Study finds sleep apnoea children risk hypertension
Children with obstructive sleep apnoea (OSA) have been found to have higher blood pressure than healthy children, a study has shown.
Chinese University studied the blood pressure and sleeping patterns of 360 children aged between six and 13 from February 2003 to December 2006 to investigate the effect of OSA, which is an obstruction of the airway that causes pausing in breathing.
The subjects were divided into three groups. The normal control group had no problem breathing while sleeping.
The mild OSA group had an apnoea/hyponoea index of less than five, which showed the number of times of breathing paused in an hour while sleeping.
The moderate-to-severe OSA group had an index higher than five. Forty-six subjects had moderate-to-severe OSA and 130 of the children had mild OSA.
'The symptoms of childhood OSA include loud, habitual snoring and sweating at night. There are also poor attention spans and morning headaches,' Ng Pak-cheung, a professor in the university's department of paediatrics, said.
The survey also found the blood-pressure levels increased with severity of OSA, and one in three children with moderate-to-severe OSA had nocturnal hypertension.
In the survey, children with OSA had significantly higher both day-time and night-time blood pressure compared with the control group.
Professor Ng warned that hypertension in children could cause serious long-term complications.
'The high blood pressure in childhood might be a potential risk factor for adulthood hypertension and the development of metabolic syndrome,' he said.
'Children and young people with elevation of blood pressure are also at increased risk of possible adverse outcomes, including cerebrovascular [brain dysfunction] accidents and congestive heart failure.'
But he added that 50 per cent of six-year-old children in Hong Kong had a normal blood pressure level, which is below 100 millimetres of mercury.
The major risk factors of children's OSA include enlarged tonsils and adenoid, and obesity.
Surgical measures to remove tonsils, adenoid or nasal corticosteroid are the two treatments for children's OSA.
Albert Li Man-chim, a professor of the university's department of paediatrics, said he had seen a case in which an eight-year-old girl suffered from heart problems because of OSA.
'Her mother was worried that her daughter had a weak heart,' he said. 'When she brought the daughter to us, we noticed the symptoms of OSA and advised surgery.'
The girl was cured after her tonsils were removed.
