Cardiovascular Outcomes and All-Cause Mortality in Patients with Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease (Overlap Syndrome)
Bibliographic record
Abstract
Abstract Rationale The combined impact of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) on cardiovascular outcomes remains controversial. Objectives We determined whether the combined presence of COPD and severe OSA defined by the apnea–hypopnea index (AHI) or degree of nocturnal hypoxemia is associated with increased hazards of cardiovascular events and mortality. Methods Prospectively collected data from adults with suspected OSA who underwent sleep study between 1994 and 2010 were linked to provincial administrative data to determine a presence of COPD and composite outcome. Exposures of interest were: 1) AHI greater than 30, and 2) 10 or more minutes of sleep time spent with oxygen saturation (SaO2) less than 90%. The primary outcome was a composite of hospitalization due to myocardial infarction, stroke, congestive heart failure, cardiac revascularization procedures, or death from any cause. Using Cox regression and controlling for confounders, hazards were compared between four groups: AHI greater than 30 with COPD, AHI greater than 30 without COPD, AHI less than or equal to 30 with COPD, and AHI less than or equal to 30 without COPD (reference). A similar approach was used for the degree of nocturnal hypoxemia. Relative excess risk due to interaction (RERI) was calculated. To adjust for the effect of positive airway pressure treatment, given that information on its acceptance, but not adherence, was available, a separate analysis was conducted only on untreated individuals who never claimed a positive airway pressure device. Results Among 10,149 participants, 30% had AHI greater than 30, 25% spent at least 10 minutes of sleep with SaO2 less than 90%, and 12% had COPD. Over a median of 9.4 years, 16.4% developed an outcome. In the total sample, a greater hazard of outcome was observed in individuals with COPD who spent at least 10 minutes of sleep with SaO2 less than 90% (hazard ratio, 1.91; 95% confidence interval [CI], 1.60 to 2.28) but not with AHI greater than 30; a synergistic effect was found in women (RERI, 1.18; 95% CI, 0.05 to 2.30), but not men (RERI, −0.08; 95% CI, −0.47 to 0.32). The highest hazard of outcome was associated with the co-occurrence of AHI greater than 30 and COPD in untreated individuals (hazard ratio, 2.01; 95% CI, 1.55 to 2.62); a synergistic effect was not found. Conclusions In adults with suspected OSA, the co-occurrence of nocturnal hypoxemia and COPD was associated with an increased hazard of cardiovascular events and mortality with a synergistic effect found only in women.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".