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BackgroundAlthough inhaled therapy reduces exacerbations among patients with COPD, the effectiveness of providing inhaled treatment per risk stratification models remains unclear.Research questionAre inhaled regimens that align with the 2017 Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy associated with clinically important outcomes?Study design and methodsWe conducted secondary analyses of Long-term Oxygen Treatment Trial (LOTT) data. The trial enrolled patients with COPD with moderate resting or exertional hypoxemia between 2009 and 2015. Our exposure was the patient-reported inhaled regimen at enrollment, categorized as either aligning with, undertreating, or potentially overtreating per the 2017 GOLD strategy. Our primary composite outcome was time to death or first hospitalization for COPD. Additional outcomes included individual components of the composite outcome and time to first exacerbation. We generated multivariable Cox proportional hazard models across strata of GOLD-predicted exacerbation risk (high vs low) to estimate between-group hazard ratios for time to event outcomes. We adjusted models a priori for potential confounders, clustered by site.ResultsThe trial enrolled 738 patients (73.4% men; mean age, 68.8 years). Of the patients, 571 (77.4%) were low risk for future exacerbations. Of the patients, 233 (31.6%) reported regimens aligning with GOLD recommendations; most regimens (54.1%) potentially overtreated. During a 2.3-year median follow-up, 332 patients (44.9%) experienced the composite outcome. We found no difference in time to composite outcome or death among patients reporting regimens aligning with recommendations compared with undertreated patients. Among patients at low risk, potential overtreatment was associated with higher exacerbation risk (hazard ratio, 1.42; 95% CI, 1.09-1.87), whereas inhaled corticosteroid treatment was associated with 64% higher risk of pneumonia (incidence rate ratio, 1.64; 95% CI, 1.01-2.66).InterpretationAmong patients with COPD with moderate hypoxemia, we found no difference in clinical outcomes between inhaled regimens aligning with the 2017 GOLD strategy compared with those that were undertreated. These findings suggest the need to reevaluate the effectiveness of risk stratification model-based inhaled treatment strategies.

RationaleCharacteristics associated with adherence to long-term oxygen therapy (LTOT) in COPD remain unclear.ObjectivesTo identify patient characteristics at the time of oxygen initiation associated with its adherence.MethodsWe conducted a secondary analysis of data from 359 COPD participants assigned to oxygen in the Long-term Oxygen Treatment Trial. Participants were prescribed continuous (n = 214) or intermittent (n = 145) oxygen based on desaturation patterns at study entry. At the time of initial prescription, participants rated their perceived readiness, confidence, and importance to use oxygen on a 0-10 scale (0 = not at all, 10 = very much). During follow-up, they self-reported average hours per day of use (adherence). Adherence was averaged over short-term (0-30 days), medium-term (months 9-12), and long-term (month 13 to last follow-up) intervals. Multivariable logistic regression models explored characteristics associated with high adherence (≥16 h/day [continuous] or ≥8 h/day [intermittent]) during each time interval.ResultsParticipant readiness, confidence, and importance at the time of oxygen initiation were associated with high short- and medium-term adherence. For each unit increase in baseline readiness, the odds of high short-term adherence increased by 21% (odds ratio [OR] 1.21, 95% confidence interval [CI] 1.05-1.40) and 94% (OR 1.94, 95% CI 1.45-2.59) in the continuous and intermittent groups, respectively. In both groups, high adherence in the medium-term was associated with high adherence in the long-term (continuous, OR 12.49, 95% CI 4.90-31.79; intermittent, OR 38.08, 95% CI 6.96-208.20).ConclusionsReadiness, confidence, and importance to use LTOT at initiation, and early high adherence, are significantly associated with long-term oxygen adherence.

The Long-Term Oxygen Treatment Trial demonstrated that long-term supplemental oxygen did not reduce time to hospital admission or death for patients who have stable chronic obstructive pulmonary disease and resting and/or exercise-induced moderate oxyhemoglobin desaturation, nor did it provide benefit for any other outcome measured in the trial. Nine months after initiation of patient screening, after randomization of 34 patients to treatment, a trial design amendment broadened the eligible population, expanded the primary outcome, and reduced the goal sample size. Within a few years, the protocol underwent minor modifications, and a second trial design amendment lowered the required sample size because of lower than expected treatment group crossover rates. After 5.5 years of recruitment, the trial met its amended sample size goal, and 1 year later, it achieved its follow-up goal. The process of publishing the trial results brought renewed scrutiny of the study design and the amendments. This article expands on the previously published design and methods information, provides the rationale for the amendments, and gives insight into the investigators' decisions about trial conduct. The story of the Long-Term Oxygen Treatment Trial may assist investigators in future trials, especially those that seek to assess the efficacy and safety of long-term oxygen therapy. Clinical trial registered with clinicaltrials.gov (NCT00692198).

BackgroundLong-term treatment with supplemental oxygen has unknown efficacy in patients with stable chronic obstructive pulmonary disease (COPD) and resting or exercise-induced moderate desaturation.MethodsWe originally designed the trial to test whether long-term treatment with supplemental oxygen would result in a longer time to death than no use of supplemental oxygen among patients who had stable COPD with moderate resting desaturation (oxyhemoglobin saturation as measured by pulse oximetry [Spo2], 89 to 93%). After 7 months and the randomization of 34 patients, the trial was redesigned to also include patients who had stable COPD with moderate exercise-induced desaturation (during the 6-minute walk test, Spo2 ≥80% for ≥5 minutes and

IntroductionThe disease spectrum for HIV-infected individuals has shifted toward comorbid non-AIDS conditions including chronic lung disease, but quantitative image analysis of lung disease has not been performed.ObjectivesTo quantify the prevalence of structural changes of the lung indicating emphysema or fibrosis on radiographic examination.MethodsA cross-sectional analysis of 510 HIV-infected participants in the multicenter Lung-HIV study was performed. Data collected included demographics, biological markers of HIV, pulmonary function testing, and chest computed tomographic examinations. Emphysema and fibrosis-like changes were quantified on computed tomographic images based on threshold approaches.ResultsIn our cohort, 69% was on antiretroviral therapy, 13% had a current CD4 cell count less than 200 cells per microliter, 39% had an HIV viral load greater than 500 copies per milliliter, and 25% had at least a trace level of emphysema (defined as >2.5% of voxels

ObjectiveHIV-infected individuals are susceptible to development of chronic lung diseases, but little is known regarding the prevalence and risk factors associated with different spirometric abnormalities in this population. We sought to determine the prevalence, risk factors and performance characteristics of risk factors for spirometric abnormalities among HIV-infected individuals.DesignCross-sectional cohort study.MethodsWe analyzed cross-sectional US data from the NHLBI-funded Lung-HIV consortium - a multicenter observational study of heterogeneous groups of HIV-infected participants in diverse geographic sites. Logistic regression analysis was performed to determine factors statistically significantly associated with spirometry patterns.ResultsA total of 908 HIV-infected individuals were included. The median age of the cohort was 50 years, 78% were men and 68% current smokers. An abnormal spirometry pattern was present in 37% of the cohort: 27% had obstructed and 10% had restricted spirometry patterns. Overall, age, smoking status and intensity, history of Pneumocystis infection, asthma diagnosis and presence of respiratory symptoms were independently associated with an abnormal spirometry pattern. Regardless of the presence of respiratory symptoms, five HIV-infected participants would need to be screened with spirometry to diagnose two individuals with any abnormal spirometry pattern.ConclusionsNearly 40% of a diverse US cohort of HIV-infected individuals had an abnormal spirometry pattern. Specific characteristics including age, smoking status, respiratory infection history and respiratory symptoms can identify those at risk for abnormal spirometry. The high prevalence of abnormal spirometry and the poor predictive capability of respiratory symptoms to identify abnormal spirometry should prompt clinicians to consider screening spirometry in HIV-infected populations.

Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO2 condition. In the control group with no PO2 cycling, intracellular ROS formation did not appear during the first 15 min of the low PO2 period. However, after 20 min of low PO2, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO2 condition. Conversely, muscles treated with PO2 cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO2 period. Furthermore, PO2 cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO2 period compared to control. Thus, our data suggest that PO2 cycling mitigates diaphragm fatigue during prolonged low PO2. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO2 cycling initiates ROS-related antioxidant defenses.

IntroductionPrior studies comparing abnormalities in pulmonary function between HIV-infected and HIV-uninfected persons in the current era are limited.ObjectivesTo determine the pattern and severity of impairment in pulmonary function in HIV-infected compared with HIV-uninfected individuals.MethodsCross-sectional analysis of 300 HIV-infected men and 289 HIV-uninfected men enrolled from 2009 to 2011 in 2 clinical centers of the Lung HIV Study. Participants completed pre- and postbronchodilator spirometry, diffusing capacity of the lung for carbon monoxide (DLCO) measurement, and standardized questionnaires.ResultsMost participants had normal airflow; 18% of HIV-infected and 16% of HIV-uninfected men had airflow obstruction. The mean percent predicted DLCO was 69% in HIV-infected vs. 76% in HIV-uninfected men (P < 0.001). A moderately to severely reduced DLCO of ≤60% was observed in 30% of HIV-infected compared with 18% of HIV-uninfected men (P < 0.001), despite the fact that 89% of those with HIV were on antiretroviral therapy. A reduced DLCO was significantly associated with HIV and CD4 cell count in linear regression adjusting for smoking and other confounders. The DLCO was lowest in HIV-infected men with CD4 cell counts

A wrist actigraph is a device used in sleep research studies to measure whole body movements. The purpose of this study was to evaluate the feasibility, sensitivity, and validity of wrist actigraphy during pulmonary rehabilitation (PR) upper-extremity exercise in chronic obstructive pulmonary disease (COPD) patients. In this study, 20 patients wore Octagonal Basic Motionlogger[R] actigraphs during two 90-minute PR sessions while the investigator recorded details of the subject's upper-extremity movements. Concurrent validity with supervised exercise records was supported for upper-extremity endurance (UEE) intensity at baseline (r = .885, p < .001) and l week (r = .935, p < .001). Criterion validity was supported for UEE (r = .56, p = .01) and combined lower- and upper-extremity resistance (r = .72, p < .01) compared with rank-ordered type of exercise. Wrist actigraphy is shown to be a feasible, sensitive, and valid instrument to measure upper-extremity movement during PR in COPD patients. Keywords: lung disease; obstructive; therapy; exercise; wrist actigraphy