Serum risk markers as predictors of cardiac and renal complications in patients with obstructive sleep apnea

ABSTRACT

Patients with obstructive sleep apnea are at high risk to develop many complications. Increased risk to develop cardiovascular and renal morbidity and mortality are the most sinister of these complications. There are various serum markers which are known to be helpful as prognostic factors for the development of cardiac and renal complications in those patients. The aim of this study is to determine the prognostic value of certain serum cardiac and renal risk markers in OSA. The study also aims to investigate the relationship between the serum level of these markers and severity of OSA. Forty five males were included in this study, classified into two groups, the obstructive sleep agroup [n=30], this group subdivided into two subgroups with respect to apnea-hypopnea index [AHl] subgroup A, [n=15], with AHI<5; and subgroup B [n=15], with AHI >5. The second group included [n=15] healthy control male subjects. All patients of obstructive sleep apnea group underwent overnight polysomonography after complete ENT examination. The serum level of cholesterol, triglycerides, C-reactive protein [CRP], homocysteine, creatinine, cystatin C were measured in both groups. Statistical significance was assessed with analysis of variance at p<0.05. In correlation analysis, pearson correlation was used. The results of over night polysomonography were significantly diagnostic for OSA in all patients of the OSA patients' group. There was significant difference-regarding serum levels of homocysteine, CRP and cystatin C in OSA patients' group compared to the control group. Serum homocysteine, CRP and cystatin C levels were significantly increased in subgroup B compared to subgroup A [p<0.05]. There was no significant difference between OSA patient's group and the control group and between subgroup A and subgroup B in serum creatinine, total cholesterol, LDL-C, HDL-C, triglyceride. Increased plasma concentrations of homocysteine and CRP can he useful in clinical practice as predictors for cardiovascular disease in patients with OSA. Also increased plasma level of cystatin C is a predictor of impaired renal function in OSA patients and it is more sensitive than serum creatinine