RESUMO
BACKGROUND: Sleep-disordered breathing (SDB) is highly prevalent in individuals with Down syndrome (DS), who cease growing earlier than individuals without DS. These characteristics may be associated with increased obesity and subsequent SDB signs, such as snoring and apnoea or excessive daytime sleepiness (EDS). Thus, we assessed the influence of growth on the association between obesity and SDB signs or EDS; we used questionnaires sent to young individuals with DS and their caregivers, in a cross-sectional study. METHODS: We sent out 2000 questionnaires to individuals with DS and their caregivers. The surveys included questions about SDB signs (witnessed snoring or apnoea), subjective sleeping time including witnessed midnight arousal, the Epworth sleepiness scale and witnessed napping as well as sex, age, body weight and body height. RESULTS: Of the 1222 questionnaires we received, 660 were from young individuals and were included in the analysis. SDB signs were highly prevalent (77.1%), and frequency of SDB signs increased with growth (P-trend: P = 0.02) in individuals with DS. Multivariate analyses showed that EDS (Epworth sleepiness scale > 10 points) was associated with body mass index Z-score (Z-BMI) in the 6-9 years age group (odds ratio [OR] 95% confidence interval [95% CI]: 1.69 [1.09-2.62], P = 0.02). Conversely, SDB signs were associated with Z-BMI in the 13-15 (OR [95% CI]: 1.99 [1.06-3.72], P = 0.03) and 16-18 years age groups (OR [95% CI]: 3.04 [1.22-7.59], P = 0.02). For the 19-21 years age group, SDB signs were associated with only male sex (OR [95% CI]: 7.28 [1.22-43.38], P = 0.03). CONCLUSIONS: This study showed that the association between Z-BMI and SDB or EDS was age dependent. In early school-age children with DS, high Z-BMI could not accurately predict the presence of SDB, but it was associated with EDS. In the pubescent period (i.e. 13-18 years), high Z-BMI was associated with SDB signs but not with EDS. Overall, obesity affected SDB signs and EDS differently based on age in young individuals with DS.
RESUMO
BACKGROUND: People with Down syndrome (DS) often have sleep-disordered breathing (SDB). Unusual sleep postures, such as leaning forward and sitting, are observed in people with DS. This study aimed to clarify the prevalence of unusual sleep postures and their relationships with SDB-related symptoms (SDB-RSs), such as snoring, witnessed apnoea, nocturnal awakening and excessive daytime sleepiness. METHODS: A questionnaire, including demographic characteristics and the presence of unusual sleep postures, as well as SDB-RSs, was completed by 1149 parents of people with DS from Japan. RESULTS: Unusual sleep postures were recorded in 483 (42.0%) people with DS. These participants were significantly younger and had a history of low muscle tone more frequently than people without unusual sleep postures. In all ages, the leaning forward posture was more frequent than sitting. People with DS with unusual sleep postures suffered from SDB-RSs. Those who slept in the sitting posture had more frequent SDB-RSs than did those who slept with the leaning forward posture. Snoring, witnessed apnoea and nocturnal awakening were observed in 73.6, 27.2 and 58.2% of participants, respectively. Snoring increased with aging. Witnessed apnoea was more common in males and in those with hypothyroidism than in females and in those without hypothyroidism. CONCLUSIONS: Our study shows that there is a close relationship between unusual sleep postures and SDB-RSs. We recommend that all people with DS with unusual sleep postures should be checked for the presence of SDB.