[Clinical study on oropharyngeal fatty infiltration on the pathogenesis of obstructive sleep apnea syndrome].
OBJECTIVE
To detect the effect of lipid metabolism, fatty infiltration of oropharyngeal tissues in the subjects with obstructive sleep apnea syndrome (OSAS) and its pathogenesis.


METHODS
Nineteen subjects in OSAS group and 9 subjects in controlled group were chosen. The related clinical index including the size and weight of uvula in two groups were measured. Each composition of uvular tissue section (transverse section) in all subjects was measured by quantitative, morphometric image analysis technique. The uvular tissue sections were evaluated by light microscope (LM), 4 of them by transmission electron microscope (TEM).


RESULTS
1. Subjects in OSAS group significantly had a greater body mass index, neck circumference, waist circumference, waist-to-hip circumference ratio (WHR), weight and size of uvula than those in controlled group. There were significant differences in TC, TG, LDL and TC/HDL between the two groups. 2. A significant difference in percentage of fat, muscle, fibrous tissue in uvula was also founded between the two groups. The serial tissue section of uvula in LM showed that there was excessive fatty infiltration that prominently founded in fibrous tissue and secondarily in muscle. And muscle fibers with partial atrophy and/or hypertrophy were prominent. We also detected that fibrous tissue and muscle fibers arranged in a disordered way. The uvula myofibril in TEM showed focal or spotted rough and deformity of Z line, sarcomere loss and vacuolation. Lipid droplet infiltration was also detected in adjoin of myofibril. 3. The degree of fatty infiltration of uvular tissue correlated with neck circumference, WHR, weight and size of uvula, TC and TC/HDL in two groups, and also had positive correlation with degree of OSAS recorded by AHI in OSAS group.


CONCLUSIONS
The results suggested that lipid metabolic disorder might exist in subjects with OSAS. And abundant oropharyneal fatty infiltration might be an important role in pathogenesis of OSAS that possibly contributed to change the size and shape of pharyngeal airway and compliance of pharyngeal wall.
Zhou
Benzhong
B
Department of Otorhinolaryngology, 105th Hospital of PLA, Hefei 230031.
Ji
Changyou
C
Zhou
Dingrong
D
D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000886:Anthropometry; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000150:complications; D050356:Lipid Metabolism; D008297:Male; D008875:Middle Aged; D009960:Oropharynx / Q000473:pathology*; D020181:Sleep Apnea, Obstructive / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D014609:Uvula / Q000473:pathology