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

Abstract

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.

Patterns of brain structural alteration in COPD with different levels of pulmonary function impairment and its association with cognitive deficits

“…The normal range for PaO 2 was defined as PaO 2 >80 mmHg; mild hypoxia was defined as 60 mmHg<PaO 2 ≤ 80 mmHg [18]. The normal range for SaO 2 was defined as SaO 2 >94%; mild hypoxia was defined as 90% ≤ SaO 2 ≤ 94% [19].…”

Cardiovascular outcomes in patients with COPD-OSA overlap syndrome: A systematic review and meta-analysis

“…Two studies, one using an AHI cut-off ≥ 5events/hr with symptoms [13] and one > 10events/hr [15] found a significantly increased risk of hypertension in the overlap population compared to the COPD population [OR=2.42, 95%CI 1.58-3.69) and OR 2.56, 95%CI 1.18-5.57 respectively]. While a remaining five studies [18,20,21,31,32] found no significant difference. Only one study investigated cardiovascular mortality [15] and found a significantly increased risk in patients with overlap compared to COPD patients (OR=2.81, 95%CI 1.40-5.64).…”

“…A total of 17 studies [11][12][13][14][15][16][17][18][19][20][21][22]29,[31][32][33][34] (n= 4580) looked at the prevalence of hypertension in the overlap population (Figure S2). Studies were heterogenous in terms of their AHI cut-off, with eight studies [11,12,16,17,22,29,33,34] using AHI ≥ 5events/hr (n=2000, pooled prevalence 57%, 95%CI 44%-71%); two [13,14] using AHI ≥ 5events/hr with symptoms (n=210, pooled prevalence 74%, 95%CI 68%-79%); two [15,21] using AHI > 10events/hr (n= 89, pooled prevalence 50%, 95%CI, 39%-60%); four [18][19][20]31] using AHI ≥ 15events/hr (n= 2267, pooled prevalence 60%, 95%CI 49%-71%) and one [32] using AHI ≥ 30events/hr (n= 14, pooled prevalence 64%, 95%CI 51%-66%).…”

“…Two studies [21,31] (n= 70) looked at the prevalence of pulmonary hypertension in the overlap population (Figure S5). The first study [21] had an AHI cut-off >10events/hr (n=56, prevalence 25%, 95%CI 16%-38%) and the second study [31] used an AHI cut-off ≥15events/hr (n=14, prevalence 18%, 95%CI 9%-265).…”

The impact of impaired sleep quality on symptom change and future exacerbation of chronic obstructive pulmonary disease

“…Compared with healthy control subjects, poor sleep quality is more frequent in COPD patients. The prevalence of sleep-disordered breathing is reported to be between 50% and 60% in patients with COPD [7,8]. The most common symptoms include sleep onset insomnia, nighttime awakenings, and sleep deprivation [9,10].…”