New risk factors for coronary heart disease

Elements of Mediterranean diet improve oxidative status in blood of kidney graft recipients

Patients were fully informed as to the study objectives and benefits, and provided written consent prior to enrolment. The study protocol was approved by the Committee on Human Research at the Pomeranian Medical University, Szczecin, Poland. An intensification of free-radical reactions may contribute to accelerated atherosclerosis in kidney graft recipients. We examined the effect of a Mediterranean-type diet (MD) on the oxidative status of the plasma and erythrocytes of kidney graft recipients. Two patient groups were formed: a study group consuming the MD diet and a control group with a low-fat diet. C-reactive protein levels in plasma, oleic acid C18: 1n-9 and linoleic acid C18: 2n-6 concentrations in triacyloglycerols were determined. To determine the oxidative status, we measured the concentrations of α-tocopherol in plasma, the content of thiobarbituric acid-reactive species (TBARS) in plasma and erythrocytes, and the activities of superoxide dismutase, catalase and glutathione peroxidase in erythrocytes. In the MD group, the activities of erythrocyte enzymes changed significantly: those of superoxide dismutase increased (P<0.001 after 6 months), catalase decreased (P<0.001 after 6 months) and glutathione peroxidase decreased (P<0.05 after 2 months). The oleic acid content of triacylglycerols was increased (P<0.006) whereas that of linoleic acid was decreased (P<0.00005), α-tocopherol levels remaining unchanged. TBARS in plasma were decreased after 6 months of MD (P<0.05). No significant correlations were observed between TBARS, oleic acid, linoleic acid and α-tocopherol levels in plasma. MD appears to protect the erythrocytes against the action of free radicals, as reflected in the modified activities of some enzymes regulating the oxidative status of these blood cells.

A comparison of the Framingham and European Society of Cardiology coronary heart disease risk prediction models in the normative aging study

BACKGROUND

A number of prediction models have been developed in an attempt to accurately identify patients at increased risk of a first coronary heart disease event. We sought to determine the ten-year incidence of coronary heart disease events in a healthy cohort with measurable risk factors, and to compare these results with the predicted number of events by use of both the Framingham and European Society of Cardiology risk prediction models.

METHODS

We compared the predicted and observed number of events in 5 risk categories in 1393 subjects aged 30 to 74 years who were enrolled in the Normative Aging Study.

RESULTS

The risk prediction models reliably stratify populations with regards to relative risk of coronary heart disease events and there is reasonable agreement between the 2 models (weighted kappa = 0.46, P <.01). The Framingham model underestimated the absolute risk of coronary heart disease events in the low-risk group, and both risk prediction models overestimated the absolute risk of events in the high- or very-high-risk groups (Framingham c-statistic = 0.60, European Society of Cardiology c-statistic = 0.58).

CONCLUSIONS

Despite simplification, the accuracy of the European model was not significantly different from the Framingham model. But the accuracy of absolute risk prediction, particularly at the extremes of risk, is imperfect. Refinement and validation of these risk prediction models is important because they affect the management of individual patients and the allocation of community resources.

[Genetic risk factors for myocardial infarct]

Interactions of genetic and environmental risk factors influence the susceptibility to coronary artery disease (CAD) and myocardial infarction. In myocardial infarction occurring at young age, genetics of this multifactorial disease may be the leading factor. A number of candidate genes have been implicated in the pathogenesis of CAD and myocardial infarction. Mutations in the DNA sequence (gene polymorphisms) have been identified that appear to play a crucial role in blood pressure regulation, lipid metabolism, endothelial function, in the pathophysiology of coagulation or thrombosis, or in interventional cardiology by interfering with restenosis development. Genetic polymorphisms seem to be clinically important because they not only potentiate the individual risk under certain circumstances, but they also determine safety and effectiveness of commonly prescribed drugs. Understanding the complexity and functional relevance of genetic risk factors will be useful in early detection and treatment of individuals that are exposed to higher risk for myocardial infarction. Thus it is important to include genetic risk factors in the concept of the classical risk factor theory. Potentially in future a genetic risk profile including relevant polymorphisms may be an essential part of the clinicians' knowledge in primary and secondary prevention of coronary artery disease.