Children with sleep apnea have 1.5 times higher risk of developing hypertension in adulthood compared to those who do not have a snoring problem, a Chinese University study has found.
The pediatrics sleep research team of the CUHK medical faculty published the world’s first longitudinal 10-year follow-up study to evaluate the long-term impact of childhood obstructive sleep apnea on blood pressure in adulthood.
Obstructive sleep apnea is a common form of sleep-disordered breathing that happens when the upper airway is blocked, leading to pauses in breathing.
Researchers invited 243 children to participate in the study from 2003 to 2005 and conducted a 10-year follow-up through an overnight sleep study and 24-hour blood pressure monitoring to measure the difference during daytime and nighttime.
Participants began aged between six and 13 years old and finished the follow-up when they were between 16 and 25.
Among them, 75 suffered from mild sleep apnea when they were young while 21 experienced moderate to severe snoring. Ninety-eight children were normal while the remaining 45 experienced habitual snoring.
The study showed that children classed under moderate to severe were 2.5 times more likely to get hypertension when they became young adults.
“This will increase their risks of having cardio-cerebrovascular diseases in the long run,” said Kate Chan Ching-ching, clinical professional consultant at the department of pediatrics.
She said the results also showed that childhood obstructive sleep apnea is an independent risk factor for higher blood pressure in adulthood.
“Sleep apnea-related vascular remodeling can begin early in childhood and lead to persistent blood pressure abnormalities.”
The follow-up study showed that patients classed under moderate to severe also had a higher nighttime systolic blood pressure compared to the normal group.
Normally, blood pressure follows a circadian rhythm and is 10 to 15 percent less during sleep than during wakefulness.
But the results showed that children classed as moderate to severe saw 4 percent less when it came to the nocturnal dipping of blood pressure during sleep compared to those who were normal.
Department chair Albert Li Man-chim said sleep apnea is common in children but it is difficult for parents to recognize.
A previous CUHK study estimated that about one in 20 schoolchildren in Hong Kong are affected by sleep apnea.
“Snoring, night sweats and mouth breathing are some common symptoms,” Li said.
“If a child has these symptoms more than three times a week, there is an 80 percent chance that the kid is already suffering from sleep apnea.”
Other symptoms include daytime inattention, hyperactivity, sleepiness and behavioral problems.
Researchers said childhood sleep apnea is usually caused by being overweight or blockage of the upper airway by enlarged tonsils and adenoids.
The team advised parents of children with symptoms to seek professional help and consider surgery if the problem is caused by enlarged tonsils and adenoids.
The CUHK research team will launch an 18- to 20-year study on the participants to trace the long-term health impacts.