Association between serum adipocyte fatty acid binding protein level and dyslipidemia in patients with obstructive sleep apnea syndrome

Abstract

To explore the association between serum adipocyte fatty acid binding protein (A-FABP) levels and dyslipidemia in patients with obstructive sleep apnea syndromes (OSAS). Eighty snoring patients were monitored by overnight polysomnography (PSG) in Second Affiliated Hospital of Soochow University from November 2010 to May 2011. There were 63 males and 17 females with a mean age of (48 ± 14) years (range: 22 - 77 years). Based on the results of apnea-hypopnea index (AHI), they were divided into 3 groups: primary snoring group (AHI < 5/h, n = 19), mild-moderate OSAS group (5/h ≤ AHI ≤ 40/h, n = 22) and severe OSAS group (AHI > 40/h, n = 39). The levels of A-FABP, total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured and compared between the primary snoring group and OSAS patients of different severities. And the correlations between serum A-FABP and plasma lipid as well as PSG parameters were further evaluated by partial correlation analysis. Compared with the primary snoring group ((15.7 ± 3.3) µg/L) and mild-moderate group ((17.3 ± 4.3) µg/L), there was a significant elevation of serum A-FABP level in the severe OSAS group ((20.4 ± 4.6) µg/L) (P = 0.001, P = 0.026). Additionally, after adjustment for body mass index and age, the serum A-FABP level showed significant positive correlations with TC, TG and LDL-C (r = 0.469, P = 0.000; r = 0.239, P = 0.035 and r = 0.366, P = 0.001). Serum A-FABP level was positively correlated with AHI and the time of oxygen saturation (SaO2) < 90% (r = 0.231, P = 0.042 and r = 0.226, P = 0.047). Nevertheless, the serum A-FABP level showed significant negative correlations with the lowest SaO2 and the mean SaO2 (r = -0.234, P = 0.039 and r = -0.270, P = 0.017). Dyslipidemia and elevated level of serum A-FABP are common in OSAS patients.