Results
A total of 40 infants were identified out of 525 children with DS who
underwent PSG. Mean age was 6.6 (3.0) months and male comprised 65% of
the cohort. The PSG studies included diagnostic (n=13, 33%) and split
night (n=27, 67%) cases. The demographic characteristics and
comorbidities of included I-DS are shown in the Table 1. PSG sleep
characteristics are described in Table 2. All met criteria for OSA with
mean oAHI 34.6 (32.3). Severe OSA was present in 34 (85%) infants. CSA
was present in 11 (27.5%) of infants. No association was found between
age and oAHI or CAI (Pearson correlation(r): -0.1 and 0.02 respectively,
P=NS for both). Infants who underwent split studies had more severe OSA
when compared with those who underwent diagnostic study. (AHI: 44.7/hr
(33.7) vs. 14.8 (9.0), p=0.003), T88 (Mean 12.5 min vs. 0.2 p=0.03) and
minO2sat (77.6% vs. 85.8, p=0.01). A total of 11 (27.5%) infants had
T88 >5 min qualifying for hypoxemia. Hypoxemia was more
common in I-DS with hypoventilation (60 vs. 16.7%, p=0.008). Hypoxemia
was also more common among those with severe OSA vs. no severe OSA (32.4
vs. 0%, p=0.16) but this difference was not statistically significant.
Hypoventilation was present in 10 (25%) infants. Characteristics of
infants with hypoventilation is depicted in Table 3. In logistic
regression there was a trend of association between hypothyroidism and
hypoventilation (OR: 5.5 [0.96-34.4], p=0.056).
There were 13 infants who underwent AT and had a follow up PSG allowing
us to compare the SDB metrics. Time interval between the two PSGs ranged
6 months to 2 years. Severity of OSA markedly decreased (Mean oAHI
reduction: 34/hr [29], p=0.0002) (Figure 1). minO2sat also improved
post AT (Mean minO2sat increase 9.7% (11.1), P=0.009).