Sleep-disordered breathing in adults with down syndrome: a cross cultural comparison

Abstract

Individuals with Down syndrome (DS) are at increased risk of sleep disordered breathing (SDB). Anatomical characteristics of DS, such as mid-facial hypoplasia, small jaw and obesity, are also risk factors for SDB, and may differ with ethnicity. Untreated SDB can lead to adverse cardiac outcomes and impaired cognitive function, thus early diagnosis and treatment may be important in DS. To date, no systematic population survey or cultural comparison has been made in DS individuals. This study aims to compare prevalence of SDB among adults aged >16 years with DS in two diverse cultures: Japan and Scotland. Questionnaires including physical profile, traditional or pictorial Epworth Sleepiness Scale (ESS) and witnessed signs of SDB (e.g. apnoeic episodes and snoring) were sent to adults aged >16 years with DS and their caregivers in Japan (J) and Scotland (S). 705 questionnaires were valid for analysis (J: 461; S: 244). Standard statistical analysis was undertaken. Similar gender distributions (male/female J: 259/202 vs. S: 139/105) and ESS (J: 6 ± 5 vs. S: 7 ± 5) were observed among Japanese and Scottish responders. Adults with DS in Scotland were older and had higher BMI than those in Japan (J: 24 ± 8 vs. S: 32 ± 11 years; J: 24.0 ± 4.1 vs. S: 29.6 ± 7.4 kg/m 2 ). In Japan, 80% of responders snored and 30% had witnessed apnoeas. Similarly, in Scotland, 74% snored and 24% had witnessed apnoeas. In Japan, snorers had significantly higher BMI (OR 1.1, 95%Cl 1.0–1.2, p < 0.01) and ESS (OR 1.2, 95%Cl 1.1–1.3, p < 0.001), and tended to be younger (OR 1.0 95%Cl 0.9–1.0, p = 0.06). Similar associations were found in Scotland, with snorers being younger (OR 1.0, 95%Cl 0.9–1.0, p < 0.05) and having significantly higher ESS (OR 1.3, 95%Cl 1.0–1.4, p < 0.01). In Japan, witnessed apnoeas were significantly associated with higher ESS (OR 1.2, 95%Cl 1.1–1.2, p < 0.001). Prevalence of symptoms of SDB was high among adults with DS in both countries. The DS population in Scotland was significantly more obese. These results imply that the anatomical characteristics of DS might overshadow the racial and anatomical differences in terms of causing SDB, although further research is required. Appropriate evaluation and treatment should be offered if symptoms of SDB are observed, regardless of ethnicity, in adults with DS. Both studies are ongoing. We sincerely appreciate Donna Fairley, RN, for helpful effort. Hiroyuki Sawatari and Elizabeth A Hill were joint 1st author. Renata L Riha and Shin-ich Ando were Joint supervisors.