Researchers at a Hong Kong university have completed the first decade-long study of how childhood sleep disorders can affect blood pressure later in life and found young people with moderate to severe obstructive sleep apnoea (OSA) were 2.5 times more likely to develop hypertension as adults.
The team from Chinese University also warned that the disease, which affected about 5 per cent of school-aged children in the city, could result in higher risk of cardiovascular, metabolic or neurobehavioural complications if left untreated.
“OSA is common in children but often unrecognised,” Professor Albert Li Man-chim, chairman of the university’s department of paediatrics, said on Monday. “Snoring, night sweats and mouth breathing are some common symptoms of OSA. Other symptoms are daytime inattention, hyperactivity, sleepiness and behavioural problems.”
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Li warned that parents might not always associate the symptoms with a sleep disorder and urged them to seek medical advice if they noticed them. Paediatricians should also routinely check whether their patients experienced them, he said.
OSA happens when the upper airway becomes blocked during sleep, leading to pauses in breathing or overly shallow breathing, which can occur many times during the course of a night.
The most common causes for the blockage in children is enlarged tonsils and adenoids or obesity. According to Li, the correct treatment is to remove the enlarged areas through surgery or for the patient to lose weight.
In the 10-year study, researchers recruited local children between the ages of six and 13, and tracked them with 24-hour blood pressure measurements and polysomnography, which records certain bodily functions when a person is asleep.
Published in leading respiratory medicine journal Thorax, the findings showed that among the 243 participants who were now aged 15 to 25, those with childhood OSA did not experience the 10 to 15 per cent reduction in blood pressure during sleep as did their counterparts without the disorder.
They were therefore 2.5 times more likely than those without the condition to develop hypertension as adults, increasing the risk of eventually developing cardio-cerebrovascular diseases – which affect blood vessels in the heart or brain.
But early detection can be crucial. Those diagnosed with mild OSA as children were at just 1.5-times greater risk of later developing hypertension.
Dr Jun Au Chun-ting, a research assistant professor with the department, said: “Blood pressure follows a circadian rhythm, with 10 per cent to 15 per cent lower values during sleep than during wakefulness.
“Higher blood pressure during childhood precedes the development of hypertension in adulthood and will worsen cardiovascular prognosis.”
The researchers intend to continue to examine the long-term health effects of OSA in a study lasting 18 to 20 years.
This article Children with obstructive sleep apnoea at higher risk of hypertension, Hong Kong researchers find first appeared on South China Morning Post