Study Title:

Abnormal mitochondria organization and oxidative activity in the palate muscles of long-term snorers with obstructive sleep apnea

Study Abstract

Background: Histopathological alterations and a reduced number of capillaries have been observed in the palate muscles of snorers with obstructive sleep apnea syndrome (OSAS). These changes may create a substrate for decreased microcirculation, impaired aerobic metabolism and muscle dysfunction and contribute to upper airway obstruction during sleep.

Objectives: The aim was to analyze mitochondria distribution and oxidative enzyme activity in relation to capillary supply in the palate muscles of patients with a history of long-term snoring and OSAS.

Methods: Palatopharyngeus (PP) and uvula (UV) muscle samples were obtained from 8 patients undergoing uvulopalatopharyngoplasty due to habitual snoring and OSAS. The muscles were analyzed with enzyme- and immunohistochemistry and morphometry.

Results: Abnormalities in the internal organization of mitochondria and oxidative activity were observed in 39 ± 15% of the fibers in the PP and 4 ± 3% in the UV, but not in control samples. The majority of these fibers had a lobulated contour and trabecular internal organization of mitochondria. The number of capillaries around abnormal fibers (PP 0.9 ± 0.3, UV 0.4 ± 0.1) was lower than in fibers of a normal appearance in both patients (PP 1.4 ± 0.6, UV 1.2 ± 0.3) and references (PP 2.7 ± 0.7, UV 1.9 ± 0.9) (p < 0.05).

Conclusions: Abnormal mitochondrial distribution, a low capillary supply and signs of impaired oxidative activity suggest that muscle dysfunction of the palate muscles in long-term snorers may contribute to the upper airway obstruction during sleep. The cause of these abnormalities remains unclear, but local muscle and nerve trauma due to vibration and stretch is a possible etiology.

Study Information

Respiration. 2012;83(5):407-17. doi: 10.1159/000336040. Epub 2012 Mar 1. PMID: 22378021.

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