But scientists now have reason to believe that even mild cases of SDB may have serious consequences for children. Even just a case of simple snoring could be the unsuspected cause of learning difficulties, and behaviours such as hyperactivity and inattention in some children, who may have been misdiagnosed as having attention-deficit/hyperactivity disorder (ADHD) (JAMA, 2007; 297: 2681-3).
In fact, nighttime breathing problems at such a critical time of development may severely damage children's health-and even lead to permanent brain damage if left untreated.
The sleep-behaviour link
About one in five children suffers from sleep-disordered breathing, which can range from snoring to its most severe form, known as 'obstructive sleep apnoea' (OSA). Apnoea refers to a temporary absence of breathing and, in OSA, this is caused by a temporary, but repeated, blockage of airflow to the lungs.
Over the past few years, numerous behavioural problems have been associated with SDB in children, including aggression, impulsivity, anxiety/depression, conduct prob-lems, hyperactivity and inattention (PLoS Med, 2006; 3: e301; J Pediatr Psychol, 2006; 31: 322-30).
However, a multicentre US study provides some of the most compelling evidence yet for a cause-and-effect relationship of nocturnal breathing and behavioural difficulties. Scientists studied 105 children, ranging from 5 to nearly 13 years of age; of these,78 were suspected of having SDB, 22 of whom met criteria for ADHD, as judged by a child psychiatrist. One year after undergoing surgery to relieve their SDB, 11 of the 22 chil-dren no longer met criteria for an ADHD diagnosis. Moreover, all of the operated-on children showed dramatic improvements in terms of hyper-activity, inattention and daytime sleepiness (Pediatrics, 2006; 117: e769-78).
"These findings help support the idea that sleep-disordered breathing is actually helping to cause behavioural problems in children," said Dr Ronald D. Chervin, lead author of the study. Indeed, the study suggests that a potentially significant proportion of children with SDB are being wrongly diagnosed with ADHD. Nevertheless, the researchers found that even children with mild-to-moderate forms of SDB, such as snoring, "may still be at risk for significant neurobehavioural consequences".
Dr Chervin, and other sleep and breathing researchers, have built up a large body of evidence linking sleep and behaviour in recent years. In 2002, Chervin and his colleagues conducted a study of nearly 900 children, aged from two to nearly 14 years old, which revealed that those who habitually snore are nearly twice as likely tohave attention and hyperactivity problems as those who don't snore. Specifically, 16 per cent of the children were reported to be habitual snorers, and 13 per cent scored high on the hyperactivity index. However, more than one in five of the habitual snorers had high hyperactivity scores compared with around one in 10 of those whose parents said they didn't usually snore.
Similar differences were found when the researchers looked at hyperactivity scores among children who scored high on measures of sleepiness, snoring severity and SDB (Pediatrics, 2002; 109: 449-56).
A follow-up study involving the same children further bolsters the sleep-behaviour connection, showing that nighttime breathing problems, such as snoring, may actually predict the development of hyperactive behaviour in children (Sleep, 2005; 28: 885-90).
In this study, the researchers found that the children who were habitual snorers, in comparison to those who were not, were about four times more likely to have developed new hyper-activity four years later. In other words, snoring early in life predicted new or worsened behavioural problems four years on.
Similar behavioural problems were seen among children who had other symptoms of SDB. More alarming, the boys under eight years of age who had the worst nighttime breathing problems in the 2002 study were roughly nine times more likely to have developed new hyperactivity four years later than boys of the same age who hadn't had such sleep disorders.
While these results don't prove that SDB causes hyperactive behaviour, they do provide important evidence to support the hypothesis of a connection between them.
Effects on the brain
How is it that nighttime breathing problems can affect daytime behaviour in children?
Animal studies have suggested that hypoxia-a fall in oxygen levels, which is one of the features of SDB-may be to blame. However, behavioural problems are also seen in a variety of sleep disorders that don't involve hypoxia, suggesting that disrupted sleep itself may also play a role (Sleep, 2005; 28: 885-90).
When breathing is obstructed during sleep, the body expresses this as a choking phenomenon. The heart rate slows, the sympathetic nervous system is stimulated, blood pressure rises, the brain is aroused and sleep is disrupted. A child's brain cannot tolerate such repeated interruptions to sleep and so, rather than simply appearing sleepy like adults who are sleep-deprived, children may, in fact, become more active or hyperactive.
However, as more and more studies show, behavioural problems are not the only consequences of SDB. More and more, researchers are finding that mental (cognitive) development can also be affected.
In one study of 19 children, aged six to 16 years with obstructive sleep apnoea (OSA), and 12 controls, scientists at Johns Hopkins School of Medicine, in Baltimore, Maryland, found that the OSA-affected children had lower mean IQ scores (86) than those who were able to breathe properly at night (101). Their per-formance was also poorer on tests of verbal working memory and verbal fluency, both of which are aspects of higher-level thinking.
Most worrying of all, brain scans of the children with OSA revealed signs of possible neural injury in the left hippocampus and right frontal cortex, areas considered critical to learning and memory. This led the researchers to speculate that untreated OSA could permanently alter a developing child's cognitive potential, "ultimately impacting both the child's health and his or her functioning level in society" (PLoS Med, 2006; 3: e301).
Other studies have also shown that OSA can be detrimental to a child's brain, possibly resulting in lowered general intelligence, memory difficul-ties and poor executive function (the ability to adapt to new situations) (PLoS Med, 2006; 3: e301).
Yet, even children without OSA, but who have milder forms of SDB, are still at risk. One study found that five-year-old children with symptoms of SDB-in this case, frequent snoring, loud or noisy breathing during sleep or witnessed sleep apnoea-tend to score lower on tests of mental development and intelligence than do other children their age. Indeed, these findings persisted even when the children with OSA were excluded from the analysis (J Pediatr, 2004; 145: 458-64).
Another study-carried out by the University of South Australia-had similar results, finding that neuro-cognitive performance is reduced in children who snore, but who are otherwise healthy and who don't have severe OSA. The results, said the researchers, suggest "that the impact of mild sleep-disordered breathing on daytime functioning may be more significant than previously realized with subsequent implications for successful academic and develop-mental progress" (J Clin Exp Neuropsychol, 2000; 22: 554-68).
Yet other researchers have demon-strated that the effects of mild SDB can have long-term consequences for children.
For example, an American study from the University of Louisville, in Kentucky, found that young children who snored loudly and frequently were more likely to have lower grades as teenagers-even years after the breathing problem was treated (by surgery) or resolved. This suggests the possibility of permanent impairment, a long-term 'learning debt', beginning in the preschool or early school years (Pediatrics, 2001; 107: 1394-9).
Other health consequences
The first decade of life is a period of rapid neurological development and it appears that SDB-even in its milder forms-at this crucial stage may result in significant mental impairment. The precise mechanism for this effect is not yet fully understood but, as with the sleep-behaviour research, it appears that reduced oxygen levels, disrupted sleep, or a combination of these, may be responsible.
Dean Beebe, from the Cincinnati Children's Hospital Medical Center in Ohio, notes that, "The developing brain does not simply unfold in a predetermined genetic process. Rather, it builds upon itself at each stage, with development dictated by the interaction of genes with the immediate cellular environment. That environment is determined by the child's life experiences (e.g. reactions to [SDB]-related behavioural distur-bances) and physiological functioning (e.g. [SDB]-related oxygen deprivation or sleep disruption)."
To put it more simply, sleep is crucial to normal childhood develop-ment, and SDB, by diminishing the quality of sleep, may have a partic-ularly marked long-term impact (PLoS Med, 2006; 3: e323).
Indeed, as well as affecting behaviour and learning, SDB in children may also result in retarded physical growth. Several studies have observed that children appear to experience a growth spurt following surgery to relieve their sleep problems, which suggests that SDB may have had negative effects on their growth-hormone production (Pediatrics, 2002; 109: e55; J Pediatr, 1999; 135: 76-80). Left untreated, therefore, SDB can permanently damage even a child's physical development.
Even more worrying, the disturbed sleep patterns and persistent lack of oxygen associated with SDB may be involved in a chain of physical reactions that go on to contribute to chronic health problems later in life. For example, while SDB is known to be an independent risk factor for cardiovascular disease in adults, emerging evidence reveals that this risk may also affect children. Recent research shows that severe SDB in children causes structural changes to the heart that are likely to increase the risk for heart disease and death at an older age (Am J Respir Crit Care Med, 2002; 165: 1395-9). Another study found that children with SDB-and especially OSA-had increased levels of C-reactive protein, an impor-tant marker of inflammation with "major implications" for cardiovas-cular disease (Pediatrics, 2004; 113: e564-9). Yet further evidence indicates that even children who just snore-SDB at its mildest-have significantly higher blood pressure than do those who don't have nighttime breathing problems, and this may also jeopardize their long-term cardiovascular health (Chest, 2003; 123: 1561-6).
In addition, other researchers have found that childhood SDB may be linked to the so-called metabolic syndrome, a constellation of condi-tions including diabetes, obesity and hypertension that is associated with an increased risk of death due to cardiovascular causes (J Pediatr, 2002; 140: 654-9; J Pediatr, 2007; 150: 608-12).
It's not surprising, then, that compared with healthy children, children with untreated SDB use more healthcare services and have a poorer health-related quality of life (JAMA, 2007; 297: 2681-3). According to one study, the quality of life for children with SDB is similar to those who have asthma or juvenile rheumatoid arth-ritis and, in some respects, may even be worse (Eur Respir J, 2005; 25: 216-7).
Clearly, this all means that it's vital that SDB be recognized and treated early on to avoid a lifetime's worth of serious consequences. But the reality is that many children suffer with the condition-and its associated prob-lems-for months or even years before receiving proper care.
The key is for parents to become informed, and to recognize the signs and symptoms before it's too late. Ultimately, none of us should ever underestimate the importance of a good night's sleep (see also page 10).
For more information on children and sleep, go to www.sleepfoundation. org or www.britishsnoring.co.uk.
The obesity link
There are a number of possible causes for the development of sleep- disordered breathing (SDB) in children, including enlarged tonsils and adenoids (a condition known as 'adenotonsillar hypertrophy'), problems of the central nervous system, genetic disorders such as Down's syndrome and structural abnormalities of the craniofacial area (J Pediatr Psychol, 2006; 31: 322-30). Passive exposure to tobacco smoke can also increase a child's risk for SDB (JAMA, 2007; 297: 2681-3).
However, in the past few years, there has been a great deal of interest in the possible connection between SDB and childhood obesity. This is because the prevalence of SDB in children is rising in tandem with the increase of over-weight and obesity. In the US, for instance, the childhood obesity rate has more than doubled for children aged two to five years, and more than tripled for those aged six to 11 years, over the past three decades (JAMA, 2007; 297: 2681-3).
A study investigating the influence of the obesity epidemic on sleep-disordered breathing between 1992 and 2004 extrapolated findings from the Wisconsin Sleep Cohort Study, and data from the US Census Bureau and Centers for Disease Control and Prevention (CDC). It estimated that 40 per cent of cases of SDB in 1992 were due to excess weight. Hand in hand with the expanding prevalence of obesity, however, the 2004 estimate was 69 per cent. The researchers predicted that, on the basis of current trends, the percentage of sleep-disordered breathing associated with excess weight will continue to rise in the future (Medscape Neurol Neurosurg, 2006; 8 2; online at www.medscape.com).
Obesity causes SDB by increasing the amount of fat tissue in the throat, neck and chest wall which, in turn, causes an increase in upper airways resistance and makes the effort of breathing hard work (Pediatr Nurs, 2006; 32: 489-94). However, the opposite may also be true: sleep-disordered breathing could represent a factor contributing to obesity (Medscape Neurol Neurosurg, 2006; 8 2; online at www.medscape.com ).
SDB: what to look for
- Laboured breathing
- Snorting or gasping
- Pauses in breathing
- Unusual sleep posture (such as knees tucked under the chest, mouth open and neck hyperextended)
- Nightmares of drowning or choking
- Difficulty following directions and completing tasks
- Poor memory (JAMA, 2007; 297: 2681-3).
Conventional SDB treatments
Treating sleep-disordered breathing such as in obstructive sleep apnoea (OSA) depends on the patient's medical history, the severity of the condition and the specific cause of the problem (see box, page 6). Nevertheless, in general, the choices offered by conventional medicine are limited:
For children with enlarged tonsils and adenoids, the most common cause of SDB, the first-line treatment is surgery to remove them, an operation known as 'adenotonsillectomy' (AT). In the US, an estimated 250,000 children undergo AT every year. Around 40 per cent of ATs in children aged five to 13 years are performed specifically for OSA (JAMA, 2007; 297: 2681-3).A review of 14 studies found that AT was successful in 83 per cent of children with OSA (Otolaryngol Head Neck Surg, 2006; 134: 979-84). Other studies found that the procedure significantly improved the children's neurobehavioural problems a year later (Pediatrics, 2006; 117: e769-78) and enhanced their quality of life (Arch Otolaryngol Head Neck Surg, 2005; 131: 308-14)However, in children with severe SDB or obesity, the operation is rarely sufficient to fully eliminate nighttime breathing problems (JAMA, 2007; 297: 2681- 3). As one study found, only 25 per cent of children had complete normalization of sleep after surgery (J Pediatr, 2006; 149: 803-8).
As with all surgical procedures, there are also a number of risks involvedand possible complications. These include problems related to anaesthesia, bleeding and infection.
Continuous positive airway pressure (CPAP) therapy.
This involves an electronic device that applies positive pressure, via a nasal mask, to preventthe throat and airways from collapsing in on itself while the child is sleeping.A number of studies have found CPAP to be effective and well tolerated, even in children who are under two years of age (J Pediatr, 1995; 127: 88-94; Chest, 2000; 117: 1608-12).
However, as the equipment needs to be worn at all times during sleep, some children may find it difficult to adapt to having something cumbersome on their face (Pediatr Nurs, 2006; 32: 489-94).
Also, CPAP does come with side-effects, such as dry or stuffy nose, irritation of the skin on the face, stomach bloating, sore eyes and headache (Pediatr Nurs, 2006; 32: 489-94). Hypoplasia (underdevelopment) of the mouth and nose as a result of pressure from the mask has also been seen (Chest, 2000; 117: 916-8). Although there are ways to reduce these effects, compliance with CPAP therapy is often low (Clin Psychol Rev, 2005; 25: 673-705).
A 10-week study of 36 patients with OSA found acupuncture to be more effective than sham acupuncture at alleviating respiratory symptoms (Sleep Med, 2007; 8: 43-50). There is also evidence that a type of acupuncture called 'auriculotherapy acupoint pressure' may help to treat sleep apnoea (Zhongguo Zhong Xi Yi Jie Za Zhi, 2003; 23: 747-9).
Allergies can cause the nasal passages, sinuses and lungs to swell, thereby contributing to symptoms of SDB. People with allergic rhinitis and asthma are more likely to snore than non-allergic individuals (Ann Otolaryngol Chir Cervicofac, 2000; 117: 168-73). Children who snore are also more likely to have allergies (Chest, 1997; 111: 170-3), and one study found that more than half of children with allergies snore (S Afr Med J, 1997; 87: 987-91). Thus, treating allergies using methods such as homeopathy or nutrition may help to improve SDB. As children with allergy symptoms, including snoring, commonly have food sensitivities, identifying and excluding the allergy-causing foods can lead to improvement of SDB symptoms (Pediatr Med Chir, 1988; 10: 103-10).
such as those used in yoga and in the Buteyko method, may help. According to Buteyko practitioners, SDB is caused by hyperventilation, or 'over-breathing'-taking in too much air-and this method can reduce the volume of air automatically taken in by 31 per cent within three months of starting the course (Med J Aust, 1998; 169: 575-8). However, there have been no studies of its use specifically for SDB.
One study has found that regular playing of the didgeridoo-which involves circular breathing-improved snoring, sleep apnoea and daytime sleepinessin 25 patients with OSA. The results suggest that playing the didgeridoo decreases the collapsibility of the upper airways (BMJ, 2006; 332: 266-70).
A variety of oral appliances may be used to treat SDB. When worn during sleep, they help to maintain an open airway by repositioning or stabilizing the lower jaw, tongue, soft palate or uvula (the flap of tissue that hangs down from the roof of the mouth). Oral-appliance therapy is recom-mended by the American Sleep Disorders Association for some patients (Sleep, 2006; 29: 240-3), and studies show that it can significantly improve quality oflife (Northwest Dent, 1995; 74: 17-25). Nevertheless, side-effects include tooth and jaw discomfort, and temporomandibular joint (TMJ) problems (Sleep, 2006; 29: 244-62), so it is essential to undergo treatment only under the supervision of an experienced dental specialist.
Although it requires commitment from both the child and the family, for obese patients with SDB, losing weight may be a successful treat-ment option as well as improve overall health (Pediatr Nurs, 2006; 32: 489-94).
SDB is often worsened when sufferers lie on their back; in fact, people with 'positional sleep apnoea' have episodes of decreased or shallow breathing at least twice as often on their back as on their side (Chest,1997; 112: 629-39). So, it may be beneficial for parents to encourage children to sleep on their side by, say, placing pillows on either side of the child, or sewing an uncomfortable button or tennis ball onto the back of the child's pyjamas.
Homeopathy. After first identifying the cause of the problem before treating it, homeopaths often recommend the following remedies for children with SDB:
- Grindelia Robusta, for those who must sit up to breathe, wake up with a start and have tenacious mucus
- Opium, for those who feel suffocated upon going to sleep, and who possibly suffered birth trauma
- Lachesis, for those whose breathing almost stops upon falling asleep, with worse symptoms when sleeping
- China Officinalis, for those who snore, fall into a heavy sleep and have anxiety dreams.
Food for sleep
Sleep is the body's best medicine, but millions of people have problems with chronic insomnia. An estimated one-quarter of the population takes sleeping pills or some form of sleeping aid in the US alone, when simple dietary measures can usually cure the problem.
A friend of mine recently began to look and feel quite unwell-blotchy face, nervousness, anxiety, a drugged feeling and nightmares. It turned out she had begun taking one of the new sleeping pills to help her sleep better. Her sleep improved only marginally with the medication, but the adverse effects were so extensive that she finally weaned herself off the drug. Most of the side-effects resolved, and she slept no worse without the drug-and at least felt better during the day and got rid of the nightmares.
Most people need seven to eight hours of sleep a night; if they get less, a nap may be in order. Some believe they can do with five or six. However, if you think you're oneof these, but you keep falling asleep during the day or loading up on coffee, it's an obvious sign that you're not getting enough good-quality sleep (see box below).
You need sleep to restore brain function and remove stress, and for healing or repair of all your tissues and organs. If you're sick or hurt, plenty of sleep helps youto get better faster.
One family in Italy who suffers from 'fatal familial insomnia' in middle-age offers evidence of the long-term effects of extreme sleep deprivation: "Your blood pressure and pulse become elevated, and you sweat heavily as your body goes into overdrive . . . A downward progression ensues as your ability to balance, walk or speak disappears . . . In the final phase, usually after several months, youfall into a state of exhaustion resembling a coma and, mercifully, die" (New York Times Magazine, 6 May 2001).
If you have sleeping problems, these few simple dietary measures can ensure that you get good night's sleep.
- Cut out caffeine in all forms, including the hidden varieties. Often, sleep problems come from stress and repetitive thoughts, and caffeine worsens those (Clin Pharmacol Ther, 1976; 20: 682-9). Even one cup of coffee the morning before may cause sleeplessness somewhere around 4 to 5 a.m. Black or green tea can have the same effects, too, even though green tea contains the relaxant l-theanine. Caffeine is found in both regular and in decaf coffee (in which traces of caffeine remain), black tea, green tea, colas, chocolate in all its forms, and in desserts, ice cream or any food or sweet containing any of the above.
It may take several days to withdraw from caffeine-and it should be done gradually, or you'll have headaches. If you get a headache and taking an over-the-counter medication helps eliminate it, read the drug's label: it's likely to contain caffeine, and taking that drug is perpetuating the problem.
- Eat light at night. Avoid red meat or heavy meals at dinner time, and eat only the minimum necessary to stop feeling hungry. This could include salad with sardines, a simple pasta or whole grain with vegetables, vegetarian mild Indian curry, soup and crackers. Drink only water. This has other benefits: my husband completely stopped snoring when he cut his dinner food intake to half or less than usual. He also lost weight.
- Cut down or completely eliminate alcohol. Although alcohol has an initial sedative effect, drinking alcohol significantly interferes with sleep (Electroenceph Clin Neuro-physiol, 1980; 48: 706-9).
- Identify food allergies or intolerances to foods thatyou may be consuming at night. Your pulse will race about six hours after eating the offending substance. Cut them out, particularly during the evening.
- Have a cup of hot herbal tea (chamomile is good) with a teaspoon of honey. Or have half a teaspoon of honey just before retiring, or if you waken during the night. Honeywill help with low-blood sugar, another common cause of insomnia (Murray M, Pizzorno J. Encyclopedia of Natural Medicine, revised 2nd edn. Rocklin, CA: Prima Publishing, 1998).
- Try my favourite anti-stress and anti-insomnia remedy: apple juice-kudzu pudding. Kudzu, made from the roots of a wild vine found in Asia, has been used in Chinese medicine since ancient times to induce relaxation. In a small saucepan, place 1 cup cold apple juice, 2 tbsp kudzu chunks and 1/4 tsp vanilla (optional). Mix juice and kudzu with a wooden spoon until no lumps remain. Add vanilla if used. Heat over a low flame, stirring all the time until it thickens and boils. Drink it hot (serves one).
If you can't find kudzu, try plain hot, unfiltered apple cider with cinnamon. Cinnamon can regulate blood sugar levels, another common reason for insomnia (ibid).
- Take other measures to regulate your blood sugar. One simple solution is to eat a banana before bedtime. High in potassium, soft and sweet, it helps to regulate blood sugar yo-yos and is very relaxing.
- Keep your bedroom dark and quiet, and sleep tight!
Annemarie Colbin, PhD
Dr Colbin is an award-winning leader and author in the field of natural health. Visit her website at www.foodandhealing.com .
You're sleeping well if . . .
- You fall asleep within 10 minutes of 'lights out'
- You feel as if you 'disappear' and, when you wake up, you 'reappear'
- You wake up naturally at the time you need to wake up (this you can do by telling yourself the night before what time you need to wake up)
- You use alarm clocks cautiously: they may interrupt you at a bad place in the sleep cycle, and then you feel grumpy and tired all day- You sleep in a blacked-out and quiet room.