Sleep disturbance after rapid ascent to moderate altitude among infants and preverbal young children.

Rapid ascent to high altitude is known to result in sleep disturbances among adults. No data exist regarding the effects of altitude exposure on sleep in children. The objective of this study was to determine the effect of rapid ascent to moderate altitude on sleep in infants and young children. In this prospective study, each child served as his or her own control. Each subject was studied over 7 days and nights. On days 1 and 2, children were studied at home (1601 m), day 3 at a hotel without ascent (travel control), day 4 at home, days 5 and 6 at a hotel after ascent (3109 m), and day 7 at home. Since increased motion is a characteristic of sleep disturbance among infants and young children, continuous measurements of motion were made using an ankle-mounted Actigraph. Thirty children, 17 girls and 13 boys, with a median age of 16.5 months (range = 4 to 33 months) participated in the study. Significant changes in the activity counts, reflecting a sleep disturbance during nocturnal sleep, were noted between the travel control night (20.9 +/- 1.9) and the first night at altitude (29.4 +/- 2.5): p < 0.01. This sleep disturbance is most significant during the first night at altitude and may be similar to sleep disturbance with altitude exposure seen in adults.