PT  - JOURNAL ARTICLE
AU  - A. Rice
AU  - S. Costy-Bennett
AU  - J. L. Goodwin
AU  - S. F. Quan
AU  - R. F. Fregosi
TI  - Control of breathing in children with mild sleep apnoea: a 6-year follow-up study
AID  - 10.1183/09031936.00178408
DP  - 2010 Jan 01
TA  - European Respiratory Journal
PG  - 124--131
VI  - 35
IP  - 1
4099  - http://erj.ersjournals.com/content/35/1/124.short
4100  - http://erj.ersjournals.com/content/35/1/124.full
SO  - Eur Respir J2010 Jan 01; 35
AB  - We have previously shown that children (average age 9 yrs) with mildly elevated obstructive apnoea/hypopnoea indices (OAHI) retained CO2 at rest. Here, we report the results of a 6-yr follow-up study on 14 children from that study. Minute ventilation (V′E) and end-tidal CO2 partial pressure (PET,CO2) were measured during hypercapnic challenge. OAHI decreased from 7.5±4.7 events·h−1 at age 9 yrs to 2.5±1.8 events·h−1 at age 15 yrs (p<0.001), despite an increase in body mass index from 20±4.6 kg·m−2 to 26±5.7 kg·m−2 (p<0.0001). Eupneic V′E increased from 4.1±0.31 L·min−1·m−2 to 5.9±0.4 L·min−1·m−2 (p<0.01), while PET,CO2 fell from 44.1±0.8 to 33±1.0 mmHg (p<0.001). The V′E–PET,CO2 obtained during hypercapnia was left shifted, such that V′E at a PET,CO2 of 50 mmHg increased from 24 L·min−1 at age 9 yrs to 36 L·min−1 at age 15 yrs. Central respiratory drive did not change. We hypothesise that somatic growth of the pharynx coupled with a regression of tonsillar tissue mass with age leads to enlargement of the upper airway lumen, a reduction in airway resistance and increased respiratory airflow at a given level of ventilatory drive.