Homocysteine Levels and Echocardiographic Findings in Obstructive Sleep Apnea Syndrome

Abstract

Background: The obstructive sleep apnea syndrome (OSAS) is characterized by repeated upper airway obstruction during sleep together with decreases in oxygen saturation leading to a series of pathological events, primarily in the cardiovascular system. Elevated plasma homocysteine levels have recently been considered as an independent risk factor for vascular disease, and increased levels are attributed to cardiovascular diseases. Objectives: We aimed to investigate the possible relationship between homocysteine levels and echocardiographic findings in OSAS patients at different stages of disease. Methods: Thirty-eight patients (23 males and 15 females) with polysomnographically verified OSAS (mean age, 49 ± 12 years, range 27–74) and a mean body mass index of 31.27 ± 5.24 kg/m² (range 22.60–47.90) were prospectively studied. Plasma levels of homocysteine, cholesterols, triglycerides, vitamin B₁₂ and high-sensitive C-reactive protein (hsCRP), as well as echocardiographic and lung function parameters were assessed. Results: Homocysteine levels were elevated in all OSAS groups and were statistically significantly different between the mild and moderate/severe groups. Significant differences were present between the variables nocturnal oxygen desaturation (NOD), respiratory arousal and light sleep among the mild and moderate/severe groups. We found a significant positive correlation between homocysteine levels and NOD duration, and hsCRP levels were positively correlated with the apnea-hypopnea index and NOD duration. Conclusions: In all OSAS groups, homocysteine levels were elevated regardless of the presence of cardiac dysfunction. Echocardiographic abnormalities were primarily left-ventricular (LV) hypertrophy and LV diastolic dysfunction and could be observed in all OSAS severity groups.