Tonsil volume, tonsil grade and obstructive sleep apnea: is there any meaningful correlation?

OBJECTIVES: The aims of this study were to evaluate the correlation between oropharyngeal examination and objective palatine tonsil volume in snoring adults and verify the influence of the oropharyngeal anatomy, body mass index, age, and severity of obstructive sleep apnea on actual tonsil volume. In addition, we aimed to assess the influence of tonsil size on obstructive sleep apnea in adults. INTRODUCTION: Pharyngeal wall geometry is often altered in adults who have obstructive sleep apnea, and this might influence the findings of the oropharyngeal examination that, in turn, are the key factors when considering surgical management for this condition. Furthermore, the correlation between the actual tonsil volume and the severity of obstructive sleep apnea in adults is currently unknown. METHODS: We prospectively studied 130 patients with obstructive sleep apnea or primary snoring who underwent pharyngeal surgery with intraoperative measurement of tonsil volume. We compared tonsil volume with preoperative polysomnography, oropharyngeal examination, and anthropometric data. RESULTS: We found a significant correlation between actual tonsil volume and subjective tonsil grade. We also found a significant correlation between tonsil volume and the apnea-hypopnea index. Using a multivariate linear regression model, tonsil volume was found to be significantly correlated with age, body mass index, and oropharyngeal examination, but not with polysomnography. Clinically, only the rare tonsil grade IV was indicative of more severe obstructive sleep apnea. CONCLUSIONS: There is a strong correlation between clinical tonsil grade and objective tonsil volume in snoring adults, and this correlation exists regardless of the presence or severity of obstructive sleep apnea. Pharyngeal tissue volume likely reflects the body mass index rather than obstructive sleep apnea severity.

Avaliação do papel da matriz extracelular na musculatura da parede lateral da faringe na fisiopatologia da síndrome da apnéia obstrutiva do sono / Extracellular matrix of the lateral pharyngeal wall in obstructive sleep apnea syndrome

A parede lateral da faringe parece ser a estrutura central envolvida no colapso da faringe nos pacientes com síndrome da apnéia obstrutiva do sono (SAOS). Os pacientes com roncos e apnéia têm uma faringe mais colapsável associada a um espessamento da musculatura da parede lateral da faringe, em grande parte formada pelo músculo constritor superior da faringe. O endomísio da matriz extracelular do músculo esquelético tem uma íntima relação com as células musculares, influenciando suas propriedades mecânicas e biológicas, podendo modificar seu comportamento e função. As fibras colágenas e elásticas formam o arcabouço do tecido conectivo, enquanto os proteoglicanos e as glicoproteínas estruturais (fibronectina) têm importante papel na propriedade de adesão e hidratação dos tecidos e as metaloproteínas são responsáveis pela degradação dos componentes da matriz extracelular. Os fatores determinantes da complacência excessiva da musculatura da parede lateral são desconhecidos. É possível que a MEC tenha um papel relevante neste aspecto. O objetivo deste estudo é descrever e comparar a densidade dos componentes da matriz extracelular do endomísio da musculatura da parede lateral da faringe em controles, roncadores e apnéicos. Neste estudo prospectivo foram avaliados 61 pacientes maiores de 18 anos e não obesos do Departamento de Otorrinolaringologia do Hospital das Clínicas da Faculdade de medicina da Universidade de São Paulo, com indicação de cirurgias faríngeas no período de 2005 e 2006. Os pacientes foram divididos em três grupos: controles (14 pacientes sem roncos ou SAOS), 18 roncadores primários e 29 pacientes com SAOS...

The lateral muscular pharyngeal wall appears to be the predominant structure involved in the collapse of the pharynx in obstructive sleep apnea (OSA). OSA patients and snorers have a narrower pharynx which is more susceptible to collapse and is associated with muscle thickening in the lateral pharyngeal wall, largely formed by superior pharyngeal constrictor. The endomysial extracellular matrix of skeletal muscle has an intimate relationship with the muscle cells and has an important influence on its mechanical and biological properties and can modify their behavior and function. Collagen and elastic fibers form the scaffolding of the connective tissue and proteoglycans and structural glycoproteins (fibronectin) have important roles in hydration, resiliency and adhesive properties of the tissues and the matrix metalloproteinases are involved in extracellular matrix components degradation. The determining factors in the compliance of lateral muscular pharyngeal wall are also unknown. It is possible that the ECM has a relevant role in this aspect. Our objective was to determine and compare the density of the components of the extracellular matrix in the deep, structural lateral pharyngeal muscular walls in snorers, OSA and control patients and correlate with age and weight. In this prospective study we evaluated 61 patients older than 18 and nonobese with indications for pharyngeal surgery at the department of Otolaryngology of the Hospital das Clínicas of the São Paulo University, between 2005 and 2006. The patients were divided in three groups: controls (14 patients), 18 primary snorers and 29 OSA patients. We obtained specimens from the lateral pharyngeal muscular wall (superior constrictor muscle) during pharyngeal surgeries...