Stanislav Oravec

Relative importance of different lipid risk factors for the development of myocardial infarction at a very young age (≤ 40 years of age)

Eur J Clin Invest 2012; 42 (6): 631–636

Effect of a plant sterol, fish oil and B vitamin combination on cardiovascular risk factors in hypercholesterolemic children and adolescents: a pilot study.

BackgroundAssessment of cardiovascular disease (CVD) risk factors can predict clinical manifestations of atherosclerosis in adulthood. In this pilot study with hypercholesterolemic children and adolescents, we investigated the effects of a combination of plant sterols, fish oil and B vitamins on the levels of four independent risk factors for CVD; LDL-cholesterol, triacylglycerols, C-reactive protein and homocysteine.MethodsTwenty five participants (mean age 16 y, BMI 23 kg/m2) received daily for a period of 16 weeks an emulsified preparation comprising plant sterols esters (1300 mg), fish oil (providing 1000 mg eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA)) and vitamins B12 (50 μg), B6 (2.5 mg), folic acid (800 μg) and coenzyme Q10 (3 mg). Atherogenic and inflammatory risk factors, plasma lipophilic vitamins, provitamins and fatty acids were measured at baseline, week 8 and 16.ResultsThe serum total cholesterol, LDL- cholesterol, VLDL-cholesterol, subfractions LDL-2, IDL-1, IDL-2 and plasma homocysteine levels were significantly reduced at the end of the intervention period (p<0.05). The triacylglycerols levels decreased by 17.6%, but did not reach significance. No significant changes in high sensitivity C-reactive protein, HDL-cholesterol and apolipoprotein A-1 were observed during the study period. After standardisation for LDL cholesterol, there were no significant changes in the levels of plasma γ-tocopherol, β-carotene and retinol, except for reduction in α-tocopherol levels. The plasma levels of n-3 fatty acids increased significantly with the dietary supplementation (p<0.05).ConclusionsDaily intake of a combination of plant sterols, fish oil and B vitamins may modulate the lipid profile of hypercholesterolemic children and adolescents.Trial registrationCurrent Controlled Trials ISRCTN89549017

Small high-density lipoprotein is associated with monocyte subsets in stable coronary artery disease

Objective: High-density lipoprotein (HDL) particles are heterogeneous in structure and function and the role of HDL subfractions in atherogenesis is not well understood. It has been suggested that small HDL may be dysfunctional in patients with coronary artery disease (CAD). Monocytes are considered to play a key role in atherosclerotic diseases. Circulating monocytes can be divided into three subtypes according to their surface expression of CD14 and CD16. Our aim was to examine whether monocyte subsets are associated with HDL subfractions in patients with atherosclerosis. Methods: We included 90 patients with angiographically stable CAD. Monocyte subsets were defined as classical monocytes (CD14++CD16-; CM), intermediate monocytes (CD14++CD16+; IM) and non-classical monocytes (CD14+CD16++; NCM). HDL subfractions were measured by electrophoresis on polyacrylamide gel. Results: Serum levels of small HDL correlated with circulating pro-inflammatory NCM and showed an inverse relationship to circulating CM independently from other lipid parameters, risk factors, inflammatory parameters or statin treatment regime, respectively. IM were not associated with small HDL. In particular, patients with small HDL levels in the highest tertile showed dramatically increased levels of NCM (14.7 ± 7% vs. 10.7 ± 5% and 10.8 ± 5%; p = 0.006) and a decreased proportion of CM (79.3 ± 7% vs. 83.7 ± 6% and 83.9 ± 6%; p = 0.004) compared to patients in the two lower tertiles. In contrast, intermediate HDL, large HDL and total HDL were not associated with monocyte subset distribution. Conclusion: Small HDL levels are associated with pro-inflammatory NCM and inversely correlated with CM. This may suggest that small HDL could have dysfunctional anti-inflammatory properties in patients with established CAD.

The effects of atorvastatin treatment on the mean platelet volume and red cell distribution width in patients with dyslipoproteinemia and comparison with plasma atherogenicity indicators—A pilot study

OBJECTIVES The mean platelet volume (MPV) and red cell distribution width (RDW) have recently arisen interest because of their association with an increased cardiovascular risk. The aim of our study was, therefore, to determine whether an association exists between MPV, RDW and lipoprotein sub-fractions, and to show the impact of statin therapy on these new possible biomarkers of atherosclerotic risk. DESIGN AND METHODS A cohort of 40 patients with hypercholesterolaemia (29 females, mean age 62.9±9 years), without previous hypolipidaemic treatment were enrolled. The patients were treated with atorvastatin 40 mg/day for 12 weeks. Total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density cholesterol (HDL-C), triglycerides (TG), LDL-C sub-fractions [large LDL-C 1-2 and small dense (sd)-LDL-C 3-7], apolipoproteins (apoA1, apoB), apoB/apoA1 ratio, atherogenic index of plasma (AIP), haematological parameters (including MPV, RDW) and safety parameters (renal, hepatic) were measured before and after 12 weeks of atorvastatin treatment. RESULTS At baseline, a strong correlation between HDL-C, TG, sd-LDL-C, apoB, apoB/apoA1, and AIP with MPV (r=-0.55, p<0.001; r=0.57, p<0.001; r=0.73, p<0.001; r=0.41, p<0.05; r=0.52, p<0.001; r=0.61, p<0.001, respectively) and RDW (r=-0.49, p<0.001; r=0.62, p<0.001; r=0.67, p<0.001; r=0.41, p<0.05; r=0.43, p<0.05; r=0.65, p<0.001, respectively) was found. After 12 weeks of treatment with atorvastatin, MPV and RDW values underwent significant modification only in those patients displaying the strongest lipid-lowering effect. CONCLUSIONS Values of MPV and RDW seem to reflect a pro-atherogenic lipoprotein profile mainly represented by the presence of sd-LDL-C.

Effect of Atorvastatin on Low-Density Lipoprotein Subpopulations and Comparison Between Indicators of Plasma Atherogenicity: A Pilot Study

Treatment with statins to achieve target low-density lipoprotein cholesterol (LDL-C) levels is still associated with residual risk. Lipoprotein subfraction evaluation can provide additional information regarding atherogenicity in these individuals. Patients (n = 40) with hypercholesterolemia (29 females, mean age 63 years), without previous hypolipemic treatment, were treated with atorvastatin 40 mg/d for 3 months. Atorvastatin significantly reduced total cholesterol (6.7 ± 1.0 vs 4.6 ± 1.3 mmol/L, P < .001), LDL-C (4.3 ± 1.0 vs 2.6 ± 0.9 mmol/L, P < .001), triglycerides (1.8 ± 0.9 vs 1.5 ± 1.00 mmol/L, P < .05), small-dense LDL (sdLDL) fraction 3 to 7 (0.22 ± 0.37 vs 0.09 ± 0.16 mmol/L, P < .001), and apolipoprotein B (apoB; 1.0 ± 0.2 vs 0.74 ± 0.2 g/L, P < .001). There was a negative correlation of atherogenic index of plasma (AIP) with buoyant LDL-1 and LDL-2 (r = −.35; P < .05) and positive with sdLDL-3 to sdLDL-7 (r = .52, P < .001). Administration of atorvastatin 40 mg/d in patients with hypercholesterolemia caused a shift in sdLDL subfractions to large, buoyant subfractions. The AIP better correlated with sdLDL than apoB levels.

Monocyte subset distribution in patients with stable atherosclerosis and elevated levels of lipoprotein(a)

Background Lipoprotein(a) (Lp(a)) is a proatherogenic plasma lipoprotein currently established as an independent risk factor for the development of atherosclerotic disease and as a predictor for acute thrombotic complications. In addition, Lp(a) is the major carrier of proinflammatory oxidized phospholipids (OxPL). Today, atherosclerosis is considered to be an inflammatory disease of the vessel wall in which monocytes and monocyte-derived macrophages are crucially involved. Circulating monocytes can be divided according to their surface expression pattern of CD14 and CD16 into at least 3 subsets with distinct inflammatory and atherogenic potential. Objective The aim of this study was to examine whether elevated levels of Lp(a) and OxPL on apolipoprotein B-100–containing lipoproteins (OxPL/apoB) are associated with changes in monocyte subset distribution. Methods We included 90 patients with stable coronary artery disease. Lp(a) and OxPL/apoB were measured, and monocyte subsets were identified as classical monocytes (CMs; CD14++CD16−), intermediate monocytes (IMs; CD14++CD16+), and nonclassical monocytes (NCMs; CD14+CD16++) by flow cytometry. Results In patients with elevated levels of Lp(a) (>50 mg/dL), monocyte subset distribution was skewed toward an increase in the proportion of IM (7.0 ± 3.8% vs 5.2 ± 3.0%; P = .026), whereas CM (82.6 ± 6.5% vs 82.0 ± 6.8%; P = .73) and NCM (10.5 ± 5.3 vs 12.8 ± 6.0; P = .10) were not significantly different. This association was independent of clinical risk factors, choice of statin treatment regime, and inflammatory markers. In addition, OxPL/apoB was higher in patients with elevated Lp(a) and correlated with IM but not CM and NCM. Conclusions In conclusion, we provide a potential link between elevated levels of Lp(a) and a proatherogenic distribution of monocyte subtypes in patients with stable atherosclerotic disease.

Impaired antioxidant HDL function is associated with premature myocardial infarction.

There is growing evidence that the predictive value of HDL cholesterol levels for cardiovascular risk stratification is limited in patients with coronary artery disease (CAD). HDL function seems to be a more sensitive surrogate of cardiovascular risk estimation than simple serum levels. Therefore, we aimed to assess whether impaired antioxidant HDL function is involved in the development of premature acute myocardial infarction (AMI).

Association of small dense LDL serum levels and circulating monocyte subsets in stable coronary artery disease.

Objective Atherosclerosis is considered to be an inflammatory disease in which monocytes and monocyte-derived macrophages play a key role. Circulating monocytes can be divided into three distinct subtypes, namely in classical monocytes (CM; CD14++CD16-), intermediate monocytes (IM; CD14++CD16+) and non-classical monocytes (NCM; CD14+CD16++). Low density lipoprotein particles are heterogeneous in size and density, with small, dense LDL (sdLDL) crucially implicated in atherogenesis. The aim of this study was to examine whether monocyte subsets are associated with sdLDL serum levels. Methods We included 90 patients with angiographically documented stable coronary artery disease and determined monocyte subtypes by flow cytometry. sdLDL was measured by an electrophoresis method on polyacrylamide gel. Results Patients with sdLDL levels in the highest tertile (sdLDL≥4mg/dL;T3) showed the highest levels of pro-inflammatory NCM (15.2±7% vs. 11.4±6% and 10.9±4%, respectively; p<0.01) when compared with patients in the middle (sdLDL=2-3mg/dL;T2) and lowest tertile (sdLDL=0-1mg/dL;T1). Furthermore, patients in the highest sdLDL tertile showed lower CM levels than patients in the middle and lowest tertile (79.2±8% vs. 83.9±7% and 82.7±5%; p<0.01 for T3 vs. T2+T1). Levels of IM were not related to sdLDL levels (5.6±4% vs. 4.6±3% vs. 6.4±3% for T3, T2 and T1, respectively). In contrast to monocyte subset distribution, levels of circulating pro- and anti-inflammatory markers were not associated with sdLDL levels. Conclusion The atherogenic lipoprotein fraction sdLDL is associated with an increase of NCM and a decrease of CM. This could be a new link between lipid metabolism dysregulation, innate immunity and atherosclerosis.

Atherogenic versus non-atherogenic lipoprotein profiles in healthy individuals. is there a need to change our approach to diagnosing dyslipidemia?

The electrophoretic separation of lipoproteins on polyacrylamide gels enables the quantification of nonatherogenic and atherogenic plasma lipoproteins including small dense low density lipoprotein (sdLDL) particles, which represent the atherogenic lipoprotein subpopulations in plasma. This methodology could help distinguish between nonatherogenic hyperlipidemia, normolipidemia with an atherogenic lipoprotein profile, non-atherogenic normolipidemia, and atherogenic hyperlipidemia. According to our pilot research of a normolipidemic population, the atherogenic lipoprotein profile might be present in about 6% of normolipidemic young healthy individuals. Therefore, if confirmed by other studies, it will be necessary to consider a different diagnostic approach and risk stratification for patients with atherogenic normolipidemia (as well as non-atherogenic hypercholesterolemia).

Paraoxonase 1 and HDL subfractions in hypercholesterolemic children and adolescents

BACKGROUND Assessment of the cardiovascular disease (CVD) risk factors in children can predict clinical manifestations of atherosclerosis in adulthood. The arylesterase (PON1-A) and lactonase (PON1-L) activities of paraoxonase 1 (PON1) and lipid parameters (Total cholesterol (TCH), VLDL-cholesterol (VLDL), triacylglycerols (TAG), HDL-cholesterol (HDL), LDL-cholesterol (LDL) and LDL- and HDL-subfractions and their mutual associations in 27 hypercholesterolemic children and adolescents were investigated. METHODS Serum levels of TCH and TAG were determined using a Hitachi 911 analyser (Roche Diagnostics, Switzerland). LDL- and HDL-subfractions were determined by Lipoprint® system (Quantimetrix, Corp., USA). PON1-A and PON1-L activities were determined according to Gan et al. (1991) and Aviram and Rosenblat (2008). RESULTS PON1-A activity was higher compared to healthy children (134.1±26.2 vs. 118.16±7.05 U/ml) and PON1-L was not different from healthy controls. Increased levels of atherogenic risk factors TCH, VLDL, IDL1 subfraction and decreased levels of the antiatherogenic IDL3 and LDL1 subfractions were observed in the hypercholesterolemic children compared to reference values. Increased levels of large HDL subfractions, comparable levels of intermediate HDL and lower levels of small HDL subfractions were observed in hypercholesterolemic children compared to healthy adults (in absence of data available for healthy children). No significant correlation between PON1-A and HDL subfractions was found. PON1-L activity positively correlated with antiatherogenic large HDL1 subfraction and negatively correlated with intermediate HDL4, 5 and 6 subfractions. CONCLUSIONS The findings suggest that the PON1-L activity rather than PON1-A activity play a protective role in atherosclerosis. We confirmed atheroprotective effect of large and atherogenic properties of small HDL subfractions. The intermediate HDL subfractions probably play no atheroprotective role.