Serum cardiovascular risk factors in obstructive sleep apnea

Abstract

Background: Obstructive sleep apnea (OSA) patients have increased cardiovascular morbidityand mortality. The cardiovascular markers associated with OSA are currently not defined.Objectives: The aims of this study were to determine whether OSA is associated with serumcardiac risk markers and to investigate the relationship between them.Methods: Sixty-two male patients were classified into two groups with respect to apnea-hypopneaindex (AHI): group 1, sleep apnea (n 30), with AHI > 5; and group 2 (n 32), with AHI < 5. Wecompared cardiovascular risk factors in both groups with control subjects (n 30) without OSA (AHI< 1). Serum cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), low-densitylipoprotein cholesterol (LDL-C), apolipoprotein A-I, apolipoprotein B, lipoprotein (a), C-reactiveprotein (CRP), and homocysteine were measured. Statistical significance was assessed with analysis ofvariance at p < 0.05. In correlation analysis, Pearson correlation was used.Results: There was no significant difference between group 1 and group 2 in total cholesterol, LDL-C,HDL-C, triglyceride, apolipoprotein A-I, apolipoprotein B, and lipoprotein (a). All of the M-modeechocardiographic parameters were in the normal reference range. Serum homocysteine and CRPlevels were significantly increased in group 1 compared to group 2 (p < 0.05). Serum CRP valueswere increased in both group 1 and group 2 when compared with control subjects (p < 0.05). Serumhomocysteine values were higher in group 1 than in control subjects (p < 0.05).Conclusions: Our results show that OSA syndrome is associated not only with slight hyperhomocysteinemiabut also with increased CRP concentrations. Increased plasma concentrations of homocysteineand CRP can be useful in clinical practice to be predictor of long-term prognosis forcardiovascular disease and the treatment of OSA.