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Rationale: Randomized controlled trials have been unable to detect a cardiovascular benefit of continuous positive airway pressure in unselected patients with obstructive sleep apnea (OSA). We hypothesize that deleterious cardiovascular outcomes are concentrated in a subgroup of patients with a heightened pulse-rate response to apneas and hypopneas (DHR).Methods: We measured the DHR in the MESA (Multi-Ethnic Study of Atherosclerosis) (N 5 1,395) and the SHHS (Sleep Heart Health Study) (N 5 4,575). MESA data were used to determine the functional form of the association between the DHR and subclinical cardiovascular biomarkers, whereas primary analyses tested the association of the DHR with nonfatal or fatal cardiovascular disease (CVD) and all-cause mortality in longitudinal data from the SHHS.Measurements and Main Results: In the MESA, U-shaped relationships were observed between subclinical CVD biomarkers (coronary artery calcium, NT-proBNP [N-terminal prohormone BNP], and Framingham risk score) and the DHR; notably, a high DHR (upper quartile) was associated with elevated biomarker scores compared with a midrange DHR (25th-75th centiles). In the SHHS, individuals with a high DHR compared with a midrange DHR were at increased risk of nonfatal or fatal CVD and all-cause mortality (nonfatal adjusted hazard ratio [95% confidence interval (CI)], 1.60 [1.28-2.00]; fatal adjusted hazard ratio [95% CI], 1.68 [1.22-2.30]; allcause adjusted hazard ratio [95% CI], 1.29 [1.07-1.55]). The risk associated with a high DHR was particularly high in those with a substantial hypoxic burden (nonfatal, 1.93 [1.36-2.73]; fatal, 3.50 [2.15-5.71]; all-cause, 1.84 [1.40-2.40]) and was exclusively observed in nonsleepy individuals.Conclusions: Individuals with OSA who demonstrate an elevated DHR are at increased risk of cardiovascular morbidity and mortality. This study identifies a prognostic biomarker for OSA that appears useful for risk stratification and patient selection for future clinical trials.

Vection is the illusion of self-motion in the absence of real physical movement. The aim of the present study was to analyze how multisensory inputs (visual and auditory) contribute to the perception of vection. Participants were seated in a stationary position in front of a large, curved projection display and were exposed to a virtual scene that constantly rotated around the yaw-axis, simulating a 360° rotation. The virtual scene contained either only visual, only auditory, or a combination of visual and auditory cues. Additionally, simulated rotation speed (90°/s vs. 60°/s) and the number of sound sources (1 vs. 3) were varied for all three stimulus conditions. All participants were exposed to every condition in a randomized order. Data specific to vection latency, vection strength, the severity of motion sickness (MS), and postural steadiness were collected. Results revealed reduced vection onset latencies and increased vection strength when auditory cues were added to the visual stimuli, whereas MS and postural steadiness were not affected by the presence of auditory cues. Half of the participants reported experiencing auditorily induced vection, although the sensation was rather weak and less robust than visually induced vection. Results demonstrate that the combination of visual and auditory cues can enhance the sensation of vection.

Level V, expert opinion.

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Study Objectives Oral appliance therapy is an increasingly common option for treating obstructive sleep apnea (OSA) in patients who are intolerant to continuous positive airway pressure (CPAP). Clinically applicable tools to identify patients who could respond to oral appliance therapy are limited. Methods Data from three studies (N = 81) were compiled, which included two sleep study nights, on and off oral appliance treatment. Along with clinical variables, airflow features were computed that included the average drop in airflow during respiratory events (event depth) and flow shape features, which, from previous work, indicates the mechanism of pharyngeal collapse. A model was developed to predict oral appliance treatment response (>50% reduction in apnea–hypopnea index [AHI] from baseline plus a treatment AHI <10 events/h). Model performance was quantified using (1) accuracy and (2) the difference in oral appliance treatment efficacy (percent reduction in AHI) and treatment AHI between predicted responders and nonresponders. Results In addition to age and body mass index (BMI), event depth and expiratory “pinching” (validated to reflect palatal prolapse) were the airflow features selected by the model. Nonresponders had deeper events, “pinched” expiratory flow shape (i.e. associated with palatal collapse), were older, and had a higher BMI. Prediction accuracy was 74% and treatment AHI was lower in predicted responders compared to nonresponders by a clinically meaningful margin (8.0 [5.1 to 11.6] vs. 20.0 [12.2 to 29.5] events/h, p < 0.001). Conclusions A model developed with airflow features calculated from routine polysomnography, combined with age and BMI, identified oral appliance treatment responders from nonresponders. This research represents an important application of phenotyping to identify alternative treatments for personalized OSA management.