Background and Objectives: Sleep related obstructive breathing disorders are frequently observed in adults. Despite extensive work of recent years, the essential pathophysiologic mechanism that mediates this process is still unclear. This study
was
conducted to determine whether distribution of connective tissue in the uvula is different among apneics, snorers and normal controls. Materials & Methods: Uvula was obtained by uvulopalatopharyngoplasty in 8 apneics, 6 snorers(mean apnea index:
17.1,
2.43 respectively) and by autopsy in 5 individuals not known to have snoring. The surgical specimen of uvula was fixed in 10% formalin and subsequently embedded in paraffin. Each specimen was cut into 5 ㎛-thick section and stained with
hematoxylin-eosin for general appearance, Masson-Trichrome stain for collagen fiber, and Verhoeff stain for elastic fiber. Microscopic examination was performed by two pathologists who were blinded to the polysomnographic data. Results:
Infiltration of
inflammatory cells and edema were significantly increased in the snorer and apneic groups compared with the control group(p<.0001, p<.05 respectively). Compared with the normal group, the density of elastic fibers and collagen fibers were
significantly
decreased in snorers and apneics(elastic fiber: p<.0005, collagen fiber: p<.01). The distribution of elastic and collagen fiber showed significantly heterogeneous patterns in the snorer and apneic group compared to the control group (elastic
fiber:
p<0.001, collagen fiber: p<0.0005). Conclusion: Since connective tissue fibers have the supportive function in the body, this condition may result in increased collapsibility of upper airway and contributes to the development of obstructive sleep
apnea.
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