Assessment of Abdominal Adiposity in Obstructive Sleep Apnea using PET/MRI: Impact of Short-Term CPAP.
Authors
Affiliations (7)
Affiliations (7)
- Divison of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Icahn School of Medicine at Mount Sinai.
- Division of General Internal Medicine, Department of Medicine, Icahn School of Medicine at Mount Sinai.
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai.
- School of Biomedical Engineering, Faculty of Engineering, Tel-Aviv University.
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai; School of Biomedical Engineering, Faculty of Engineering, Tel-Aviv University.
- Center for Biostatistics, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai.
- Divison of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Icahn School of Medicine at Mount Sinai. Electronic address: [email protected].
Abstract
Obesity is a major risk factor for obstructive sleep apnea (OSA), and visceral adiposity may mediate its cardiometabolic consequences. However, studies evaluating the impact of continuous positive airway pressure (CPAP) on visceral obesity have yielded conflicting results. What is the relationship between OSA and visceral adipose tissue (VAT) volume and metabolic activity, and how does short-term CPAP effect these measures? Adults with newly-diagnosed, moderate-to-severe OSA underwent [<sup>18</sup>F]-Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) before and after short-term CPAP. Using a novel deep-learning approach to segment abdominal adipose compartments, we quantified adipose volumes and metabolic activity using standardized-uptake values (SUVmean). The primary outcome was VAT SUVmean. Secondary outcomes included VAT and subcutaneous adipose tissue (SAT) volume, and VAT/SAT volume ratio. Associations between OSA severity and adipose metrics, and CPAP effects, were assessed using multivariable regression and linear mixed-effects models. Among 134 participants, OSA severity was not associated with increased VAT SUVmean in adjusted analyses (p=0.70) and CPAP did not significantly alter VAT metabolic activity after 3 months (p=0.66). A modest reduction in VAT/SAT volume ratio (p=0.03) was observed following CPAP, despite no changes in weight or total abdominal adipose tissue volume. While CPAP did not affect VAT volume (p=0.09) overall, we observed a significant reduction in VAT volume in patients with obesity (-2.08%; CI: -3.9,-0.24; p=0.03). Short-term CPAP was not associated with a reduction in VAT metabolic activity, although there was a modest redistribution of fat from the visceral to subcutaneous compartment. Notably, patients with obesity experienced a significant reduction in VAT volume, highlighting potential heterogeneity of treatment effects. Our findings underscore the need for longer-term studies to evaluate how CPAP, and importantly, adjunct weight-loss pharmacotherapies may alter fat distribution and visceral adiposity, potentially modifying OSA-related cardiometabolic risk.