Validation of the oxygen desaturation index in the diagnostic workup of obstructive sleep apnea

Comparison of efficacy and usability of custom mandibular advancement devices fabricated with the conventional method and digital workflow: A pilot clinical study

PURPOSE

To compare the effects of fabricating methods of custom monoblock mandibular advancement devices (MADs) on usability and efficacy in patients with mild and moderate obstructive sleep apnea (OSA).

MATERIALS AND METHODS

Digitally fabricated custom MADs (dMADs) were produced for 11 OSA participants who had previously used conventionally fabricated custom MADs (cMADs). The participants answered a modified usability questionnaire for both MADs, and the average scores that were given to the questionnaire were evaluated by age, sex, and body mass index (BMI), and the scores of cMADs and dMADs were compared. After 6 months of usage of each MAD, the apnea-hypopnea index (AHI), mean and lowest oxygen saturations, and total sleep time were measured for efficacy assessment. Data were analyzed with Cronbach's alpha, Mann-Whitney U, Kruskal-Wallis, Wilcoxon signed-rank, one-way repeated measures analyses of variance, and Bonferroni tests (α = 0.05).

RESULTS

Cronbach's alpha was found at 0.834 and 0.722 for the conventional and digital questionnaires, respectively. The usability scores of the dMADs were significantly higher than those of cMADs (p = 0.013). There was no difference in usability scores in terms of sex or BMI (p > 0.05). No statistically significant difference was found for cMAD (p = 0.113) among age groups; however, there was a significant difference for dMAD (p = 0.046). The AHI, mean, and lowest oxygen saturation values were significantly affected by MAD usage (p < 0.001). However, total sleep time values did not differ after the MAD treatments (p > 0.05). Significantly lower AHI and significantly higher lowest oxygen saturation values were observed with dMAD, while both appliances led to similar results for mean oxygen saturation and total sleep time values (p > 0.05).

CONCLUSIONS

Participant usability scores were higher for digitally manufactured MADs than conventionally manufactured MADs. However, both conventional and digital MADs were found effective in decreasing the AHI levels and increasing the mean and lowest oxygen saturation values of the participants.

Prediction of Oxygen Desaturation by Using Sound Data From a Noncontact Device: A Proof-of-Concept Study

OBJECTIVES/HYPOTHESIS

Prediction of the apnea-hypopnea index (AHI) from breathing sounds during sleep could be used to prescreen for obstructive sleep apnea (OSA). In addition, the oxygen desaturation index (ODI) is a known risk factor for developing cardiovascular disease in OSA patients. This study focused on estimation of ODI from a noncontact manner from sleep breathing sounds.

STUDY DESIGN

Retrospective study.

METHODS

Patients who visited the sleep center due to snoring or sleep apnea underwent polysomnography in lab overnight. Sound recordings were made during polysomnography using a microphone. After noise reduction, the sound data were segmented into 5 seconds windows and features were extracted. Binary classification and regression analyses were performed to estimate the ODI during sleep (model 1). This was re-tested after inclusion of body mass index (BMI) and age as additional features (model 2: BMI only, model 3: BMI and age).

RESULTS

We included 116 patients. The mean age and AHI of all patients were 50.4 ± 16.7 years and 23.0 ± 24.0 events/hr. In binary classification, for ODI cutoff values of 5, 15, and 30 events/hr, the areas under the curve were 0.88, 0.93, 0.91, respectively, and accuracies were 85.34, 86.21, and 87.07, respectively. In regression analysis, the correlation coefficient and mean absolute error were 0.80 and 9.60 events/hr, respectively. In models 2 and 3, the correlation coefficient and mean absolute error were 0.82, 9.44 events/hr and 0.81, 9.6 events/hr, respectively.

CONCLUSION

Prediction of ODI from sleep sound seems to be feasible. Additional clinical feature such as BMI may increase overall predictability.

LEVEL OF EVIDENCE

IV Laryngoscope, 2021.

Diagnostic accuracy of oximetry for obstructive sleep apnea: a study on older adults in a home setting

OBJECTIVES

Owing to the fact that obstructive sleep apnea (OSA) is an underreported disease, the strategy used for the diagnosis of OSA has been extensively dissected to devise a simplified process that can be accessed by the public health services. Polysomnography (PSG) type I, the gold standard for the diagnosis of OSA, is expensive and difficult to access by low-income populations. In this study, we aimed to verify the accuracy of the oxyhemoglobin desaturation index (ODI) in comparison to the apnea-hypopnea index (AHI) using a portable monitor.

METHODS

We evaluated 94 type III PSG home test results of 65 elderly patients (69.21±6.94 years old), along with information, such as the body mass index (BMI) and sex, using data obtained from a clinical trial database.

RESULTS

A significant linear positive correlation (r=0.93, p<0.05) was observed between ODI and AHI, without any interference from sex, BMI, and positional component. The sensitivity of ODI compared to that of AHI increased with an increase in the severity of OSA, while the specificity of ODI in comparison to that of AHI was high for all degrees of severity. The accuracy of ODI was 80.7% for distinguishing between patients with mild and moderate apnea and 84.4% for distinguishing between patients with moderate and severe apnea.

CONCLUSION

The ODI values obtained in uncontrolled conditions exhibited high sensitivity for identifying severe apnea compared to the AHI values, and correctly identified the severity of OSA in more than 80% of the cases. Thus, oximetry is promising strategy for diagnosing OSA.

Association Between Obstructive Sleep Apnea and Brain White Matter Hyperintensities in a Population-Based Cohort in Germany

Importance

Underlying pathomechanisms of brain white matter hyperintensities (WMHs), commonly observed in older individuals and significantly associated with Alzheimer disease and brain aging, have not yet been fully elucidated. One potential contributing factor to WMH burden is chronic obstructive sleep apnea (OSA), a disorder highly prevalent in the general population with readily available treatment options.

Objective

To investigate potential associations between OSA and WMH burden.

Design, Setting, and Participants

Analyses were conducted in 529 study participants of the Study of Health in Pomerania-Trend baseline (SHIP-Trend-0) study with complete WMH, OSA, and important clinical data available. SHIP-Trend-0 is a general population-based, cross-sectional, observational study to facilitate the investigation of a large spectrum of common risk factors, subclinical disorders, and clinical diseases and their relationships among each other with patient recruitment from Western Pomerania, Germany, starting on September 1, 2008, with data collected until December 31, 2012. Data analysis was performed from February 1, 2019, to January 31, 2021.

Exposures

The apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) were assessed during a single-night, laboratory-based polysomnography measurement.

Main Outcomes and Measures

The primary outcome was WMH data automatically segmented from 1.5-T magnetic resonance images.

Results

Of 529 study participants (mean [SD] age, 52.15 [13.58] years; 282 female [53%]), a total of 209 (40%) or 102 (19%) individuals were diagnosed with OSA according to AHI or ODI criteria (mean [SD] AHI, 7.98 [12.55] events per hour; mean [SD] ODI, 3.75 [8.43] events per hour). Both AHI (β = 0.024; 95% CI, 0.011-0.037; P <.001) and ODI (β = 0.033; 95% CI, 0.014-0.051; P <. 001) were significantly associated with brain WMH volumes. These associations remained even in the presence of additional vascular, metabolic, and lifestyle WMH risk factors. Region-specific WMH analyses found the strongest associations between periventricular frontal WMH volumes and both AHI (β = 0.0275; 95% CI, 0.013-0.042, P < .001) and ODI (β = 0.0381; 95% CI, 0.016-0.060, P < .001) as well as periventricular dorsal WMH volumes and AHI (β = 0.0165; 95% CI, 0.004-0.029, P = .008).

Conclusions and Relevance

This study found significant associations between OSA and brain WMHs, indicating a novel, potentially treatable WMH pathomechanism.

Nocturnal oximetry in bariatric surgery patients referred to overnight in-lab polysomnography

OBJECTIVE

This study aimed to evaluate nocturnal oximetry approaches in identifying obstructive sleep apnea (OSA) among bariatric surgical candidates.

METHODS

This was a cross-sectional study involving adult bariatric patients who were undergoing in-lab polysomnography and who were previously screened with the GOAL questionnaire. OSA severity was established as any OSA, moderate/severe OSA, and severe OSA. Oximetry data were evaluated as oxygen saturation (average and nadir), oxygen desaturation index (ODI) at 3%, and proportion of time spent with oxygen saturation <90%. Associations between oximetry data and the apnea-hypopnea index (AHI) were assessed by Spearman correlation index (r), linear regression, logistic regression, and discrimination.

RESULTS

All oximetry values were significantly correlated with the AHI among 1,178 individuals, with the ODI emerging as the better parameter (r = 0.911, p < 0.001). Using linear regression, the ODI was the only predictor of the AHI (β = 0.952, p < 0.001). In the multivariate analysis, the ODI was the only independent parameter predicting OSA at all severity levels. In addition, the ODI exhibited excellent discrimination to predict OSA and displayed improved performance among individuals screened as being at high risk versus those at low risk with the GOAL instrument.

CONCLUSIONS

The ODI emerges as a valid surrogate predictor of the AHI, particularly among those screened as being at high risk for OSA.

The Impact of Opioid Medications on Sleep Architecture and Nocturnal Respiration During Acute Recovery From Moderate to Severe Traumatic Brain Injury: A TBI Model Systems Study

OBJECTIVES

To describe patient and clinical characteristics associated with receipt of opioid medications and identify differences in sleep quality, architecture, and sleep-related respiration between those receiving and not receiving opioid medications.

SETTING

Acute inpatient rehabilitation care for moderate to severe traumatic brain injury (TBI).

PARTICIPANTS

A total of 248 consecutive admissions for inpatient rehabilitation care following moderate to severe TBI (average age of 43.6 years), who underwent level 1 polysomnography (PSG) (average time since injury: 120 days) across 6 sites.

DESIGN

Cross-sectional, secondary analyses.

MAIN MEASURES

The PSG sleep parameters included total sleep time (TST), sleep efficiency (SE), wake after sleep onset, rapid eye movement (REM) latency, sleep staging, and arousal and awakening indices. Respiratory measures included oxygen saturation, central apnea events per hour, obstructive apnea and hypopnea events per hour, and total apnea-hypopnea index.

RESULTS

After adjustment for number of prescribed medication classes, those receiving opioid medications on the day of PSG experienced increased TST relative to those not receiving opioid medications (estimated mean difference [EMD] = 31.58; 95% confidence interval [CI], 1.9-61.3). Other indices of sleep did not differ significantly between groups. Among respiratory measures those receiving opioids on the day of PSG experienced increased frequency of central sleep apnea events during total (EMD = 2.92; 95% CI, 0.8-5.0) and non-REM sleep (EMD = 3.37; 95% CI, 1.0-5.7) and higher frequency of obstructive sleep apnea events during REM sleep (EMD = 6.97; 95% CI, 0.1-13.8). Compared with those who did not, receiving opioids was associated with lower oxygen saturation nadir during total sleep (EMD = -3.03; 95% CI, -5.6 to -0.4) and a greater number of oxygen desaturations across REM (EMD = 8.15; 95% CI, 0.2-16.1), non-REM (EMD = 7.30; 95% CI, 0.3-14.4), and total sleep (EMD = 8.01; 95% CI, 0.8-15.2) Greater total apnea-hypopnea index was observed during REM (EMD = 8.13; 95% CI, 0.8-15.5) and total sleep (EMD = 7.26; 95% CI, 0.08-14.4) for those receiving opioids.

CONCLUSION

Opioid use following moderate to severe TBI is associated with an increase in indicators of sleep-related breathing disorders, a modifiable condition that is prevalent following TBI. As sleep-wake disorders are associated with poorer rehabilitation outcomes and opioid medications may frequently be administered following traumatic injury, additional longitudinal investigations are warranted in determining whether a causal relation between opioids and sleep-disordered breathing in those following moderate to severe TBI exists. Given current study limitations, future studies can improve upon methodology through the inclusion of indication for and dosage of opioid medications in this population when examining these associations.

Contribution of pulse oximetry in relation to respiratory flow events in a home-based approach aimed at diagnosing obstructive sleep apnea

Objective

To compare pulse oximetry with manual analysis against all signals of respiratory polygraphy.

Material and Methods

This retrospective study estimated sensitivity (S), specificity (Sp) and positive/negative likelihood ratio (LR+/-) of the oxygen desaturation index (ODI-test) and apnea-hypopnea index (AHI-reference).

Results

3854 patients (61.5% men) were included. Age, BMI, Epworth sleepiness scale and AHI were: 55 years (44-65), 30.9kg/m² (27-36), 7 points (4-11), and 14 events/hour (6-25), respectively. 18% showed an AHI <5 events/hour, 34% = 5 and <15, 27% = or > 15 and < 30, and 31% > 30. The S, Sp, and LR+/- of ODI for AHI = 5 events/hour was 93%, 92%, 12 and 0.08 with an accuracy of 93%. For AHI = 15 events/hour, the values were: S 94%, Sp 94%, LR+ 15 and LR- 0.06 and 94% accuracy (r⁽²⁾ Spearman: 0.92).

Conclusion

In a population at a high risk for OSA, home-based pulse oximetry had a diagnostic accuracy > 90% when is compared against all respiratory signals obtained from simplified home sleep testing.

Factors related to oxygen desaturation index during sleep 7 days after bilateral sagittal splitting ramus osteotomy in patients without previous obstructive sleep apnea

PURPOSE

The incidence of obstructive sleep apnea (OSA) immediately after surgery in patients with dentofacial deformities without previous OSA remains unknown. We aimed to perioperatively evaluate factors associated with oxygen desaturation index (ODI) during sleep, 7 days after bilateral splitting ramus osteotomy (BSSRO) in patients without previous OSA.

METHODS

Fifty-one patients (15 males, 36 females) with dentofacial deformities, scheduled to undergo BSSRO, were included. Polysomnography was performed before orthognathic surgery. Perioperative OSA was evaluated with peripheral arterial tonometry on the day of surgery and 1, 2, 3, 4, and 7 days postoperatively. Rapid eye movement (REM) sleep periods and the ODI were measured. Factors associated with perioperative ODI after surgery were statistically analyzed.

RESULTS

REM sleep periods were significantly decreased on the day of surgery and significantly increased at 4 and 7 days postoperatively, compared to the preoperative period. ODI increased on the day of surgery, decreased after 1 day, and increased again at 4 and 7 days postoperatively. ODI on the day of surgery was significantly increased due to increased preoperative ODI, overjet, and SN-MP angle and decreased SNA and SNB angle. ODI at 7 days postoperatively was significantly increased due to increased REM sleep periods and decreased SN-MP and gonial angle. ODI was increased in response to REM sleep periods 7 days after BSSO.

CONCLUSION

Airway management in patients with dentofacial deformity should be given more attention by preoperative assessment for OSA, even in the absence of previous OSA, until 7 days postoperatively due to REM rebound.

Longer and Deeper Desaturations Are Associated With the Worsening of Mild Sleep Apnea: The Sleep Heart Health Study

Study Objectives

Obesity, older age, and male sex are recognized risk factors for sleep apnea. However, it is unclear whether the severity of hypoxic burden, an essential feature of sleep apnea, is associated with the risk of sleep apnea worsening. Thus, we investigated our hypothesis that the worsening of sleep apnea is expedited in individuals with more severe desaturations.

Methods

The blood oxygen saturation (SpO₂) signals of 805 Sleep Heart Health Study participants with mild sleep apnea [5 ≤ oxygen desaturation index (ODI) < 15] were analyzed at baseline and after a mean follow-up time of 5.2 years. Linear regression analysis, adjusted for relevant covariates, was utilized to study the association between baseline SpO₂-derived parameters and change in sleep apnea severity, determined by a change in ODI. SpO₂-derived parameters, consisting of ODI, desaturation severity (DesSev), desaturation duration (DesDur), average desaturation area (avg. DesArea), and average desaturation duration (avg. DesDur), were standardized to enable comparisons between the parameters.

Results

In the group consisting of both men and women, avg. DesDur (β = 1.594, p = 0.001), avg. DesArea (β = 1.316, p = 0.004), DesDur (β = 0.998, p = 0.028), and DesSev (β = 0.928, p = 0.040) were significantly associated with sleep apnea worsening, whereas ODI was not (β = -0.029, p = 0.950). In sex-stratified analysis, avg. DesDur (β = 1.987, p = 0.003), avg. DesArea (β = 1.502, p = 0.024), and DesDur (β = 1.374, p = 0.033) were significantly associated with sleep apnea worsening in men.

Conclusion

Longer and deeper desaturations are more likely to expose a patient to the worsening of sleep apnea. This information could be useful in the planning of follow-up monitoring or lifestyle counseling in the early stage of the disease.

Neural network analysis of nocturnal SpO2 signal enables easy screening of sleep apnea in patients with acute cerebrovascular disease

Current diagnostics of sleep apnea relies on the time-consuming manual analysis of complex sleep registrations, which is impractical for routine screening in hospitalized patients with a high probability for sleep apnea, e.g. those experiencing acute stroke or transient ischemic attacks (TIA). To overcome this shortcoming, we aimed to develop a convolutional neural network (CNN) capable of estimating the severity of sleep apnea in acute stroke and TIA patients based solely on the nocturnal oxygen saturation (SpO₂) signal. The CNN was trained with SpO₂ signals derived from 1379 home sleep apnea tests (HSAT) of suspected sleep apnea patients and tested with SpO₂ signals of 77 acute ischemic stroke or TIA patients. The CNN's performance was tested by comparing the estimated respiratory event index (REI) and oxygen desaturation index (ODI) with manually obtained values. Median estimation errors for REI and ODI in patients with stroke or TIA were 1.45 events/hour and 0.61 events/hour, respectively. Furthermore, based on estimated REI and ODI, 77.9% and 88.3% of these patients were classified into the correct sleep apnea severity categories. The sensitivity and specificity to identify sleep apnea (REI > 5 events/hour) were 91.8% and 78.6%, respectively. Moderate-to-severe sleep apnea was detected (REI > 15 events/hour) with sensitivity of 92.3% and specificity of 96.1%. The CNN analysis of the SpO₂ signal has great potential as a simple screening tool for sleep apnea. This novel automatic method accurately detects sleep apnea in acute cerebrovascular disease patients and facilitates their referral for a differential diagnostic HSAT or polysomnography evaluation.

Polysomnographic phenotyping of obstructive sleep apnea and its implications in mortality in Korea

Conventionally, apnea–hypopnea index (AHI) is used to define and categorize the severity of obstructive sleep apnea. However, routine polysomnography (PSG) includes multiple parameters for assessing the severity of obstructive sleep apnea. The goal of this study is to identify and categorize obstructive sleep apnea phenotypes using unsupervised learning methods from routine PSG data. We identified four clusters from 4,603 patients by using 29 PSG variable and arranged according to their mean AHI. Cluster 1, spontaneous arousal (mean AHI = 8.52/h); cluster 2, poor sleep and periodic limb movements (mean AHI = 12.16/h); cluster 3, hypopnea (mean AHI = 38.60/h); and cluster 4, hypoxia (mean AHI = 69.66/h). Conventional obstructive sleep apnea classification based on apnea–hypopnea index severity showed no significant difference in cardiovascular or cerebrovascular mortality (Log rank P = 0.331), while 4 clusters showed an overall significant difference (Log rank P = 0.009). The risk of cardiovascular or cerebrovascular mortality was significantly increased in cluster 2 (hazard ratio = 6.460, 95% confidence interval 1.734–24.073) and cluster 4 (hazard ratio = 4.844, 95% confidence interval 1.300–18.047) compared to cluster 1, which demonstrated the lowest mortality. After adjustment for age, sex, body mass index, and underlying medical condition, only cluster 4 showed significantly increased risk of mortality compared to cluster 1 (hazard ratio = 7.580, 95% confidence interval 2.104–34.620). Phenotyping based on numerous PSG parameters gives additional information on patients’ risk evaluation. Physicians should be aware of PSG features for further understanding the pathophysiology and personalized treatment.

Diagnostic meta-analysis of the Pediatric Sleep Questionnaire, OSA-18, and pulse oximetry in detecting pediatric obstructive sleep apnea syndrome

The aim of this meta-analysis was to compare the pooled sensitivity and specificity of the Pediatric Sleep Questionnaire (PSQ), Obstructive Sleep Apnea Questionnaire (OSA-18), and pulse oximetry (PO) according to OSAS severity. Three electronic databases were searched for studies evaluating sensitivity and specificity of the three tools against the apnea-hypopnea index measured using overnight in-laboratory or in-home polysomnography in children and adolescents from inception until January 11, 2020. A random-effects bivariate model was used to estimate the summary sensitivity and specificity of the tools. We identified 39 studies involving 6131 clinical and community children (aged 2.9-16.7 y). The PSQ exhibited the highest sensitivity (74%) for detecting symptoms of mild pediatric OSAS. The PSQ and PO had comparable sensitivity in screening moderate and severe pediatric OSAS (0.82 and 0.89 vs 0.83 and 0.83, respectively). PO yielded superior specificity in detecting mild, moderate, and severe pediatric OSAS (86%, 75%, and 83%, respectively) than did the PSQ and OSA-18 (all p < 0.05). Age, percentage of girls, index test criteria, methodology quality, and sample size significantly moderated sensitivity and specificity. For early detection of pediatric OSAS, the combined use of PSQ and PO is recommended when polysomnography is not available. PROSPERO REGISTRATION NUMBER: CRD42018090571.

Does nesfatin-1 influence the hypothalamic–pituitary–gonadal axis in adult males with obstructive sleep apnoea?

There is growing evidence that obstructive sleep apnoea (OSA) influences the hypothalamic–pituitary–gonadal axis (HPG axis) in men. The aim of the study was to assess the association of nesfatin-1 with HPG axis disturbances in OSA. This is a prospective study with consecutive enrolment. It comprises 72 newly diagnosed OSA patients ((AHI: apnoea-hypopnea index) 18 subjects: 5 ≤ AHI < 15; 24: 15 ≤ AHI < 30; 30: AHI ≥ 30) and a control group composed of 19 patients (AHI < 5). All patients underwent polysomnography and fasting blood collection for nesfatin-1, testosterone, luteinising hormone (LH), high-sensitivity C-reactive protein (hsCRP), aspartate transaminase (AST), alanine aminotransferase (ALT), creatinine and glucose. Groups had similar levels of LH, nesfatin-1 and testosterone (p = 0.87; p = 0.24; p = 0.08). Nesfatin-1 was not correlated to LH (p = 0.71), testosterone (p = 0.38), AHI (p = 0.34) or the oxygen desaturation index (ODI) (p = 0.69) either in the whole group, or in sub-groups. The study did not reveal any association between the HPG axis and nesfatin-1 in OSA adult males. It is possible that nesfatin-1 is not a mediator of HPG axis disturbances in adult patients with OSA.

Effectiveness of smoking cessation in smokers with COPD and nocturnal oxygen desaturation: Functional analysis

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is the fourth cause of mortality and it's frequently associated with breathing sleep disorders.

OBJECTIVE

The aim of the study is to point out the benefit of smoking cessation over three months in terms of improvement of respiratory functional variables.

METHODS

A retrospective analysis was performed evaluating the impact of smoking cessation on 145 patients with COPD and nocturnal oxygen desaturation. For this purpose, for all patients, overnight pulse oxymetry detection on room air, arterial blood sampling, plethysmography and exhaled test for carbon monoxide were performed at baseline and 3 months after the beginning. Smoking cessation was achieved by varenicline plus individual counselling.

RESULTS

About 51% of patients quit smoking which was established by exhaledcarbon monoxide (eCO) measure (cut-off 5 ppm). Patients who quit smoking displayed notably better results compared with patients who did not. The eCO significantly decreased by 16 ppm versus 4 (P = 0.01), oxygen desaturation index (ODI) was reduced by 3 points versus 0.8 (P = 0.01) and forced expiratory in 1 second volume increased by 7% of predicted value versus 1% (P = 0.01). The walking test was improved by 102 m versus 25 in sustainers (P = 0.01). The CAT score was also improved by 10 versus 8 in sustainers (P = 0.01) and PaO2 increased by 5 mm Hg versus 0.5 (P = 0.04). The percentage of SaO2 < 90% was improved by 6.7 versus 2.1 (P = 0.04).The logistic regression analysis displayed the possible influence of CAT (P = 0.02) and modified medical research council dyspnea test (P = 0.05) on ODI value.

CONCLUSIONS

Smoking cessation notably improves pulmonary functional parameters in quitters reporting nocturnal oxygen desaturation.

Effect of Nocturnal Hypoxia on Nocturia in Patients With Obstructive Sleep Apnea

Purpose

To identify the association between nocturia and obstructive sleep apnea (OSA), we compared results of polysomnography (PSG) with the presence or absence of nocturia in patients with suspected OSA.

Methods

Patients underwent PSG for suspected OSA. The International Prostate Symptom Score and quality of life (IPSS/QoL) questionnaire was evaluated to assess voiding symptoms that may affect sleep quality. The results of PSG were compared between patient groups with or without nocturia.

Results

In logistic regression analysis, age (odds ratio [OR], 1.052; P=0.004), diabetes mellitus (OR, 6.675; P<0.001), mean O₂ saturation (OR, 0.650; P=0.017), oxygen desaturation index (ODI) 3 (OR, 1.193; P=0.010), and ODI4 (OR, 1.136; P=0.014) affected nocturia independently among the OSA-suspected patients.

Conclusions

Hypoxia caused by OSA affects the incidence of nocturia. Less desaturated OSA patients with nocturia may require more urological evaluation and treatment for nocturia even after the correction of OSA.

The acute effects of aerobic exercise on sleep in patients with depression: study protocol for a randomized controlled trial

BACKGROUND

Unipolar depression is one of the most important mental disorders. Insomnia is a symptom of cardinal importance in depression. It increases the risk to develop depression, negatively affects disease trajectory, is the most common symptom after remission, increases the risk of relapse, and is associated with higher suicide rates. Existing therapies for insomnia in depression have limitations. Further adjuvant therapies are therefore needed. Acute aerobic exercise has been shown to have beneficial effects on sleep in healthy individuals and patients with insomnia. We therefore hypothesize that a single session of aerobic exercise has a positive impact on sleep in patients with unipolar depression. This trial aims to investigate the effects of a single bout of aerobic exercise on the subsequent night's sleep in patients with depression.

METHODS/DESIGN

This is a two-arm parallel group, randomized, outcome assessor blinded, controlled, superiority trial. Patients between 18 and 65 years of age with a primary diagnosis of unipolar depression (without a psychotic episode) are included. Exclusion criteria are regular use of hypnotic agents, opioids, and certain beta-blockers, as well as the presence of factors precluding exercise, history of epilepsy, restless legs syndrome, moderate obstructive sleep apnea, and a BMI > 40. The intervention is a single bout of aerobic exercise, performed for 30 min on a bicycle ergometer at 80% individual anaerobic threshold. The control group sits and reads for 30 min. The primary outcome is sleep efficiency measured by polysomnography. Secondary outcomes include further polysomnographic variables, subjective pre-sleep arousal, nocturnal cardiovascular autonomic modulation, subjective sleep quality, daytime sleepiness, and adverse events. According to the sample size calculation, a total of 92 patients will be randomized using minimization.

DISCUSSION

This trial will add new information to the body of knowledge concerning the treatment of insomnia in patients with depression. Thereby, the results will inform decision makers on the utility of acute aerobic exercise.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03673397 . Protocol version 1 registered on 17 September 2018.

The use of oximetry and a questionnaire in primary care enables exclusion of a subsequent obstructive sleep apnea diagnosis

Purpose

The study aims to prospectively validate the prognostic value of oximetry alone or combined in a two-step strategy with a questionnaire for the exclusion of obstructive sleep apnea (OSA) in primary care.

Methods

A total of 140 subjects with suspected OSA were included from 54 participating primary care practices. All subjects completed the Philips questionnaire and underwent one night of oximetry prior to referral to a sleep center. The prognostic value of two strategies was evaluated against the diagnosis of the sleep center as the gold standard: (1) assume OSA and subsequently refer to a sleep center if the oxygen desaturation index (ODI) is ≥ 5 and (2) assume OSA and refer to a sleep center if the Philips questionnaire score is ≥ 55% (regardless of the ODI) or if the Philips questionnaire score is < 55% and the ODI is ≥ 5.

Results

OSA was diagnosed in the sleep centers in 100 (71%) of the included subjects. Using ODI ≥ 5 alone resulted in a sensitivity of 99.0%, a specificity of 50.0%, a negative predictive value of 95.2%, and a positive predictive value 83.2%. Using the two-step strategy, oximetry would be performed on 39% of the subjects. This strategy resulted in a sensitivity of 100%, a specificity of 35.0%, a negative predictive value of 100%, and a positive predictive value of 79.4%.

Conclusions

In a Dutch primary care population with a clinical suspicion of OSA and low frequency of cardiovascular comorbidities, the use of oximetry alone or combined in a two-step strategy with a questionnaire enables exclusion of a sleep center diagnosis of OSA.

Electronic supplementary material

The online version of this article (10.1007/s11325-019-01834-2) contains supplementary material, which is available to authorized users.