SLEEP APNEA, HYPOPNEA AND OXYGEN DESATURATION IN NORMAL SUBJECTS - STRONG MALE PREDOMINANCE

Thirty asymptomatic men and 19 asymptomatic women were monitored during one night's sleep to determine the incidence of breathing abnormalities and oxygen desaturation in normal subjects. Twenty men accounted for 264 episodes of nocturnal oxygen desaturation or abnormal breathing. Women never experienced oxygen desaturation, and only three had a total of nine episodes of apnea. These sex differences were highly significant (P<0.003). In men, increasing age and obesity correlated positively with the incidence of nocturnal oxygen desaturation and abnormal breathing. Four asymptomatic men weighing more than 90 kg dropped their saturation to very low levels (68 to 72 per cent). Abnormal breathing and oxygen desaturation during sleep in subjects with chronic obstructive lung disease or the syndrome of hypersomnolence with periodic breathing may represent the superimposition of smoking or obesity on a normal tendency to snoring and oxygen desaturation in men. (N Engl J Med 300:513–517, 1979) SLEEP apnea and nocturnal oxygen desaturation have been reported in various clinical syndromes, including the Pickwickian syndrome, the syndrome of hypersomnolence with periodic breathing and chronic obstructive lung disease.1 2 3 4 5 6 7 8 9 The majority of patients in these papers have been men. We have found periodic breathing, oxygen desaturation or both during sleep in 22 of 27 patients with chronic obstructive lung disease.7 8 9 Because of this high frequency in patients, we determined the incidence of these phenomena in a large asymptomatic group of subjects. The results presented below clearly show that sleep apnea, hypopnea, and oxygen desaturation occur in normal subjects and that. © 1979, Massachusetts Medical Society. All rights reserved.