Obstructive sleep apnea and influenza infection

Objectives: Influenza infection could trigger acute myocardial infarction. Obstructive sleep apnea (OSA) increases risk for myocardial infarction. Evidence evaluating the risk of influenza in patients with OSA is limited. We aimed to investigate the association between OSA and influenza using a nationwide population-based data set. Methods: A total of 5483 individuals with OSA were enrolled from January, 2000, to December, 2012, and compared with a control group of 21,932 individuals who had never been diagnosed with OSA (at a 1:4 ratio propensity score matched by age, sex, index years, and comorbidities) in the context of subsequent influenza infection. Cox proportional hazard regression analysis was conducted to analyze the association between OSA and influenza incidence. We conducted sensitivity analyses to examine our finding. Results: During the 1.81 (±2.12) years of the follow-up period, the incidence rate of influenza infection was higher in the OSA group compared with the non-OSA group (36.40 and 30.09 per 100 person-years). After adjusting for age, sex, comorbidities, outpatients visits, the risk of influenza infection among patients with OSA was significantly higher (hazard ratio = 1.18; 95% confidence interval = 1.14–1.23; P < 0.001). Sensitivity analyses showed consistent positive association. Males with OSA had increased risk of influenza infection compared with males without OSA (adjusted HR, 1.21; 95% CI, 1.16–1.27; P value for interaction = 0.03). Conclusions: This study found a significantly higher risk of influenza infection in patients with OSA, and sex acted as an effect modifier between OSA and risk of influenza infection.