly identified as risk factors associated with obstructive sleep apnoea in middle age, an Australian study finds.
Maternal smoking, childhood pleurisy and pneumonia, and frequent asthma and bronchitis were also revealed as possible predictors of OSA in adulthood.
The condition is underdiagnosed, and prevention and early intervention in adults is hampered by a lack of evidence for early childhood risk factors, according to the authors.
“This could be important knowledge needed to predict, screen for and diagnose OSA early in adults to provide them with beneficial interventions. Such knowledge could also trigger further research into the lifelong evolution and relevant pathophysiology of OSA,” they wrote in Respirology.
Researchers used data from 3550 individuals in the Tasmanian Longitudinal Health Study, which included parent surveys from when participants were seven years old and information on probable OSA when participants were 53.
By middle age, one in seven had probable OSA, based on their snoring, tiredness, observed apnoea, high blood pressure, BMI, age, neck circumference and gender.
Maternal asthma was the biggest risk for probable OSA in adulthood, increasing the risk by 50% compared to children without mothers with asthma, who had little-to-no exposure to childhood OSA or general respiratory illness risk factors.
This was followed by doctor-diagnosed childhood pleurisy/pneumonia (30%), frequent asthma and bronchitis in childhood (30%), parental smoking (30%), maternal smoking (20%) and frequent childhood bronchitis (20%).
BMI, premature birth, and feeding (bottle or breast) factors, associated with childhood OSA, were not associated with probable adult OSA, suggesting the pathways for childhood and adult OSA were different, the study authors said. But the pathophysiology pathways between these new risk factors and OSA was not clear.
“For example, [it is] difficult to theorize how maternal asthma would cause OSA in adult offspring. However, as OSA symptoms might be misconstrued as nocturnal asthma, at least some of the maternal asthma could be maternal OSA and may indicate a familial inheritance of OSA as previously shown,” the authors wrote.
“Furthermore, maternal asthma could also suggest abnormal airways, a trait the offspring could inherit and be associated with adult OSA … Studies of OSA epidemiology must explore maternal asthma as an alternative pathway to OSA,” they said.
Exposure to passive smoking had been previously linked to childhood OSA, as were frequent respiratory tract infections, so it could be that in these cases there was childhood OSA that had continued into adulthood, they added.
It was possible that frequent respiratory infections were affecting the growth of the airways and increasing the risk of OSA that way, or that an independent factor might be causing both the childhood infections and the adult OSA, they hypothesised.
Importantly, chronic bronchitis was associated with adult OSA, but childhood bronchitis is not linked to adult bronchitis, so the finding that chronic bronchitis in children was linked to OSA in adults was new, the researchers said.
They warned that it was not possible to draw conclusions about causation, given that the data came from two different sources. It was also possible that OSA incidence had been underestimated and some associations undetected.
However, “this first known study to investigate the role of both individual and profiles of childhood risk factors reinforced the suggestions of childhood origins of adult OSA and provided new insights into modifiable early life risk factors for OSA,” the authors said.
“There were strong signals that early exposures to smoking and lower respiratory tract infections could be risks for adult OSA, which could be used in general practice … to identify those who may be at risk of developing OSA [and] … to create population awareness, enabling those at risk to be vigilant of OSA which is likely to help detect any OSA early.”