Pediatric snoring and obstructive sleep apnea

Sleep problems are very common in children. Those between the ages of 2-8 years-old often exhibit snoring or breathing difficulties, which can be a sign of obstructive sleep apnea (OSA). [1] The main reason for this is due to the size of the adenoids and/or tonsils relative to the diameter of the upper airway at this point of physical development. [1] The consequences of this go beyond being a “noisy” sleeper as apnea can induce intermittent hypoxia (lack of oxygen delivery), and can manifest as behavioural and neurocognitive problems in children. [1]

The gold standard treatment for most cases is surgical removal of the adenoids and/or tonsils. However, continuing respiratory care in the form of key nutrients, immune system modulation, and myofunctional therapy, may be an essential part in preventing the recurrence of symptoms, as well as other respiratory infections and diseases. OSA is characterized by a passive pressure that closes the upper airway: With minor pressure the airway narrows, but with enough pressure, and the airway can completely collapse. [2] Most causes of OSA are structural in this manner, either due to the adenoids and/or tonsils, or to other structural issues such as craniofacial malformations, and obesity. [1] Additionally, inflammation and infections also play a role: asthma occurs due to inflammation of the airways leading to narrowing of bronchioles in the lungs. Other examples of increased pressure and inflammation include allergic and non-allergic rhinitis, and acute or chronic sinusitis. [1]

Hypertrophy of the adenoid and/or tonsils are most commonly found in children with OSA, the pressure of which can partially or completely occlude the airway. [1] As children age, these masses of lymphoid tissue, which play a role in the immune system, enlarge at a faster rate than other airway structures. This is most apparent between the ages of 3 and 6 years old. [3] In these cases, adenoidectomy, tonsillectomy, and/or adenotonsillectomy, in order to surgically remove the tissues, remains the treatment of choice. [1] Other physical variations can also play a role. Dental abnormalities and craniofacial malformations can lead to a decrease in physical space within the posterior oropharynx, the site most associated with obstructive breathing. [3] Obesity is also a significant risk factor for OSA in children, though much less common than tonsil hypertrophy. It has been noted that for each kg/m2 increase in BMI above the 50th percentile, adjusted for age and gender, there is a 12% increased risk of OSA. [1] In cases of obesity, there is a narrowing of the upper airway due to fatty infiltrate in the surrounding soft tissue which can increase the collapsibility of the pharynx. As well, visceral fat can impinge the chest wall leading to reduced lung functional residual capacity, making obese children more susceptible to episodes of hypoxia during sleep. [1] These decreases in lung volume can reduce airway stability, therefore increasing the risk of airway collapse. [1]

Symptoms and sequelae of OSA

Children who experience partial or complete obstruction of the airway during sleep will often experience fragmented sleep, an increase in respiratory effort, and alterations of gas exchange. [1] Most commonly, parents or caregivers may notice that their child snores at night, especially while in REM sleep. [1] Caregivers may also notice that their child is restless during sleep, wakes frequently, experiences bed-wetting, parasomnia, and/or they may actually witness episodes of apnea. [1] Outside of sleep, children may exhibit mouth breathing, hypo-nasal speech, difficulty waking, morning headaches, excessive daytime sleepiness and napping. [1] Mood can also be greatly affected with children experiencing symptoms of attention-deficit hyperactivity, aggressive behaviour and impulsivity, and thus poor school performance. [1] If left untreated, these effects can be exacerbated, impairing learning and memory, decreasing language and/or verbal skills, and a diminishing their adaptive abilities. [1] Intermittent hypoxia from OSA can have detrimental effects on the body by increasing oxidative stress (increasing the need for antioxidant nutrients) and inflammatory responses; The result of which is cellular damage. The cardiovascular system is also impeded via increased pulmonary vasoconstriction and endothelial dysfunction. One study in children showed an increase in left ventricular strain as a result. [1]

Surgical Intervention and Outcomes

A sleep study, also called polysomnography, is the gold standard for diagnosing OSA syndromes. Once confirmed, surgical treatment is often recommended as it has been shown to have better outcomes compared with watchful waiting. [1] One study reviewed outcomes at 7-months post-surgery and noticed a greater reduction in OSA symptoms as well as greater improvement in behavioural and polysomnographic outcomes compared to the watchful-waiting group. [1] In particular, teachers and caregivers reported improvements in restlessness, impulsiveness and emotional lability in the early-adenotonsillectomy group compared to controls. [4] Complications can arise with any surgery, and in the case of adenotonsillectomy, care must be taken with recovery as many children will experience localized pain or discomfort which will hinder their normal eating habits. Children may need to adhere to a soft and/or liquid diet initially and water intake must be maintained to prevent dehydration. [1] Interestingly, by including myofunctional therapy as part of rehabilitation, children are able to remain free of OSA long-term. One study of children who underwent two months of oropharyngeal exercises post-adenotonsillectomy showed a 62% reduction in the number of apnea events per hour, compared to the control group (no exercises) who showed minimal changes. [2] Another study followed up with children 4 years after adenotonsillectomy. Of those who received myofunctional therapy and continued to practice it long-term, they remained free from OSA events compared to children who were never trained to perform the exercises and had recurrences of OSA. [2]

Adjunctive and Preventative Care

Where inflammation and cases of allergic rhinitis play a role in OSA, nasal and upper respiratory anti-inflammatories can be a helpful treatment. Systemic inflammatory markers such as C Reactive protein, TNF-alpha, IL-6, IL-8 and others are often elevated in patients with OSA, indicating a pro-inflammatory state. [1] This can lead to degrading of type IV collage and therefore endothelial dysfunction, which is associated with the severity of OSA. [1] Conventional treatment may include nasal corticosteroid sprays, or an oral anti-inflammatory medication called montelukast, often prescribed for the prophylaxis of childhood asthma. [1] However, discontinuing these nasal sprays often causes a relapse of symptoms and may not be manageable long-term. Therefore, complementary medicine in the form of anti-oxidants, anti-inflammatories, and immunomodulators may play a supportive and preventative role.

Immune and anti-inflammatory support for the respiratory tract

Although we know OSA is most commonly a structural issue, there are ways in which we can support proper functioning and regulation of the immune system. An imbalance in TH1 and TH2 immune responses can present as allergies, rhinitis, sinusitis, asthma, eczema, and gut/digestive issues. The pathophysiology of chronic rhinosinusitis includes a disruption of the mucus membranes from either allergens, infections, and/or dysregulation of the immune system. [5] Reducing excess TH2 responses may help alleviate the symptoms of allergies and upper respiratory ailments, creating possible adjunctive treatments for children either who are undergoing watchful waiting, or post-surgery for those who are looking to support immune and respiratory function. For example, mucus hypersecretion is associated with the Rhinovirus, and the common cold. An inability to clear excess mucous would contribute to an impedance of respiratory function. Increased tissue swelling within the nasal passages can block drainage, and induce nasal and/or sinus congestion due to an ability to drain fluid from the extracellular space. Improving drainage and respiratory function may help reduce exacerbations of OSA, especially as function of the adenoids and tonsils are so closely linked to immune system responses.

Vitamin D

Studies suggest that vitamin D deficiency predisposes patients to respiratory tract infections, and may play a role in the development of asthma. [6] Vitamin D has repeatedly been shown to have an immunomodulating effect. Receptors for vitamin D are found in almost every tissue in the body with the ability to influence multiple types of white blood cells and components of the innate and adaptive immune systems. [6]  One 2013 meta-analysis showed that Vitamin D supplementation may be effective in preventing respiratory diseases [6], while another study in children found a reduced risk of asthma exacerbations with vitamin D. [7] Dosing should be prescribed by a medical or naturopathic practitioner, but in general, the tolerable upper intake level for infants and young children is between 1,000IU and 3,000IU, depending on age. [6] Serum vitamin D levels may also be measured and can influence dosing.

Probiotics and Vitamin C

Allergic diseases have been strongly linked to a reduction in early microbial exposure. As probiotics affect the local gut microflora, we can use them to influence cytokine secretion away from a heavier TH2 immune response by influencing more TH1 cytokine activation. [8] For example, the strains Lactobacillus plantarum and Lactobacillus reuteri have been shown to reduce the expression of pro-inflammatory cytokines in respiratory disorders in animal models. [9] One study in children ages 3-6 showed that a combination of 50mg of Vitamin C with a multi-strain probiotic supplement was able to reduce the incidence and duration of upper respiratory tract infections. [9] The results included fewer days absent from preschool and less unscheduled visits to the doctor. [9] Vitamin C has been shown to hinder the response of pro-inflammatory cytokines in monocytes and lymphocytes of healthy adults, as well as inhibit histamine secretion by white blood cells. [9] In particular, we find that oral supplementation with vitamin C leads to lower blood histamine levels. [5] This makes vitamin C an important modulator in allergic diseases, but also overall for immune system responses.

Conclusion

Although surgical intervention remains as the gold standard treatment for children with OSA, complimentary therapies may play an important role in the prevention of recurring symptoms, and also in overall respiratory function. By decreasing the incidence of respiratory infections and inflammation of the upper airway, we can help alleviate the pressure on the airways and reduce the occurrence of OSA-related symptoms and sequelae. These complimentary therapies include myofunctional therapy, anti-oxidant and anti-inflammatory support, and immunomodulators such as vitamin C, vitamin D and probiotics.