Efeitos sistêmicos da hipoxemia noturna em pacientes com doença pulmonar obstrutiva crônica sem síndrome da apnéia obstrutiva do sono

Subjective sleep quality is associated with disease status in COPD patients. The cross-sectional Greek UNLOCK study

PURPOSE

The association of chronic obstructive pulmonary disease (COPD) severity and related health status with sleep quality remains unclear. We aimed to investigate the association between COPD and sleep quality in the Greek national branch of the UNLOCK cohort.

METHODS

A sample of 257 COPD patients enrolled cross-sectionally from primary care in Greece. Sleep quality was assessed by the COPD and Asthma Sleep Impact Scale (CASIS-7 items) questionnaire (higher score indicates worse sleep quality). We tested for associations of sleep impairment with health status (CAT and mMRC scores), exacerbations, hospitalizations, GOLD 2018 ABCD status, inhaler adherence, frailty, and sense of coherence, adjusting for age, gender, smoking status, and comorbidities.

RESULTS

The majority of patients reported uncontrolled symptoms (91% with ≥ 10 CAT or 61% with ≥ 2 mMRC). Mean (SD) age was 65 (12.3) with 79% males. CASIS-7 mean (SD) score was 37.7 (12.9). After adjustments, CASIS was significantly associated with worse health status (e.g., CASIS increased with CAT ≥ 10 [β = 12.53, (95% CI, 6.82, 18.25); p < 0.001], mMRC ≥ 2 [β = 4.96, (95% CI, 1.56, 8.34); p = 0.004]), COPD severity (CAT-based GOLD BD [β = 8.88 (95% CI, 2.50, 15.26); p = 0.007]), frailty [β = 8.85 (95% CI 4.45,13.25); p < 0.001], and sense of coherence [β = -0.14 (95% CI -0.21, -0.06), p < 001]. When using a CASIS cut-off score of 30 as indicator of sleep impairment, additional to the aforementioned associations, we found increased risk for sleep impairment with ≥ 2 exacerbations/year and poor inhaler adherence (p value < 0.05).

CONCLUSIONS

Our study suggests that worse health status and COPD severity are associated with poor sleep quality in COPD patients.

Effects of different modalities of inspiratory muscle training as an add-on to conventional treatment of patients with chronic obstructive pulmonary disease (COPD): study protocol for a randomized controlled trial

Background

Chronic obstructive pulmonary disease (COPD) leads to peripheral and respiratory muscle dysfunctions. Nowadays, inspiratory muscle training can be geared toward strength or endurance gains. This study aims to investigate the effects of an inspiratory muscle training (IMT) protocol using different therapeutic modalities to be implemented in pulmonary rehabilitation programs. The effects of IMT on exercise capacity were considered as the primary endpoint, and the effects of IMT on inspiratory muscle function, health-related quality of life, and daily physical activity level were considered as the secondary outcomes.

Methods

This study is a blinded-investigator randomized controlled clinical trial. Sixty subjects will be randomly allocated into three groups: (1) pulmonary rehabilitation (PR) associated with inspiratory muscle training without any load (PRWIMT), (2) PR associated with inspiratory muscle training with a linear load (PRIMTLL), and (3) PR associated with inspiratory muscle training with isocapnic voluntary hyperpnea (PRIMTIVH). The protocol will be performed 5 days a week (3 days with supervision) for 10 weeks. The study will assess anthropometric data, lung function, respiratory muscle strength, and functional capacity by the Incremental Shuttle Walking Test and the Six-Minute Walk Test, lung volumes during the submaximal endurance test, peripheral muscle strength of the upper and lower limbs, dyspnea, and quality of life related to health, before and after the training protocol. Normality will be tested using the Kolmogorov-Smirnov test, and variables will be compared by two-way analysis of variance. The significance level was set at p < 0.05. Ethics approval was obtained from the Institutional Ethics Committee in Research (1.663.411). The study results will be disseminated through presentation at specific scientific conferences and publication in peer-reviewed journals.

Discussion

The different IMT protocols used in our study will be able to guide respiratory therapists to understand and to include in conventional PR programs the most effective respiratory muscle training type in subjects with COPD.

Trial registration

Brazilian Clinical Trials Registry, RBR-94v6kd. Registered on 11 March 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3271-1) contains supplementary material, which is available to authorized users.

Sleep-disordered breathing in patients with COPD and mild hypoxemia: prevalence and predictive variables

OBJECTIVE:

To infer the prevalence and variables predictive of isolated nocturnal hypoxemia and obstructive sleep apnea (OSA) in patients with COPD and mild hypoxemia.

METHODS:

This was a cross-sectional study involving clinically stable COPD outpatients with mild hypoxemia (oxygen saturation = 90-94%) at a clinical center specializing in respiratory diseases, located in the city of Goiânia, Brazil. The patients underwent clinical evaluation, spirometry, polysomnography, echocardiography, arterial blood gas analysis, six-minute walk test assessment, and chest X-ray.

RESULTS:

The sample included 64 patients with COPD and mild hypoxemia; 39 (61%) were diagnosed with sleep-disordered breathing (OSA, in 14; and isolated nocturnal hypoxemia, in 25). Correlation analysis showed that PaO2 correlated moderately with mean sleep oxygen saturation (r = 0.45; p = 0.0002), mean rapid eye movement (REM) sleep oxygen saturation (r = 0.43; p = 0.001), and mean non-REM sleep oxygen saturation (r = 0.42; p = 0.001). A cut-off point of PaO2 ≤ 70 mmHg in the arterial blood gas analysis was significantly associated with sleep-disordered breathing (OR = 4.59; 95% CI: 1.54-13.67; p = 0.01). The model showed that, for identifying sleep-disordered breathing, the cut-off point had a specificity of 73.9% (95% CI: 51.6-89.8%), a sensitivity of 63.4% (95% CI: 46.9-77.9%), a positive predictive value of 81.3% (95% CI: 67.7-90.0%), and a negative predictive value of 53.1% (95% CI: 41.4-64.4%), with an area under the ROC curve of 0.69 (95% CI: 0.57-0.80), correctly classifying the observations in 67.2% of the cases.

CONCLUSIONS:

In our sample of patients with COPD and mild hypoxemia, the prevalence of sleep-disordered breathing was high (61%), suggesting that such patients would benefit from sleep studies.

OBJETIVO:

Inferir a prevalência e as variáveis preditivas de hipoxemia noturna e apneia obstrutiva do sono (AOS) em pacientes portadores de DPOC com hipoxemia leve.

MÉTODOS:

Estudo transversal realizado em pacientes ambulatoriais, clinicamente estáveis, portadores de DPOC e hipoxemia leve (saturação de oxigênio = 90-94%) em um centro clínico especializado no atendimento de doenças respiratórias em Goiânia (GO). Os pacientes foram submetidos à avaliação clínica, espirometria, polissonografia, ecocardiografia, gasometria arterial, teste de caminhada de seis minutos e radiografia de tórax.

RESULTADOS:

Foram avaliados 64 pacientes com DPOC e hipoxemia leve, e 39 (61%) apresentaram distúrbios respiratórios do sono (14 com AOS e 25 com hipoxemia noturna isolada). A análise de correlação mostrou moderada correlação da PaO2 com saturação média do sono (r = 0,45; p = 0,0002), saturação média do sono rapid eye movement (REM; r = 0,43; p = 0,001) e saturação média do sono não-REM (r = 0,42; p = 0,001). Um ponto de corte de PaO2 ≤ 70 mmHg (OR = 4,59; IC95%: 1,54-13,67; p = 0,01) na gasometria arterial foi significativamente associada com distúrbios respiratórios do sono. O modelo mostrou que, para identificar distúrbios respiratórios do sono, o ponto de corte teve uma especificidade de 73,9% (IC95%: 51,6-89,8%), uma sensibilidade de 63,4% (IC95%: 46,9-77,9%) e valores preditivos positivo e negativo de 81,3% (IC95%: 67,7-90,0%) e 53,1% (IC95%: 41,4-64,4%), respectivamente. A área sob a curva ROC foi de 0,69 (IC95%: 0,57-0,80), e a proporção de observações corretamente classificadas foi de 67,2% dos casos.

CONCLUSÕES:

A elevada prevalência de distúrbios respiratórios do sono em portadores de DPOC e hipoxemia leve nesta amostra (61%) sugere que esses pacientes podem se beneficiar da realização de estudos do sono.

Tiotropium Respimat Soft Mist Inhaler versus HandiHaler to improve sleeping oxygen saturation and sleep quality in COPD

PURPOSE

Patients with chronic obstructive pulmonary disease (COPD) have poor sleep quality as a result of various alterations in oxygenation parameters and sleep macro- and micro-architecture. There is a shortage of data to support the efficacy of long-acting inhaled anticholinergic agents in improving these adverse effects, which are known to have a negative impact on clinical outcomes. We aimed to compare the tiotropium Respimat Soft Mist Inhaler and the HandiHaler in terms of their effects on sleeping oxygen saturation (SaO2) and sleep quality in patients with COPD.

METHODS

In a randomized, open-label, parallel-group trial involving 200 patients with mild to moderate COPD (resting arterial oxygen tension >60 mmHg while awake), we compared the effects of 6 months' treatment with the two devices on sleeping SaO2 and sleep quality. Overnight polysomnography and pulmonary function testing were performed at baseline and after 6 months' treatment.

RESULTS

A total of 188 patients completed the trial. Both groups showed significant improvement in minimum sleep SaO2 and time of sleep spent with SaO2 below 90 (TST90) compared to baseline. The patients using the Respimat had significantly better TST90 than did those using the HandiHaler. Sleep disturbance was highly variable in these patients, but the sleep stage durations were significantly better in the Respimat group.

CONCLUSIONS

Sleeping SaO2 can be improved by tiotropium delivered using either the HandiHaler device or the Respimat Soft Mist Inhaler. However, the patients who used the Respimat device had significantly better TST90 and sleep architecture parameters.

Estimating glomerular filtration rate in older people

We aimed at reviewing age-related changes in kidney structure and function, methods for estimating kidney function, and impact of reduced kidney function on geriatric outcomes, as well as the reliability and applicability of equations for estimating glomerular filtration rate (eGFR) in older patients. CKD is associated with different comorbidities and adverse outcomes such as disability and premature death in older populations. Creatinine clearance and other methods for estimating kidney function are not easy to apply in older subjects. Thus, an accurate and reliable method for calculating eGFR would be highly desirable for early detection and management of CKD in this vulnerable population. Equations based on serum creatinine, age, race, and gender have been widely used. However, these equations have their own limitations, and no equation seems better than the other ones in older people. New equations specifically developed for use in older populations, especially those based on serum cystatin C, hold promises. However, further studies are needed to definitely accept them as the reference method to estimate kidney function in older patients in the clinical setting.

Sleep-induced hypoxaemia in patients with chronic obstructive pulmonary disease

Patients with moderate or severe chronic obstructive pulmonary disease run a high risk of developing sleep-induced hypoxaemia, because of alveolar hypoventilation and ventilation-perfusion mismatch. This article looks at the prevalence, significance and treatment of sleep-induced hypoxaemia in chronic obstructive pulmonary disease.

The effects of sleep hypoxia on coagulant factors and hepatic inflammation in emphysematous rats

Objectives

To develop a sleep hypoxia (SH) in emphysema (SHE) rat model and to explore whether SHE results in more severe hepatic inflammation than emphysema alone and whether the inflammation changes levels of coagulant/anticoagulant factors synthesized in the liver.

Methods

Seventy-five rats were put into 5 groups: SH control (SHCtrl), treated with sham smoke exposure (16 weeks) and SH exposure (12.5% O₂, 3 h/d, latter 8 weeks); emphysema control (ECtrl), smoke exposure and sham SH exposure (21% O₂); short SHE (SHEShort), smoke exposure and short SH exposure (1.5 h/d); mild SHE (SHEMild), smoke exposure and mild SH exposure (15% O₂); standard SHE (SHEStand), smoke exposure and SH exposure. Therefore, ECtrl, SHEShort, SHEMild and SHEStand group were among emphysematous groups. Arterial blood gas (ABG) data was obtained during preliminary tests. After exposure, hepatic inflammation (interleukin -6 [IL-6] mRNA and protein, tumor necrosis factor α [TNFα] mRNA and protein) and liver coagulant/anticoagulant factors (antithrombin [AT], fibrinogen [FIB] and Factor VIII [F VIII]) were evaluated. SPSS 11.5 software was used for statistical analysis.

Results

Characteristics of emphysema were obvious in emphysematous groups and ABGs reached SH criteria on hypoxia exposure. Hepatic inflammation parameters and coagulant factors are the lowest in SHCtrl and the highest in SHEStand while AT is the highest in SHCtrl and the lowest in SHEStand. Inflammatory cytokines of liver correlate well with coagulant factors positively and with AT negatively.

Conclusions

When SH is combined with emphysema, hepatic inflammation and coagulability enhance each other synergistically and produce a more significant liver-derivative inflammatory and prothrombotic status.

Cognition and chronic hypoxia in pulmonary diseases

Lung disease with chronic hypoxia has been associated with cognitive impairment of the subcortical type.