Age and comorbidities are crucial predictors of mortality in severe obstructive sleep apnoea syndrome

Survival and Risk Factors Associated with Mortality in Patients with Sleep Apnoea in Colombia: A Retrospective Cohort Study

Background

Survival in patients with sleep apnoea (SA) can be reduced by variables such as age, sex, and comorbidities. However, survival data in patients with SA in Colombia remains scarce.

Methods

This is a retrospective cohort study of patients diagnosed with SA between 2005 and 2022. Five-year survival was assessed using the Kaplan-Meier method, and survival curves were stratified by age, sex, and cardiovascular disease. Risk factors associated with survival were evaluated using Hazard Ratio (HR) by adjusting for confounding variables with a Cox regression model. A minimum sample size of 1537 patients were estimated to be necessary to estimate a survival incidence rate with a 5% precision.

Results

The five-year survival rate in the general population was 94.6%, with lower survival in patients over 65 years (88.5% vs 97.9%; p < 0.001) and in patients with cardiovascular disease (89% vs 95.2%; p < 0.001) compared to the control group. In the Cox regression, age showed an HR of 1.05 (95% CI: 1.02-1.07; p < 0.001). Male sex had an HR of 2.31 (95% CI: 1.25-4.25; p = 0.007), congestive heart failure an HR of 4.00 (95% CI: 2.31-6.94; p < 0.001), chronic obstructive pulmonary disease (COPD) an HR of 1.75 (95% CI: 1.04-2.96; p = 0.035), chronic kidney disease (CKD) an HR of 2.23 (95% CI: 1.31-3.78; p = 0.003), and metastatic cancer an HR of 4.96 (95% CI: 1.95-12.60; p = 0.001).

Conclusion

The study showed a high five-year survival rate in patients with SA. The risk factors associated with decreased overall five-year survival were age, male sex, cardiovascular disease, COPD, CKD, and metastatic cancer.

Long-term mortality risk in obstructive sleep apnea: the critical role of oxygen desaturation index

BACKGROUND

Mortality predictors in obstructive sleep apnea (OSA) patients yet to be comprehensively understood, especially within large cohorts undergoing long-term follow-up. We aimed to determine the independent predictors of mortality in OSA patients.

METHODS

In our retrospective cohort study, 3,541 patients were included and survival data was obtained from electronic medical records. Demographic characteristics, anthropometric measurements, comorbidities, laboratory tests, and polysomnography parameters were analyzed for the survived and deceased patient groups. Univariate and multivariate Cox regression analyses were performed to determine independent predictors of all-cause mortality in patients followed for at least 5 years.

RESULTS

Among all patients, 2,551 (72%) patients were male, with a mean age of 49.7 years. 231 (6.5%) patients had died. Deceased patients were significantly older and had higher waist-to-hip ratio and Epworth Sleepiness Scale (p < 0.001, p < 0.001, p = 0.003). OSA (nonpositional and not-rapid eye movement-related), periodic limb movements in sleep and Comorbidities of Sleep Apnea Score ≥ 1 were found to be associated with increased mortality (p < 0.001). Systemic immune-inflammation index was also significantly higher in the deceased group (p < 0.001). Higher oxygen desaturation index (ODI) and apnea-hypopnea index (AHI) were associated with increased mortality (p < 0.001). Due to the high correlation between ODI and AHI, two separate multivariate Cox regression models were created. While AHI lost its significance in the multivariate analysis, ODI remained significantly higher in the deceased patient group (HR = 1.007, 1.001-1.013, p = 0.01).

CONCLUSION

ODI, as the only polysomnography parameter, emerged as an independent predictor of mortality in OSA patients.

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.

Association between obstructive sleep apnea and low bone mass in adults: a systematic review and meta-analysis

Introduction

This study aimed to synthesize existing evidence on the potential association between obstructive sleep apnea (OSA) and low bone mass in adults.

Methods

Electronic searches of four main databases were performed. The inclusion criteria consisted of observational studies investigating the relationship between OSA and bone mass, osteoporosis, fractures, or bone metabolism markers in adult population. Bone mineral density (BMD) and T score of lumbar and femur neck, incidence of osteoporosis and fractures, bone metabolism marker levels were extracted as primary outcomes.

Results

Among the 693 relevant publications, 10 studies consisting of 158,427 participants met with the inclusion and exclusion criteria. Meta-analysis showed a significant lower BMD of lumbar (mean difference (MD) = - 0.03; 95% CI - 0.05, - 0.01; I2 = 46%), femur neck (MD = - 0.06; 95% CI - 0.12, 0.00; I2 = 71%), and a significant lower T score of lumbar (MD = - 0.42; 95% CI - 0.79, - 0.05; I2 = 63%) in the OSA group. The results suggested that both male (odds ratio (OR) = 2.03; 95% CI 1.23, 3.35; I2 = 38%) and female (OR = 2.56; 95% CI 1.96, 3.34; I2 = 0%) had higher risk of osteoporosis in the OSA group. Besides, meta-analysis also showed that bone-specific alkaline phosphatase was significantly lower in OSA patients (MD = - 1.90; 95% CI - 3.48, - 0.32; I2 = 48%).

Conclusions

A potential association between OSA and lower bone mass in adults is preliminarily proved. It also seems plausible that both male and female with OSA have a higher risk of osteoporosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-023-00481-1.

Comparison of seven prehospital early warning scores to predict long-term mortality: a prospective, multicenter, ambulance-based study

The long-term predictive validity of early warning scores (EWS) has not been fully elucidated yet. The aim of the present study is to compare seven prehospital EWS to predict 1-year mortality. A prospective, multicenter, ambulance-based study of adult patients with an acute illness involving six advanced life support units and 38 basic life support units, referring to five emergency departments in Spain. The primary outcome was long-term mortality with a 1-year follow-up. The compared scores included: National Early Warning Score 2, VitalPAC early warning score, modified rapid emergency medicine score (MREMS), Sepsis-related Organ Failure Assessment, Cardiac Arrest Risk Triage Score, Rapid Acute Physiology Score, and Triage Early Warning Score. Discriminative power [area under the receiver operating characteristic curve (AUC)] and decision curve analysis (DCA) were used to compare the scores. Additionally, a Cox regression and Kaplan-Meier method were used. Between 8 October 2019, and 31 July 2021, a total of 2674 patients were selected. The MREMS presented the highest AUC of 0.77 (95% confidence interval, 0.75-0.79), significantly higher than those of the other EWS. It also exhibited the best performance in the DCA and the highest hazard ratio for 1-year mortality [3.56 (2.94-4.31) for MREMS between 9 and 18 points, and 11.71 (7.21-19.02) for MREMS > 18]. Among seven tested EWS, the use of the MREMS presented better characteristics to predict 1-year mortality; however, all these scores present moderate performances.

COVID-19 as a risk factor for long-term mortality in patients managed by the emergency medical system: A prospective, multicenter, ambulance-based cohort study

Introduction

COVID-19 has initially been studied in terms of an acute-phase disease, although recently more attention has been given to the long-term consequences. In this study, we examined COVID-19 as an independent risk factor for long-term mortality in patients with acute illness treated by EMS (emergency medical services) who have previously had the disease against those who have not had the disease.

Methods

A prospective, multicenter, ambulance-based, ongoing study was performed with adult patients with acute disease managed by EMS and transferred with high priority to the emergency department (ED) as study subjects. The study involved six advanced life support units, 38 basic life support units, and five emergency departments from Spain. Sociodemographic inputs, baseline vital signs, pre-hospital blood tests, and comorbidities, including COVID-19, were collected. The main outcome was long-term mortality, which was classified into 1-year all-cause mortality and 1-year in- and out-of-hospital mortality. To compare both the patients with COVID-19 vs. patients without COVID-19 and to compare survival vs non-survival, two main statistical analyses were performed, namely, a longitudinal analysis (Cox regression) and a logistic regression analysis.

Results

Between 12 March 2020 and 30 September 2021, a total of 3,107 patients were included in the study, with 2,594 patients without COVID-19 and 513 patients previously suffering from COVID-19. The mortality rate was higher in patients with COVID-19 than in patients without COVID-19 (31.8 vs. 17.9%). A logistic regression showed that patients previously diagnosed with COVID-19 presented higher rates of nursing home residency, a higher number of breaths per minute, and suffering from connective disease, dementia, and congestive heart failure. The longitudinal analysis showed that COVID-19 was a risk factor for mortality [hazard ratio 1.33 (1.10-1.61); p < 0.001].

Conclusion

The COVID-19 group presented an almost double mortality rate compared with the non-COVID-19 group. The final model adjusted for confusion factors suggested that COVID-19 was a risk factor for long-term mortality.

Obstructive Sleep Apnea and Role of the Diaphragm

Obstructive sleep apnea (OSA) causes multiple local and systemic pathophysiological consequences, which lead to an increase in morbidity and mortality in patients suffering from this disorder. OSA presents with various nocturnal events of apnoeas or hypopneas and with sub-clinical airflow limitations during wakefulness. OSA involves a large percentage of the population, particularly men, but the estimate of OSA patients could be much broader than data from the literature. Most of the research carried out in the muscle field is to understand the causes of the presence of chronic nocturnal desaturation and focus on the genioglossus muscle and other muscles related to dilating the upper airways. Sparse research has been published regarding the diaphragm muscle, which is the main muscle structure to insufflate air into the airways. The article reviews the functional anatomy of the muscles used to open the upper respiratory tract and the non-physiological adaptation that follows in the presence of OSA, as well as the functional anatomy and pathological adaptive aspects of the diaphragm muscle. The intent of the text is to highlight the disparity of clinical interest between the dilator muscles and the diaphragm, trying to stimulate a broader approach to patient evaluation.

Mortality and Cardiovascular Events in Patients With Chronic Kidney Disease and Sleep Apnea Syndrome

Background

The incidence of sleep apnea syndrome (SAS) is reported to be markedly high in patients with chronic kidney disease (CKD). Therefore, it is extremely important to know whether SAS affects prognosis in patients with CKD. Further, it is imperative to understand the prognostic impact of home continuous positive airway pressure (CPAP) therapy, which is one of the most common treatments for SAS.

Materials and Methods

We used a clinical database to identify patients with CKD using diagnosis codes. We included patients with CKD aged 20 years or more, not on renal replacement therapy, with a known change in renal function for at least 1 year. The propensity score was used to compare event rates for patients with SAS and those without SAS. In addition, the prognostic impact of CPAP therapy was investigated. The primary outcome is a composite of death, initiation of renal replacement therapy, hospitalization for heart failure, ischemic heart disease, and cerebrovascular disease.

Results

From the database, 31,294 patients with CKD without SAS and 1,026 with SAS were found to be eligible. Of these, 419 (41%) patients with SAS and 10,713 (34%) patients without SAS (P < 0.01) reached the primary outcome. After adjustment with the propensity score, the SAS group was found to have a similarly poor prognosis (P < 0.01): the hazard ratio for the primary outcome was 1.26 (95% CI, 1.08–1.45, P < 0.01) in the group with SAS compared with the group without SAS. Conversely, in patients with SAS and using CPAP, the hazard ratio was lower and did not differ significantly (HR 0.96, 95% CI: 0.76–1.22, P = 0.76).

Conclusion

In patients with CKD and SAS, the risk of death and cardiovascular disease is high. In addition, patients treated with CPAP may have improved life expectancy.