OBJECTIVETo observe the relationship between serum and monocyte-derived-macrophages secreted adipocyte fatty acid binding protein (A-FABP), adiponectin (or A-FABP/adiponectin ratio) and coronary artery disease.

METHODSThree hundred and forty subjects underwent coronary angiography (CAG) were classified into CAD group (n = 211) and non-CAD group (n = 129) according to the CAG results. The severity of coronary artery stenosis was assessed by the numbers of involved coronary artery branches and the sum of the Gensini scores. Fasting venous blood was collected from all subjects and peripheral monocytes were isolated from 20 subjects (10 selected from each group with age-, gender-, and BMI-matched). Peripheral blood monocytes were obtained and stimulated into macrophages with PMA, cell culture supernatant was collected. The concentration of serum/supernatant A-FABP and adiponectin levels were assayed by enzyme-linked immunosorbent assays.

RESULTS(1) A-FABP levels tended to be higher in CAD patients compared to non-CAD subjects [18.3(13.2, 22.8) µg/L vs. 16.4(13.5, 20.4) µg/L, P = 0.088]. The concentration of adiponectin in CAD group was significantly lower than those in non-CAD group [13.9 (9.8, 17.1) mg/L vs. 19.7 (14.5, 27.6) mg/L, P < 0.05]. (2) The A-FABP levels increased and the adiponectin levels decreased as the number of stenotic vessels increased. Gensini scores were positively correlated with serum A-FABP (r = 0.120, P = 0.043) and inversely correlated with adiponectin (r = -0.405, P = 0.007). (3) The difference in A-FABP/adiponectin ratio was more prominent between subjects with CAD and subjects without CAD [(1.51 ± 0.79) µg/mg vs. (0.89 ± 0.30) µg/mg, P < 0.01] and there was a stronger positive correlation of Gensini score to A-FABP/adiponectin ratio(r = 0.531, P = 0.000). (4) Monocyte-derived-macrophages from patients with CAD had higher A-FABP/adiponectin ratio than that in patients without CAD [(0.51 ± 0.19) µg/mg vs. (0.36 ± 0.11) µg/mg, P < 0.05].

CONCLUSIONSIncreased levels of serum A-FABP and reduced levels of adiponectin in CAD patients serves as a novel biomarker for the severity of the coronary stenosis. A-FABP/adiponectin ratio is superior to A-FABP or adiponectin alone on predicting CAD risks.