A nationwide cross-sectional study on congenital heart diseases and symptoms of sleep-disordered breathing among Japanese Down's syndrome people

Growth-related changes in the influence of obesity on signs suggesting sleep-disordered breathing and sleepiness in young individuals with Down syndrome

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.

A Cross-Sectional Comparison of the Prevalence of Obstructive Sleep Apnea Symptoms in Adults With Down Syndrome in Scotland and Japan

Small studies in Western populations report a high prevalence of obstructive sleep apnea (OSA) in adults with Down syndrome. To date, ethnic differences have not been explored. A questionnaire sent to 2,752 adults with Down syndrome aged ≥16 years in Scotland and Japan (789 valid responses) estimated OSA prevalence based on reported symptoms. Symptoms were common in both countries, with snoring (p = 0.001) and arousals (p = 0.04) more prevalent in Japan. Estimated OSA prevalence in adults with Down syndrome was similar in the two countries, and raised in comparison with the general adult population (19.6% in Scotland and 14.3% in Japan; p = 0.08), though BMI was a confounder. Identification and treatment of OSA is recommended in adults with Down syndrome, regardless of ethnicity.

The Population Prevalence, Associations of Congenital Heart Defect and Mortality Risk for Down's Syndrome in South Korea Based on National Health Insurance Service (NHIS) Data

Background

In the present study, we estimated the population prevalence, associations of congenital heart defect (CHD) and mortality risk for DS using data from National Health Insurance Service (NHIS) and Rare Diseases Registry (RDR).

Methods

We collected data on subjects with DS who were registered in the RDR between 2010 and 2015. To estimate associations of CHD and mortality risk of DS, the data of DS subjects were compared with 1:5 age- and sex-matched controls.

Results

In 2015, 2077 individuals with DS were identified out of the total population of 51,574,044 South Koreans and the prevalence was 4.03 per 100,000 persons. The trend of DS population prevalence across 10-year-old intervals showed a peak in the group under the age of 10 years (26.0 per 100,000 persons) and then declined sharply after the age of 20 years (0.98 per 100,000 persons at 30-39 years of age). In subjects with DS, the frequencies of atrial septal defect [odds ratios (OR) =65.9; 95% CI, 84.1-99.1], ventricular septal defect (OR = 88.1, 95% CI, 57.9-134.1), patent ductus arteriosus (OR = 56.9, 95% CI, 40.1-80.8), tetralogy of fallot (OR = 42.1, 95% CI, 19.3-92.3), or atrioventricular septal defect (OR = 510.0, 95% CI, 126.7-999.0) were higher than those of age- and sex-matched controls. The risk of death in patients with DS was significantly higher than that of age- and sex-matched controls [hazard ratio (HR) =41.7, 95% CI 20.0-87.0].

Conclusion

In South Korea, the DS population prevalence was 4.03 per 100,000 persons in 2015. The subjects with DS were more likely to accompany CHD and have higher mortality risk than healthy controls.

A nationwide, cross-sectional survey on unusual sleep postures and sleep-disordered breathing-related symptoms in people with Down syndrome

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.