Abstract
INTRODUCTION: Obstructive sleep apnea (OSA) and type 2 diabetes (T2D) are common in adults with obesity, both contributing to vascular dysfunction and increased cardiovascular risk. In individuals with obesity, OSA is associated with increased carotid intima-media thickness (CIMT) and reduced flow-mediated dilation (FMD), key markers of early atherosclerosis and endothelial dysfunction. However, its additional effects in individuals with coexisting T2D remain unclear. METHODS: This cross-sectional study included adults with obesity, aged 20-59 years. Participants were categorized into four groups based on their diagnostic status: T2D alone, OSA alone, T2D+OSA, and healthy controls. CIMT and FMD% were assessed using Doppler ultrasound by blinded assessors. RESULTS: CIMT was higher in the T2D+OSA group than in the T2D group (P < 0.001) but comparable with the OSA group (P = 0.15). No difference in CIMT was observed between the OSA and T2D groups (P = 0.84). FMD% did not differ among pathological groups (P > 0.05). All pathological groups had significantly higher CIMT and lower FMD% than controls (P < 0.05). CONCLUSION: OSA and T2D impaired vascular health in adults with obesity. While all pathological groups exhibited endothelial dysfunction, the coexistence of OSA and T2D did not exacerbate FMD impairment beyond either condition alone. The additional impact of OSA on CIMT remains uncertain. Longitudinal studies are needed to determine their long-term vascular effects.