Inflammatory markers and plaque morphology: an optical coherence tomography study.

BACKGROUND: OCT with its unique image resolution is the ideal method to detect culprit lesion characteristics in different clinical presentations. The identification of inflammatory markers related to plaque characteristics may be of clinical importance. METHODS: Thirty-two patients with acute coronary syndromes (ACS) and fourteen patients with stable angina pectoris (SAP) were enrolled in this study. Culprit lesion morphology was assessed by optical coherence tomography (OCT) in patients with ACS and SAP. The possible relations between serum levels of high sensitivity-C reactive protein (hs-CRP) and interleukin-18 (IL-18) with plaque characteristics were investigated in those patients. RESULTS: Plaque rupture and thin-cap fibroatheroma (TCFA) were detected more frequently in ACS patients compared with SAP patients, (78.6% vs. 14.3%, p<0.001, 92.9% vs. 14.3%, p<0.001, respectively). Higher levels of serum hs-CRP and IL-18 were found in patients with plaque rupture vs. those with no plaque rupture (median value: 19.2mg/L vs. 1.6 mg/L, p<0.001 and 219.5 pg/ml vs. 127.5 pg/ml, p=0.001 respectively), and TCFA vs. those without TCFA (median value: 15.2mg/L vs. 1.6 mg/L, p=0.004 and 209.0 pg/ml vs.153.2 pg/ml, p=0.03 respectively). Serum hs-CRP was the only independent predictor of plaque rupture (p=0.02, odds ratio 1.1, 95% confidence interval 1.0 to 1.2). A cut-off value of hs-CRP>4.5mg/L could detect ruptured plaque with a sensitivity of 91.7% and a specificity of 77.8%. CONCLUSIONS: OCT detected plaque rupture and TCFA more frequent in ACS patients compared with SAP. Elevated hs-CRP and IL-18 were positively related to plaque instability and rupture.

Background diet influences the anti-inflammatory effect of alpha-linolenic acid in dyslipidaemic subjects.

Long-chain n-3 PUFA from fish oils are known to have anti-inflammatory effects. We evaluated the effect of alpha-linolenic acid (ALA), precursor of n-3 fatty acids, on serum inflammatory markers and soluble cellular adhesion molecules (sCAM) of dyslipidaemic males, relative to their background diet. Participants were assigned to two groups, based upon food intake patterns: (a) twenty-one dyslipidaemic subjects who habitually ate a Mediterranean-Cretan-type diet; (b) nineteen dyslipidaemic subjects who normally ate a Westernised Greek diet. All were supplemented with 8.1 g ALA/d for 12 weeks. We determined serum amyloid A (SAA), C-reactive protein (CRP), macrophage colony-stimulating factor (MCSF), IL-6, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 and soluble E-selectin concentrations at the beginning and the end of the ALA supplementation period. Serum baseline concentrations of inflammatory markers and sCAM were similar across the diet groups. Type of diet had a significant impact on the response of inflammatory markers to ALA supplementation. The Westernised Greek diet group showed a reduction in SAA (P<0.001), CRP (P=0.002), MCSF (P=0.005) and IL-6 (P=0.04) concentrations. The Mediterranean-Cretan-type background diet group showed a significant reduction only in MCSF concentrations (P=0.003). The sVCAM-1 concentrations were significantly reduced in both the Westernised Greek diet group (P=0.001) and the Mediterranean-Cretan-type diet group (P<0.001). The present study demonstrated that ALA supplementation lowered the serum concentrations of inflammatory markers more profoundly when the background diet was rich in saturated fatty acids and poor in MUFA.

The effect of diet enriched with alpha-linolenic acid on soluble cellular adhesion molecules in dyslipidaemic patients.

BACKGROUND: Leukocyte adhesion and transendothelial migration, the critical pathogenic components in the development of atherosclerotic lesions, are largely mediated by cellular adhesion molecules (CAMs). We examined whether dietary supplementation with alpha-linolenic acid (ALA, 18:3n-3) affects the levels of soluble forms of CAMs in dyslipidaemic patients. METHODS: We recruited 90 male dyslipidaemic patients (mean age=51+/-8 years) following a typical Greek diet. They were randomly assigned either to 15 ml of linseed oil (rich in ALA) per day (n=60) or to 15 ml of safflower oil (rich in linoleic acid [LA, 18:2n-6]) per day (n=30). The ratio of n-6:n-3 in linseed oil supplemented group was 1.3:1 and in safflower oil supplemented group 13.2:1. Dietary intervention lasted for 12 weeks. Blood lipids, soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble E-selectin (sE-selectin) were measured. RESULTS: Dietary supplementation with ALA significantly decreased sVCAM-1 levels (median decrease 18.7% [577.5 ng/ml versus 487 ng/ml, P=0.0001]). In the LA supplemented group, sVCAM-1 was also significantly decreased but to a lesser extent (median decrease 10.6% [550.5 ng/ml versus 496 ng/ml, P=0.0001]). After controlling for smoking habits, no significant difference was observed in the reduction of sVCAM-1 levels between the two treatment arms (P=0.205). The decrease of sVCAM-1 was independent of lipid changes in both groups. CONCLUSIONS: Dietary supplementation with ALA for 12 weeks significantly decreases sVCAM-1 levels in dyslipidaemic patients. This effect presents a potential mechanism for the beneficial effect of plant n-3 polyunsaturated fatty acids in the prevention of coronary artery disease. In addition, dietary supplementation with LA significantly decreases sVCAM-1 levels, an effect which requires further investigation.

Dietary alpha-linolenic acid decreases C-reactive protein, serum amyloid A and interleukin-6 in dyslipidaemic patients.

BACKGROUND: Inflammation plays an important role in the pathogenesis of coronary artery disease. We examined whether dietary supplementation with alpha-linolenic acid (ALA, 18:3n-3) affects the levels of inflammatory markers in dyslipidaemic patients. METHODS: We recruited 76 male dyslipidaemic patients (mean age=51+/-8 years) following a typical Greek diet. They were randomly assigned either to 15 ml of linseed oil (rich in ALA) per day (n=50) or to 15 ml of safflower oil (rich in linoleic acid (LA, 18:2n-6)) per day (n=26). The ratio of n-6:n-3 in linseed oil supplemented group was 1.3:1 and in safflower oil supplemented group 13.2:1. Dietary intervention lasted for 3 months. Blood lipids and C-reactive protein (CRP), serum amyloid A (SAA), and interleukin-6 (IL-6) levels were determined prior and after intervention. CRP and SAA were measured by nephelometry and IL-6 by immunoassay. RESULTS: Dietary supplementation with ALA decreased significantly CRP, SAA and IL-6 levels. The median decrease of CRP was 38% (1.24 vs. 0.93 mg/l, P=0.0008), of SAA 23.1% (3.24 vs. 2.39 mg/l, P=0.0001) and of IL-6 10.5% (2.18 vs. 1.7 pg/ml, P=0.01). The decrease of inflammatory markers was independent of lipid changes. Dietary supplementation with LA did not affect significantly CRP, SAA and IL-6 concentrations but decreased cholesterol levels. CONCLUSIONS: Dietary supplementation with ALA for 3 months decreases significantly CRP, SAA and IL-6 levels in dyslipidaemic patients. This anti-inflammatory effect may provide a possible additional mechanism for the beneficial effect of plant n-3 polyunsaturated fatty acids in primary and secondary prevention of coronary artery disease.