Korean J Otolaryngol-Head Neck Surg.  2002 May;45(5):473-478.

Distribution of Myosin Heavy Chain Isoforms in the Musculus Uvulae of Patients with Snoring and Obstructive Sleep Apnea Syndrome Using ATPase Staining Method

• Seo MC
• lee SH
• Kim JH

Abstract

BACKGROUND AND OBJECTIVES: OSAS is thought to be due to an excessive loss of muscle tone in the upper airway or an abnormal reflex regulation of upper airway function during sleep. The aim of this study was to investigate the distribution of myosin heavy chain (MHC) isoforms of musculus uvulae in OSAS and snorers.
Materials and Methods
Thirty seven patients included in the study underwent an uvulo-palato-pharyngoplasty (UPPP). All subjects had polysomnographic study before UPPP. ATPase stain at pH 9.4 were applied to muscle specimens obtained during UPPP. The numbers of MHC type I and II isoforms were counted. The patients were divided into three groups according to their repiratory disturbance index (RDI):mild (0-20), moderate (21-40), severe (>40). The differences in the distribution of muscle fiber types were compared between these groups. The correlation between the distribution of the fibers and the body mass index / age / RDI / minimum O2 saturation / duration of sleep apnea was investigated.
RESULTS
The mean percentages standard deviation of type I fibers according to the severity of sleep apnea were as follows:22.5+/-3.2% in mild sleep apnea group (n=5), 19.8+/-2.3% in moderate sleep apnea group (n=1), 17.5+/-3.6% in severe sleep apnea group (n=1). There were statistically significant differences in the distribution of MHC type I and II isoforms between mild group and moderate and / or severe group (p<0.05). There was statistically significant negative correlation between the proportion of type I fibers and RDI / duration of sleep apnea (p<.01). We could not find meaningful correlation between the proportion of MHC type I isoforms and body mass index / age of the patients (p>.05).
CONCLUSION
The proportion of MHC type I isoforms in musculus uvulae was decreased according to the severity and duration of sleep apnea (p<.01).

Keyword

Snoring; Obstructive sleep apnea syndrome; Uvula; Adenosinetriphosphatase; Myosin heavy chains

MeSH Terms

Adenosine Triphosphatases
Body Mass Index
Humans
Hydrogen-Ion Concentration
Myosin Heavy Chains*
Myosins*
Protein Isoforms*
Reflex, Abnormal
Sleep Apnea Syndromes
Sleep Apnea, Obstructive*
Snoring*
Uvula*
Adenosine Triphosphatases
Myosin Heavy Chains
Myosins
Protein Isoforms