Acute Prolonged Exercise Reduces Moderately Oxidized LDL in Healthy Men

Lipid Oxidation Products and the Risk of Cardiovascular Diseases: Role of Lipoprotein Transport

Cholesterol has for decades ruled the history of atherosclerotic cardiovascular diseases (CVDs), and the present view of the etiology of the disease is based on the transport of cholesterol by plasma lipoproteins. The new knowledge of the lipoprotein-specific transport of lipid oxidation products (LOPs) has introduced another direction to the research of CVD, revealing strong associations between lipoprotein transport functions, atherogenic LOP, and CVD. The aim of this review is to present the evidence of the lipoprotein-specific transport of LOP and to evaluate the potential consequences of the proposed role of the LOP transport as a risk factor. The associations of cholesterol and lipoprotein LOP with the known risk factors of CVD are mostly parallel, and because of the common transport and cellular intake mechanisms it is difficult to ascertain the independent effects of either cholesterol or LOP. While cholesterol is known to have important physiological functions, LOPs are merely regarded as metabolic residues and able to initiate and boost atherogenic processes. It is therefore likely that with the increased knowledge of the lipoprotein-specific transport of LOP, the role of cholesterol as a risk factor of CVD will be challenged.

The Placebo-Controlled Effect of Percutaneous Coronary Intervention on Exercise Induced Changes in Anti-Malondialdehyde-LDL Antibody Levels in Stable Coronary Artery Disease: A Substudy of the ORBITA Trial

Aim: Malondialdehyde-modified low-density lipoprotein (MDA-LDL) forms a significant component of oxidised LDL. The effects of exercise on levels of MDA-LDL and anti-MDA-LDL antibodies are not well-understood. Furthermore, it is not known whether these can be modified in patients with coronary artery disease by percutaneous coronary intervention (PCI). Methods: The Objective Randomised Blinded Investigation with optimal medical Therapy of Angioplasty in stable angina (ORBITA) trial was the first blinded, multi-centre randomised trial of PCI vs. placebo procedure for angina relief. Serum samples were available at four time-points: pre-randomisation pre- (P1) and post- (P2) exercise and post-randomisation (6-weeks following the PCI or placebo procedure), pre- (P3) and post- (P4) exercise. ELISAs were performed using laboratory-developed assays for MDA-LDL (adjusted for Apolipoprotein B) and anti-MDA-LDL antibodies. Results: One hundred ninety-six of the 200 patients (age 66.1 [SD 8.99] years, 28% female) with severe single vessel coronary artery disease suitable for PCI enrolled in the ORBITA trial had blood available for analysis. With exercise at pre-randomisation (P2-P1) there was no significant change in adjusted MDA-LDL (-0.001, 95% CI -0.004 to 0.001; p = 0.287); however, IgG and IgM anti-MDA-LDL significantly declined (-0.022, 95% CI -0.029 to -0.014, p < 0.0001; -0.016, 95% CI -0.024 to -0.008, p = 0.0002, respectively). PCI did not have a significant impact on either the pre-exercise values (P3 controlling for P1) of MDA-LDL (p = 0.102), IgG (p = 0.444) or IgM anti-MDA-LDL (p = 0.909). Nor did PCI impact the exercise induced changes in these markers (P4 controlling for P1, P2, and P3) for MDA-LDL (p = 0.605), IgG (p = 0.725) or IgM anti-MDA-LDL (p = 0.171). Pre-randomisation ischaemia on stress echo did not impact these interactions. Conclusions: Exercise results in an acute reduction in anti-oxLDL antibodies in patients with severe single vessel coronary disease, possibly indicating an induction in homoeostatic clearance via the innate immune system. However, PCI did not ameliorate this effect.

Effects of a Two-Year Home-Based Exercise Training Program on Oxidized LDL and HDL Lipids in Coronary Artery Disease Patients with and without Type-2 Diabetes

We investigated the effect of two-year home-based exercise training program on oxidized low-density lipoprotein LDL (ox-LDL) and high-density lipoprotein HDL (ox-HDL) lipids in patients with coronary artery disease (CAD), both with and without type-2 diabetes (T2D). Analysis of lipoprotein-oxidized lipids was based on the determination of baseline conjugated dienes in lipoprotein lipids. In order to study the effect of an exercise load on ox-LDL and ox-HDL lipids patients in both CAD and CAD + T2D intervention, groups were divided in three based on exercise load (high, medium, and low). During the two-year home-based exercise training program, the study showed that only higher training volume resulted in a decreased concentration of ox-LDL, while the two groups with lower training volumes showed no change. This result indicates that the training load needs to be sufficiently high in order to decrease the concentration of atherogenic ox-LDL lipids in patients with CAD and CAD + T2D. Interestingly, the concentration of ox-HDL did not change in any of the subgroups. This could indicate that the lipid peroxide-transporting capacity of HDL, suggested by results from exercise training studies in healthy adults, may not function similarly in CAD patients with or without T2D. Moreover, the lipid-lowering medication used may have had an influence on these results.

Psoriasis and physical activity: a review

Psoriasis is a common, chronic inflammatory skin disease that can cause significant discomfort and impairment to quality of life. Recent research indicates that individuals with moderate-to-severe psoriasis are likely at greater risk for chronic cardiometabolic co-morbidities such as cardiovascular disease, type 2 diabetes, obesity and metabolic syndrome. Physical activity can be an effective primary and adjunctive treatment for these maladies in other populations. Unfortunately, only a limited number of studies have examined physical activity in psoriasis, which are limited by poor design and lack of validated physical activity assessment methodologies. A variety of data suggest shared physiologic pathways between physical activity, psoriasis, and psoriasis cardiometabolic co-morbidities. Increased adiposity, inflammation, oxidative stress, adhesion molecules and lipids are physiologically linked to psoriasis, the risk of psoriasis cardiometabolic co-morbidities, and low levels of physical activity. In addition, epigenetic pathways are involved in psoriasis and could be influenced by physical activity. The physical and psychosocial impairments common in psoriasis may make it difficult to participate in regular physical activity, and future studies should aim to determine if physical activity interventions improve functioning and reduce co-morbidities in psoriasis.

Lipoprotein-specific transport of circulating lipid peroxides

BACKGROUND

Serum lipoproteins, the carriers of cholesterol and other lipophilic substances in blood, are known to contain variable amounts of lipid peroxides. We investigated the transport of food-derived and endogenously formed lipid peroxides by serum lipoproteins under physiological conditions.

METHODS

Five independent trials were conducted in which different groups of healthy volunteers either consumed a test meal (a standard hamburger meal rich in lipid peroxides) or underwent strenuous physical exercise. The transport function was characterized by analyzing the kinetics of lipid peroxides in lipoprotein fractions. For evaluation of their potential involvement, indicators of oxidative stress (8-isoprostanes, malondialdehyde, 8-oxo-deoxyguanosine), antioxidant functions (total antioxidant potential, paraoxonase activity), and serum lipids were also analyzed.

RESULTS

We found that food lipid peroxides are incorporated into serum triglyceride-rich lipoproteins and low-density lipoprotein, directing the flow of lipid peroxides towards peripheral tissues. High-density lipoprotein appears to have an opposite and protective function, and is able to respond to oxidative stress by substantially increasing the reverse transport of lipid peroxides.

CONCLUSIONS

We propose that the specific atherosclerosis-related effects of serum lipoproteins are not explained by cholesterol transport alone and may rather result from the transport of the more directly atherogenic lipid peroxides.

A influência da intensidade do exercício físico aeróbio no processo aterosclerótico

A aterosclerose é um processo inflamatório crônico e degenerativo que acomete os vasos, sendo caracterizada pelo acúmulo de lipídeos no espaço subendotelial da íntima, acúmulo de células inflamatórias e elementos fibrosos. A oxidação de LDL-c parece ser o principal evento para o início da aterosclerose. O exercício físico aeróbio melhora os sistemas de defesa orgânicos contra aterosclerose, diminuindo o estresse oxidativo e aumentando a síntese de enzimas antioxidantes; aumento da vasodilatação via óxido nítrico (NO) e óxido nítrico sintase endotelial (eNOS) e diminuição da inflamação sistêmica com produção de citocinas pró-inflamatórias e aumento de fatores anti-inflamatórios. Porém, de maneira aguda, o exercício aeróbio de alta intensidade aumenta o risco de desenvolvimento de eventos cardiovasculares e, de forma crônica, pode atuar negativa ou positivamente na prevenção do processo aterosclerótico.

Nutritional status of adventure racers

OBJECTIVE

We describe the usual food intake, body composition, and biochemical profile of adventure racers during their training season and evaluate their energy and nutrient intake in relation to current recommendations for ultraendurance athletes.

METHODS

Twenty-four adventure race athletes (18 men and 6 women), 24 to 42 y of age, participated in the study. Food intake was determined with a 3-d food record and body composition by plethysmography. Blood samples were obtained from all subjects for biochemical analyses. All assessments were made during the usual training phase.

RESULTS

Female athletes had a higher body fat percentage than did male athletes (20.2 +/- 5.7% versus 12.5 +/- 3.5%). For men and women, food intake was high in protein (1.9 +/- 0.5 g/kg in men, 2.0 +/- 0.4 g/kg in women) and fat (1.6 +/- 0.3 g/kg in men, 1.5 +/- 1.3 g/kg in women). Carbohydrate intake of male athletes was at the lower limit of that recommended (5.9 +/- 1.8 g/kg). For most vitamins and minerals, athletes' intake was adequate, with the exception of magnesium, zinc, and potassium in men and women and vitamin E and calcium in women, which presented a high probability of being inadequate compared with reference values. High blood levels of total cholesterol and low-density lipoprotein cholesterol were found in female athletes (201.0 +/- 44.7 and 104.1 +/- 43.1 mg/dL, respectively) and all other biochemical analyses were within normal reference values.

CONCLUSION

The adventure racers presented an inadequate nutritional profile when compared with recommendations for endurance exercise. These athletes need to be educated about consuming an adequate diet to meet the nutritional needs of their activity.