This study investigated with sleep-disordered breathing events either with, or without hypoxia, resulted in measures that were more strongly associated with hypertension and sleepiness.
1002 subjects from the Wisconsin Sleep Cohort were analysed using a tailored algorithm. Breathing events were time locked to associated oxygen desaturations resulting in a desaturating breathing disturbance index (H-BDI) and a non-desaturations breathing disturbance index (NH-BDI) regardless of arousals. Subjective sleepiness was measured by the Epworth Sleepiness Scale questionnaire and objective sleepiness was analysed from a subset of 865 subjects with multiple sleep latency test data.
The results showed that H-BDI (desaturating events) correlated more strongly with 3% oxygen desaturation index (ODI) and AHI with 4% desaturations as expected. As the number of desaturation associated events doubled, there was an associated prevalence of hypertension which was significant for ODI but not H-BDI. Sleepiness was
Interestingly, non-desaturating events were more associated with objective sleepiness on MSLT, but had less association with subjectively sleepiness.
Over a 4 year follow up, baseline non-desaturating events were associated with worsening H-BDI suggesting a progression of severity.
Reference:
Henriette Koch, Logan Douglas Schneider, Laurel A Finn, Eileen B Leary, Paul E Peppard, Erika Hagen, Helge Bjarup Dissing Sorensen, Poul Jennum, Emmanuel Mignot; Breathing Disturbances Without Hypoxia Are Associated With Objective Sleepiness in Sleep Apnea, Sleep, Volume 40, Issue 11, 1 November 2017, zsx152, https://doi.org/10.1093/sleep/zsx152
