Serum of obstructive sleep apnea patients impairs human coronary endothelial cell migration

INTRODUCTION Endothelial cell migration and proliferation play an important role in the growth and development of new blood vessels and endothelium healing. This process occurs in response to injury, inflammation and immune reactions. Dysfunction of the endothelium may play a significant role in development and progression of cardiovascular disease related to sleep-disordered breathing. The aim of our study was to evaluate the chemo-attractant activity of serum from obstructive sleep apnea (OSA) and normal subjects on coronary artery endothelial cell migration. MATERIAL AND METHODS We studied 12 severe OSA patients, free of other co-morbidities and on no treatment, along with 12 age-, body mass index, and gender matched healthy controls. Blood was collected at three time points: at 21:00 before sleep, at 6:00 after waking from sleep, and at 11:00 (after 5 h of normal daytime activity). Serum chemo-attractant activity for human coronary endothelial cells was assessed using a colorimetric cell migration assay kit. RESULTS In healthy subjects, serum chemo-attractant activity peaked in the morning after waking from sleep (p = 0.02). This early morning increase was blunted in severe OSA subjects, in whom chemo-attractant activity was weaker than in normal controls (p = 0.02), and did not change significantly at the different time-points (p < 0.001 vs. controls). CONCLUSIONS Chemo-attractant activity of the serum from OSA patients is lower compared to serum from healthy subjects, especially in the morning. Altered chemo-attractant serum activity may conceivably contribute to the impairment of endothelial function in obstructive sleep apnea patients.