Measures of nocturnal oxyhemoglobin desaturation in children with neuromuscular disease or Prader-Willi syndrome.

OBJECTIVES: Evidence for nocturnal oximetry interpretation in patients with abnormal neuromuscular function is limited. We aimed to compare children with neuromuscular disease (NMD) or Prader-Willi syndrome (PWS) to otherwise healthy subjects with obstructive sleep-disordered breathing (SDB) or without respiratory disorder (controls) regarding nocturnal oximetry parameters. METHODS: We analyzed recordings from children with: (a) NMD; (b) PWS; (c) snoring and adenotonsillar hypertrophy and/or obesity (SDB); and (d) controls. Outcomes included: (a) basal SpO2 ; (b) proportions of subjects with McGill oximetry score (MOS) >1 (clusters of desaturations); and (c) desaturation index (SpO2 drops ≥3%/h-ODI3). RESULTS: Data of 12 subjects with NMD (median age, 5.2 years; IQR, 2.7, 8.2), 14 children with PWS (5 years; 2.3, 6.9), 21 children with SDB (5.8 years; 4.6, 9.6), and 20 controls (6.2 years; 5.4, 11.2) were analyzed. Children with NMD, PWS, and SDB had lower basal SpO2 than controls (95.6% [94.5%, 96.9%], 96.2% [95.1%, 97.4%], 96.1% [95.8%, 97.5%] vs 97.8% [97.2%, 97.9%], respectively; (P < .01). NMD and PWS showed the greatest negative effect on basal SpO2 (P < .05). Children with SDB or PWS had a higher risk of MOS >1 than patients with NMD (OR, 25.9 [95% CI, 3.4-200.4] and 9.5 [1.5-62.6]). NMD, PWS, and SDB were similar regarding ODI3, which was elevated compared to ODI3 in controls (P < .05). Frequent desaturations predominated in NMD, while periods of sustained desaturation were noted in NMD and PWS. CONCLUSION: PWS and NMD have a negative effect on basal SpO2 , while clusters of desaturations are prevalent in patients with PWS or obstructive SDB.

Family history of adenotonsillectomy as a risk factor for tonsillar hypertrophy and snoring in childhood.

OBJECTIVE: Accumulating evidence supports a role for familial predisposition in the pathogenesis of OSA. In this study, it was hypothesized that parental history of adenoidectomy and/or tonsillectomy (AT), which is the standard treatment for pediatric OSA is a risk factor for tonsillar hypertrophy and habitual snoring (>3 nights/week) in the offspring. METHODS: Children were recruited from the emergency department and the pediatric pulmonology clinic. Paternal or maternal history of AT (explanatory variables) and habitual snoring (outcome) were recorded and presence of tonsillar hypertrophy (outcome) was assessed. RESULTS: Two hundred ninety-two children (2-14 y.o.) were recruited; 37 (12.7%) of them had paternal history of AT, 39 (13.4%) maternal history of AT, 60 (20.5%) tonsillar hypertrophy, and 48 (16.4%) habitual snoring. Maternal and paternal history of AT were significantly associated with the presence of tonsillar hypertrophy even after adjustment for age, gender, obesity, passive smoking, and physician-diagnosed wheezing requiring treatment with inhaled medications over the past year [odds ratios (95% confidence interval): 3.52 (1.54-8.06); P < 0.01 and 4.70 (2.13-10.36); P < 0.01, respectively]. Only maternal history of AT predicted history of snoring [4.12 (1.86-9.12); P < 0.01]. When entered in the same multivariate logistic regression analysis model, tonsillar hypertrophy was a stronger predictor of habitual snoring than maternal history of AT [4.00 (1.97-8.14) vs. 2.73 (1.20-6.20)]. CONCLUSIONS: Children with parental history of AT have more frequently tonsillar hypertrophy than those without such history. Tonsillar hypertrophy mediates at least in part the association between maternal history of AT and habitual snoring in childhood.

Age-dependent changes in the size of adenotonsillar tissue in childhood: implications for sleep-disordered breathing.

OBJECTIVE: To analyze age-associated changes in linear and cross-sectional area (CSA) measurements of adenoid, tonsils, and pharyngeal lumen. STUDY DESIGN: Measurements were completed in head magnetic resonance imaging examinations performed for diagnostic purposes. Linear and nonlinear regression models were applied to describe the effect of age on the size of soft tissues and upper airway. RESULTS: Magnetic resonance imaging data were analyzed in 149 children without snoring (aged 0-15.9 years) and in 33 children with snoring (aged 1.6-15 years). In the children without snoring, adenoid size increased during the first 7-8 years of life and then decreased gradually [% (adenoid oblique width/mental spine-clivus length) = 11.38 + 1.52 (age) - 0.11 (age)(2), R(2) = 0.22, P < .01; adenoid CSA = 90.75 + 41.93 (age) - 2.47 (age)(2); R(2) = 0.50; P < .01]. Nasopharyngeal airway CSA increased slowly up to age 8 years and rapidly thereafter. Similar patterns were noted for the tonsils and oropharyngeal airway. In contrast, in children with snoring, adenoid and tonsils were large irrespective of age, and nasopharyngeal airway size increased slowly with age. CONCLUSIONS: In children without snoring, growing adenotonsillar tissue narrows the upper airway lumen to variable degrees only during the first 8 years of life. In contrast, in children with snoring, appreciable pharyngeal lymphoid tissue enlargement is present during the preschool years and persists beyond the eighth birthday.

Cysteinyl leukotriene receptors in tonsillar B- and T-lymphocytes from children with obstructive sleep apnea.

OBJECTIVES: Cysteinyl leukotrienes have been implicated in the pathogenesis of adenotonsillar hypertrophy in children with obstructive sleep apnea (OSA). This study aimed to quantify the expression of cysteinyl leukotriene receptors (CysLT(1), CysLT(2)) by tonsillar lymphocyte subpopulations from children with OSA and to make comparisons to lymphocyte subpopulations from control subjects with recurrent tonsillitis (RT). METHODS: Tonsillar tissue from children with OSA or RT was studied for CysLT(1) and CysLT(2) expression by RT-PCR, flow cytometry (FC), and immunofluorescence. RESULTS: Ten children with OSA and 10 control subjects were recruited. In OSA participants, CysLT(1)+ fraction of small-size CD19+ B-lymphocytes was similar to the CysLT(1)+ CD3+ T-lymphocytes fraction (FC: 36.5 [16.5-55.4] vs. 14 [2.8-22.1]) (p>0.05) and higher than the CysLT(1)+ moderate/large-size CD19+ B-lymphocytes fraction (6.6 [1.5-14.4]) (p<0.01). Similar trends were recognized for CysLT(2). CysLT(1) and CysLT(2) immunoreactivity was detected by immunofluorescence in the tonsillar mantle zones (small B-lymphocytes) and the extrafollicular areas (T-lymphocytes). Compared to subjects with RT, children with OSA had significantly higher expression of CysLT(1) in small-size CD19+ B-lymphocytes (FC) and in CD3+ T-lymphocytes (RT-PCR and FC) (p<0.05). CONCLUSIONS: Increased expression of leukotriene receptors by immunologically active tonsillar areas in children with OSA is a potential therapeutic target for pediatric sleep apnea.