Systematic Evaluation of the Upper Airway in a Sample Population: Factors Associated with Obstructive Sleep Apnea Syndrome.

OBJECTIVES

To investigate the anatomy of the upper airway (UA) of a representative sample of the adult population of São Paulo city, Brazil, and to identify factors associated with the presence of obstructive sleep apnea syndrome (OSAS), as confirmed using full-night polysomnography (PSG).

STUDY

DESIGN

Cross-sectional study.

SETTING

Population-based sample.

METHODS

A 3-stage sampling procedure was used to proportionally recruit adult residents of São Paulo city according to gender, age, and socioeconomic status. A complete evaluation was performed, including a systematic evaluation of the UA prior to conducting PSG.

RESULTS

Nine-hundred ninety-three (90.2%) of the participants were seen by an ear, nose, and throat (ENT) specialist. Individuals who were diagnosed with OSAS (32.9%) presented a higher frequency of nasal symptoms and structural abnormalities (both nasal and oropharyngeal) compared with those without OSAS. No anatomical differences were observed in the facial skeleton. An abnormal nasal structure visible via anterior rhinoscopy was the only UA factor predicting OSAS after adjustments for the other common OSAS risk factors (male sex, aging, obesity, and increased neck circumference).

CONCLUSION

This is the first study in which a systematic evaluation of the UA was followed by a sleep study in a population-based sample. In a sample of the general population that had not previously been screened for OSAS, having an abnormal nasal structure was found to be a risk factor for OSAS, in conjunction with other well-established clinical and demographic factors, such as male gender, increased age, increased neck circumference, and body mass index.