A new study suggests that teenagers with the breathing disorder sleep apnea may be at increased risk of developing metabolic syndrome — a collection of risk factors for diabetes and heart disease.
Researchers found that among 270 teenagers they assessed, those with sleep apnea were 6.5 times more likely to have metabolic syndrome than their peers without the breathing disorder.
In sleep apnea, soft tissues in the throat temporarily collapse during sleep, causing repeated stops and starts in breathing throughout the night. Loud snoring and daytime sleepiness are two prime symptoms.
Metabolic syndrome refers to a clustering of risk factors for type 2 diabetes, heart disease and stroke — including abdominal obesity, high blood pressure, elevated blood sugar, high triglycerides (a type of blood fat) and low levels of "good" HDL cholesterol. The syndrome is generally diagnosed when a person has any three of these problems.
Both sleep apnea and metabolic syndrome are related to obesity, but studies in adults have suggested that the breathing disorder is a risk factor for metabolic syndrome, independent of body weight.
It hasn't been clear whether this is true of teenagers, however.
The new findings, published in the American Journal of Respiratory & Critical Care Medicine, suggest that sleep apnea may in fact contribute to metabolic syndrome in children.
Overall, researchers found, 59 percent of teens with sleep apnea had metabolic syndrome, versus 16 percent of those without sleep apnea. The large majority of teenagers with sleep apnea were overweight, but the breathing disorder appeared to be related to certain components of metabolic syndrome independent of body weight.
It's difficult to separate the effects of obesity and sleep apnea itself, according to the study's lead author, Dr. Susan Redline of Case Western Reserve University in Cleveland, Ohio.
However, she told Reuters Health, the findings do suggest that the "overnight stresses" of the sleep apnea contribute to metabolic syndrome.
Repeated sleep interruptions and dips in oxygen may raise the body's levels of stress hormones like cortisol, Redline explained. This, in turn, may lead to elevations in blood sugar and blood pressure, as well as problems with cholesterol metabolism.
According to Redline and her colleagues, it would be a good idea to screen teenagers with sleep apnea for metabolic syndrome. Similarly, teenagers who are overweight and have metabolic syndrome should be screened for sleep apnea.
Given the role of excess weight in both conditions, Redline noted, this study also underscores the importance of children maintaining a healthy weight.