Effect of different anti-cardiovascular disease treatments on the severity of obstructive sleep apnea.

Obstructive sleep apnea (OSA) and cardiovascular co-morbidities have a mutually reinforcing effect, but existing studies have focussed only on the improvement of the associated co-morbidities by treatment for OSA. To provide fresh guidelines for the treatment of OSA from a co-morbidity standpoint, we conducted a systematic search of Web of Science, PubMed, EMBASE, and the Cochrane Library for articles published from inception up to 2 May 2023. Fourteen original studies of patients with OSA with cardiovascular co-morbidities and who received related treatment were included in the analysis. We found that diuretic treatment can reduce the apnea-hypopnea index in patients with OSA and hypertension (-19.41/h, p = 1.0 × 10-5 ), aldosterone-angiotensin inhibitors also have a 9.19/h reduction (p = 0.003), while the effect of renal sympathetic denervation is insignificant (-2.32/h, p = 0.19). The short-term treatment (<4 weeks) did not show an improvement (-2.72/h, p = 0.16), while long-term treatment (>4 weeks) produced surprising outcomes (-12.78/h, p = 0.002). Patients with milder disease (baseline AHI < 35/h) had insignificant improvements (-1.05/h, p = 0.46), whereas those with more severe disease (baseline AHI > 35/h) could achieve satisfactory outcomes (-14.74/h, p < 0.00001). In addition, it also showed some improvement in the oxygen desaturation index and blood oxygen. Our results support the additional benefit of antihypertensive treatment for OSA symptoms, and the efficacy can be affected by different therapy, treatment duration, and severity levels. It could be useful in developing clinical therapy, educating patients, and exploring interaction mechanisms. The proposal was registered with PROSPERO (CRD42022351206).

The effect of longitudinal sleep monitoring on clinician agreement in obstructive sleep apnea diagnosis: The ELSA study.

There is strong evidence for clinically relevant night-to-night variability of respiratory events in patients with suspected obstructive sleep apnea. Sleep experts retrospectively evaluated diagnostic data in 56 patients with suspected obstructive sleep apnea. Experts were blinded to the fact that they were diagnosing the same case twice, once based on a short report of a single in-laboratory respiratory polygraphy and once with the additional information of 14 nights of pulse oximetry at home. All experts (n = 22) were highly qualified, 13 experts (59.1%) treated > 100 patients with suspected obstructive sleep apnea per year. In 12 patients, the apnea-hypopnea index in the respiratory polygraphy was < 5 per hr, but the mean oxygen desaturation index of 14 nights of pulse oximetry was ≥ 5 per hr. The additional information of 14 nights of pulse oximetry helped to diagnose obstructive sleep apnea with a 70% consensus in two of those patients (16.7% [95% confidence interval: 4.7/44.8]). In eight patients, experts could not agree to a 70% consensus regarding continuous positive airway pressure therapy recommendation after respiratory polygraphy. The additional information of multiple-night testing led to a consensus in three of those cases (37.5% [95% confidence interval: 14/69]). Change of obstructive sleep apnea diagnosis and continuous positive airway pressure recommendation was significantly negatively associated with the number of treated obstructive sleep apnea patients > 100 per year compared with 0-29 patients per year (Coef. [95% confidence interval] -0.63 [-1.22/-0.04] and -0.61 [-1.07/-0.15], respectively). Experts found already a high level of consensus regarding obstructive sleep apnea diagnosis, severity and continuous positive airway pressure recommendation after a single respiratory polygraphy. However, longitudinal sleep monitoring could help increase consensus in selected patients with diagnostic uncertainty.

The role of physical activity on obstructive sleep apnea severity and hypoxic load, and the mismatch between subjective and objective physical activity assessments.

Obesity is the primary risk factor for the development of obstructive sleep apnea, and physical inactivity plays an important role. However, most studies have either only evaluated physical activity subjectively or objectively in obstructive sleep apnea. The objectives of this study were: (i) to assess the relationship between obstructive sleep apnea severity (both apnea-hypopnea index and desaturation parameters) and both objectively and subjectively measured physical activity after adjustment for anthropometry and body composition parameters; and (ii) to assess the relationship between objective and subjective physical activity parameters and whether obstructive sleep apnea severity has a modulatory effect on this relationship. Fifty-four subjects (age 47.7 ± 15.0 years, 46% males) were categorized into groups according to obstructive sleep apnea severity: no obstructive sleep apnea; mild obstructive sleep apnea; and moderate-to-severe obstructive sleep apnea. All subjects were evaluated with subjective and objective physical activity, anthropometric and body composition measurements, and 3-night self-applied polysomnography. A one-way ANOVA was used to evaluate the differences between the three obstructive sleep apnea severity groups and multiple linear regression to predict obstructive sleep apnea severity. Differences in subjectively reported sitting time (p ≤ 0.004) were found between participants with moderate-to-severe obstructive sleep apnea, and those with either mild or no obstructive sleep apnea (p = 0.004). Age, body mass index and neck circumference explained 63.3% of the variance in the apnea-hypopnea index, and age, body mass index and visceral adiposity explained 67.8% of the variance in desaturation parameters. The results showed that the person's physical activity does not affect obstructive sleep apnea severity. A weak correlation was found between objective and subjective physical activity measures, which could be relevant for healthcare staff encouraging patients with obstructive sleep apnea to increase their physical activity.

Erectile dysfunction in patient with obstructive sleep apnea: effects of continuous positive airway pressure.

BACKGROUND: Obstructive sleep apnea (OSA) is linked to various health complications, including erectile dysfunction (ED), which is more prevalent in individuals with OSA. This study explored ED in Korean OSA patients and assessed the impact of continuous positive airway pressure (CPAP) therapy on ED. METHODS: A total of 87 male patients with OSA from four different sleep centers underwent physical measurements and completed sleep and mental health (MH) questionnaires, including the Korean version of the International index of erectile function (IIEF), before and three months after initiating CPAP therapy. RESULTS: After three months of CPAP therapy, the patients demonstrated a significant improvement in ED as measured on the IIEF. However, the study found no significant correlation between the duration of CPAP use and the improvement in IIEF score. It did identify the SF36 quality of life assessment as a significant factor influencing ED improvement after CPAP. CONCLUSIONS: ED is a prevalent issue that escalates with age and is associated with OSA. CPAP therapy has shown potential in alleviating ED symptoms, particularly in those with underlying psychological conditions, although further research is required to confirm these findings and understand the underlying mechanisms.

Fine particulate matter and sleep-disordered breathing severity in a large Italian cohort.

BACKGROUND: Air pollution and obstructive sleep apnea (OSA) are both linked with cardiovascular co-morbidities and share similar pathophysiological mechanisms. A causal association between the two has been postulated. However, the results of the studies on this topic are conflicting mainly because of the lack of adjustment for important confounders such as seasonality and temperature. We aimed to evaluate if such an association exists in a highly polluted area like Lombardy region (Italy) when accounting for all confounders. METHODS: Data of adult patients seen at the Sleep Disorder Centre in Milan from 2010 to 2020 were analysed and the main polygraphic data were retrieved. Air pollutant concentrations of the following pollutants NO2, O3, PM2.5, and PM10 were collected through monitoring stations. RESULTS: A total of 3493 patients were included: males (2358, 67.5%) mean age 60.1 (SD = 14.3) years, BMI 29.2 (6.2) kg/m2, mean AHI 16.5 (18.1) events/h. After adjusting for all confounders, in the multivariable analysis, the only associations that remained significant were long-term exposure to O3 with indexes of OSA severity (AHI and ODI) but only in spring. Furthermore, a positive association was seen between long-term exposure to PM10 and ODI but in springtime only. CONCLUSION: The findings of the current study does not support an association between fine particulate matter and OSA severity.

Preoperative sleep-disordered breathing and craniofacial abnormalities are risk factors for postoperative sleep-disordered breathing in patients undergoing skin-flap oropharyngeal reconstruction surgery for oral cavity cancer: a prospective case-control study.

PURPOSE: After oropharyngeal reconstruction surgery, excessive flap volume within the oral cavity may increase the risk of pharyngeal obstruction during sleep. This prospective observational study aimed to test a hypothesis that the skin-flap oropharyngeal reconstructive surgery increases nocturnal apnea-hypopnea index (nAHI, primary variable) after surgery. METHODS: Adult patients undergoing oropharyngeal reconstruction surgery participated in this study. The hypothesis was tested by comparing the results of portable type 4 sleep study and craniofacial assessments with lateral head and neck computed tomography scout image before and after surgery. Multiple linear regression analyses were performed to identify predictors for nAHI increase after the surgery. RESULTS: In 15 patients, a postoperative sleep study was performed at 41 (27, 59) (median (IQR)) days after the surgery. nAHI did not increase after the surgery (mean (95% CI), 13.0 (7.2 to 18.7) to 18.4 (10.2 to 26.6) events.hour-1, p = 0.277), while apnea index significantly increased after the surgery (p = 0.026). Use of the pedicle flap for the oropharyngeal reconstruction (p = 0.051), small mandible (p = 0.008), longer lower face (0.005), and larger tongue size (p = 0.008) were independent predictors for worsening of nAHI after surgery. Hospital stay was significantly longer in patients with the pedicle flap (n = 8) than in those with the free flap (n = 7) (p = 0.014), and the period of hospital stay was directly associated with increase of nAHI after surgery (r = 0.788, p < 0.001, n = 15). CONCLUSIONS: Oropharyngeal reconstruction surgery worsens sleep-disordered breathing in some patients with craniofacial and surgical risk factors. TRIAL REGISTRATION: UMIN Clinical Trial Registry (UMIN000036260, March 22, 2019), https://rctportal.niph.go.jp/s/detail/um?trial_id=UMIN000036260.

The effect of hypoxia on interoception in patient with obstructive sleep apnea.

PURPOSE: Obstructive Sleep Apnea (OSA) is the most common sleep-related disorder. Interoception is the collection of sensory and cognitive processes that involve receiving and interpreting physiological signals from internal body structures and conveying the perception of inner sensations. In this study, it was hypothesized that the impairment in cognitive functions associated with chronic hypoxemia and the insular effects due to OSA would negatively affect interoceptive functions. The aim of this study was to evaluate whether interoception in OSA changes consistent with the hypothesis. METHODS: A total of 102 patients diagnosed with OSA were included in this study. All participants were divided into groups based on their T90 values: desaturated OSA (T90 ≥ 20%) and non-desaturated OSA (T90 < 20%). The Heartbeat Counting Task was used to assess interoceptive accuracy, while the Interoceptive Sense Questionnaire (ISQ) was employed to identify subjective challenges in evaluating interoception. RESULTS: Interoceptive accuracy was lower in the desaturated OSA group than in the non-desaturated OSA group (Z = -2.463; p = 0.014). Interoceptive accuracy was negatively correlated with the body mass index (r = -0.228; p = 0.021), T90 (r = -0.269; p = 0.006), and positively correlated with the average SaO2 (r = 0.377; p < 0.001) and SaO2 nadir (r = 0.243; p = 0.014). CONCLUSION: This study examined interoceptive functions in patients with OSA. It was concluded that interoceptive accuracy is affected by the severity of hypoxia as hypothesized.

The benefits of hypoglycemic therapy for patients with obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) is often associated with glycemic abnormalities. This study is conducted to investigate the effects of hypoglycemic therapy on OSA-related indicators. METHOD: We systematically searched Web of Science, PubMed, Embase, and the Cochrane Library for articles on OSA patients receiving any hypoglycemic drugs, published until December 25, 2022. Seven original studies were finally included. The proposal was registered with PROSPERO (CRD42022351206). RESULTS: In summary, in addition to reduced glycosylated hemoglobin A1c (HbA1c), we found that hypoglycemic treatment can lower the apnea-hypopnea index (AHI) by 7.07/h (p = 0.0001). Although long-term treatment (> 12 weeks) achieved a more significant reduction in HbA1c (- 1.57% vs. - 0.30%) compared to short-term treatment (≤ 12 weeks), there was no significant difference between the two in terms of AHI (intergroup p-value = 0.27). We also found that patients using sodium glucose cotransporter 2 inhibitors (SGLT2i) experienced a greater reduction in AHI (- 11.00/h, p < 0.00001). Additionally, hypoglycemic treatment also showed certain improvements in related indicators like Epworth Sleepiness Scale, body mass index, and blood pressure. CONCLUSIONS: Our results affirm the benefits of hypoglycemic treatment for OSA patients and highlight the notable effect of SGLT2i. Further researches are needed to help doctors gain a comprehensive understanding of the interaction between OSA and glycemic abnormalities.

Effects of mandibular advancement devices on the evolution of obstructive sleep apnea.

PURPOSE: Mandibular advancement devices (MADs) are a treatment for obstructive sleep apnea (OSA). Titration is a necessary component of proper fitting of MADs, yet little is known about what happens at each step of the titration. The objectives of this study were to determine the clinical and paraclinical evolution of OSA at every mm of MAD advancement. METHODS: Volunteers were fitted with MADs set to 50% of maximum advancement. MAD clinical and paraclinical results were recorded at every additional mm-titration, including apnea-hypopnea index (AHI), as well as symptoms of sleepiness and fatigue. RESULTS: In 20 volunteers with OSA, the MAD had a significant effect on every polygraphic parameter at the onset of use. The mean AHI with MAD fell by 15.2/h (p < 0.001). The mean Epworth Sleepiness Score and Pichot Fatigue questionnaire with MAD fell by 2.0 (p = 0.0687) and 2.4 (p = 0.1073) respectively. There was no proportionality between clinical gains (drowsiness and fatigue) and AHI improvements. CONCLUSIONS: MADs led to a significant improvement in AHI and other polygraphic parameters from the onset of use. The decrease of clinical symptoms (drowsiness and fatigue) was more complex to interpret because of the small decreases observed. The absence of concordance between AHI improvement and clinical symptoms was nevertheless objectively quantified and symptoms were alleviated with advancements. The findings suggest that it may be appropriate to use clinical symptoms as a main aim of titration, since the improvement in AHI is reached at the onset of MAD use.

Homocysteine as a predictor of apnea-hypopnea index in obstructive sleep apnea: a longitudinal epidemiological study (EPISONO).

BACKGROUND: Obstructive sleep apnea (OSA) affects nearly 1 billion people globally, and has established links with cardiovascular and neurocognitive complications. Although it has some limitations, the apnea-hypopnea index (AHI) is commonly used to gauge OSA severity and therapeutic response. Homocysteine (Hcy) metabolism, when impaired, can elicit cellular senescence mechanisms that may be shared with OSA. Hence, our objective was to explore the role of Hcy concentrations both as a predictor of AHI values and as a potential risk factor for OSA. METHODS: Involving 1042 volunteers aged 20 to 80 years, the initial study (2007) included polysomnographic evaluations, questionnaires on sleep and general health, as well as biochemical analyses. After an 8-year interval, 715 participants from the initial study were invited for a follow-up assessment in 2015. RESULTS: Our findings showed that Hcy was a predictor for an increased AHI, and AHI increased over time. Individuals with plasma Hcy concentrations ≥ 15 µmol/L experienced an average AHI increase of 7.43 events/hour ([beta coefficient] ß = 7.43; 95%CI 2.73 to 12.13) over time, compared to those with plasma concentrations < 10 µmol/L. A similar trend was apparent in those with plasma Hcy concentrations between 10 ≥ and < 15 µmol/L, who had an AHI increase with an average beta coefficient of 3.20 events/hour (95%CI 1.01 to 5.39) compared to those with plasma Hcy concentrations < 10 µmol/L. CONCLUSIONS: In summary, our study suggests that increased plasma Hcy concentrations could be considered a risk factor for the development of OSA. These findings highlight that elevated plasma Hcy concentrations can predict the severity of OSA, underscoring their correlation with the AHI.

In-Laboratory Polysomnography Worsens Obstructive Sleep Apnea by Changing Body Position Compared to Home Testing.

(1) Background: Home sleep apnea testing, known as polysomnography type 3 (PSG3), underestimates respiratory events in comparison with in-laboratory polysomnography type 1 (PSG1). Without head electrodes for scoring sleep and arousal, in a home environment, patients feel unfettered and move their bodies more naturally. Adopting a natural position may decrease obstructive sleep apnea (OSA) severity in PSG3, independently of missing hypopneas associated with arousals. (2) Methods: Patients with suspected OSA performed PSG1 and PSG3 in a randomized sequence. We performed an additional analysis, called reduced polysomnography, in which we blindly reassessed all PSG1 tests to remove electroencephalographic electrodes, electrooculogram, and surface electromyography data to estimate the impact of not scoring sleep and arousal-based hypopneas on the test results. A difference of 15 or more in the apnea-hypopnea index (AHI) between tests was deemed clinically relevant. We compared the group of patients with and without clinically relevant differences between lab and home tests (3) Results: As expected, by not scoring sleep, there was a decrease in OSA severity in the lab test, similar to the home test results. The group of patients with clinically relevant differences between lab and home tests presented more severe OSA in the lab compared to the other group (mean AHI, 42.5 vs. 20.2 events/h, p = 0.002), and this difference disappeared in the home test. There was no difference between groups in the shift of OSA severity by abolishing sleep scoring in the lab. However, by comparing lab and home tests, there were greater variations in supine AHI and time spent in the supine position in the group with a clinically relevant difference, either with or without scoring sleep, showing an impact of the site of the test on body position during sleep. These variations presented as a marked increase or decrease in supine outcomes according to the site of the test, with no particular trend. (4) Conclusions: In-lab polysomnography may artificially increase OSA severity in a subset of patients by inducing marked changes in body position compared to home tests. The location of the sleep test seems to interfere with the evaluation of patients with more severe OSA.

Unstable periodontal disease and its association with sleep-disordered breathing.

Periodontal therapy results in successful disease management for some patients, but patients whose periodontal disease cannot be managed with standard-of-care protocols are treated repeatedly without success. For this set of patients, a systemic rather than an oral origin is possible. This clinical study investigated the connection between unresolved periodontal disease and sleep-disordered breathing (SDB) in 71 patients (44 women and 27 men), aged 19 to 75 years (mean, 45 years), who were enrolled in periodontal maintenance therapy for Stage I or II periodontitis. The results of an at-home sleep testing device served as the basis for evaluating 4 SDB screening tools: Papillary Bleeding Index (PBI), Epworth Sleepiness Scale (ESS) questionnaire, STOP-Bang questionnaire, and salivary cortisol testing. At-home sleep testing indicated that 33 participants had an apnea-hypopnea index ≥ 5, signifying probable obstructive sleep apnea. A finding of unstable periodontal disease (PBI ≥ 2) was able to identify 21 of these 33 participants, while the ESS and STOP-Bang questionnaires identified only 2 and 6 participants, respectively. The difference between the PBI and both the ESS and STOP-Bang questionnaires was statistically significant (P < 0.05; 2-sample proportion test). There was no relationship between participants' cortisol levels and the PBI findings. This clinical study found a link between unresolved periodontal disease and SDB. The results of this study suggested that the PBI is a reliable, objective means for general dentists to identify SDB in patients with unresolved periodontal disease. Once identified, these patients can be referred for treatment to address their SDB, which may positively impact management of their periodontal disease.

Association between Obstructive Sleep Apnea and Intracranial Artery Calcification Stratified by Gender and Body Mass Index: A Hospital-Based Observational Study.

BACKGROUND AND OBJECTIVES: Obstructive sleep apnea (OSA) is an independent risk factor for stroke. Furthermore, intracranial arterial calcification (IAC) has been validated as a marker for subclinical cerebrovascular disease. However, the relationship between OSA with IAC was less studied compared with its established association with coronary artery calcification. In this study, we aimed to investigate the association between the severity of OSA and the degree of IAC in hospitalized patients without preexisting cardiovascular disease. METHODS: This hospital-based observational study was conducted from June 1, 2017, to May 1, 2019. In total, 901 consecutive patients who underwent head computed tomography scans and portable sleep monitoring were included. On the basis of the apnea-hypopnea index (AHI), patients were divided into four OSA severity groups (normal: AHI <5/h; mild: 5≤ AHI <15/h; moderate: 15≤ AHI <30/h; severe: AHI ≥30/h). Associations of OSA with IAC scores were assessed by using multivariate logistic regression analysis. RESULTS: Of the 901 patients, 484 (53.7%) were men; the mean (SD) age was 66.1 (10.0) years. The non-OSA group included 207 (23.0%) patients; mild OSA, 209 (23.2%); moderate OSA, 235 (26.1%); and severe OSA, 169 (18.8%). Mean IAC scores were higher in the severe OSA group compared with non-, mild, and moderate OSA groups (4.79 vs. 2.58; 4.79 vs. 2.94; 4.79 vs. 3.39; p < 0.001). Multivariate analysis adjusted for confounding factors revealed that only severe OSA was associated with a higher IAC score (odds ratio [OR]: 1.65; 95% confidence interval [CI]: 1.43-1.91; p < 0.001). In stratified analyses by BMI, among participants with a BMI <25 kg/m2, the positive association between AHI values and IAC scores was found in the moderate OSA group (OR: 1.23; 95% CI: 1.05, 1.43; p = 0.01) and the severe OSA group (OR: 1.96; 95% CI: 1.55, 2.48; p < 0.001). When stratified by gender, in women, the positive association was found in the moderate OSA group (adjusted OR: 1.21; 95% CI: 1.02-1.51; p = 0.016) and the severe OSA group (adjusted OR: 1.76; 95% CI: 1.36-2.25; p < 0.001). For the men group, a positive association between IAC scores and AHI was only observed in the severe OSA group. DISCUSSION: These findings suggest that OSA, in particular severe OSA (AHI ≥30), is independently associated with higher IAC scores. Women and no-obesity individuals appeared more susceptible to adverse OSA-related subclinical cerebrovascular disease as measured by IAC scores.

Obstructive sleep apnea-related intermittent hypoxaemia is associated with impaired vigilance.

Obstructive sleep apnea (OSA)-related intermittent hypoxaemia is a potential risk factor for different OSA comorbidities, for example cardiovascular disease. However, conflicting results are found as to whether intermittent hypoxaemia is associated with impaired vigilance. Therefore, we aimed to investigate how desaturation characteristics differ between the non-impaired vigilance and impaired vigilance patient groups formed based on psychomotor vigilance task (PVT) performance and compared with traditional OSA severity parameters. The study population comprised 863 patients with suspected OSA who underwent a PVT test before polysomnography. The conventional OSA parameters, for example, the apnea-hypopnea index, oxygen desaturation index, and arousal index were computed. Furthermore, the median desaturation area, fall area, recovery area, and desaturation depth were computed with the pre-event baseline reference and with reference to the 100% oxygen saturation level. Patients were grouped into best- and worst-performing quartiles based on the number of lapses in PVT (Q1: PVT lapses <5 and Q4: PVT lapses >36). The association between parameters and impaired vigilance was evaluated by cumulative distribution functions (CDFs) and binomial logistic regression. Based on the CDFs, patients in Q4 had larger desaturation areas, recovery areas, and deeper desaturations when these were referenced to 100% saturation compared with Q1. The odds ratio (OR) of the median desaturation area (OR = 1.56), recovery area (OR = 1.71), and depth (OR = 1.65) were significantly elevated in Q4 in regression models. However, conventional OSA parameters were not significantly associated with impaired vigilance (ORs: 0.79-1.09). Considering desaturation parameters with a 100% SpO2 reference in the diagnosis of OSA could provide additional information on the severity of OSA and related daytime vigilance impairment.

Quality of life in patients with obstructive sleep apnea: Results from the study of health in Pomerania.

Obstructive sleep apnea is known to be an overall public health problem that, among other things, increases morbidity and mortality. Risk factors as well as symptoms of this multidimensional sleep-related breathing disorder negatively affect quality of life. With our study we aimed to expose the association between obstructive sleep apnea and quality of life in the population of Pomerania, Germany. We utilized data from the population-based Study of Health in Pomerania (SHIP). Information on health status and risk factors about 4420 participants (2275 women) were gathered within the cohort SHIP-TREND, of which 1209 (559 women) underwent an overnight polysomnography and completed sleep questionnaires. The quality of life of the participants was measured using the Short-Form 12 questionnaire. For our study, an ordinal regression analysis with age, sex, body mass index and the Short-Form 12 health survey as predictors for apnea-hypopnea index was computed. The potential factors affecting quality of life are different between physical and mental dimensions of quality of life. Significant effects were found regarding age, sex, body mass index and the Short-Form 12 Mental Component Score, but not the Physical Component Score.

In search of a cut-off apnea-hypopnea index in type 3 home portable monitors to diagnose and treat obstructive sleep apnea: a mathematical simulation.

The American Academy of Sleep Medicine (AASM) uses similar apnea-hypopnea index (AHI) cut-off values to diagnose and define severity of sleep apnea independent of the technique used: in-hospital polysomnography (PSG) or type 3 portable monitoring (PM). Taking into account that PM theoretically might underestimate the AHI, we explored whether a lower cut-off would be more appropriate. We performed mathematical re-calculations on the diagnostic PSG-AHI (scored using AASM 1999 rules) of 865 consecutive patients with an AHI of ≥20 events/h who started continuous positive airway pressure (CPAP). For a PSG-AHI of ≥15 events/h re-scored using AASM 2012 rules (PSG-AHIAASM2012 ), a PM-respiratory event index (REI)AASM2012 cut-off point of ≥15 events/h resulted in a post-test probability of 100% of having the disease, but with negative tests in 57.1%. A PM-REIAASM2012 cut-off of 8 events/h, still resulted in a positive post-test probability of 100% but with negative tests in only 34.3%. Combination of the cut-off values with clinical estimation of being 'at high risk' based on Epworth Sleepiness Scale (ESS) and Berlin Questionnaire scores only resulted in a small reduction in the percentage of negative tests (respectively 52.7% and 32.7%). After 6 months, CPAP adherence was not lower using the PM-REIAASM 2012 cut-off ≥8 events/h in comparison to ≥15 events/h (median 5.7 vs. 5.8 h/night, p = 0.368) and the reduction in ESS was similar too (median -4 and -5 points, p = 0.083). Consequently, using a lower PM-REIAASM2012 cut-off could result in cost savings because of less negative studies and lesser need for a confirmatory PSG or a performance of a CPAP trial.

A 24% prevalence of excessive fragmentary myoclonus in 500 consecutive sleep laboratory patients.

Excessive fragmentary myoclonus (EFM) is a frequent finding during routine video-polysomnography (VPSG). We aimed to automatically measure the prevalence of EFM according to current American Academy of Sleep Medicine (AASM) criteria, and the fragmentary myoclonus index (FMI) in sleep stage N1, N2, N3, rapid eye movement (REM) sleep and wake in a large patient population. A total of 500 VPSG recordings of patients admitted to the Sleep Laboratory, Department of Neurology, Medical University of Innsbruck, Austria, between May 1, 2022 and February 28, 2023, were included. EFM according to AASM criteria and FMI were computed by applying a previously validated algorithm. EFM was automatically detected in 121 of the 500 Sleep Laboratory patients (24.2%, 95% confidence interval 20.1%-28.9%). FMI increased with age, male gender, apnea-hypopnea-index (AHI), oxygen desaturation index (ODI), and periodic leg movements of sleep (PLMS) index. FMI was highest in REM sleep behaviour disorder (RBD), followed by neurodegenerative and internal medicine diseases, but the increase in the FMI was not explained by the disease itself but rather by the age and sex of the patients. Almost a quarter of our patient population had EFM. However, the prevalence of EFM does not allow the drawing of any conclusions about the pathophysiology of EFM or even the determination of a pathological FMI cut-off value. Associations of the FMI with age, sex, AHI, ODI and PLMS are in line with previous studies, but the FMI needs to be evaluated in different disease entities to learn more about its pathophysiology.

Association between obstructive sleep apnea and gastroesophageal reflux disease: A systematic review and meta-analysis.

BACKGROUND AND AIM: We aim to conduct a systematic review and determine the association between obstructive sleep apnea (OSA) and gastroesophageal reflux disease (GERD). METHODS: Literature search for eligible studies was performed across major databases. The main endpoint was to assess the association between GERD and OSA. Subgroup analyses were performed to determine this strength of the association stratified by the diagnostic tools used for OSA (nocturnal polysomnogram or Berlin questionnaire) and GERD (validated reflux questionnaire or esophagogastroduodenoscopy). We also compared sleep efficiency, apnea hypopnea index, oxygen desaturation index, and Epworth Sleepiness Scale in OSA patients with or without GERD. Results were pooled together using Reviewer Manager 5.4. RESULTS: Six studies involving 2950 patients with either GERD or OSA were included in the pooled analysis. Our findings suggest that there was a statistically significant unidirectional association between GERD and OSA (odds ratio [OR] = 1.53, P = 0.0001). Subgroup analyses redemonstrated an OSA-GERD association irrespective of the tools used for diagnosing either GERD or OSA (P = 0.24 and P = 0.82, respectively). Sensitivity analyses demonstrated the same association after controlling for gender (OR = 1.63), BMI (OR = 1.81), smoking (OR = 1.45), and alcohol consumption (OR = 1.79). In patients with OSA, there were no statistically significant differences between patients with or without GERD in terms of apnea hypopnea index (P = 0.30), sleep efficiency (P = 0.67), oxygen desaturation index (P = 0.39), and Epworth Sleepiness Scale (P = 0.07). CONCLUSION: There exists an association between OSA and GERD that is independent of the modalities used for screening or diagnosing both disorders. However, the presence of GERD did not affect the severity of OSA.

Targeted Genome Sequencing Identifies Multiple Rare Variants in Caveolin-1 Associated with Obstructive Sleep Apnea.

Rationale: Obstructive sleep apnea (OSA) is a common disorder associated with increased risk for cardiovascular disease, diabetes, and premature mortality. There is strong clinical and epidemiologic evidence supporting the importance of genetic factors influencing OSA but limited data implicating specific genes. Objectives: To search for rare variants contributing to OSA severity. Methods: Leveraging high-depth genomic sequencing data from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program and imputed genotype data from multiple population-based studies, we performed linkage analysis in the CFS (Cleveland Family Study), followed by multistage gene-based association analyses in independent cohorts for apnea-hypopnea index (AHI) in a total of 7,708 individuals of European ancestry. Measurements and Main Results: Linkage analysis in the CFS identified a suggestive linkage peak on chromosome 7q31 (LOD = 2.31). Gene-based analysis identified 21 noncoding rare variants in CAV1 (Caveolin-1) associated with lower AHI after accounting for multiple comparisons (P = 7.4 × 10-8). These noncoding variants together significantly contributed to the linkage evidence (P < 10-3). Follow-up analysis revealed significant associations between these variants and increased CAV1 expression, and increased CAV1 expression in peripheral monocytes was associated with lower AHI (P = 0.024) and higher minimum overnight oxygen saturation (P = 0.007). Conclusions: Rare variants in CAV1, a membrane-scaffolding protein essential in multiple cellular and metabolic functions, are associated with higher CAV1 gene expression and lower OSA severity, suggesting a novel target for modulating OSA severity.

Prevalence of obstructive sleep apnea in patients with chronic kidney disease: a hospital-based study.

BACKGROUND: Chronic kidney disease (CKD) is has been rising over the past few years, and obstructive sleep apnea (OSA) is a prevalent comorbidity in this population. AIM: To determine the prevalence of OSA in patients with chronic kidney disease stages I-V and end-stage renal disease (ESRD). METHODS: Patients with CKD of varying grades and ESRD routinely visiting outpatient nephrology clinic or admitted in department of nephrology were included in the study. Stages I-III were categorized as early stages of CKD and stages IV-V and ESRD as late stages of CKD. Patients were categorized into a high risk group based on STOP-BANG and Berlin questionnaires. Patients who were high risk were subjected to in-hospital overnight level III polysomnography. Student's independent t-test and analysis of variance (ANOVA) were employed for the comparison of continuous variables. Chi-square test and Fisher's exact test, as appropriate, were used for the comparison of categorical variables. RESULTS: Of 111 patients, 46 (41%) were found to have OSA. Of these patients, 15 (33%) had mild OSA (AHI 5-14/h), 13 (28%) had moderate OSA (15-29/h), and 18 (39%) had severe OSA (AHI ≥ 30/h). Overall, 31% of patients in the early stage of CKD and 45% in the late stage were found to have OSA. CONCLUSION: This study demonstrated a high prevalence of OSA in patients with CKD when compared to the general population affecting both genders equally. The risk of OSA was higher in the advanced stages of CKD compared to the early stages, and dialysis had no effect on prevalence. Since OSA increases the cardiovascular morbidity in CKD the leading cause of death in these patients, early diagnosis and treatment of OSA may have promise to affect the mortality.