AI Analysis Reveals How CPAP Therapy Affects Abdominal Fat in Obstructive Sleep Apnea Patients

A study using AI analyzed how CPAP therapy affects abdominal fat in OSA patients. After three months, CPAP shifted the visceral-to-subcutaneous fat ratio but didn’t change overall fat volume.

Using AI to Explore CPAP’s Impact on Abdominal Obesity in OSA

Obstructive sleep apnea (OSA) is a widespread disorder closely linked with obesity, especially abdominal fat. While continuous positive airway pressure (CPAP) therapy is the standard treatment for OSA, its effect on cardiovascular outcomes remains unclear. Recent research presented at the American Thoracic Society (ATS) International Conference 2025 sheds light on how CPAP might influence abdominal obesity metrics in OSA patients.

Research Overview

Jennifer Prevot, MD, a pulmonary and critical care medicine fellow at Mount Sinai Hospital, led a study that applies artificial intelligence to examine the relationship between OSA severity and abdominal obesity. The study focused on visceral and subcutaneous adipose tissue (VAT and SAT) volumes, as well as VAT metabolic activity, before and after CPAP therapy. This was measured using [18F]-Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) combined with magnetic resonance imaging (MRI).

Prevot explained the motivation behind the work: “There is a lot of interest in obesity and obstructive sleep apnea, and CPAP has been the standard treatment for a very long time. However, it's still questionable if it actually does anything in terms of cardiovascular risk factors. One thing that we know is that obesity kind of links everything, so I thought it would be interesting to look at abdominal obesity in particular and see the relationship it has with OSA and if CPAP therapy can modulate any risk factors.”

Methodology and AI Application

The research team analyzed PET/MRI scans from 115 adults newly diagnosed with OSA, both before and after three months of CPAP therapy. OSA severity was assessed using portable sleep testing and defined by the respiratory disturbance index (pRDI). A deep learning model with a transfer learning approach segmented the subcutaneous and visceral adipose tissue compartments on MRI scans.

Prevot highlighted the novel aspect of their approach: “We used a unique imaging technique—PET/MRI—to look at visceral adipose tissue inflammation, something no one else has done before. We also collaborated with our biomedical engineering department to automate the segmentation of fat compartments, which improved accuracy and efficiency.”

Key Findings

Participants had an average age of 47 years, were predominantly male (84%), and had an average BMI of 31.85 kg/m².
OSA severity showed no significant association with baseline VAT metabolic activity (SUVmean).
After three months of CPAP therapy, there were no significant changes in VAT metabolic activity, VAT volume, or overall weight.
A significant reduction was observed in the VAT/SAT volume ratio, suggesting a possible shift in fat distribution.

Implications and Future Directions

These findings suggest that while CPAP may not significantly alter abdominal fat volume or metabolic activity in the short term, it could influence the balance between visceral and subcutaneous fat. This shift might have implications for cardiovascular risk.

Prevot sees potential in expanding this work by investigating how emerging metabolic therapies, such as GLP-1 receptor agonists, affect fat distribution in OSA patients. Additionally, examining changes in tongue fat—a contributor to airway obstruction in OSA—could provide further insights.