The impact of obstructive sleep apnea on homocysteine and carotid remodeling in metabolic syndrome

Obstructive sleep apnea (OSA) and metabolic syndrome (MetS) are associated with increased cardiovascular morbidity and mortality. Increased homocysteine is suggested as an independent risk factor for atherosclerosis and cardiovascular disease but remains disputed in OSA. We assessed polysomnography, carotid intima-media thickness (CIMT) and biology in 35 MetS patients, according to the presence (OSA + MetS; n = 26) or the absence of OSA (MetS; n = 9). In OSA + MetS patients, homocysteine levels were increased compared to MetS subjects (12.8 ± 3.8 vs. 9.5 ± 2.5 μmol/L; P = 0.026). In the whole population, homocysteine correlated with apnea-hypopnea index (AHI) (r = 0.522; P = 0.001) and CIMT (r = 0.376; P = 0.026). Homocysteine was negatively correlated with plasma thiols (r = -0.406; P = 0.017) and positively with urinary 15-F2t-isoprostanes (r = 0.347; P = 0.044). Multivariate regression analysis revealed that AHI (β = 0.559; P < 0.001) and urinary 15-F2t-isoprostane (β = 0.310; P = 0.018) were independently associated with homocysteine level. We conclude that homocysteine level was higher in MetS when associated with OSA and proportional to OSA severity. In this context, vascular remodeling appeared more severe and mediated by oxidative stress.

► Homocysteine (Hcy) level remains disputed in OSA. ► Assessment of Hcy, CIMT and oxidative stress in metabolic syndrome ± OSA patients. ► Hcy was increased in OSA + MetS group compared to MetS. ► Hcy was associated with AHI and CIMT and oxidative stress. ► Hcy was related to vascular remodeling in OSA.