Sleep-disordered breathing & Downs Syndrome

Sleep-disordered breathing and Down syndrome: what you need to know Lizzie Hill BSc(Hons) RPSGT EST PhD Research Student, Sleep Research Unit, The University of Edinburgh Specialist Respiratory Clinical Physiologist, Royal Hospital For Sick Children, Edinburgh PastedGraphic-1 Sleep-disordered breathing (SDB) is the commonest medical cause of sleepiness. Muscle relaxation during sleep leads to a partial or complete collapse of the airway, resulting in a repeated cycle of pauses in breathing. These breathing pauses disrupt sleep, leading to daytime sleepiness. A clinically-significant number of breathing pauses during sleep is known as obstructive sleep apnoea (OSA). Snoring can occur due to vibration of the narrowed airway. Children and adults with Down syndrome (DS) are predisposed to SDB because some of the common features of DS overlap with the risk factors for SDB. These include a tendency to be overweight, generalised hypotonia, short midface, thick neck, large tonsils/adenoids and a relatively large tongue. We think around 55% of children with DS have SDB. We have been running a research study here in Edinburgh to work out the prevalence of SDB in adults with DS. Early results from our survey of over 1000 people suggest around 20% of adults with DS may have OSA, with over three-quarters of responders reporting snoring and over a quarter reporting breathing pauses. Unfortunately, many of the daytime symptoms of OSA, which includes sleepiness, may be overlooked in individuals with DS and dismissed as “just part of their condition” ~ despite the increased risk of OSA in people with DS, only 7% of people in our study had been diagnosed with OSA, and only 5% were currently receiving treatment. However, untreated OSA can have serious consequences. Impaired daytime function can result in problems with learning and memory, and is likely to worsen cognitive impairment already present in some people with DS ~ one study estimates that untreated SDB in children can lead to a 10-point reduction in IQ. Sleepiness can lead to a generally reduced quality of life for the individual and their family. Repeated pauses in breathing cause surges in blood pressure, putting extra strain on the heart, and there is a high risk of developing pulmonary hypertension in children with OSA and DS, especially if they already have co-existing heart problems. National guidelines from the Royal College of Paediatrics and Child Health (RCPCH) state that all children with DS should
be screened for OSA at age 6-9 months using a test called oximetry, which measures blood oxygen levels using a finger-clip. If the oximetry result is normal, screening should be repeated annually until the age of 3-5 years. If the oximetry is abnormal, a more detailed sleep study at home or in hospital is recommended, recording further information on breathing, oxygen levels, body position, snoring and sleep stages. The Down’s Syndrome Association recently published a Health Book for adults with DS, which includes sleep as one of the areas to be reviewed by their GP annually. The first-line treatment for OSA in children is removal of the tonsils and adenoids (T&A). This cures OSA in the majority of cases. The first-line treatment for OSA in adults or children who still have OSA after T&A is continuous positive airway pressure (CPAP). This involves wearing a mask over the nose or nose and mouth, blowing pressurised air in to hold the airway open from the inside. However, this simple, non-invasive and generally effective treatment is a therapy rather than a cure and so has to be used every night to feel the benefit. One study showed improvement in sleepiness, behaviour and quality of life in 10 children with neurodevelopmental disability (including DS) when using CPAP. In Edinburgh, we looked at 28 adults with DS and OSA to see how they got on with CPAP. Of the 28 people in the study, 20 were still using CPAP after 12 months. Overall, using CPAP leads to significant improvements in sleepiness, general health, cognitive function and behavioural/emotional outcomes. The full results of this study will be available soon. In summary, children and adults with DS are at an increased risk of SDB/OSA which, left untreated, can have a negative impact on health and wellbeing. However, effective treatment is available and should be offered to all children and adults who need it, whether they have DS or not. If you suspect someone you know has sleep-disordered breathing, please visit your GP in the first instance. Further information Further information on sleep and DS for families: carers/growing-up/sleep/ The British Lung Foundation provides a booklet on OSA in children, including a checklist to take to your GP: RCPCH guidelines on OSA and DS: Information on sleep in adults with DS, aimed at GPs: professionals/health-information-for-medical-professionals/annual-health-check-information-for- gps/ For more information on our research into sleep and DS in Edinburgh, please visit: schools-departments/clinical-sciences/sleep-research-unit