Variation in Human Erythrocyte Membrane Unsaturated Fatty Acids: Correlation With Cardiovascular Disease

2010 ◽  
Vol 134 (1) ◽  
pp. 73-80
Author(s):  
Jorge L. Sepulveda ◽  
Yvette C. Tanhehco ◽  
Monica Frey ◽  
Lida Guo ◽  
Lorna J. Cropcho ◽  
...  

Abstract Context.—Whether cell membrane fatty acid (FA) composition is a useful indicator of vascular disease is unclear. Objective.—To study variation of erythrocyte (RBC) membrane FA in samples from healthy volunteers, hospitalized patients, and cardiac troponin I–elevated patients with myocardial damage without a priori assumptions as to FA composition. Design.—We separated FAs extracted from RBCs by gas chromatography and identified them by mass spectrometry. Fatty acids with abundance greater than 1% of total were quantified and compared: hexadecanoic (C16:0), octadecadienoic (C18:2), cis- and trans-octadecenoic (C18:1), and eicosatetraenoic (C20:4) acids. Deuterated standards established proportionality of FA recovery. The cis- and trans-C18:1 identification was verified by comparison with standards. Results.—In troponin-positive samples, C18:2 to C18:1 ratios were increased 30% compared with healthy controls or with random patient samples. Erythrocyte trans-C18:1 had a wide variation, ∼10-fold, in all groups but without differences between groups. Replicates showed that the wide range of RBC trans-FA load is not due to analytic variation. In healthy subjects, the RBC content of lower– molecular weight FAs (C16-C18) correlated with serum low-density lipoprotein cholesterol, but despite the established relationship between dietary trans-FA and increased low-density lipoprotein cholesterol, lipid profiles had no correlation with RBC trans-FA content. Conclusions.—Erythrocyte accumulation of unsaturated FA may be a useful indicator of vascular disease, whereas the wide range in trans-FAs suggests that both diet and genetic variation affect RBC trans-FA accumulation. Unsaturated FAs increase membrane fluidity and may reflect a natural response to subclinical vascular changes, which may in turn reflect increased risk of clinical disease.

Author(s):  
Fotios Barkas ◽  
Tzortzis Nomikos ◽  
Evangelos Liberopoulos ◽  
Demosthenes Panagiotakos

Background: Although a cholesterol-lowering diet and the addition of plant sterols and stanols are suggested for the lipid management of children and adults with familial hypercholesterolemia, there is limited evidence evaluating such interventions in this population. Objectives: To investigate the impact of cholesterol-lowering diet and other dietary interventions on the incidence or mortality of cardiovascular disease and lipid profile of patients with familial hypercholesterolemia. Search methods: Relevant trials were identified by searching US National Library of Medicine National Institutes of Health Metabolism Trials Register and clinicaltrials.gov.gr using the following terms: diet, dietary, plant sterols, stanols, omega-3 fatty acids, fiber and familial hypercholesterolemia. Selection criteria: Randomized controlled trials evaluating the effect of cholesterol-lowering diet or other dietary interventions in children and adults with familial hypercholesterolemia were included. Data collection and analysis: Two authors independently assessed the trial eligibility and bias risk and one extracted the data, with independent verification of data extraction by a colleague. Results: A total of 17 trials were finally included, with a total of 376 participants across 8 comparison groups. The included trials had either a low or unclear bias risk for most of the parameters used for risk assessment. Cardiovascular incidence or mortality were not evaluated in any of the included trials. Among the planned comparisons regarding patients’ lipidemic profile, a significant difference was noticed for the following comparisons and outcomes: omega-3 fatty acids reduced triglycerides (mean difference [MD]: -0.27 mmol/L, 95% confidence interval [CI]: -0.47 to -0.07, p<0.01) when compared with placebo. A non-significant trend towards a reduction in subjects’ total cholesterol (MD: -0.34, 95% CI: -0.68 to 0, mmol/L, p=0.05) and low-density lipoprotein cholesterol (MD: -0.31, 95% CI: -0.61 to 0, mmol/L, p=0.05) was noticed. In comparison with cholesterol-lowering diet, the additional consumption of plant stanols decreased total cholesterol (MD: -0.62 mmol/l, 95% CI: -1.13 to -0.11, p=0.02) and low-density lipoprotein cholesterol (MD: -0.58 mmol/l, 95% CI: -1.08 to -0.09, p=0.02). The same was by plant sterols (MD: -0.46 mmol/l, 95% CI: -0.76 to -0.17, p<0.01 for cholesterol, and MD: -0.45 mmol/l, 95% CI: -0.74 to -0.16, p<0.01 for low-density lipoprotein cholesterol). No heterogeneity was noticed among the studies included in these analyses. Conclusions: Available trials confirm that the addition of plant sterols or stanols has a cholesterol-lowering effect on such individuals. On the other hand, supplementation with omega-3 fatty acids effectively reduces triglycerides and might have a role in lowering the cholesterol of patients with familial hypercholesterolemia. Additional studies are needed to investigate the effectiveness of a cholesterol-lowering diet or the addition of soya protein and dietary fibers to a cholesterol-lowering diet in familial hypercholesterolemia.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
You-Guo Niu ◽  
Rhys D. Evans

The heart is a major consumer of energy and is able to utilise a wide range of substrates including lipids. Nonesterified fatty acids (NEFA) were thought to be a favoured carbon source, but their quantitative contribution is limited because of their relative histotoxicity. Circulating triacylglycerols (TAGs) in the form of chylomicrons (CMs) and very-low-density lipoprotein (VLDL) are an alternative source of fatty acids and are now believed to be important in cardiac metabolism. However, few studies on cardiac utilisation of VLDL have been performed and the role of VLDL in cardiac energy metabolism remains unclear. Hearts utilise VLDL to generate ATP, but the oxidation rate of VLDL-TAG is relatively low under physiological conditions; however, in certain pathological states switching of energy substrates occurs and VLDL may become a major energy source for hearts. We review research regarding myocardial utilisation of VLDL and suggest possible roles of VLDL in cardiac energy metabolism: metabolic regulator and extracardiac energy storage for hearts.


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