Several studies have shown that infants with genetic or metabolic disease have increased incidence of both central and obstructive apnea. However, those studies have not assessed the effect of sleep apnea on sleep architecture. Since apnea and associated hypoxemia and hypoventilation can lead to sleep fragmentation due to respiratory arousals, we evaluated the effect of apnea on sleep architecture in this population.
A retrospective review of polysomnographic recordings was performed in infants with genetic or metabolic disease and normal control infants who were referred to our sleep laboratory from 1999-2004. All infants underwent an overnight polysomographic studies. Any infants with significant lung diseases or infants who were on respiratory stimulants, or supplemental oxygen were excluded from the study.
Thirty three infants met the criteria for entry into the analysis; 17 infants with metabolic or genetic disease [S] and 15 age-matched controls [C]. The average apnea index of infants with genetic or metabolic disease was 23.9±6.8/hr; 58.8 % (10/17) had predominately central apnea and 41.2 % (7/17) had predominately obstructive apnea. Infants with genetic or metabolic disease had significant lower average SpO2 (95.6±3.4 %[S] vs. 99.1±0.9[C]; P<0.05) and higher average EtpCO2 (44.6±5.7 mmHg[S] vs. 38.7±4.9[C]; P<0.05) during sleep. However, there was no significant difference in the sleep efficiency (73.1±12.8%[S] vs. 78.6±5.5[C]; P=NS), percentage of REM sleep (54.3±16.2%[S] vs. 53.0±8.0[C]; P=NS) and NREM sleep (42.2±14.3%[S] vs. 43.5±8.2[C]; P=NS) between infants with genetic or metabolic disease and control. Analysis of the respiratory arousals revealed that only 11.6 % of apnea in infants with genetic or metabolic disease was followed by arousals.
It is concluded that apnea in infants with genetic or metabolic disease is not associated with significant changes in sleep architecture. It is speculated that the intact sleep architecture despite the presence of central and obstructive apnea may be due to blunted arousal response in these infants.
Infants with genetic or metabolic disease may be at risk of developing significant adverse events from sleep apnea.
Wish Banhiran, None.