Abstract
OBJECTIVE: This pilot study compared the effects of high-intensity interval training (HIIT) and continuous positive airway pressure (CPAP) on vascular health in Thai adults with obesity, obstructive sleep apnea (OSA), and type 2 diabetes mellitus. METHODS: Participants were recruited from a university hospital in Chiang Mai, Thailand (July 2023-April 2024). Thirty participants were age-matched and sequentially assigned to CPAP, HIIT, or usual care groups. The HIIT group completed four 4-min treadmill intervals at 85 %-95 % of maximum heart rate, three times weekly for 12 weeks. The CPAP group used CPAP ≥ four hours/night. Primary outcomes were flow-mediated dilation (FMD) and carotid intima-media thickness (CIMT). Secondary outcomes included sleep indices, blood biomarkers, and body composition. RESULTS: Adherence was high in both HIIT (97.78 %) and CPAP (95.89 %) groups. The HIIT group showed lower CIMT than controls (p = 0.05) and improved FMD and CIMT from baseline (p < 0.01). Both HIIT and CPAP groups reduced apnea-hypopnea index and body mass index compared with controls and baseline (p ≤ 0.01). Only the CPAP group improved oxygen saturation (p ≤ 0.01). No significant changes were observed in blood biomarkers (p > 0.05). CONCLUSIONS: HIIT may benefit vascular health and OSA severity. Both HIIT and CPAP improved body mass index. Larger trials are warranted.