TY  - JOUR
PY  - 2021//
TI  - Altered K-complex morphology during sustained inspiratory airflow limitation is associated with next-day lapses in vigilance in obstructive sleep apnea
JO  - Sleep
A1  - Rapoport, David M.
A1  - Eckert, Danny J.
A1  - Varga, Andrew W.
A1  - Mazumdar, Madhu
A1  - Berkalieva, Asem
A1  - Mullins, Anna E.
A1  - Kam, Korey
A1  - Castillo, Bresne
A1  - Parekh, Ankit
A1  - Ayappa, Indu
SP  - ePub
EP  - ePub
VL  - ePub
IS  - ePub
N2  - STUDY OBJECTIVES: Determine if changes in K-complexes associated with sustained inspiratory airflow limitation (SIFL) during N2 sleep are associated with next-day  vigilance and objective sleepiness. <br><br>METHODS: Data from thirty subjects with  moderate-to-severe OSA who completed three in-lab polysomnograms: diagnostic, on  therapeutic continuous positive airway pressure (CPAP), and on suboptimal CPAP  (4cmH20 below optimal titrated CPAP level) were analyzed. Four 20-min psychomotor  vigilance tests (PVT) were performed after each PSG, every two hours. Changes in  proportion of spontaneous K-complexes and spectral characteristics surrounding  K-complexes were evaluated for K-complexes associated with both delta (∆SWAK), alpha  (∆αK) frequencies. <br><br>RESULTS: Suboptimal CPAP induced SIFL (14.7(20.9) vs. 2.9(9.2);  %total sleep time, p<0.001) with a small increase in apnea hypopnea index (AHI3A:  6.5(7.7) vs. 1.9(2.3); p<0.01) versus optimal CPAP. K-complex density (num./min of  stage N2) was higher on suboptimal CPAP (0.97±0.7 vs. 0.65±0.5, #/min, mean±SD,  p<0.01) above and beyond the effect of age, sex, AHI3A, and duration of SIFL. A  decrease in ∆SWAK with suboptimal CPAP was associated with increased PVT lapses and  explained 17% of additional variance in PVT lapses. Within-night during suboptimal  CPAP K-complexes appeared to alternate between promoting sleep and as arousal  surrogates. EEG changes were not associated with objective sleepiness. <br><br>CONCLUSIONS:  Sustained inspiratory airflow limitation is associated with altered K-complex  morphology including increased occurrence of K-complexes with bursts of alpha as  arousal surrogates. These findings suggest that sustained inspiratory flow  limitation may be associated with non-visible sleep fragmentation and contribute to  increased lapses in vigilance.<p />  <p>Language: en</p>
LA  - en
SN  - 0161-8105
UR  - http://dx.doi.org/10.1093/sleep/zsab010
ID  - ref1
ER  -