Serum free fatty acids are associated with severe coronary artery calcification, especially in diabetes: a retrospective study

BACKGROUND: Serum free fatty acid (FFA) concentrations are associated with coronary heart disease and diabetes mellitus (DM). Few studies focused on the relationship between serum FFA levels and coronary artery calcification (CAC). METHODS: This was a retrospective, single-centered study recruiting patients underwent FFA quantification, coronary angiography and intravascular ultrasound (IVUS). CAC severity was assessed with the maximum calcific angle (arc) of the calcified plaque scanned by IVUS. Patients with an arc ≥ 180° were classified into the severe CAC (SCAC) group, and those with an arc < 180° were classified into the non-SCAC group. Clinical characteristics, serum indices were compared between 2 groups. Logistic regression, receiver operating characteristic (ROC) curves and area under the curves (AUC) were performed. RESULTS: Totally, 426 patients with coronary artery disease were consecutively included. Serum FFA levels were significantly higher in the SCAC group than non-SCAC group (6.62 ± 2.17 vs. 5.13 ± 1.73 mmol/dl, p < 0.001). Logistic regression revealed that serum FFAs were independently associated with SCAC after adjusting for confounding factors in the whole cohort (OR 1.414, CI 1.237-1.617, p < 0.001), the non-DM group (OR 1.273, CI 1.087-1.492, p = 0.003) and the DM group (OR 1.939, CI 1.388-2.710, p < 0.001). ROC analysis revealed a serum FFA AUC of 0.695 (CI 0.641-0.750, p < 0.001) in the whole population. The diagnostic predictability was augmented (AUC = 0.775, CI 0.690-0.859, p < 0.001) in the DM group and decreased (AUC = 0.649, CI 0.580-0.718, p < 0.001) in the non-DM group. CONCLUSIONS: Serum FFA levels were independently associated with SCAC, and could have some predictive capacity for SCAC. The association was strongest in the DM group.