Influence of age and gender on upper airway resistance in NREM and REM sleep.

The prevalence of irregular breathing during sleep is age and gender dependent, but the reason for this is unknown. This study tested the hypothesis that older men have a greater sleep-related increase in respiratory resistance. In 48 healthy subjects, 12 in each of four groups of younger and older men and women, airway resistance was measured during wakefulness and sleep using a mask, pneumotachograph, and catheter-mounted pressure sensors. Total respiratory resistance and total "low-flow," and "high-flow" oropharyngeal resistance were analyzed from 170,000 breaths, high flow being at rates above 50% maximal inspiratory flow. High-flow oropharyngeal and total respiratory resistance increased during non-rapid eye movement (NREM) sleep in all groups but not low-flow resistance. Total respiratory resistance increased from 12 +/- 1.2 cmH(2)O. l(-1). s(-1) awake to 16.2 +/- 2.4 in NREM sleep in young men, from 22.8 +/- 3.6 to 33.6 +/- 5.4 in young women, from 18 +/- 3 to 34.8 +/- 4.8 in older men, and from 26.6. +/- 4.2 to 34.2 +/- 6 in older women. The percentage of change in total respiratory resistance from awake to NREM sleep was not different between age groups or genders. We conclude that there are no major age or gender differences in the changes in airway resistance with sleep in normal subjects.