Scalloped tongue: a clinical sign of severe obstructive sleep apnea?

<bold>Introduction:</bold> The volume of the tongue can influence the risk of developing obstructive sleep apnea (OSA). However, there is limited evidence supporting the link between scalloped tongue (ST) and nocturnal intermittent hypoxia. This study aimed to investigate if ST could serve as a clinical indicator of OSA, particularly severe OSA. <bold>Materials and Methods:</bold> Over a 4-month period from October 2023 to January 2024, 160 patients underwent level 1 polysomnography (PSG) at a sleep laboratory in Rio de Janeiro. Demographics, body mass index (BMI), neck circumference (NC), presence of ST, Epworth Sleepiness Scale score, apnea hypopnea index, oxygen desaturation index (ODI) and time under 90% of oxygen saturation were included in a database. Logistic and multiple linear regression models were performed. A p-value <0.05 was considered as the lower threshold of significance. <bold>Results:</bold> Most (90%) patients had OSA, with 41% classified as severe. Older age and a wider NC significantly increased the risk of OSA. Older age, higher BMI and ST significantly increased the risk of severe OSA (OR 2.844, p=0.009), and there was a statistically significant positive linear correlation between the presence of ST and ODI (p=0.001). For each additional year of age, ODI increased 0.34/h while the presence of ST increased ODI by 6.72/h. The combined presence of NC ≥ 40cm and ST significantly increased the risk of severe OSA (OR 3.717 [1.698-8.136], p=0.001). <bold>Conclusion:</bold> Our findings suggest that the presence for ST increases the likelihood of severe OSA among OSA patients. Adding tongue assessment to NC observation, both objective and easily observable clinical signs, should be considered in OSA screening.