Cross-sectional general survey on the relationship between congenital heart diseases and sleep disordered breathing in patients with Down syndrome

Abstract

Purpose: Abundant evidences have been accumulated about the deteriorating effects of sleep disordered breathing (SDB) on cardiovascular disease, especially heart failure. On the other hand, it has been well recognized that heart failure itself worsens SDB and makes a vicious cycle. Early recognition and treatment of SDB, therefore, might be crucial to prevent aggravation of their heart diseases and to improve the prognosis of the patients with heart diseases. Down syndrome (DS) is known to frequently comorbid with congenital heart diseases (CHD) and it is suggested that SDB is accompanied to many DS patients due to the muscular hypotonia and anatomical predisposition of their face. As there was no investigation about their inter-relationship in DS, we studied it as a nationwide survey to establish the fundamental information of their relationship to improve their quality of life and prognosis. Methods: We sent out 2,090 questionnaires to the caregivers of the DS patients who belonged to the Japan Down syndrome society. The questionnaires included the type of CHD and signs of SDB such as witnessed nocturnal apneic episodes, nocturnal arousal episodes, nocturia and snoring. We analyzed the data using logistic regression analysis adjusted by age, sex and obesity. We defined obesity using Kaup index, Rohrer index, and body mass index according to their age. Results: Of 1,287 replies (sex: men=716, women=551, unanswered=20; age: median=13, range:5-80 y.o.), 683 (53.7%) were complicated with CHD (ventricular septal defect 20.3%, atrial septal defect 19.4%, patent ductus arteriosus 10.8%, atrio-ventricular septal defect 5.1%, valvular disease 3.6%, tetralogy of Fallot (TOF) 2.7%, arrhythmia 1.9%, and the others 1.0%: multiple answers) and 88% of DS had some of signs of SDB. Logistic regression analysis revealed that DS patients with CHD was significantly frequently related to apneic episode compared to those without CHD (OR 1.34, 95%Cl 1.02-1.77, p=0.04). Among them, those with TOF was more frequently associated with apneic episodes (OR 3.08 95%Cl 1.36-6.98, p=0.007) and they tended to have more episodes of arousal and nocturia as well (OR 1.98, 95%Cl 0.87-4.5 p=0.1; OR 1.94, 95%Cl 0.90-4.19, p=0.09; respectively). Conclusions: SDB is widely prevailed in DS patients especially in those with CHD, particularly with TOF. Because SDB and heart disease may exacerbate each other in such patients, we should pay more attention to signs of SDB and try to resolve SDB, hopefully in their early stage, to improve their quality of life and prognosis.