Feasibility and performance of home sleep apnea testing in youth with Down syndrome.

STUDY OBJECTIVES: In-laboratory polysomnography is recommended for the evaluation of obstructive sleep apnea (OSA) in youth with Down syndrome. However, insufficient sleep laboratories are available, particularly for youth with neurocognitive disabilities such as Down syndrome. We hypothesized that level II home sleep apnea testing (HSAT) would be feasible, acceptable, and accurate in detecting polysomnography-defined moderate-severe OSA in youth with Down syndrome. METHODS: Youth 6 to 25 years old with Down syndrome were recruited to undergo in-home level II HSAT with electroencephalogram and in-lab polysomnography. Parents completed questionnaires assessing feasibility, acceptability, and test preference. HSAT, scored blinded to polysomnography result, were compared to reference polysomnography. RESULTS: Forty-three youth (23 female) aged [median (range)] 15.5 (6.1, 25.1) years participated in the study. Forty-one participants were able to complete HSAT and 41 completed polysomnography, with 40 who underwent both tests. HSAT was preferred to polysomnography by 73.7% of parents. Total sleep time for HSAT was 437 ± 123 minutes vs 366 ± 90 minutes for polysomnography (P = .003). Obstructive apnea-hypopnea index by polysomnography was 12.7 events/h (0.2, 113.8), and 32 youth (80%) who completed all testing had OSA. Compared to polysomnography, sensitivity of HSAT was: 0.81, specificity was 0.75, accuracy was 0.8 including 2 youth whose HSAT demonstrated OSA when polysomnography did not. CONCLUSIONS: In youth with Down syndrome, level II HSAT was well-tolerated, preferred compared to in-lab polysomnography, and had good accuracy for detecting moderate-severe OSA. Level II HSAT could provide a means for expanding the evaluation of OSA in youth with Down syndrome. CITATION: Cielo CM, Kelly A, Xanthopoulos M, et al. Feasibility and performance of home sleep apnea testing in youth with Down syndrome J Clin Sleep Med. 2023;19(9):1605-1613.

Physical Activity in Youth with Down Syndrome and Its Relationship with Adiposity.

PURPOSE: The aims of this study are to (1) compare physical activity (PA) and sedentary activity (SA) in youth with and without Down syndrome (DS and non-DS) and examine the relationships of PA and SA with their traditional risk factors (age, sex, race, and body mass index Z score [BMI-Z]) and (2) explore the relationship of PA with visceral fat (VFAT) in both groups. METHODS: SenseWear accelerometry data from at least 2 weekdays and 1 weekend day were collected from youth with DS (N = 77) and non-DS (N = 57) youth. VFAT was measured by dual x-ray absorptiometry. RESULTS: In age-, sex-, race-, and BMI-Z-adjusted models, those with DS engaged in more minutes of light PA (LPA) ( p < 0.0001) and less SA ( p = 0.003) and trended toward fewer minutes of moderate-to-vigorous PA (MVPA) ( p = 0.08) than non-DS youth. No race or sex differences in MVPA were detected in those with DS, unlike non-DS. After additional adjustment for pubertal status, the relationship between MVPA and VFAT approached significance ( p = 0.06), whereas the relationships of LPA and SA with VFAT were maintained ( p ≤ 0.0001 for both). CONCLUSION: Youth with DS engage in more LPA compared with non-DS, which, in typically developing populations, can confer a more favorable weight status. Increasing the opportunity for youth with DS to engage in LPA as part of their activities of daily living may offer a viable strategy for achieving healthy weight when barriers restrict pursuit of more vigorous PA.

Prevalence of unsuspected abnormal echocardiograms in adolescents with down syndrome.

The purpose of this article is to describe the prevalence of cardiac disease previously undiagnosed in healthy asymptomatic children and adolescents with Down syndrome (DS). Subjects with DS ages 10-20 years were recruited from two sites, the Children's Hospital of Philadelphia (Philadelphia, PA) and Children's National Health System (Washington, DC) for a cross-sectional study of body composition and cardiometabolic risk. Echocardiographic and clinical data were collected from patients enrolled in the parent study of cardiometabolic risk. Nine (6%) new cardiac diagnoses were identified out of 149 eligible patients. All new findings resulted in outpatient referrals to pediatric cardiology. Current guidelines recommend screening all newborns with DS for congenital heart disease. Older patients with DS may benefit from rescreening.

Cross-Sectional Study of Arterial Stiffness in Adolescents with Down Syndrome.

OBJECTIVES: To test whether youth with Down syndrome have aortic stiffness indices, as measured by pulse wave velocity (PWV), that differ from youth without Down syndrome and to compare reference-based age-adjusted (age-PWV-Z) and height-adjusted (Ht-PWV-Z) in youth with and without Down syndrome. STUDY DESIGN: Cross-sectional study of PWV in 129 adolescents with Down syndrome and 97 youth of comparable age, sex, race/ethnicity, and body mass index (BMI). PWV, age-PWV-Z, and Ht-PWV-Z were compared. Regression models were developed to test for associations with PWV. RESULTS: Youth with Down syndrome and controls were comparable in BMI-Z (1.4 [-1.5 to 2.8] vs 1.2 [-2.0 to 2.8], P = .57) but not Ht-Z (-2.3 [-4.7 to 0.8] vs 0.4 [-2.0 to 2.6], P < .0001). PWV (m/s, 5.0 [3.1-7.9] vs 5.0 [3.6-8.0], P = .5) and mean arterial pressure (MAP, mm Hg) (78 [61-102] vs 74 [64-97], P = .09) were not different between groups. In adjusted analyses confined to Down syndrome, PWV was associated only with BMI, but not age, black race, or MAP (R2 = 0.11). In contrast, BMI, age, black race, and MAP were all positively associated with and better explained PWV in controls (R2 = 0.50). PWV was not associated with height in youth with or without Down syndrome. Although age-PWV-Z was not different in Down syndrome (-0.36 [-2.93 to 3.49]) vs -0.15 [-2.32 to 3.22]), Ht-PWV-Z was greater in Down syndrome (0.32 [-2.28 to 4.07] vs -0.08 [-2.64 to 2.64], P = .002), and Ht-PWV-Z was greater than age-PWV-Z in Down syndrome (P < .0001). CONCLUSIONS: The lack of relationship of PWV, an independent predictor of adult cardiovascular events, with its traditional determinants including MAP suggests Down syndrome-specific phenomena may alter such relationships in this population. In youth with Down syndrome, Ht-adjusted PWV may overestimate aortic stiffness. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01821300.

Relationships of Body Composition to Cardiac Structure and Function in Adolescents With Down Syndrome are Different than in Adolescents Without Down Syndrome.

Median survival in Down syndrome (DS) is 60 years, but cardiovascular disease risk and its markers such as left ventricular mass (LVM) have received limited attention. In youth, LVM is typically scaled to height2.7 as a surrogate for lean body mass (LBM), the strongest predictor of LVM, but whether this algorithm applies to DS, a condition which features short stature, is unknown. To examine the relationships of LVM and function with height, LBM, and moderate-to-vigorous physical activity(MVPA) in DS, DS youth aged 10-20 years, and age-, sex-, BMI-, race-matched nonDS controls underwent echocardiography for LVM, ejection fraction (EF), and left ventricular diastolic function (measured as E/E'); dual-energy X-ray absorptiometry (DXA)-measured LBM; accelerometry for MVPA. (DS vs. nonDS median [min-max]): DS had lower height (cm) (144.5 [116.7-170.3] vs. 163.3 [134.8-186.7]; p < 0.0001); LBM (kg) (33.48 [14.5-62.3] vs 41.8 [18.07-72.46], p < 0.0001); and LVM (g) (68.3 [32.1-135] vs 94.0 [43.9-164.6], p < 0.0001); similar EF (%) (65 [54-77] vs 64 [53-77], p = 0.59); and higher E/E' (8.41 [5.54-21.4] vs 5.81 [3.44-9.56], p < 0.0001). In height2.7-adjusted models, LVM was lower in DS (ß = - 7.7, p = 0.02). With adjustment for LBM, LVM was even lower in DS (ß = - 15.1, p < 0.0001), a finding not explained by MVPA. E/E' remained higher in DS after adjustment for age, height, HR, SBP, and BMI (ß = 2.6, p < 0.0001). DS was associated with stiffer left ventricles and lower LVM, the latter magnified with LBM adjustment. Scaling to height2.7, the traditional approach for assessing LVM in youth, may underestimate LVM differences in DS. Whether lower LVM and diastolic function are intrinsic to DS, pathologic, or protective remains unknown.Clinical Trial Registration: NCT01821300.

Caregiver-Reported Quality of Life in Youth with Down Syndrome.

OBJECTIVES: To describe caregiver-reported quality of life (QOL) in youth with Down syndrome (DS) and to examine the role of obesity on QOL. STUDY DESIGN: Caregivers of youth with and without DS aged 10 through 20 years completed questionnaires examining QOL (Pediatric Quality of Life Questionnaire) and weight-related QOL (Impact of Weight on Quality of Life - Kids). Age- and sex-specific z scores were generated for body mass index. Obesity was defined as a body mass index ≥95th percentile for age and sex. RESULTS: Caregiver-reported Total QOL, Physical Health, and Psychosocial Health summary scores were all lower in the DS group compared with the non-DS controls (P < .001). Social and School Functioning were also lower (P < .001), but Emotional Functioning did not differ between DS and non-DS groups (P = .31). Physical Functioning (P = .003) and Total scores (P = .03) differed between youth without DS with and without obesity, but no differences were reported between youth with DS with and without obesity. On the Impact of Weight on Quality of Life - Kids, caregivers of youth with DS reported greater Body Esteem (P = .020) and Social Life scores (P = .03) than caregivers of non-DS youth. Caregivers of youth with obesity, regardless of DS status, reported significantly lower weight-specific QOL scores than caregivers of youth without obesity. CONCLUSION: Caregivers reported lower QOL in youth with DS compared with youth without DS with the exception of emotional functioning. Obesity influences most domains of weight-related QOL in youth with and without DS; therefore, providers should address weight concerns in youth with obesity even in the presence of DS. CLINICAL TRIAL REGISTRATION: NCT01821300.