Abstract: Objective  To study the changes of endothelial progenitor cells in peripheral blood of patients with obstructive sleep apnea hypopnea syndrome（OSAHS）.
  Methods  A prospectivestudy of 30 obstructive sleep apnea hypopnea syndrome patients were selected in the department of otolaryngology, the first hospital of Hebei Medical University. Thirty healthy subjects were selected as control group. Monocytes were obtained from 10 mL of venous blood by density gradientcentrifugation, Endothelial progenitor cells(EPCs）were cultured and identified byfluorescence microscopy. The number, migration, proliferation and adhesion of EPCs in two groups were evaluated.
  Results  The number of proliferating cells, migratingcellsand adheringrate  in the normal control group were significantlyhigher than those in the OSAHS group(P＜0.05).
  Conclusion  The number of endothelial progenitorcells in OSAHS patients with hard plaque is small, and their proliferation, migration andadhesion ability are impaired.

Key words: sleep apnea, obstructive, endothelial cells, cell adhesion