Obstructive sleep apnoea and risks of all-cause mortality: preliminary evidence from prospective cohort studies

Prevalence of obstructive sleep apnea in whole spectrum chronic kidney disease patients: A systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is a common sleep disorder among chronic kidney disease (CKD) patients, associated with considerable morbidity. Various studies from around the globe have reported different prevalence rates.

OBJECTIVE

This systematic review and meta-analysis aimed to determine the prevalence of OSA and quantify the relationship between OSA and mortality risk in patients with CKD.

METHODS

Four databases were systematically searched, and additional references to relevant articles were manually searched. The prevalence of OSA and the mortality risk based on random-effects models were assessed using percentages and hazard ratio (HR) with a 95 % confidence interval (95 % CI). In addition, the heterogeneity between studies was assessed using I2 statistics.

RESULTS

A total of 44 literature (47 studies with 223,967 participants) met the eligibility criteria for the meta-analysis. The results showed that the prevalence of OSA in CKD patients was reported to be 39.3 % (95 % CI, 32.3-46.7). Among study participants in different age groups, the highest prevalence of OSA was found in CKD respondents aged 60 years or older, at 47.1 % (95 % CI 34.4-60.3). Of the eight literature (10 cohorts) that provided survival data, the pooled estimates indicated a 26.5 % (HR: 1.265; 95 % CI 1.021-1.568) higher mortality risk in subjects with OSA than CKD patients without OSA.

CONCLUSIONS

This systematic review and meta-analysis found that more than 1/3 of CKD patients have comorbid OSA, which increases the risk of early death in CKD patients. These results should help policymakers to provide adequate healthcare for this population.

PROSPERO REGISTRATION ID

CRD42023465497.

Sleep is Essential for Cardiovascular Health: An Analytic Review of the Relationship Between Sleep and Cardiovascular Mortality

The American Heart Association recently included sleep health as one of eight factors that define cardiovascular health. Restorative sleep is a pillar of lifestyle medicine influenced by sleep duration, quality, and disorders. Short and long sleep duration are associated with greater risk of cardiovascular disease. Short sleep appears causally related to cardiovascular risk. Long sleep is more strongly predictive of cardiovascular risk, which may be due to comorbidities and other risk factors. Good-quality sleep appears to protect against the increased risk and is independently associated with risk of cardiovascular disease (CVD). Insomnia, particularly difficulty falling asleep and non-restorative sleep, is associated with an increase in cardiac events. Obstructive sleep apnea (OSA) is associated with cardiac risk and outcomes, which is typically observed in the context of contributing comorbidities. However, treating OSA with continuous positive airway pressure (CPAP) may not improve prognosis. Further research is needed to understand the causal mechanisms connecting sleep health with CVD and whether modifying sleep can improve outcomes. Sleep health should be considered as part of a holistic approach to improving cardiovascular health, as reflected in the scoring of LE8 and as one of the interrelated components of lifestyle medicine.

A review of obstructive sleep apnea and lung cancer: epidemiology, pathogenesis, and therapeutic options

Despite undeniable advances in modern medicine, lung cancer still has high morbidity and mortality rates. Lung cancer is preventable and treatable, and it is important to identify new risk factors for lung cancer, especially those that can be treated or reversed. Obstructive sleep apnea (OSA) is a very common sleep-breathing disorder that is grossly underestimated in clinical practice. It can cause, exacerbate, and worsen adverse outcomes, including death and various diseases, but its relationship with lung cancer is unclear. A possible causal relationship between OSA and the onset and progression of lung cancer has been established biologically. The pathophysiological processes associated with OSA, such as sleep fragmentation, intermittent hypoxia, and increased sympathetic nervous excitation, may affect normal neuroendocrine regulation, impair immune function (especially innate and cellular immunity), and ultimately contribute to the occurrence of lung cancer, accelerate progression, and induce treatment resistance. OSA may be a contributor to but a preventable cause of the progression of lung cancer. However, whether this effect exists independently of other risk factors is unclear. Therefore, by reviewing the literature on the epidemiology, pathogenesis, and treatment of lung cancer and OSA, we hope to understand the relationships between the two and promote the interdisciplinary exchange of ideas between basic medicine, clinical medicine, respiratory medicine, sleep medicine, and oncology.

Apnea-hypopnea index and the polysomnographic risk factors for predicting 5- to 8-year mortality in patients with OSA

BACKGROUND

The purpose of this study was to investigate the long-term mortality rates of patients with obstructive sleep apnea (OSA) who received an overnight polysomnogram (PSG) for obtaining the diagnosis and to determine the relationship between PSG parameters and overall mortality.

METHODS

Between 2007 and 2013, patients who had overnight PSG and were diagnosed with OSA were included in the study. Factors which are thought to influence mortality were assessed for 5-year and overall survival using the log rank test and Kaplan-Meier survival curves. Using multivariable Cox regression analysis, a model was constructed for factors influencing 5-year and overall survival.

RESULTS

A total of 762 patients with a mean age of 52.7 (±10.8) and a dominance of men (74.7%) were studied. Gender, OSA severity subgroups, and apnea hypopnea index (AHI) were not statistically significantly associated with either 5-year or overall mortality (p<0.05 for both). Age, having a cardiovascular comorbidity, proportion of rapid eye movement (%REM), and total sleep time with an oxyhemoglobin saturation of less than 90% (T90) all showed a significant correlation with overall all-cause mortality in the model. For 5-year mortality and overall mortality, the hazard ration (HR) for T90 was 3.6 (95% CI (1.6-8.0) p=0.001) and 3 (95% CI (1.6-5.7) p=0.001), respectively.

CONCLUSION

The study findings suggest that not AHI but PSG parameters of hypoxia, mainly T90, having cardiovascular comorbidity, and %REM sleep were significant risk factors for all-cause mortality in patients with OSA. The association of OSA, hypoxia, and mortality is an area that deserves further study.

Sleep disorders and mortality: A prospective study in the Canadian longitudinal study on aging

BACKGROUND AND OBJECTIVES

Sleep disorders are commonly linked to various health conditions, although it remains unclear to what degree they are linked with overall mortality. We compared mortality in different self-reported sleep disorders in a large population-based prospective study.

METHODS

In this case-control study within the CLSA cohort, participants completed a questionnaire at baseline (2011-2015) measuring overall sleep satisfaction, daily sleep duration, sleep-onset and sleep-maintenance insomnia, daytime somnolence, REM sleep behavior disorder (RBD), restless leg syndrome (RLS), and obstructive sleep apnea (OSA). The vital status of participants was assessed in July 2019. Baseline sleep problems of participants who died (cases) were compared to those who survived (controls). For each case, five age/sex-matched controls were selected. Binary logistic regression was used to estimate the association between sleep symptoms and mortality, adjusting for age, sex, marital status, province, education, alcohol consumption, smoking, caffeine, and body mass index. In a complementary model, anxiety and depression were also added.

RESULTS

Among 30,097 participants at baseline, 974 deaths were reported in 2019 (60.7 % male, age = 72.3 ± 9.4 years). In the initial analysis, mortality cases reported more baseline sleep-maintenance insomnia (12.1 % vs. 8.0 %, Adjusted OR[95%CI] = 1.62[1.15,2.29]), daytime somnolence (2.4 % vs. 1.1 %, AOR = 2.70[1.34,5.44]), and higher possible RLS (16.4 % vs. 12.4 %, AOR = 1.50[1.09,2.05]). They were also more likely to screen positive for possible OSA (33.8 % vs. 24.2 %, AOR = 1.32[1.07,1.64]); however, this effect was not related to core apnea symptoms. Sleep durations exceeding 10 h/day were also associated with increased mortality (3.4 % vs. 1.9 %, AOR = 1.83[1.04,3.24]). Other sleep symptoms/disorders, such as sleep-onset insomnia (7.3 % vs. 4.3 %, AOR = 1.54 [1.00,2.37]), possible RBD (5.3 % vs. 5.1 %, AOR = 1.02[0.62,1.69]), and overall sleep dissatisfaction (26.5 % vs. 22.6 %, AOR = 1.14[0.93,1.41]) were not different among these groups. After adding anxiety and depression to the adjustment model, all differences attenuated to become statistically non-significant, except for daytime somnolence disorder. When stratified by sex, the association between sleep disorders and mortality was only observed in women, with men showing no association.

DISCUSSION

We confirm a relationship between numerous sleep disorders and mortality. This effect is most evident in women, and appears to be strongly related to co-existing anxiety and depression.

Risk of obstructive sleep apnea among health workers: results of a screening in a large Italian University Hospital

PURPOSE

Obstructive sleep apnea (OSA) is a common respiratory sleep disorder, related to increased mortality, poor quality of life, and higher risk of work accidents and injuries. Studies on the risk of OSA (rOSA) among health workers (HW) are scant. The aims of this study were to investigate this issue in a large University Hospital and to assess the effectiveness of a screening program.

METHODS

The STOP-BANG questionnaire (SBQ) was sent via e-mail to the 5031 HW employed at the University Hospital of Verona. HW who completed the SBQ were classified at low, moderate, and high rOSA. HW at high rOSA were invited to undergo nocturnal polygraphy. The determinants of rOSA were studied by non-parametric Kruskal-Wallis test, Pearson's chi-squared, and multinomial logistic model.

RESULTS

Of 5031 HW, 1564 (31.1%) completed the online questionnaire. Responders with low, moderate, and high rOSA were 72.7%, 13.7%, and 13.6%. Male gender, older age, and higher body mass index (BMI) were significant predictors of high rOSA, as expected. Physicians had the lowest probability of being in the high-risk category. Polygraphy was performed in 64 subjects. The positive predictive value of the self-administered SBQ was 68.8% (95%C.I. 55.9-79.8%) but raised to 96.9% (95%C.I. 89.2-99.6%) when re-administered by medical staff.

CONCLUSION

SBQ showed its effectiveness as a screening tool in detecting undiagnosed OSA in HW. Systematic screening for OSA in work settings could allow early diagnosis and treatment, reducing short- and long-term health effects of OSA.

Prevalence of sleep-disordered breathing in an African general population: The Benin Society and Sleep (BeSAS) study

BACKGROUND

Data on the prevalence of sleep-disordered breathing (SDB) in the African general population are scarce, and a better understanding is urgently needed. Our study aimed to objectively determine the prevalence of, and factors associated with, SDB in a large sample in Benin, west Africa.

METHODS

In the Benin Society and Sleep (BeSAS) cross-sectional study, participants aged 25 years and older were recruited from both urban and rural areas. Rural participants were recruited from Tanve, a village located 200 km north of Cotonou, and urban participants were recruited from Cotonou. The participants underwent respiratory polygraphy at home using a type-3 device that measures airflow through a nasal pressure sensor, respiratory effort (thoracic movement), and pulse oximetry. Clinical and morphometric data were also collected. SDB severity categories were defined according to the apnoea-hypopnoea index (AHI), with mild-to-severe SDB (AHI ≥5/h), moderate-to-severe SDB (AHI ≥15/h), and severe SDB (AHI ≥30/h).

FINDINGS

The study was completed from April 4, 2018 to Jan 15, 2021. Of 2909 participants recruited in the BeSAS study, 2168 (74·5%) underwent respiratory polygraphy. For the 1810 participants with complete polygraphic data (mean age 46 years, SD 15; 1163 [64·2%] women), the prevalence of mild-to-severe SDB (AHI ≥5/h) was 43·2% (95% CI 40·9-45·5), of moderate-to-severe SDB (AHI ≥15/h) was 11·6% (10·2-13·1), and of severe SDB (AHI ≥30/h) was 2·7% (2·0-3·5). Factors independently associated with SDB were advanced age, male sex, large neck circumference, abdominal obesity, overweight or obesity, and snoring. After multivariable adjustment, severe SDB was independently associated with hypertension in women (odds ratio 3·99, 95% CI 1·04-15·33; p_trend=0·044), but not in men (odds ratio 0·67, 0·22-2·05; P_trend=0·63).

INTERPRETATION

The BeSAS study provides the first large-scale objective evaluation of SDB prevalence and associated factors in Africa. The high prevalence of SDB identified should stimulate the development of public health policies to prevent and treat this condition in African countries.

FUNDING

Ligue Pulmonaire Vaudoise, Switzerland.

Preoperative preparation and premedication of bariatric surgical patient

The prevalence of obesity has tripled worldwide over the past four decades. The United States has the highest rates of obesity, with 88% of the population being overweight and 36% obese. The UK has the sixth highest prevalence of obesity. The problem of obesity is not isolated to the developed world and has increasingly become an issue in the developing world as well. Obesity carries an increased risk of many serious diseases and health conditions, including type 2 diabetes, heart disease, stroke, sleep apnea, and certain cancers. Our ability to take care of this population safely throughout the perioperative period begins with a thorough and in-depth preoperative assessment and meticulous preparation. The preoperative assessment begins with being able to identify patients who suffer from obesity by using diagnostic criteria and, furthermore, being able to identify patients whose obesity is causing pathologic and physiologic changes. A detailed and thorough anesthesia assessment should be performed, and the anesthesia plan individualized and tailored to the specific patient's risk factors and comorbidities. The important components of the preoperative anesthesia assessment and patient preparation in the patient suffering from obesity include history and physical examination, airway assessment, medical comorbidities evaluation, functional status determination, risk assessment, preoperative testing, current weight loss medication, and review of any prior weight loss surgeries and their implications on the upcoming anesthetic. The preoperative evaluation of this population should occur with sufficient time before the planned operation to allow for modifications of the preoperative management without needing to delay surgery as the perioperative management of patients suffering from obesity presents significant practical and organizational challenges.

Sensorimotor nerve lesion of upper airway in patients with obstructive sleep apnea

The pathogenesis of obstructive sleep apnea (OSA) remains controversial. The role of anatomic stenosis is indisputable, and neural regulation of the upper airway remains to be elucidated. The upper airway maintains patency through the upper airway reflex. Lesions in any link of the reflex can increase the collapsibility of the upper airway. In this study, we investigated sensorimotor nerve lesions and their possible relationship with OSA. Tissue samples were obtained from the pharyngopalatine arch in 47 patients with OSA and 45 control participants to examine changes in the expression levels of myelin basic protein (MBP) and agrin through immunohistochemistry and western blotting. Downregulation of MBP in the mucosa reflects myelinated degeneration of mucosal sensory nerve axons, whereas upregulation of agrin in the neuromuscular junction reflects synaptic regeneration following denervation. The two neural factors correlate significantly with polysomnographic parameters, such as the apnea hypopnea index and lowest oxygen saturation. Our findings suggest that sensorimotor nerve damage in the upper airway of patients with OSA may be associated closely with the mechanism of OSA.

Cardiopulmonary coupling-derived sleep quality is associated with improvements in blood pressure in patients with obstructive sleep apnea at high-cardiovascular risk

OBJECTIVE

Investigate if changes in objective sleep quality index (SQI) assessed through cardiopulmonary-coupling analysis impacts blood pressure (BP) in patients with obstructive sleep apnea at high-cardiovascular risk.

METHODS

Secondary analysis of ECG and pulse-oximetry-[oxygen saturation (SpO2)] data from the Heart Biomarker Evaluation in Apnea Treatment study, multicenter, controlled trial in patients with cardiovascular disease and moderate-severe obstructive sleep apnea, randomly assigned to intervention of healthy lifestyle and sleep hygiene education (HLSE; control group), continuous positive airway pressure (CPAP) or nocturnal supplemental oxygen (NSO). Participants with good-quality ECG-signal and SpO2-signal (n = 241) were included.

RESULTS

CPAP-therapy significantly improved BP, with net average improvement in mean arterial blood pressure during sleep (MAP) when compared with nocturnal supplemental oxygen-therapy or healthy lifestyle and sleep education-therapy, -3.92 (P = 0.012) and -3.83 (P = 0.016), respectively. When stratified on the basis of baseline-SQI, CPAP-therapy improves 24-h MAP -3.02 (P = 0.030) and MAP -5.00 (P = 0.001), in patients with compromised baseline-SQI (SQI < 55). Stratifying the cohort based on changes in SQI during the study period (SQI-SQI), controlling for sex, age over 60, apnea-hypopnea index, SpO2 less than 80%, baseline BP and cardiovascular disease, significant differences are observed comparing the groups that Improved-SQI (SQI < 55, SQI ≥ 55) and Declined-SQI (SQI ≥ 55, SQI < 55) in MAP -4.87 (P = 0.046) and mean diastolic blood pressure (MDP) -4.42 (P = 0.026) as well as MAP -6.36 (P = 0.015), mean systolic blood pressure wake (MSP) -7.80 (P = 0.048) and MDP -5.64 (P = 0.009), respectively. Improved SQI reflects the magnitude of positive effect on BP which is reached mostly through initiation of CPAP-therapy.

CONCLUSION

Cardiopulmonary coupling-derived sleep quality impacted 24-h MAP and MDP, as well as BP during wake, in patients participating in the Heart Biomarker Evaluation in Apnea Treatment-study.

An umbrella review of systematic reviews and meta-analyses of observational investigations of obstructive sleep apnea and health outcomes

Purpose

The previous analysis of systematic reviews and meta-analyses have illustrated that obstructive sleep apnea (OSA) is correlated with multiple health outcomes. In the present research, our main aim was to execute an umbrella review to assess the available evidence for the associations between OSA and health outcomes.

Methods

Herein, a meta-analysis of previous observational investigations that have reported associations between OSA and health outcomes in all human populations and settings was performed. We used these studies to execute an umbrella review of available meta-analyses and systematic reviews.

Results

Sixty-six articles comprising 136 unique outcomes were enrolled in this analysis. Of the 136 unique outcomes, 111 unique outcomes had significant associations (p < 0.05). Only 7 outcomes (coronary revascularization after PCI, postoperative respiratory failure, steatosis, alaninetrans aminase (ALT) elevation, metabolic syndrome (MS), psoriasis, and Parkinson’s disease) had a high quality of evidence. Twenty-four outcomes had a moderate quality of evidence, and the remaining 80 outcomes had a weak quality of evidence. Sixty-nine outcomes exhibited significant heterogeneity. Twenty-five outcomes exhibited publication bias. Sixty-three (95%) studies showed critically low methodological quality.

Conclusion

Among the 66 meta-analyses exploring 136 unique outcomes, only 7 statistically significant outcomes were rated as high quality of evidence. OSA may correlate with an increased risk of coronary revascularization after PCI, postoperative respiratory failure, steatosis, ALT elevation, MS, psoriasis, and Parkinson’s disease.

Perioperative care of the obese patient

Background

Obesity has become an increasing problem worldwide during the past few decades. Hence, surgeons and anaesthetists will care for an increasing number of obese patients in the foreseeable future, and should be prepared to provide optimal management for these individuals. This review provides an update of recent evidence regarding perioperative strategies for obese patients.

Methods

A search for papers on the perioperative care of obese patients (English language only) was performed in July 2019 using the PubMed, Scopus, Web of Science and Cochrane Library electronic databases. The review focused on the results of RCTs, although observational studies, meta-analyses, reviews, guidelines and other reports discussing the perioperative care of obese patients were also considered. When data from obese patients were not available, relevant data from non-obese populations were used.

Results and conclusion

Obese patients require comprehensive preoperative evaluation. Experienced medical teams, appropriate equipment and monitoring, careful anaesthetic management, and an adequate perioperative ventilation strategy may improve postoperative outcomes. Additional perioperative precautions are necessary in patients with severe morbid obesity, metabolic syndrome, untreated or severe obstructive sleep apnoea syndrome, or obesity hypoventilation syndrome; patients receiving home ventilatory support or postoperative opioid therapy; and obese patients undergoing open operations, long procedures or revisional surgery.

Morbidity and mortality in patients with cardiovascular risk factors and obstructive sleep apnoea: results from the DIAST-CHF cohort

STUDY OBJECTIVES

Aim of the study was to investigate the association between obstructive sleep apnoea (OSA) and cardiovascular morbidity and mortality in a cohort of patients with cardiovascular risk factors.

METHODS

In this prospective study, 378 patients of the DIAST-CHF cohort were screened for OSA by home polygraphy. Inclusion criteria were risk factors for diastolic heart failure, such as hypertension, diabetes mellitus, atherosclerotic disease, or history of chronic heart failure. Patients were followed up after 1, 2, 5, 9 and 10 years for the occurrence of major adverse cardiac and cerebrovascular events (MACE and MACCE).

RESULTS

344 patients were included in the analysis, of which 60% were diagnosed with OSA (apnoea-hypopnoea index ≥5/h). Overall mortality was higher in the OSA group (14.9% vs. 5.9%; p = 0.007), but significance disappeared after adjustment for age and sex (hazard ratio (HR) 1.89, 95% confidence interval (CI) 0.86-4.16, p = 0.12). There was no significant difference in the occurrence of MACE or MACCE in patients with OSA compared to those without OSA (MACE: 31% vs. 30%; p = 0.61; MACCE: 32% vs. 30%; p = 0.53).

CONCLUSION

We did not find evidence of an adverse effect of OSA on cardiovascular morbidity and mortality in a cohort of patients with cardiovascular risk factors.

Formyl peptide receptor 1 up-regulation and formyl peptide receptor 2/3 down-regulation of blood immune cells along with defective lipoxin A4/resolvin D1 production in obstructive sleep apnea patients

BACKGROUND

This study aims to investigate the role of FPR 1/2/3 expressions in patients with obstructive sleep apnea (OSA).

METHOD

We made cross-sectional comparisons of FPR1/2/3 expressions of blood neutrophil, M1/M2a monocyte, and natural killer (NK) cell between 16 healthy subjects (HS), 16 primary snoring (PS) subjects, 46 treatment-naive OSA patients, and 18 severe OSA patients under long-term continuous positive airway pressure treatment (severe OSA on CPAP).

RESULTS

FPR1 expressions on neutrophil were increased in treatment-naive OSA and severe OSA on CPAP groups versus either HS or PS. FPR2 expressions on neutrophil were decreased in treatment-naive OSA versus HS, and returned to normal in severe OSA on CPAP group. FPR1/FPR2 expression ratio on neutrophil was increased in treatment-naive OSA versus either HS or PS. Serum lipoxin A4, resolvin D1 levels, and FPR3 expressions of M1, M2a and NK cells were all decreased in treatment-naive OSA versus HS. OSA patients with hypertension had decreased FPR2 expressions on neutrophil and FPR3 expressions of NK cell. FPR1 expression, FPR1/FPR2 expression ratio on neutrophil, and FPR3 expression of M1 cell were all reversed after > 6-month CPAP treatment in 9 selected patients. In vitro intermittent hypoxia with re-oxygenation treatment in THP-1 cells resulted in increased FPR1/FPR2 expression ratio of M1 cells, and increased FPR1/FPR3 expression ratio of M2a cells.

CONCLUSIONS

FPR1 over-expression and insufficiency of FPR2 and FPR3 in association with defective lipoxin A4 and resolving D1 production were associated with disease severity of OSA and its adverse consequences.

Quality of an ambulatory monitoring technique for diagnosing obstructive sleep apnea under conditions of limited resources

Objectives:

To: 1) evaluate the quality of an ambulatory monitoring technique for diagnosing Obstructive Sleep Apnea Syndrome (OSAS) while patients move through the city; and 2) identify factors that lead to data loss.

Methods:

Clinical histories were reviewed and ambulatory portable monitorings of adults with high pretest probability for OSAS were included, the signals monitored were pulse oximetry, heart rate, nasal pressure, snoring, chest band and body position. The equipment was connected from 14:00-20:00 h and then patients moved through the city turning it off and on at home. Results were analyzed visually to record all the minutes lost. A good-quality study was defined as recording time 240 min and signal loss <20%. A cost/benefit analysis was performed using Golpe et al.'s methodology.

Results:

A total of 70 recordings were analyzed. Most subjects were obese men with severe OSAS. Signal quality was determined to be good with a median signal loss of 4.9 min (0-405) that represented 1% (0-99) of total recording time. The signal lost most often was pulse oximetry at 1.8 min (0-403, p=0.0001). Of the 70 studies performed, 57 (81%) met the definition of good quality, while 13 (19%) had to be repeated. Men lost the pulse oximetry signal more often than women. This technique could represent savings of 65-75%.

Conclusions:

Placing a portable OSAS monitor during the day while patients move around the city turning it on and off at home does not affect the quality of the study results obtained and is a cost-effective method.

Preoperative obstructive sleep apnea screening in gynecologic oncology patients

BACKGROUND

Women with a gynecologic cancer tend to be older, obese, and postmenopausal, characteristics that are associated with an increased risk for obstructive sleep apnea. However, there is limited investigation regarding the condition's prevalence in this population or its impact on postoperative outcomes. In other surgical populations, patients with obstructive sleep apnea have been observed to be at increased risk for adverse postoperative events.

OBJECTIVE

We sought to estimate the prevalence of obstructive sleep apnea among gynecologic oncology patients undergoing elective surgery and to investigate for a relationship between obstructive sleep apnea and postoperative outcomes.

STUDY DESIGN

Patients referred to an academic gynecologic oncology practice were approached for enrollment in this prospective, observational study. Patients were considered eligible for study enrollment if they were scheduled for a nonemergent inpatient surgery and could provide informed consent. Enrolled patients were evaluated for a preexisting diagnosis of obstructive sleep apnea. Those without a prior diagnosis were screened using the validated, 4-item STOP questionnaire (ie, Snore loudly, daytime Tiredness, Observed apnea, elevated blood Pressure). All patients who screened positive for obstructive sleep apnea were referred for polysomnography. The primary outcome was the prevalence of women with obstructive sleep apnea or those who screened at high risk for the condition. Secondary outcomes examined the correlation between body mass index (kg/m²) with obstructive sleep apnea and assessed for a relationship between obstructive sleep apnea and postoperative outcomes.

RESULTS

Over a 22-month accrual period, 383 eligible patients were consecutively approached to participate in the study. A cohort of 260 patients were enrolled. A total of 33/260 patients (13%) were identified as having a previous diagnosis of obstructive sleep apnea. An additional 66/260 (25%) screened at risk for the condition using the STOP questionnaire. Of the patients who screened positive, 8/66 (12%) completed polysomnography, all of whom (8/8 [100%]) were found to have obstructive sleep apnea. The prevalence of previously diagnosed obstructive sleep apnea or screening at risk for the condition increased as body mass index increased (P < .001). Women with untreated obstructive sleep apnea and those who screened at risk for the condition were found to have an increased risk for postoperative hypoxemia (odds ratio, 3.5; 95% confidence interval, 1.8-4.7; P = .011) and delayed return of bowel function (odds ratio, 2.1; 95% confidence interval, 1.3-4.5; P = .009).

CONCLUSION

The prevalence of obstructive sleep apnea or screening at risk for the condition is high among women presenting for surgery with a gynecologic oncologist. Providers should consider evaluating a patient's risk for obstructive sleep apnea in the preoperative setting, especially when risk factors for the condition are present.

Meta-analysis of all-cause and cardiovascular mortality in obstructive sleep apnea with or without continuous positive airway pressure treatment

PURPOSE

The associations between obstructive sleep apnea (OSA) and all-cause and cardiovascular mortality are well established but are not entirely consistent. To accurately evaluate these associations as well as the therapeutic effects of continuous positive airway pressure (CPAP), we conducted a comprehensive meta-analysis of all eligible cohort studies.

METHODS

Electronic literature databases (i.e., PubMed and Embase) were searched for relevant studies published before January 2016 that evaluated the associations between OSA and all-cause or cardiovascular mortality. Random-effect models were used to calculate the pooled hazard ratio (HR) and corresponding 95 % confidence intervals (CIs) for categorical risk estimates. The therapeutic effects of CPAP treatment for all-cause and cardiovascular mortality in OSA were examined through the meta-analysis.

RESULTS

The 27 cohort studies included in the meta-analysis included 3,162,083 participants. Compared to the control group, the pooled HR of all-cause mortality was 1.19 (95 % CI, 0.86-1.65) for mild OSA, 1.28 (0.96-1.69) for moderate OSA, and 2.13 (1.68-2.68) for severe OSA. The pooled HR of cardiovascular mortality was 1.24 (0.53-2.55) for mild OSA, 2.05 (0.57-5.47) for moderate OSA, and 2.73 (1.94-3.85) for severe OSA. All-cause mortality (HR 0.66; 0.59-0.73) and cardiovascular mortality (HR 0.37; 0.16-0.54) were significantly lower in CPAP-treated than in untreated patients. There were no differences in cardiovascular mortality in CPAP-treated OSA patients vs. normal control subjects (HR 0.82; 0.52-1.29).

CONCLUSIONS

Greater attention should be paid to severe OSA, as it is an independent predictor for risk for all-cause and cardiovascular mortality. CPAP is an effective treatment that reduces risk of mortality.

Effect of CPAP therapy on cardiovascular events and mortality in patients with obstructive sleep apnea: a meta-analysis

PURPOSE

Continuous positive airway pressure (CPAP) therapy may decrease the risk of mortality and cardiovascular events in patients with obstructive sleep apnea. However, these benefits are not completely clear.

METHODS

We undertook a meta-analysis of randomized clinical trials identified in systematic searches of MEDLINE, EMBASE, and the Cochrane Database.

RESULTS

Eighteen studies (4146 patients) were included. Overall, CPAP therapy did not significantly decrease the risk of cardiovascular events compared with the control group (odds ratio (OR), 0.84; 95 % confidence intervals (CI), 0.62-1.13; p = 0.25; I (2) = 0 %). CPAP was associated with a nonsignificant trend of lower rate of death and stroke (for death: OR, 0.85; 95 % CI, 0.35-2.06; p = 0.72; I (2) = 0.0 %; for stroke: OR, 0.56; 95 % CI, 0.18-1.73; p = 0.32; I (2) = 12.0 %), a significantly lower Epworth sleepiness score (ESS) (mean difference (MD), -1.78; 95 % CI, -2.31 to -1.24; p < 0.00001; I (2) = 76 %), and a significantly lower 24 h systolic and diastolic blood pressure (BP) (for 24 h systolic BP: MD, -2.03 mmHg; 95 % CI, -3.64 to -0.42; p = 0.01; I (2) = 0 %; for diastolic BP: MD, -1.79 mmHg; 95 % CI, -2.89 to -0.68; p = 0.001; I (2) = 0 %). Daytime systolic BP and body mass index were comparable between the CPAP and control groups. Subgroup analysis did not show any significant difference between short- and mediate-to-long-term follow-up groups with regard to cardiovascular events, death, and stroke.

CONCLUSIONS

CPAP therapy was associated with a trend of decreased risk of cardiovascular events. Furthermore, ESS and BP were significantly lower in the CPAP group. Larger randomized studies are needed to confirm these findings.