Predictors of obstructive sleep apnea in lung transplant recipients

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

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.

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.

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