Sleep apnea and risk of pneumonia: a nationwide population-based study

Abstract

Background: Evidence evaluating the risk of pneumonia in patients with obstructive sleep apnea is limited and mostly focuses on patients who receive continuous positive airway pressure (CPAP) therapy or on pediatric patients. We aimed to explore the risk of incident pneumonia among adults with sleep apnea, either with or without the need of CPAP therapy.

Methods: From Jan. 1, 2000, we identified adult patients with sleep apnea from the Taiwan National Health Insurance Research Database. A control cohort without sleep apnea, matched for age, sex and comorbidities, was selected for comparison. The 2 cohorts were followed until Dec. 31, 2010, and observed for occurrence of pneumonia.

Results: Of the 34,100 patients (6816 study patients and 27,284 matched controls), 2757 (8.09%) had pneumonia during a mean follow-up period of 4.50 years, including 638 (9.36%) study patients and 2119 (7.77%) controls. Kaplan-Meier analysis showed a higher incidence of pneumonia among patients with sleep apnea (log rank test, p < 0.001). After multivariate adjustment, patients with sleep apnea experienced a 1.20-fold (95% confidence interval 1.10-1.31) increase in incident pneumonia. The risk was even higher among patients who received CPAP therapy.

Interpretation: Sleep apnea appeared to confer a higher risk for future pneumonia, possibly in a severity-dependent manner.

Figure 1:

Kaplan–Meier curves showing a significant difference in cumulative incidences of pneumonia among patients with sleep apnea and controls.

Figure 2:

Multivariable analysis showing risk of pneumonia associated with patient characteristics and comorbidities. Values greater than 1.0 indicate an increased risk. CI = confidence interval, CKD = chronic renal disease, COPD = chronic obstructive pulmonary disease, GERD = gastroesophageal reflux disease, HR = hazard ratio.

Figure 3:

Detailed multivariable analysis showing risk of pneumonia associated with patient characteristics and comorbidities. Values greater than 1.0 indicate an increased risk. CI = confidence interval, CKD = chronic renal disease, COPD = chronic obstructive pulmonary disease, GERD = gastroesophageal reflux disease, HR = hazard ratio.