Central Obesity and Recurrent Cardiovascular Events in Patients With Obstructive Sleep Apnea: The SAVE Study

Area of Science:

• Cardiology
• Sleep Medicine
• Obesity Research

Background:

• Obesity is a significant risk factor for both obstructive sleep apnea (OSA) and cardiovascular disease (CVD).
• Understanding the relationship between different measures of obesity and CVD risk in patients with co-occurring OSA and CVD is crucial for risk stratification and management.

Purpose of the Study:

• To investigate the differential associations of various adiposity indices, specifically body mass index (BMI) and waist-to-height ratio (WHtR), with recurrent CVD events.
• To determine which adiposity measure better predicts cardiovascular outcomes in individuals with established CVD and moderate-to-severe OSA.

Main Methods:

• Post hoc analysis of the international Sleep Apnea Cardiovascular Endpoints (SAVE) trial.
• Included participants with moderate-to-severe OSA and established CVD, randomized to continuous positive airway pressure (CPAP) or usual care.
• Used Cox proportional hazards models to assess the association of BMI and WHtR with composite CVD events.

Main Results:

• Nearly all participants (95.6%) exhibited central adiposity (WHtR ≥0.50), while 31.8% were classified as obese by BMI (≥30 kg/m²).
• Waist-to-height ratio (WHtR) demonstrated a significant association with composite CVD events (p=0.0187), with the highest quartile showing a 1.52-fold increased risk.
• Body mass index (BMI) categories showed no clear association with CVD events, though nonlinear relationships were suggested.

Conclusions:

• Central adiposity, assessed by WHtR, is a more consistent predictor of future CVD events in patients with OSA and established CVD.
• Conventional BMI categories may not fully capture cardiovascular risk in this population, highlighting the importance of central adiposity measures.