Comparison of LDL trap assay to other tests of antioxidant capacity; effect of vitamin E and lovastatin treatment

Statins and foam cell formation: Impact on LDL oxidation and uptake of oxidized lipoproteins via scavenger receptors

The uptake of oxidized lipoproteins via scavenger receptors and the ensuing formation of foam cells are key events during atherogenesis. Foam cell formation can be reduced by treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins). The efficacy of statins is evidently due not only to their cholesterol-lowering properties, but also to lipid-independent pleiotropic effects. This review focuses on lipid-independent pleiotropic effects of statins that influence foam cell formation during atherogenesis, with special emphasis on oxidative pathways and scavenger receptor expression.

Selenoproteins, Cholesterol-Lowering Drugs, and the Consequences Revisiting of the Mevalonate Pathway

3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and peroxisome proliferator-activated receptor alpha activators (fibrates) are the backbone of pharmacologic hypercholesterolemia and dyslipidemia treatment. Many of their clinical effects, however, are still enigmatic. This article describes how a side road of the mevalonate pathway, characterized in recent years, can rationalize a major fraction of these unexplained observations. This side road is the enzymatic isopentenylation of selenocysteine-tRNA([Ser]Sec) (Sec-tRNA), the singular tRNA to decode the unusual amino acid selenocysteine. The functionally indispensable isopentenylation of Sec-tRNA requires a unique intermediate from the mevalonate pathway, isopentenyl pyrophosphate, which concomitantly constitutes the central building block for cholesterol biosynthesis, and whose formation is suppressed by statins and fibrates. The resultant inhibition of Sec-tRNA isopentenylation profoundly decreases selenoprotein expression. This effect might seamlessly explain the immunosuppressive, redox, endothelial, sympatholytic, and thyroidal effects of statins and fibrates as well as their common side effects and drug interactions.

Effects of preventive group education on the resistance of LDL against oxidation and risk factors for coronary heart disease in bypass surgery patients

BACKGROUND

Comprehensive preventive education for heart patients is effective in reducing cardiac events. However, very demanding counselling protocols cannot easily be implemented as an integral part of clinical practice in hospitals.

AIM

To evaluate whether recurrent preventive group education for coronary artery bypass grafting patients affects the resistance of LDL against oxidation and the classical risk factors for coronary heart disease.

METHODS

A prospective, controlled study with one-year follow-up was carried out in Southern Finland. Coronary artery bypass patients were allocated late (> or = 18 months) after the operation in the intervention and control groups.

RESULTS

Seventy two patients (65 men and 7 women) completed the study. Twelve-hour group education on healthy life-style had a significant (25%, P = 0.01) but transient positive effect on the resistance of LDL against oxidation. There was a trend towards increased physical activity in the intervention group. The impact of education on patients' weight was also more consistent (1.2 kg at 12 months, P < 0.05), whereas long-term effects on fibrinogen and serum lipids were small.

CONCLUSIONS

Repeated group education applied as an economically feasible part of specialist care had only small positive effects on patients' risk factors. There was a significant, but transient, increase in the resistance of LDL against oxidation. However, effective lipid lowering drug treatment is indicated for most coronary artery bypass patients rather than repeated health education alone.