Impact of obstructive sleep apnea on pulmonary hypertension in patients with chronic obstructive pulmonary disease

Abstract

Background: Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) syndrome are highly prevalent respiratory conditions. Their coexistence is referred to as the overlap syndrome. They are both related to pulmonary hypertension (PH) development. This study investigated the effects of OSA on PH in patients with COPD and the associated factors. Methods: Consecutive patients with stable COPD were recruited for an observational cross-sectional study from September 2016 to May 2018 at Peking University Third Hospital. In total, 106 patients with COPD were enrolled and performed home portable monitoring and echocardiography. OSA was defined by an apnea hypopnea index (AHI) ≥10 events/h. Based on OSA absence or presence, patients were divided into the COPD with OSA and COPD without OSA groups. Factors affecting pulmonary artery pressure (PAP) and PH were identified using univariate analysis and logistic regression models. Results: In the 106 patients with COPD, the mean age was 69.52 years, 91.5% were men, and the mean forced expiratory volume in 1 s (FEV 1 ) percentage of predicted was 56.15%. Fifty-six (52.8%) patients with COPD were diagnosed with OSA, and 24 (22.6%) patients with COPD were diagnosed as PH. Compared with COPD without OSA group, the median PAP in COPD with severe OSA group increased by 5 mmHg (36.00 [26.00–50.00] mmHg vs. 31.00 [24.00–34.00] mmHg, P = 0.036). COPD with percent of night-time spent with oxygen saturation below 90% (T90) > 10% group had higher PAP than COPD with T90 ≤ 1% group (36.00 [29.00–50.00)] mmHg vs. 29.00 [25.50–34.00] mmHg, F = 7.889, P = 0.007). Univariate analysis revealed age, FEV 1 % predicted, T90, and Charlson index had statistically significant effects on PH. Multiple regression analysis showed a significant and independent effect of both FEV 1 % predicted (odds ratio [OR] = 3.46; 95% confidence interval [CI]: 1.15–10.46; P = 0.028) and AHI (OR = 3.20; 95% CI: 1.09–19.35; P = 0.034) on PH. Conclusions: Patients with COPD with OSA are more susceptible to PH, which is associated with declining lung function and increased severity of OSA. Thus, nocturnal hypoxemia and OSA in elderly patients with COPD should be identified and treated.

The deleterious effects of chronic obstructive pulmonary disease and obstructive sleep apnea: pathophysiology and implications on treatment

“…In a recent study, authors from China examined 106 patients with COPD and found that pulmonary artery pressure (PAP) was increased by 5 mmHg in the group of patients with the OS (52.8%) compared with COPD only patients. The increase in PAP positively correlated with reduced mean SpO 2 levels during the night [21].…”

“…In contrast, other studies investigated the prevalence of the OS in OSA and COPD respectively with highly variable prevalence figures reported depending on the diagnostic techniques employed but with more than half of patients with COPD were found to have associated OSA [21,22]. In a cross-sectional study on a large number of patients, the OS was the final diagnosis in 12% of patients diagnosed with OSA [23].…”

Obstructive Sleep Apnea and Pulmonary Hypertension: A Review of Literature

“…A major study examining the prevalence of OSA was the 1993 Wisconsin Sleep Cohort Study, which found that OSA is prevalent in approximately 4% of men and 2% of women among the middle-aged population and increases with age [ 1 ]. The prevalence is thought to range from 28% to 72% in elderly men and 20% to54% in elderly women [ 7 ]. These numbers are rough estimates and thought to be falsely low given how often OSA is undiagnosed [ 2 ].…”

“…There are several factors that increase the risk of both PH and OSA, such as older age, obesity, left-sided heart disease, parenchymal lung disease, and nocturnal desaturation. The level of the pulmonary artery pressure correlates with the severity of OSA [5,[7][8][9][10].…”

Predictors and outcomes of obstructive sleep apnea in patients with chronic obstructive pulmonary disease in China: a cross-sectional study

“…Peripheral edema and emphysema have been reported to predict OSA, 13,14 but the predictive values of age, sex, body mass index (BMI), neck circumference, and smoking status remain controversial. 15,16 Further investigations are therefore needed to clarify the roles of these factors in predicting OSA. Furthermore, a better understanding of the important risk factors and clinical outcomes of patients with overlap syndrome in different geographical areas would help the relevant health authorities to implement targeted intervention strategies.…”