Abstract: Objective To investigate hypoxia inducible factor-1 alpha(HIF-1α)and vascular endothelial growth factor(VEGF)expression in the soft palate in patients with obstructive sleep apnea-hypopnea syndrome(OSAHS), and to explore the role of these factors in the pathogenesis of OSAHS. Methods Immunohistochemistry was used to detect HIF-1α and VEGF expression in the soft palate of 30 patients with OSAHS(experiment group)and six who had undergone tonsillectomy(control group). Results Hematoxylin-eosin staining of the soft palate revealed epithelial hyperplasia, thickening of the lamina propria, disordered muscle fibers in various stages of degeneration, and angiogenesis in the experimental group. Immunohistochemical staining revealed overexpression of HIF-1α in the nuclei and cytoplasm of cells in the squamous, epithelial, basal, and spinous layers, and strongly positive expression of VEGF in the cytoplasm of cells in the squamous, epithelial, basement, and stratum spinosum layers of the soft palate mucosa in patients with moderate to severe OSAHS. VEGF showed focal positive expression in glandular epithelial cells and vascular endothelial cells. HIF-1α and VEGF expression was positively correlated with the apnea-hypopnea index(P<0.05)and negatively correlated with the lowest nocturnal oxygen saturation(P<0.01). Conclusion Pathologic changes in the soft palate of patients with OSAHS were strongly correlated with the degree of hypoxia. HIF-1α and VEGF may play an important role in the development of OSAHS.

Key words: Soft palate, Hypoxia inducible factor-1 alpha, Vascular endothelial growth factor, Immunohistochemistry, Sleep apnea, obstructive