Inflammatory markers, lipids and metabolic hormones in lung transplant recipients with obstructive sleep apnea

Background The prevalence of obstructive sleep apnea (OSA) is high in patients after lung transplantation (LTX). OSA is associated with i) systemic inflammation and ii) metabolic dysfunction as indicated by levels of leptin, adiponectin, ghrelin, HDL, LDL and triacylglyceride (TAG). The aim of our ongoing prospective study was to compare markers of systemic inflammation and metabolic dysfunction in LTX patients with and without OSA. Methods Full in-lab polysomnography was performed in 40 clinically stable LTX recipients (≥6 months after transplantation) according to AASM standards. We compared the non-OSA group (apnea-hypopnea index (AHI) Results The OSA group included 15 patients (12 male, age 58.6±6.1yrs, BMI 28.1±4.2kg/m², AHI 45.0±24.6/h), and the non-OSA group comprised of 13 patients (5 male, age 47.3±12.5yrs, BMI 23.4±4.3kg/m², AHI 2.2±1.5/h). There was no difference in markers of systemic inflammation such as hs-CRP, IL-6, VCAM-1 and ICAM-1. Metabolic markers such as LDL (p=0.001), TAG (p=0.02) and HDL (p=0.01) were significantly increased in the OSA group. Adiponectin (3253±975vs.4787±2537ng/ml, p=0.058) and ghrelin (400±334vs.779±514pg/ml, p=0.009) were lower in the OSA group. Conclusion OSA did not increase systemic inflammation in stable LTX recipients. There was a profound metabolic dysbalance associated with OSA. The unexpected decrease of ghrelin in the OSA group requires further investigation.