Retatrutide Cuts Apnea-Hypopnea Index by 25 Events per Hour in Phase 3 OSA Trials

The TRIUMPH-1-OSA and TRIUMPH-2-OSA trials randomized adults with BMI ≥27 and moderate-to-severe obstructive sleep apnea to weekly retatrutide 4 mg, 9 mg, 12 mg or placebo. Polysomnography measured AHI at baseline, 24 and 80 weeks. Higher doses produced 39–52% of participants reaching no or mild disease without excessive daytime sleepiness, compared with 13% on placebo. Reductions occurred in both participants with and without type 2 diabetes.

Retatrutide activates GLP-1, GIP and glucagon receptors, producing greater weight loss and energy expenditure than semaglutide or tirzepatide. Absolute AHI drops of 23–25 events per hour at 4–12 mg doses exceeded typical CPAP adherence gains in real-world settings. These outcomes link weight reduction directly to disease modification rather than symptom masking.

Prior SURMOUNT-OSA data on tirzepatide showed smaller AHI improvements at similar weight loss, suggesting the glucagon component may add metabolic benefit. Long-term cardiovascular and adherence data remain absent. Next steps require 104-week extension studies and head-to-head trials versus CPAP to establish whether pharmacologic AHI reduction translates to fewer incident hypertension and arrhythmia events.