Analysis of Possible Predictors of Moderate and Severe Obstructive Sleep Apnea in Obese Patients

Objectives: To determine if there are clinical or anatomical differences between patients with grade II-IV obesity without obstructive sleep apnea (OSA) or mild OSA and patients with moderate or severe OSA and to assess whether any of these factors are predictive of moderate/severe OSA. Methods: Observational case-control study with consecutive sampling including patients between 18 and 65 years of age with grade II-IV obesity who were candidates for bariatric surgery. An anamnesis regarding OSA symptoms, a physical examination of the upper airway and a cardiorespiratory polygraphy were performed. Results: A total of 124 patients were included in the study, of whom 61.3% did not have OSA or had mild OSA and 38.7% had moderate or severe OSA. Age over 48 years was the only independent factor associated with moderate or severe OSA. Other factors showed a relation with moderate/severe OSA after multivariate analysis: male sex, STOP-BANG questionnaire ≥ 3, weight ≥ 105 kg, thick neck, neck circumference ≥ 41.25 cm, flaccid palate, Mallampati III-IV index, Friedman tongue position III-IV and retropalatal narrowing. Conclusions: The only independent predictive factor related to moderate or severe OSA in patients with morbid obesity was age over 48 years, therefore a sleep study remains essential for its diagnosis.