Marcelo Tavella

Trans fatty acid content of a selection of foods in Argentina

Abstract Several studies have reported an association between consumption of trans fatty acids and risk of cardiovascular disease (CVD). These fatty acids enter the human diet most commonly as byproducts of hydrogenation of polyunsaturated fats. The amount of trans fats in foods exhibit great variation, due to differences in hydrogenation methods and intensity. In order to quantify the level of trans fats available in widely consumed commercial food items in Argentina, we measured total fat, saturated fat, and the trans fatty acid elaidic acid in 46 food items. As an example from most common items, total fat was 2.0–3.4% in sliced bread, 2.9–25% in cookies and crackers, 50–80% in margarines, 85% in butter, and 34–39% in snack products. In the same items, content of the trans fatty acid elaidic acid was: 2.35–27.7% in sliced bread, 2.85–28.95% in cookies and crackers, 18.15–31.84% in margarines, 4.63% in butter, and 0–10.58% in snacks. In order to compare the results on the fatty-acid composition by using different analysis methods, the same food items mentioned were analyzed in a column of lower polarity and shorter length, and we found trans fatty acids were masked by cis unsaturated fatty acids. A comparison with available data from similar products from other parts of the world indicates that Argentinian products in the categories studied have higher content of trans fatty acids.

Metalloproteases 2 and 9, Lp-PLA2 and Lipoprotein Profile in Coronary Patients

BACKGROUND AND AIMS Many studies suggest that the different steps of the atherosclerotic process may be mediated by metalloproteases (MMPs). MMP-9 and MMP-2, which are highly expressed in the vulnerable regions of the atherosclerotic plaques, have been suggested to be causally involved in plaque rupture. In another manner linked with LDL, lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) hydrolyzes phospholipids generating proinflammatory and proatherogenic products. Our aim was to evaluate plasma activity of MMP-2 and 9, as well as Lp-PLA(2), in subjects with coronary artery stenosis in comparison with controls and to correlate these activities with lipoprotein profile and general biomarkers of inflammation. METHODS Forty two subjects who had undergone coronary angiography were divided into two groups: patients with coronary vessels with at least 45% stenosis (CAD [coronary artery disease], n = 24) and patients without angiographically detectable coronary artery disease (controls, n = 18). Plasma activity of MMP-2 and MMP-9 was measured and correlated with markers of systemic inflammation (hs-CRP), subendothelial inflammation (Lp-PLA(2)) and lipoprotein profile. RESULTS Plasma activity of both MMPs was consistently higher in patients than in controls (p <0.01). Pro-MMP-2 (r = 0.34, p <0.01) and MMP-9 (r = 0.51, p <0.02) activities correlated with apoprotein B. Pro-MMP-2 correlated with hs-CRP (r = 0.47, p <0.01) and inversely with HDL cholesterol (r = -0.35, p <0.02). No differences were observed in Lp-PLA(2) between patients and controls (15.2 +/- 4.0 vs. 15.4 +/- 4.5 micromol/mL/h, p = NS, respectively), and no correlation was observed with MMPs. CONCLUSIONS MMP activity was higher in CAD than in controls. The correlation observed between pro-MMP-2 and high-sensitive C-reactive protein (hs-CRP) may be due to specific systemic inflammatory processes. No correlation was observed between Lp-PLA(2) and MMPs.

Association between the APOE*4 allele and atherosclerosis is age dependent among argentine males

Several studies have shown evidence of an association between the *4 allele of apolipoprotein E (APOE) and coronary heart disease (CHD) in different populations. We determined the APOE genotype and total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterol (HDLC) values in 189 patients with angiographically evaluated atherosclerosis. The APOE*4 allele was found to be statistically significantly more frequent (odds ratio, 1.93; 95% confidence interval, 1.12–3.32) among male patients than in a randomly chosen population-based sample. No significant difference was found when female patients were compared to the general population. The APOE*4 allele was found primarily among young (30–45-year-old) male patients (p < 0.04). Despite the ascending linear tendency of the mean TC values for genotypes APOE*2/*3, APOE*3/*3, and APOE*3/*4 reported in our case population, no differences were observed among our patients. We conclude that the APOE*4 allele is associated with an increased risk for atherosclerotic vascular disease, that this association has an age-dependent effect, and that it acts as a genetic factor that increases susceptibility to developing the disease in young to middle-aged male adults in our population.

Linoleic acid enrichment of serum phosphatidylcholine in humans by low doses of sodium linoleate

Fifteen volunteers were treated daily during a week with 250 mg of sodium linoleate supply as suppository. A day before and a day after treatment venous blood samples were drawn, high density lipoproteins (HDL) fractionated and 3-sn phosphatidylcholine isolated by thin-layer chromatography from total serum and HDL and their fatty acid composition analyzed by gas-liquid chromatography. The positional esterification of linoleic acid in the phosphatidylcholine molecule was determined by enzymatic hydrolysis. Increases of linoleic acid of 1.8--136.3% in the serum phosphatidylcholine were observed in 14 out of 15 volunteers and an increment of 6.3--32.2% was also detected in the lipid fraction from HDL. In both fractions about 98% of the linoleic acid is located in the C2 position of the phosphatidylcholine molecule. The results reported in the present paper show that it is possible to promote the enrichment of linoleic acid in the phosphatidylcholine fractions of both serum and HDL from humans subjected to low doses of sodium linoleate supply as suppository.