Abstract
Study objectives: To investigate the fiber-type distribution in palatopharyngeal muscle via adenosine triphosphatase and quantitative real-time polymerase chain reaction in children with severe obstructive sleep apnea (OSA). Methods: Study participants were 12 children with severe OSA and 15 children with simple snoring as the control group. Both groups were diagnosed by polysomnography and treated with tonsillectomy. The samples of palatopharyngeus muscle were studied under adenosine triphosphatase staining and quantitative real-time polymerase chain reaction to classify the different fiber types. Results: There were no differences in baseline age, body mass index, tonsil size, or sleep stage constitution between the 2 groups. Dominance (>60%) of type I fiber was observed both in children with simple snoring (3/15, 20%) and in those with severe OSA (1/12, 8.3%) via adenosine triphosphatase staining. Predominance of type II fibers was seen in 3/15 (20%) in the control group and 6/12 (50%) in the severe OSA group, respectively. Type grouping was also seen in 8/15 (53.3%) in non-OSA and 6/12 (50%) in severe OSA groups, respectively. There was no difference in distribution of subtype fibers assessed by quantitative real-time polymerase chain reaction between the 2 groups; the mean percentages of type I fibers were 25.8% ± 19.5% and 20.9% ± 16.6%, respectively (P > .05), similar to type IIa fibers (35.2% ± 23.4% and 40.9% ± 28.8%) (P > .05). There was a decrease in the percentage of type I fibers between children younger and older than 12 years (P < 0.05), although this was not due to OSA (P > 0.05). Conclusions: There were no specific changes via adenosine triphosphatase staining or a difference in distribution of subtype fibers via quantitative real-time polymerase chain reaction between children with severe pediatric OSA and those with simple snoring, whereas the percentage of type I fiber decreased dynamically due to age but not OSA. Clinical trial registration: Registry: Chinese Clinical Trials Registry; Name: A study of the mechanism of the conversion of upper airway expasion muscle's fiver types of OSA patient which may be mediated by estrogen-related receptor alpha; URL: https://www.chictr.org.cn/showproj.aspx?proj=6144; Identifier: ChiCTR-CCC-13003415.