Association between A/N ratio and polysomnographic findings in children
with obstructive sleep apnea hypopnea syndrome
Abstract
Purpose: To explore the screening value of the adenoidectomy /
nasopharyngeal (A/N) ratio from nasopharyngeal lateral radiography in
children with obstructive sleep apnoea hypopnea syndrome (OSAHS).
Methods: Children who had visited the respiratory department due to
snoring and/or mouth breathing’ were enrolled. Nasopharyngeal lateral
radiography and polysomnography (PSG) were performed. PSG monitoring is
the gold standard for OSAHS. The differences in PSG monitoring results
among different A/N groups were compared, and the correlation between
the A/N ratio and PSG monitoring results was analysed. The receiver
operating characteristic curve (ROC) was plotted to evaluate the
screening value of OSAHS in children with the A/N ratio from
nasopharyngeal lateral radiography to determine the diagnostic critical
point. Results: A total of 425 children were enrolled. A total of 183
patients (43.1%) were diagnosed with OSAHS, including 113 cases
(26.6%) of mild OSAHS and 70 cases (16.5%) of moderate to severe
OSAHS. A total of 52 patients (12.2%) had an A/N ratio ≤ 0.60, 77
patients (18.1%) had an A/N ratio from 0.61~0.70, 142
patients (33.4%) had an A/N ratio from 0.71~0.80, and
154 patients (36.2%) had an A/N ratio ≥0.80 The patients with
moderate-severe OSAHS had a higher A/N ratio than those with mild OSAHS
and non-OSAHS. The OAHI, ODI, and the diagnostic rate of OSAHS were
higher and the LSaO 2 was lower in the A/N≥0.80 group than in the other
three groups. Spearman’s rank correlation showed that the A/N ratio was
correlated with OAHI, ODI, and LSaO 2 (r=0.275, 0.227, -0.225,
respectively). The area under the ROC curve for the diagnosis of OSAHS
by the A/N ratio was 0.659, the critical value was 0.825, and the
sensitivity and specificity were 45.1% and 80.9%, respectively. An A/N
ratio ≥0.825 was identified as the main influencing factor of OSAHS by
logistic multivariable regression analysis. Conclusion: There is a
correlation between the degree of adenoid hypertrophy and OSAHS, and an
A/N ratio ≥0.825 has good suggestive value for the diagnosis of OSAHS
but is not a substitute for PSG.