After injury occurs to the body, whether it be major or minor, the body responds with inflammation. Inflammatory responses differ according to the location and severity of the injury, but in general, inflammation acts to eliminate the cause of cell injury, remove dead cells from the area, and initiate tissue repair. A marker of inflammation called C-Reactive Protein (CRP) is present in the system after non-specific cell injury occurs. In other words, whenever something bad happens to the body, CRP shows up to mediate injury. Given that sleep apnea does a considerable amount of damage to the body on a nightly basis, might CRP be present in those with untreated sleep apnea?
This question was investigated using an interesting population – kids! Children studies are especially important because their growing brains are more fragile than our older, worn out brains. Protecting brains at a young age helps cognition across the lifespan, so these investigations are crucial.
Children who habitually snored and did not snore were included as research participants in this study. Each child was screened with an overnight sleep study to determine whether any had obstructive sleep apnea. The children were then divided into three groups: (1) no snoring or apnea, (2) snoring but no apnea, and (3) apnea. CRP levels were assessed in each child (the lower the level of CRP, the less inflammation, the better). The children were also given neurocognitive examinations so that cognitive functioning could be gauged.
It was found that, as expected, CRP levels were highest in the obstructive sleep apnea group of children (0.36) compared to the children who only snored (0.19). The control (non-apnea and non-snoring) children had similar CRP levels than snoring children (.18). What’s more, interestingly, when looking only at children with sleep apnea, the children with the cognitive deficits had much higher CRP levels than those without cognitive deficits (0.48 vs. 0.21).
This is a significant study, as it brings up two important points. First, general bodily inflammation is higher in children who have sleep apnea but not in those who snore. Second, cognition is affected in children with sleep apnea, but only when inflammation is present. This indicates that sleep apnea affects children differentially, and we now have an identifying marker of which kids are influenced to a greater extent. Finding this marker is an important first step in alleviating cognitive deficits caused by sleep apnea in children. In general, inflammation or not, if your child or a child you know suffers from sleep apnea, they should be treated no matter what. There are many treatment options out there – so take care of the tiny brains!
Gozal, D., Crabtree, V. M., Sans Capdevila, O., Witcher, L. A., & Kheirandish-Gozal, L. (2007). C-reactive protein, obstructive sleep apnea, and cognitive dysfunction in school-aged children. American journal of respiratory and critical care medicine, 176(2), 188-193.