Predictors of obstructive sleep apnea in lung transplant recipients

Abstract

Background: The aim of our study was to determine the prevalence and clinical predictors of obstructive sleep apnea in lung transplantation recipients.

Methods: In a cross-sectional analysis we studied 77 clinically stable lung transplant recipients (45 men, time range after lung transplantation [LTX]: from one month to 15 years). Indications for LTX were 36 chronic obstructive lung disease (COPD), 27 idiopathic pulmonary fibrosis (IPF), eight cystic fibrosis, and six others. In-lab polysomnography (PSG) was performed to investigate sleep characteristics. Obstructive sleep apnea (OSA) and central sleep apnea were defined by an apnea-hypopnea index (AHI) ≥ 10/h.

Results: The prevalence of OSA and central sleep apnea (CSA) were 42.9% and 6.5%, respectively. OSA was present in 61% of patients with pre-transplant COPD and 52% of patients with pre-transplant IPF. Univariate analysis showed that OSA was significantly associated with neck circumference per 1-cm size increment (odds ratio [OR] = 1.21, 95% confidence interval [CI] = 1.04-1.42, p = 0.01) and pre-transplant COPD/IPF vs other lung diseases (cystic fibrosis, pulmonary arterial hypertension, α-1 antitrypsin deficiency, and lymphangioleiomyomatosis) (OR = 6.89, 95% CI = 1.41-33.56, p = 0.02), whereas age ≥57 years (OR = 1.76, 95% CI = 0.69-4.48, p = 0.24), male gender (OR = 2.33, 95% CI = 0.89-6.01, p = 0.08), and BMI ≥ 24.6 kg/m(2) (OR = 1.73, 95% CI = 0.68-4.40, p = 0.25) did not reach a level of statistical significance. In a multivariate analysis neck circumference per 1-cm size increment (OR = 1.20, 95% CI = 1.02-1.41, p = 0.025) and pre-transplant COPD/IPF (OR = 5.34, 95% CI = 1.01-28.13, p = 0.048) remained independently associated with OSA.

Conclusions: The prevalence of OSA is high in stable lung transplant recipients. Pre-transplant COPD is an independent predictor of OSA.

Keywords: Lung transplantation; Obstructive sleep apnea.