Parapharyngeal Fat Pads as an Obesity-Related Parameter for Apnea-Hypopnea Index Severity.

In this study, the association between obstructive sleep apnea severity and the parapharyngeal fat pad volume is examined in a population-based sample. We included 680 participants who underwent standardised overnight polysomnography between 2008 and 2012 as part of the Study of Health in Pomerania in a sleep laboratory in Greifswald, Germany. The apnea-hypopnea index was used as a marker of obstructive sleep apnea severity and the parapharyngeal fat pad volume, as our variable of interest, was analysed based on Magnetic Resonance Imaging data by automated image segmentation. We performed an ordinal logistic regression analysis to test the effect of parapharyngeal fat pad volume on apnea-hypopnea index, controlling for body-mass index as a confounder. The results indicated that greater parapharyngeal fat volume was associated with a higher apnea-hypopnea index in an unadjusted analysis. After adjustment for body-mass index, this association was no longer significant. An exploratory body-mass index-stratified analysis suggested that the association between parapharyngeal fat volume and apnea-hypopnea index may be present primarily in non-obese individuals. These findings highlight the importance of considering body-mass index as a measure for overall obesity when evaluating the specific role of parapharyngeal fat in obstructive sleep apnea.