The language of sleepiness in obstructive sleep apnea beyond the Epworth

PURPOSE

Obstructive sleep apnea (OSA) is underdiagnosed, partially from variable clinical presentations. Emphasis is often placed on Epworth Sleepiness Scale (ESS), a subjective measure of sleepiness, but variable in OSA. We hypothesized that daytime complaints measured with Language of Sleepiness Questionnaire (LOS) in OSA are not being captured by ESS.

METHODS

Adults referred to a tertiary sleep clinic undergoing sleep studies completed ESS and LOS questionnaires (20 items with various patient-reported descriptors). LOS was examined in patients who had or did not have OSA without sleepiness based on ESS < 10. Cluster analysis was performed to assess whether or not groups of individuals differed based on classification with or without OSA and with or without ESS-based sleepiness.

RESULTS

Approximately half the study population (n = 185 completed) had OSA. ESS score (mean ± SD) was 9.0 ± 5.4. There was no significant difference in ESS between patients with and without OSA (9.0 ± 5.1 vs 9.1 ± 5.7, p = 0.969). In patients with OSA, females, older patients and white patients were significantly less likely to have an ESS ≥ 10 when compared to patients with an ESS < 10. In patients with an ESS < 10, there were no significant differences in descriptors of sleepiness between patients with and without OSA with the most common descriptors selected being "I lack energy," "I wake up sleepy," "I keep waking up," and "I don't sleep enough."

CONCLUSIONS

The ESS failed to discriminate patients with OSA from those without OSA. Despite an ESS < 10, both daytime and sleep complaints using the LOS questionnaire were present in patients with OSA. Asymptomatic OSA may be less common than previously reported.

Diagnostic performance of screening tools for the detection of obstructive sleep apnea in people living with HIV

STUDY OBJECTIVES

Many people living with HIV (PLWH) have undiagnosed obstructive sleep apnea (OSA), which may contribute to commonly reported fatigue and the high cardiovascular disease burden in this population. Our objective was to assess the utility of traditional OSA screening tools (STOP-BANG, Berlin Questionnaire (BQ), and Epworth Sleepiness Scale (ESS)) for detecting OSA in PLWH.

METHODS

Adult PLWH were recruited from sleep/HIV clinics and the community into a larger clinical trial which included completion of these questionnaires before in-laboratory polysomnography. Discriminatory performance of these screening tools was assessed using area under receiver operating characteristic curves (AUC). The reference standard for the primary analysis was OSA based on an AHI≥5/h using recommended "1A"-criteria (hypopnea with 3%-desaturation and/or arousal). Secondary analyses explored acceptable "1B"-criteria (hypopnea with 4%-desaturation) and/or higher AHI cut-offs (≥15/h).

RESULTS

120 PLWH were included (mean-age: 50±11 years; body mass index: 27±4 kg/m², 84% male) and OSA was diagnosed in 75% using 1A-criteria. In the primary analysis, the discriminatory performance of the three screening tools was low (AUCs 0.58 to 0.70) and similar across the tools (P≥0.14). In secondary analyses, STOP-BANG showed moderate-high discriminatory ability (AUCs 0.77-0.80) and performed significantly better (P≤0.008) than the BQ or ESS (AUCs 0.53-0.62).

CONCLUSIONS

OSA was highly prevalent in our cohort of PLWH. Although STOP-BANG could reasonably identify moderate-severe OSA, the tools were not reliable for mild disease. Specifically, the questionnaires perform poorly for PLWH with mild OSA manifesting with arousals, yet such people may be at risk of fatigue/sleepiness and impaired memory consolidation.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Obstructive Sleep Apnea Endotypes and Impact on Phenotypes of People Living With HIV (PLWH/OSA); Identifier: NCT03575143; URL: https://clinicaltrials.gov/ct2/show/NCT03575143.

A Pilot Randomized Controlled Trial of Effect of Genioglossus Muscle Strengthening on Obstructive Sleep Apnea Outcomes

The genioglossus is a major upper airway dilator muscle. Our goal was to assess the efficacy of upper airway muscle training on Obstructive Sleep Apnea (OSA) as an adjunct treatment. Sixty-eight participants with OSA (AHI > 10/h) were recruited from our clinic. They fall into the following categories: (a) Treated with Automatic Positive Airway Pressure (APAP), (n = 21), (b) Previously failed APAP therapy (Untreated), (n = 25), (c) Treated with Mandibular Advancement Splint (MAS), (n = 22). All subjects were given a custom-made tongue strengthening device. We conducted a prospective, randomized, controlled study examining the effect of upper airway muscle training. In each subgroup, subjects were randomized to muscle training (volitional protrusion against resistance) or sham group (negligible resistance), with a 1:1 ratio over 3 months of treatment. In the baseline and the final visit, subjects completed home sleep apnea testing, Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), SF-36 (36-Item Short Form Survey), and Psychomotor Vigilance Test (PVT). Intervention (muscle training) did not affect the AHI (Apnea-Hypopnea Index), (p-values > 0.05). Based on PSQI, ESS, SF-36 scores, and PVT parameters, the changes between the intervention and sham groups were not significant, and the changes were not associated with the type of treatment (p-value > 0.05). The effectiveness of upper airway muscle training exercise as an adjunct treatment requires further study.

Impact of obstructive sleep apnea on cardiopulmonary performance, endothelial dysfunction, and pulmonary hypertension during exercise

RATIONALE

OSA has been associated with reduced exercise capacity. Endothelial dysfunction and exercise-induced pulmonary hypertension (ePH) may be mediators of this impairment. We hypothesized that OSA severity would be associated with impaired exercise performance, endothelial dysfunction, and ePH.

METHODS

Subjects with untreated OSA were recruited. Subjects underwent endothelial function, and cardiopulmonary exercise testing with an echocardiogram immediately before and following exercise.

RESULTS

22 subjects were recruited with mean age 56 ± 8 years, 74 % male, BMI 29 ± 3 kg/m², and AHI 22 ± 12 events/hr. Peak V˙O₂ did not differ from normal (99.7 ± 17.3 % predicted; p = 0.93). There was no significant association between OSA severity (as AHI, ODI) and exercise capacity, endothelial function, or pulmonary artery pressure. However, ODI, marker of RV diastolic dysfunction, and BMI together explained 59.3 % of the variability of exercise performance (p < 0.001) via our exploratory analyses.

CONCLUSIONS

Exercise capacity was not impaired in this OSA cohort. Further work is needed to elucidate mechanisms linking sleep apnea, obesity, endothelial dysfunction and exercise impairment.

Cognitive function and mood at high altitude following acclimatization and use of supplemental oxygen and adaptive servoventilation sleep treatments

Impairments in cognitive function, mood, and sleep quality occur following ascent to high altitude. Low oxygen (hypoxia) and poor sleep quality are both linked to impaired cognitive performance, but their independent contributions at high altitude remain unknown. Adaptive servoventilation (ASV) improves sleep quality by stabilizing breathing and preventing central apneas without supplemental oxygen. We compared the efficacy of ASV and supplemental oxygen sleep treatments for improving daytime cognitive function and mood in high-altitude visitors (N = 18) during acclimatization to 3,800 m. Each night, subjects were randomly provided with ASV, supplemental oxygen (SpO2 > 95%), or no treatment. Each morning subjects completed a series of cognitive function tests and questionnaires to assess mood and multiple aspects of cognitive performance. We found that both ASV and supplemental oxygen (O2) improved daytime feelings of confusion (ASV: p < 0.01; O2: p < 0.05) and fatigue (ASV: p < 0.01; O2: p < 0.01) but did not improve other measures of cognitive performance at high altitude. However, performance improved on the trail making tests (TMT) A and B (p < 0.001), the balloon analog risk test (p < 0.0001), and the psychomotor vigilance test (p < 0.01) over the course of three days at altitude after controlling for effects of sleep treatments. Compared to sea level, subjects reported higher levels of confusion (p < 0.01) and performed worse on the TMT A (p < 0.05) and the emotion recognition test (p < 0.05) on nights when they received no treatment at high altitude. These results suggest that stabilizing breathing (ASV) or increasing oxygenation (supplemental oxygen) during sleep can reduce feelings of fatigue and confusion, but that daytime hypoxia may play a larger role in other cognitive impairments reported at high altitude. Furthermore, this study provides evidence that some aspects of cognition (executive control, risk inhibition, sustained attention) improve with acclimatization.