Current evidence on prevalence and clinical outcomes of co-morbid obstructive sleep apnea and chronic obstructive pulmonary disease: A systematic review

The objective of this systematic review is to synthesize the evidence on prevalence, polysomnographic findings and clinical outcomes of co-morbid obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) – known as the “overlap syndrome”. We systematically searched PubMed on 1 December 2015 using appropriate medical subject headings (MeSH) and text words to capture prevalence studies and comparative studies of any observational design examining the clinical outcomes in patients with co-existent COPD and OSA. We reviewed 591 articles and included 27 in the final review. In total, 21 observational studies (n = 29,341 participants) provided prevalence estimates. Overlap syndrome is not common in the general and hospital population (range: 1.0–3.6%), but is highly prevalent in patients diagnosed with either obstructive sleep apnea (range: 7.6–55.7%) or COPD (range: 2.9–65.9%). Overlap syndrome patients have been shown to have greater nocturnal oxygen desaturation (NOD) (i.e., reduced mean peripheral capillary oxygen saturation (SpO2) and increased sleep time spent with SpO2 < 90% (T90)) and worse sleep quality than patients with only OSA. It is associated with more frequent cardiovascular morbidity, poorer quality of life (QoL), more frequent COPD exacerbation and increased medical costs. This systematic review on overlap syndrome highlights the limitations and knowledge gaps of its prevalence, etiology and underlying pathophysiologic mechanisms related to increased morbidity and mortality.</p

Sleep apnoea in Australian men: disease burden, co-morbidities, and correlates from the Australian longitudinal study on male health

BACKGROUND: Obstructive sleep apnoea is a common disorder with under-rated clinical impact, which is increasingly being recognised as having a major bearing on global disease burden. Men are especially vulnerable and become a priority group for preventative interventions. However, there is limited information on prevalence of the condition in Australia, its co-morbidities, and potential risk factors. METHODS: We used data from 13,423 adult men included in the baseline wave of Ten to Men, an Australian national study of the health of males, assembled using stratified cluster sampling with oversampling from rural and regional areas. Those aged 18-55 years self-completed a paper-based questionnaire that included a question regarding health professional-diagnosed sleep apnoea, physical and mental health status, and health-related behaviours. Sampling weights were used to account for the sampling design when reporting the prevalence estimates. Odds ratios were used to describe the association between health professional-diagnosed sleep apnoea and potential correlates while adjusting for age, country of birth, and body-mass index (BMI). RESULTS: Prevalence of self-reported health professional-diagnosed sleep apnoea increased from 2.2 % in age 18-25 years to 7.8 % in the age 45-55 years. Compared with those without sleep apnoea, those with sleep apnoea had significantly poorer physical, mental, and self-rated health as well as lower subjective wellbeing and poorer concentration/remembering (p < 0.001 for all). Sleep apnoea was significantly associated with older age (p < 0.001), unemployment (p < 0.001), asthma (p = 0.011), chronic obstructive pulmonary disease/chronic bronchitis (p = 0.002), diabetes (p < 0.001), hypercholesterolemia (p < 0.001), hypertension (p < 0.001), heart attack (p < 0.001), heart failure (p < 0.001), angina (p < 0.001), depression (p < 0.001), post-traumatic stress disorder (p < 0.001), other anxiety disorders (p < 0.001), schizophrenia (p = 0.002), overweight/obesity (p < 0.001), insufficient physical activity (p = 0.006), smoking (p = 0.005), and high alcohol consumption (p < 0.001). CONCLUSION: Health professional-diagnosed sleep apnoea is relatively common, particularly in older males. Associations between sleep apnoea and cardiovascular, metabolic, respiratory, and psychiatric disorders have important clinical and public health implications. As men are especially vulnerable to sleep apnoea as well as some of its chronic co-morbidities, they are potentially a priority group for health interventions. Modifiable lifestyle related factors such as smoking, alcohol consumption, level of physical activity and BMI are possible key foci for interventions

Nocturnal symptoms perceived as asthma are associated with obstructive sleep apnoea risk, but not bronchial hyper-reactivity

Background and objective:Obstructive sleep apnoea (OSA) and asthma are associated, and nocturnal breathing difficulty that is usually identified as asthma‐like symptoms can be present in both conditions. We investigated how nocturnal asthma‐like symptoms (NAS) and bronchial hyper‐reactivity (BHR) contribute to the association between OSA risk and current asthma, which is currently unknown but a clinically important question.Methods:We used data from 794 middle‐aged participants in a population‐based cohort who provided information on OSA risk (defined by a STOP‐Bang questionnaire score of at least 3), current asthma and NAS, and underwent methacholine bronchial challenge testing. Using regression models, we examined the association between OSA risk and current asthma‐NAS subgroups and investigated any effect modification by BHR.Results:The participants were aged 50 years (49.8% male). OSA risk was associated with NAS with or without current asthma (odds ratio (OR): 2.6; 95% CI = 1.3–5.0; OR: 4.2; 95% CI = 1.1–16.1, respectively), but not with current asthma in the absence of NAS. BHR was associated with current asthma with or without NAS (OR: 2.9; 95% CI = 1.4–5.9; OR: 3.4; 95% CI = 2.0–7.0, respectively) but not with NAS in the absence of current asthma. The associations between OSA risk and current asthma were neither modified nor mediated by BHR.Conclusion:Our findings suggest that some of the nocturnal symptoms perceived as asthma may be OSA symptoms. Patients with nocturnal asthma symptoms should be considered for possible OSA

Prediction models for the development of COPD: a systematic review

Melanie C Matheson,1,2,* Gayan Bowatte,1,3,* Jennifer L Perret,1,4 Adrian J Lowe,1,2 Chamara V Senaratna,1,5 Graham L Hall,6&ndash;8 Nick de Klerk,6,8 Louise A Keogh,9 Christine F McDonald,4 Nilakshi T Waidyatillake,1 Peter D Sly,10 Deborah Jarvis,11,12 Michael J Abramson,13 Caroline J Lodge,1,2,* Shyamali C Dharmage1,2,* 1Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia; 2Murdoch Children&rsquo;s Research Institute, Melbourne, VIC, Australia; 3National Institute of Fundamental Studies, Kandy, Sri Lanka; 4Department of Respiratory and Sleep Medicine, Institute for Breathing and Sleep, Austin Health, University of Melbourne, Melbourne, VIC, Australia; 5Department of Community Medicine, University of Sri Jayewardenepura, Nugegoda, Sri Lanka; 6Telethon Kids Institute, Perth, WA, Australia; 7School of Physiotherapy and Exercise Science, Curtin University, Perth, WA, Australia; 8Centre of Child Health Research, University of Western Australia, Perth, WA, Australia; 9Centre for Health Equity, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia; 10Child Health Research Centre, The University of Queensland, Brisbane, QLD, Australia; 11MRC-PHE Centre for Environment and Health, Imperial College London, London, UK; 12Population Health and Occupational Diseases, National Heart and Lung Institute, Imperial College London, London, UK; 13School of Public Health &amp; Preventive Medicine, Monash University, Melbourne, VIC, Australia *These authors contributed equally to this work Abstract: Early identification of people at risk of developing COPD is crucial for implementing preventive strategies. We aimed to systematically review and assess the performance of all published models that predicted development of COPD. A search was conducted to identify studies that developed a prediction model for COPD development. The Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies was followed when extracting data and appraising the selected studies. Of the 4,481 records identified, 30 articles were selected for full-text review, and only four of these were eligible to be included in the review. The only consistent predictor across all four models was a measure of smoking. Sex and age were used in most models; however, other factors varied widely. Two of the models had good ability to discriminate between people who were correctly or incorrectly classified as at risk of developing COPD. Overall none of the models were particularly useful in accurately predicting future risk of COPD, nor were they good at ruling out future risk of COPD. Further studies are needed to develop new prediction models and robustly validate them in external cohorts. Keywords: COPD, early detection, predictors and risk prediction model