Can a simple forced inspiratory maneuver help identify subjects at risk for sleep-disordered breathing?

Application of a negative pressure has been utilized in experimental settings to demonstrate abnormal upper airways compliance. We hypothesized that a simple forced inspiratory maneuver could be used as a screening test for this abnormality in an epidemiological setting. 277 men and women, aged 30 years or more, who attended a Preventive Medicine Centre, volunteered for completing a sleep questionnaire, having standard anthropometric measurements, a non-invasive upper airways examination, and for performing an oronasal peak inspiratory maneuver. The peak inspiratory flow (PIF) of 127 females was significantly less compared to that of the 137 males (211±47 vs. 269±59 l.min-1). PIF was significantly inversely related to age in both sexes; a positive correlation with height was found in males only. Males with enlarged soft palates had a significantly lower PIF (256±54 vs. 277±62 l.min-1; p=0.04). No difference in PIF was found in subjects who stated that they experienced breathing pauses during sleep. Habitual snoring males had a significantly lower PIF as compared to the non-snorers (251±59 vs. 282±57 l.min-1; p=0.003); after adjustment for age, this difference was borderline significant (p=0.06). A forced inspiratory flow maneuver yielded a PIF which was different between genders, was age-dependent in both sexes, and related to height in males. PIF did not identify male subjects with breathing pauses during sleep, but was associated with a larger soft palate and was borderline decreased in habitual snoring males. The present results suggest that, with further validation, the PIF test could represent a simple means to indirectly explore upper airways compliance.