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BackgroundCOPD increases susceptibility to sleep disturbances, which may in turn predispose to increased respiratory symptoms. The objective of this study was to evaluate, in a population-based sample, the relationship between subjective sleep quality and risk of COPD exacerbations.MethodsData were obtained from the Canadian Cohort Obstructive Lung Disease (CanCOLD) study. Participants with COPD who had completed 18 months of follow-up were included. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI) and a three-factor analysis. Symptom-based (dyspnea or sputum change ≥ 48 h) and event-based (symptoms plus medication or unscheduled health services use) exacerbations were assessed. Association of PSQI with exacerbation rate was assessed by using negative binomial regression. Exacerbation-free survival was also assessed.ResultsA total of 480 participants with COPD were studied, including 185 with one or more exacerbations during follow-up and 203 with poor baseline sleep quality (PSQI score > 5). Participants with subsequent symptom-based exacerbations had higher median baseline PSQI scores than those without (6.0 [interquartile range, 3.0-8.0] vs 5.0 [interquartile range, 2.0-7.0]; P = .01), and they were more likely to have baseline PSQI scores > 5 (50.3% vs 37.3%; P = .01). Higher PSQI scores were associated with increased symptom-based exacerbation risk (adjusted rate ratio, 1.09; 95% CI, 1.01-1.18; P = .02) and event-based exacerbation risk (adjusted rate ratio, 1.10; 95% CI, 1.00-1.21; P = .048). The association occurred mainly in those with undiagnosed COPD. Strongest associations were with Factor 3 (sleep disturbances and daytime dysfunction). Time to symptom-based exacerbation was shorter in participants with poor sleep quality (adjusted hazard ratio, 1.49; 95% CI, 1.09-2.03).ConclusionsHigher baseline PSQI scores were associated with increased risk of COPD exacerbation over 18 months' prospective follow-up.

Chronic obstructive pulmonary disease patient care must include confirming a diagnosis with postbronchodilator spirometry. Because of the clinical heterogeneity and the reality that airflow obstruction assessed by spirometry only partially reflects disease severity, a thorough clinical evaluation of the patient should include assessment of symptom burden and risk of exacerbations that permits the implementation of evidence-informed pharmacologic and nonpharmacologic interventions. This guideline provides recommendations from a comprehensive systematic review with a meta-analysis and expert-informed clinical remarks to optimize maintenance pharmacologic therapy for individuals with stable COPD, and a revised and practical treatment pathway based on new evidence since the 2019 update of the Canadian Thoracic Society (CTS) Guideline. The key clinical questions were developed using the Patients/Population (P), Intervention(s) (I), Comparison/Comparator (C), and Outcome (O) model for three questions that focuses on the outcomes of symptoms (dyspnea)/health status, acute exacerbations, and mortality. The evidence from this systematic review and meta-analysis leads to the recommendation that all symptomatic patients with spirometry-confirmed COPD should receive long-acting bronchodilator maintenance therapy. Those with moderate to severe dyspnea (modified Medical Research Council ≥ 2) and/or impaired health status (COPD Assessment Test ≥ 10) and a low risk of exacerbations should receive combination therapy with a long-acting muscarinic antagonist/long-acting ẞ2-agonist (LAMA/LABA). For those with a moderate/severe dyspnea and/or impaired health status and a high risk of exacerbations should be prescribed triple combination therapy (LAMA/LABA/inhaled corticosteroids) azithromycin, roflumilast or N-acetylcysteine is recommended for specific populations; a recommendation against the use of theophylline, maintenance systemic oral corticosteroids such as prednisone and inhaled corticosteroid monotherapy is made for all COPD patients. [ABSTRACT FROM AUTHOR]

Acute hypoxia increases cerebral blood flow (CBF) and ventilation (...E). It is unknown if these responses are impacted with normal aging, or in patients with enhanced oxidative stress, such as (COPD). The purpose of the study was to 1) investigate the effects of aging and COPD on the cerebrovascular and ventilatory responses to acute hypoxia, and 2) to assess the effect of vitamin C on these responses during hypoxia. In 12 Younger, 14 Older, and 12 COPD, we measured peak cerebral blood flow velocity (...P; index of CBF), and ...E during two 5-min periods of acute isocapnic hypoxia, under conditions of 1) saline-sham; and 2) intravenous vitamin C. Antioxidants [vitamin C, superoxide dismutase (SOD), glutathione peroxidase, and catalase], oxidative stress [malondialdehyde (MDA) and advanced protein oxidation product], and nitric oxide metabolism end products (NOx) were measured in plasma. Following the administration of vitamin C, vitamin C, SOD, catalase, and MDA increased, while NOx decreased. ...P and ...E sensitivity to hypoxia was reduced in Older by ~60% (P < 0.02). COPD patients exhibited similar ...P and ...E responses to Older (P > 0.05). Vitamin C did not have an effect on the hypoxic ...E response but selectively decreased the ...P sensitivity in Younger only. These findings suggest a reduced integrative reflex (i.e., cerebrovascular and ventilatory) during acute hypoxemia in healthy older adults. Vitamin C does not appear to have a large influence on the cerebrovascular or ventilatory responses during acute hypoxia. [ABSTRACT FROM AUTHOR]