The effect of physical exercise on reverse cholesterol transport

Cardiorespiratory fitness, atrial fibrillation and stroke: a review of the evidence in 2024

INTRODUCTION

The body of evidence linking cardiorespiratory fitness (CRF) levels with the risk of atrial fibrillation (AF) and stroke - two interconnected cardiovascular conditions - is not entirely consistent. Furthermore, specific CRF thresholds beyond which the risk of AF or stroke might not decrease are not well defined.

AREAS COVERED

This review summarizes research evidence on the role of CRF in the development of AF and stroke including dose-response relationships in general population participants, explores the biological mechanisms through which CRF may exert its effects, assesses the potential implications for clinical care and population health, identifies gaps in the current evidence, and suggest directions for future research. MEDLINE and Embase were searched from inception until July 2024 to identify observational longitudinal and interventional studies as well as systematic reviews and meta-analyses related to these study designs.

EXPERT OPINION

In the general population, increasing levels of CRF, achieved through consistent physical activity, can significantly reduce the likelihood of developing AF and stroke. The findings also advocate for a tailored approach to exercise prescriptions, acknowledging the plateau in benefits for AF risk beyond certain CRF levels, while advocating for higher intensity or prolonged activity to further reduce stroke risk.

Effectiveness of Combined Aerobic and Resistance Exercise on Cognition, Metabolic Health, Physical Function, and Health-related Quality of Life in Middle-aged and Older Adults With Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis

OBJECTIVES

To evaluate the effectiveness of combined aerobic and resistance exercise on cognition, metabolic health, physical function, and health-related quality of life (HRQoL) in middle-aged and older adults with type 2 diabetes mellitus (T2DM).

DATA SOURCE AND STUDY SELECTION

Systematic search of CINAHL, Cochrane, EMBASE, Scopus, PubMed, ProQuest Dissertation and Thesis, PsycINFO, Web of Science databases, and gray literature from Google Scholar. Pertinent randomized controlled trials (RCTs) were selected. The Protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42023387336).

DATA EXTRACTION

The risk of bias was evaluated using the Cochrane Risk of Bias tool by 2 reviewers independently. Outcome data were extracted in a fixed-effect model if heterogeneity test were not significant and I2≤50%; otherwise, the random-effects model was used.

DATA SYNTHESIS

Sixteen studies with 2426 participants were included in this review. Combined aerobic and resistance exercise had significant positive effects on cognition (SMD=0.34, 95% CI: 0.13 to 0.55), metabolic health on HbA1c (SMD=-0.35, 95% CI: -0.48 to -0.22) and lipid profile (total cholesterol SMD=-0.20, 95% CI: -0.34 to -0.07; low-density lipoprotein SMD=-0.19, 95% CI: -0.33 to -0.05; high-density lipoprotein SMD=0.25, 95% CI: 0.12 to 0.39; and triglycerides SMD=-0.18, 95% CI: -0.31 to -0.04), physical function on aerobic oxygen uptake (SMD=0.58, 95% CI: 0.21 to 0.95) and body mass index (MD=-1.33, 95% CI: -1.84 to -0.82), and physical HRQoL (MD=4.17, 95% CI: 0.86 to 7.48). Our results showed that clinically important effects on cognition may occur in combining the low-moderate intensity of aerobic exercise and progressive intensity of resistance training, the total duration of the exercise needs to be at least 135 minutes per week, among which, resistance training should be at least 60 minutes.

CONCLUSION

Combined aerobic and resistance exercise effectively improves cognition, ameliorates metabolic health, enhances physical function, and increases physical HRQoL in middle-aged and older adults with T2DM. More RCTs and longitudinal follow-ups are required to provide future evidence of structured combined aerobic and resistance exercise on other domains of cognition.

Physical activity, exercise and adverse cardiovascular outcomes in individuals with pre-existing cardiovascular disease: a narrative review

INTRODUCTION

The evidence supporting the cardiovascular health benefits of physical activity and/or exercise training is well-established. While the role of physical activity in primary prevention is unequivocal, its significance in secondary prevention (among those with preexisting cardiovascular disease) is less definitive. Though guidelines universally recommend physical activity as part of the secondary preventive strategy, the empirical evidence underpinning these recommendations is not as robust as that for primary prevention.

AREAS COVERED

This review distills the body of available observational and interventional evidence on the relationship between physical activity, exercise, and adverse cardiovascular outcomes among those with preexisting cardiovascular disease. The postulated biologic mechanisms underlying the relationships, areas of prevailing uncertainty, and potential public health implications are also discussed.

EXPERT OPINION

A physical activity level of 500 MET-min/week (equivalent to 150 min of moderate-intensity physical activity or 75 min of vigorous-intensity physical activity or an equivalent combination) may be a minimum requirement for patients with preexisting CVD. However, to reap the maximum benefits of physical activity and also minimize adverse effects, physical activity and/or exercise regimens should be tailored to unique factors such as individual's baseline physical activity habits, cardiovascular health status and the specific nature of their cardiovascular disease.

The Impact of Aerobic Exercise on HDL Quantity and Quality: A Narrative Review

High-density lipoproteins comprise roughly 25-30% of the circulating proteins involved in the transport of lipids in circulation. These particles differ in size and lipid composition. Recent evidence suggests that the quality of HDL particles (which depends on shape, size and the composition of proteins and lipids determining HDL functionality) may be more important than their quantity. The functionality of HDL is mirrored by its cholesterol efflux activity, as well as its antioxidant (including the protection of LDL against oxidation), anti-inflammatory and antithrombotic properties. The results of many studies and meta-analyses imply the beneficial impact of aerobic exercise on HDL-C levels. Physical activity was found to be usually associated with an increase in HDL cholesterol and a decrease in LDL cholesterol and triglycerides. Exercise, apart from inducing quantitative alterations in serum lipids, exerts a beneficial impact on HDL particle maturation, composition and functionality. The Physical Activity Guidelines Advisory Committee Report underlined the importance of establishing a program recommending exercises that enable attainment of maximal advantage at the lowest level of risk. The aim of this manuscript is to review the impact of different types of aerobic exercise (various intensities and durations) on the level and quality of HDL.

Objectively Assessed Cardiorespiratory Fitness and All-Cause Mortality Risk: An Updated Meta-analysis of 37 Cohort Studies Involving 2,258,029 Participants

OBJECTIVE

To detail the magnitude and specificity of the association between cardiorespiratory fitness (CRF) and all-cause mortality risk.

METHODS

Cohort studies with at least 1 year of follow-up were sought from inception until December 2021 in MEDLINE, Embase, Web of Science, and a manual search of relevant articles. Relative risks (RRs) with 95% CIs were pooled using random-effects models. Quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool.

RESULTS

A total of 37 unique studies comprising of 2,258,029 participants with 108,613 all-cause mortality events were eligible. The pooled multivariable-adjusted RR for all-cause mortality comparing the top vs bottom tertiles of CRF levels was 0.55 (95% CI, 0.50 to 0.61). When CRF was expressed in metabolic equivalent task (MET) units, the corresponding pooled RR was 0.56 (95% CI, 0.50 to 0.62). For every 1-MET increase in CRF, the RR for all-cause mortality was 0.89 (95% CI, 0.86 to 0.92). Strength of the association did not differ by publication year, age, sex, follow-up duration, CRF assessment method, or risk of bias.

CONCLUSION

Aggregate analysis of observational cohort studies confirms a strong inverse and independent association between CRF and all-cause mortality risk. The results suggest that guideline bodies should consider the inclusion of CRF in standard risk panels for mortality risk assessment.

Exercise Ameliorates Atherosclerosis via Up-Regulating Serum β-Hydroxybutyrate Levels

Atherosclerosis, accompanied by inflammation and metabolic disorders, is the primary cause of clinical cardiovascular death. In recent years, unhealthy lifestyles (e.g., sedentary lifestyles) have contributed to a worldwide epidemic of atherosclerosis. Exercise is a known treatment of atherosclerosis, but the precise mechanisms are still unknown. Here, we show that 12 weeks of regular exercise training on a treadmill significantly decreased lipid accumulation and foam cell formation in ApoE^−/− mice fed with a Western diet, which plays a critical role in the process of atherosclerosis. This was associated with an increase in β-hydroxybutyric acid (BHB) levels in the serum. We provide evidence that BHB treatment in vivo or in vitro increases the protein levels of cholesterol transporters, including ABCA1, ABCG1, and SR-BI, and is capable of reducing lipid accumulation. It also ameliorated autophagy in macrophages and atherosclerosis plaques, which play an important role in the step of cholesterol efflux. Altogether, an increase in serum BHB levels after regular exercise is an important mechanism of exercise inhibiting the development of atherosclerosis. This provides a novel treatment for atherosclerotic patients who are unable to undertake regular exercise for whatever reason. They will gain a benefit from receiving additional BHB.

Percentage of Age-Predicted Cardiorespiratory Fitness and Risk of Incident Hypertension: A PROSPECTIVE COHORT STUDY

PURPOSE

There are inverse and independent associations between cardiorespiratory fitness (CRF) and several adverse cardiometabolic outcomes including hypertension (HTN). The prospective relationship between percentage of age-predicted CRF and risk of HTN has not been previously investigated. We aimed to assess the association of percentage of age-predicted CRF with incident HTN in a long-term prospective cohort study.

METHODS

Cardiorespiratory fitness, as measured by peak oxygen uptake, was assessed using the gold standard respiratory gas exchange analyzer in 1602 men who underwent cardiopulmonary exercise testing. The age-predicted CRF estimated from a regression equation for age was converted to percentage of age-predicted CRF ([achieved CRF/age-predicted CRF] × 100). The HR with 95% CI were estimated for HTN.

RESULTS

During a median follow-up of 26.8 yr, 308 HTN cases were recorded. There was a linear relationship between age-predicted CRF and incident HTN (P value for nonlinearity = .68). A 1-SD increase in percentage of age-predicted CRF was associated with a decreased risk of HTN in analysis adjusted for established risk factors (HR = 0.79: 95% CI, 0.69-0.90), which remained consistent on further adjustment for several other potential confounders including alcohol consumption, physical activity, socioeconomic status, and inflammation (HR = 0.83: 95% CI, 0.72-0.95). The corresponding adjusted HRs were 0.55 (95% CI, 0.38-0.80) and 0.63 (95% CI, 0.43-0.91), respectively, when comparing extreme quartiles of percentage of age-predicted CRF levels.

CONCLUSIONS

Percentage of age-predicted CRF is linearly, inversely, and independently associated with risk of incident HTN, and it is comparable to absolute CRF as a risk indicator for HTN in a general population of middle-aged men.

Indices of Cardiovascular Health, Body Composition and Aerobic Endurance in Young Women; Differential Effects of Two Endurance-Based Training Modalities

Endurance training (ET) has multiple beneficial effects on cardiovascular health (CVH), but there is an evident lack of knowledge on differential effects of various types of ET on indices of CVH in women. The aim of this study was to analyse the effectiveness of two different types of ET on changes in indicators of CVH in apparently healthy adult women. The sample included 58 women (24 ± 3 years; height: 165 ± 6 cm, mass: 66.7 ± 7.2 kg, BMI: 24.3 ± 2.5 kg/m², at baseline) divided into one control non-exercising group (n = 19), and two exercising experimental groups (EE). The first EE participated in choreographed aerobic-endurance training (CAT; n = 19), while the second participated in treadmill-based endurance exercise (TEE; n = 20) during the experimental protocol (8 weeks, 24 training sessions). The testing included pre- and post-exercise protocols and measures of anthropometric/body composition indices, lipid panel, and endurance capacity. Two-way analysis of variance for repeated measurements with consecutive post hoc analysis was applied to the “group” and “measurement” variables. The main significant ANOVA effects found for measurement, and “Group x Measurement” interaction (p < 0.05) were found for all variables but body height. The EE induced positive changes in lipid panel variables, anthropometric/body-build status, and endurance capacity. However, TEE improved endurance capacity to a greater extent than CAT. The results suggest that that the optimal exercise intensity and self-chosen type of physical-activity may result in positive effects on indices of CVH, even in women of young age and good health status.

Percentage of age-predicted cardiorespiratory fitness and risk of sudden cardiac death: A prospective cohort study

BACKGROUND

The inverse associations between cardiorespiratory fitness (CRF) and vascular outcomes have been established. However, there has been no prospective evaluation of the relationship between percentage of age-predicted cardiorespiratory fitness (%age-predicted CRF) and risk of sudden cardiac death (SCD).

OBJECTIVE

The purpose of this study was to assess the association of %age-predicted CRF with SCD risk in a long-term prospective cohort study.

METHODS

CRF was assessed using the gold standard respiratory gas exchange analyzer in 2276 men who underwent cardiopulmonary exercise testing. The age-predicted CRF estimated from a regression equation for age was converted to %age-predicted CRF using (Achieved CRF/Age-predicted CRF) × 100. Hazard ratios (HRs) [95% confidence intervals (CIs)] were calculated for SCD.

RESULTS

During median follow-up of 28.2 years, 260 SCDs occurred. There was a dose-response relationship between age-predicted CRF and SCD. A 1-SD increase in %age-predicted CRF was associated with a decreased risk of SCD in analysis adjusted for established risk factors (HR 0.60; 95% CI 0.53-0.70), which remained consistent on further adjustment for several potential confounders, including alcohol consumption, physical activity, socioeconomic status, and systemic inflammation (HR 0.73; 95% CI 0.62-0.85). The corresponding adjusted HRs were 0.34 (0.23-0.50) and 0.52 (0.34-0.79), respectively, when comparing extreme quartiles of %age-predicted CRF levels. HRs for the associations of absolute CRF levels with SCD risk in the same participants were similar.

CONCLUSION

Percentage of age-predicted CRF is continuously, strongly, and independently associated with risk of SCD and is comparable to absolute CRF as a risk indicator for SCD.

The effect of 10 days of energy-deficit diet and high-intensity exercise training on the plasma high-density-lipoprotein (HDL) level among healthy collegiate males

ABSTRACTAn energy-deficit (ED) diet increases lipid mobilisation, while endurance exercise improves lipid profile by promoting formation of high-density lipoproteins (HDLs) among moderately active population. However, it is not clear whether ED with high-intensity exercise training can improve lipid profiles. Therefore, 20 recreationally active males (20.3 ± 2.7 years old with peak oxygen consumption (V˙O₂peak) of 2.8 ± 0.2 L min^-1) with HDL concentration of 1.44 ± 0.32 mmol L^-1, were evenly allocated to either an ED group (1590 ± 79 kcal day^-1: 40% of total caloric omitted at lunchtime) or a control (CON) group (2570 ± 139 kcal day^-1). Participants in both groups performed high-intensity cycling at 90% V˙O₂peak at a constant workload for 8 min, 2 h after breakfast on day D₀, D₂, D₄, D₆, D₈ and D₁₀ (D_n is day number), after which blood samples were collected. In ED, compared to D₀, triglycerides (TG) decreased on D_6-10 (p < .01) while total low-density lipoprotein (LDL), total cholesterol (TC) increased on D_2-10, while HDL progressively increased on D_6-10 (p = .01) with a final value of 1.67 ± 0.24 mmol L^-1. In CON, there were no changes in TG, TC and HDL while LDL was reduced on D_8-10 (p = .01). Moreover, the proportions of TC/HDL and LDL/HDL increased in ED on D_2-10 and D_2-8 (p = .05), respectively, while LDL/HDL in CON was reduced on D_8-10 (p = .01). In brief, 10 days of ED and a series of high-intensity exercise sessions show progressive elevation of HDL which suggest longer period is required to observe changes in lipid ratios.

Cholesterol Efflux Efficiency of Reconstituted HDL Is Affected by Nanoparticle Lipid Composition

Cardiovascular disease (CVD), the leading cause of mortality worldwide is primarily caused by atherosclerosis, which is promoted by the accumulation of low-density lipoproteins into the intima of large arteries. Multiple nanoparticles mimicking natural HDL (rHDL) have been designed to remove cholesterol excess in CVD therapy. The goal of this investigation was to assess the cholesterol efflux efficiency of rHDLs with different lipid compositions, mimicking different maturation stages of high-density lipoproteins (HDLs) occurring in vivo. Methods: the cholesterol efflux activity of soybean PC (Soy-PC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), DPPC:Chol:1-palmitoyl-2-hydroxy-sn-glycero-3-phosphocholine (LysoPC) and DPPC:18:2 cholesteryl ester (CE):LysoPC rHDLs was determined in several cell models to investigate the contribution of lipid composition to the effectiveness of cholesterol removal. Results: DPPC rHDLs are the most efficient particles, inducing cholesterol efflux in all cellular models and in all conditions the effect was potentiated when the ABCA1 transporter was upregulated. Conclusions: DPPC rHDLs, which resemble nascent HDL, are the most effective particles in inducing cholesterol efflux due to the higher physical binding affinity of cholesterol to the saturated long-chain-length phospholipids and the favored cholesterol transfer from a highly positively curved bilayer, to an accepting planar bilayer such as DPPC rHDLs. The physicochemical characteristics of rHDLs should be taken into consideration to design more efficient nanoparticles to promote cholesterol efflux.

Prognostic Relevance of Cardiorespiratory Fitness as Assessed by Submaximal Exercise Testing for All-Cause Mortality: A UK Biobank Prospective Study

OBJECTIVE

To investigate whether the inverse associations of cardiorespiratory fitness (CRF) with all-cause and cardiovascular mortality in the general population vary among individuals who are at different levels of pretest risk.

PATIENTS AND METHODS

Cardiorespiratory fitness was assessed through submaximal bicycle tests in 58,892 participants aged 40 to 69 years who completed baseline questionnaires between January 1, 2006, and December 31, 2010, in the UK Biobank Prospective Study. Participants were categorized into risk categories, which determined allocation to an individualized bicycle protocol. The groups at minimal risk (category 1), small risk (category 2), and medium risk (category 3) were tested at 50%, 35% of the predicted maximal workload, and constant level, respectively. We investigated associations of CRF with mortality across different levels of pretest risk and determined whether CRF improves risk prediction.

RESULTS

During a median follow-up of 5.8 years, 936 deaths occurred. Cardiorespiratory fitness was linearly associated with mortality risk. Comparing extreme fifths of CRF, the multivariable-adjusted hazard ratios (95% CIs) for mortality were 0.63 (0.52-0.77), 0.54 (0.36-0.82), 0.81 (0.46-1.43), and 0.58 (0.48-0.69) in categories 1, 2, and 3 and overall population, respectively. The addition of CRF to a 5-year mortality risk score containing established risk factors was associated with a C-index change (0.0012; P=.49), integrated discrimination improvement (0.0005; P<.001), net reclassification improvement (+0.0361; P=.005), and improved goodness of fit (likelihood ratio test, P<.001). Differences in 5-year survival were more pronounced across levels of age, smoking status, and sex.

CONCLUSION

Cardiorespiratory fitness, assessed by submaximal exercise testing, improves mortality risk prediction beyond conventional risk factors and its prognostic relevance varies across cardiovascular risk levels.

The effect of curcumin and exercise rehabilitation on liver paraoxonase-1 and NF-kβ gene expression in the rat induced by forced drinking of ethanol

Aim of the study

Binge ethanol drinking causes liver damage and decreased paraoxonase-1 (PON-1) gene expression. On the other hand, regular physical activity and curcumin consumption as non-invasive interventions can have liver protective effects through enhancing antioxidant defense, and improving PON-1 and NF-kβ (nuclear factor kappa B) gene expression. The aim of this study was to investigate the interactive effect of exercise rehabilitation and curcumin consumption on hepatocyte damage as well as NF-kβ and PON-1 gene expression in rats.

Material and methods

Fifty-six male Wistar rats were randomly selected and equally divided into seven groups: dextrose-control (Dext-Con), ethanol-control (Eth-Con), ethanol-saline (Eth-sal), ethanol-DMSO (Eth-DMSO), ethanol-curcumin (Eth-Cur), ethanol-swimming training (Eth-SWT) and ethanol-SWT + curcumin (Eth-SWT + Cur). After four days of the binge drinking protocol followed by six days of quitting, the interventions of SWT and curcumin (50 mg/kg) were employed for 14 days. Afterwards, the rats’ liver tissues were collected and sent to the laboratory for biochemical assays.

Results

The interaction of SWT and curcumin caused an increase in PON-1 gene expression (p = 0.02). In addition, curcumin consumption (p = 0.003) and its interaction with SWT (p = 0.004) resulted in a reduction in NF-kβ gene expression. Also, liver tissue damage was observed in the Eth-Con group compared to other groups.

Conclusions

The combination of curcumin and SWT may be used to reduce the side effects of binge ethanol drinking and improve recovery in the quitting period.

Paraoxonase 3: Structure and Its Role in Pathophysiology of Coronary Artery Disease

Spanning three decades in research, Paraoxonases (PON1) carried potential of dealing with neurotoxicity of organophosphates entering the circulation and preventing cholinergic crisis. In the past few years, the Paraoxonase multigene family (PON1, PON2, PON3) has been shown to play an important role in pathogenesis of cardiovascular disorders including coronary artery disease (CAD). The PON genes are clustered in tandem on the long arm of human chromosome 7 (q21, 22). All of them have been shown to act as antioxidants. Of them, PON3 is the least studied member as its exact physiological substrate is still not clear. This has further led to limitation in our understanding of its role in pathogenesis of CAD and development of the potential therapeutic agents which might modulate its activity, expression in circulation and tissues. In the present review, we discuss the structure and activity of human PON3 enzyme and its Single nucleotide variants that could potentially lead to new clinical strategies in prevention and treatment of CAD.

Effects of alternate day fasting and exercise on cholesterol metabolism in overweight or obese adults: A pilot randomized controlled trial

BACKGROUND AND PURPOSE

The objective of this pilot randomized controlled trial was to investigate the effect of alternate day fasting (ADF) and exercise on serum sterol signatures, which are surrogate markers of cholesterol absorption and biosynthesis.

METHODS

We randomly assigned 112 overweight or obese participants to four groups: 1) ADF and exercise (E-ADF); 2) ADF; 3) exercise; and 4) control. We studied 31 completers in this exploratory analysis and measured their serum sterol signatures using gas chromatography-mass spectrometry.

RESULTS

After intervention, most serum sterol signatures that correspond to cholesterol metabolism were significantly different between groups (p < 0.05 by analysis of covariance [ANCOVA]). We found no differences in plant sterols, which are markers of cholesterol absorption. In the exercise group, desmosterol, cholesteryl esters, and oxysterols decreased significantly. Furthermore, only changes in physical activity levels negatively correlated with changes in the metabolic ratios of desmosterol and 7-dehydrocholesterol to cholesterol, which reflect cholesterol biosynthesis (r = -0.411; p = 0.030, and r = -0.540; p = 0.003, respectively).

CONCLUSION

These findings suggest that exercise with or without ADF improves cholesterol metabolism as measured by serum sterol signatures, and increased physical activity has a greater effect on cholesterol biosynthesis than weight reduction or calorie restriction.

Reverse Cholesterol Transport: Molecular Mechanisms and the Non-medical Approach to Enhance HDL Cholesterol

Dyslipidemia (high concentrations of LDL-c and low concentrations of HDL-c) is a major cause of cardiovascular events, which are the leading cause of death in the world. On the other hand, nutrition and regular exercise can be an interesting strategy to modulate lipid profile, acting as prevention or treatment, inhibiting the risk of diseases due to its anti-inflammatory and anti-atherogenic characteristics. Additionally, the possibility of controlling different training variables, such as type, intensity and recovery interval, can be used to maximize the benefits of exercise in promoting cardiovascular health. However, the mechanisms by which exercise and nutrients act in the regulation of cholesterol and its fractions, such as reverse cholesterol transport, receptors and transcription factors involved, such as PPARs and their role related to exercise, deserve further discussion. Therefore, the objective of this review is to debate about non-medical approaches to increase HDL-c, such as nutritional and training strategies, and to discuss the central mechanisms involved in the modulation of lipid profile during exercise, as well as that can be controlled by physical trainers or sports specialists in attempt to maximize the benefits promoted by exercise. The search for papers was performed in the databases: Medline (Pubmed), Science Direct, Scopus, Sport Discus, Web of Science, Scielo and Lilacs until February 2016.

Aerobic training performed at ventilatory threshold improves liver enzymes and lipid profile related to non-alcoholic fatty liver disease in adolescents with obesity

BACKGROUND

Despite the positive effects of high-intensity training on weight management and health-related outcomes, it is postulated that high-intensity training may also induce oxidative stress, increasing hepatic damage.

AIM

The aim of this study was to compare the effects of low versus high-intensity training on biomarkers related to non-alcoholic fatty liver disease (NAFLD) in adolescents with obesity.

METHODS

For this study 107 adolescents (15 ± 1 years) with obesity (BMI = 34.7 ± 4.1 kg/m²) were randomized into High-Intensity Training (HIT, n = 31), Low-Intensity Training (LIT, n = 31) or Control Group (CG, n = 45). Adolescents from HIT and LIT received nutritional, psychological and clinical counseling. Blood lipids, Castelli risk index, glucose, insulin and hepatic enzymes were measured at baseline and after 12 weeks.

RESULTS

Castelli risk index 1 was reduced in all groups ( p < 0.001) with moderate effect size ( d) for HIT ( d = 0.62) and LIT ( d = 0.66). Castelli risk index 2 also decreased ( p < 0.001 for all groups; HIT d = 0.65; LIT d = 0.79). High-density lipoprotein increased in all groups ( d = 0.25 and d = 0.18 in HIT and LIT), while alanine aminotransferase tended to reduce ( p = 0.062) in HIT ( d = 0.34) and LIT ( d = 0.73) and aspartate aminotransferase decreased ( p = 0.024) in both HIT ( d = 0.24) and LIT ( d = 0.45). There were no changes in glucose, insulin and insulin resistance.

CONCLUSION

Both high and low-intensity training improved biomarkers related to NAFLD. Thus, high-intensity training can be a safe and effective alternative to prevent and treat NAFLD in adolescents with obesity.

Associations of cardiovascular and all-cause mortality events with oxygen uptake at ventilatory threshold

BACKGROUND

Oxygen uptake (VO₂) at ventilatory threshold (VT), is a cardiopulmonary exercise testing parameter which may be a proxy for peak VO₂. We aimed to assess the associations of VO₂ at VT with sudden cardiac death (SCD), fatal coronary heart disease (CHD) and cardiovascular disease (CVD), and all-cause mortality.

METHODS AND RESULTS

VO₂ at VT was assessed during a submaximal exercise test using respiratory gas analyzers in the Kuopio Ischemic Heart Disease cohort of 1639 middle-aged men. Hazard ratios (HRs) (95% CIs) were assessed. During a median follow-up of 25.6years, 121 SCDs, 202 fatal CHDs, 312 fatal CVDs, and 703 all-cause mortality events occurred. VO₂ at VT was correlated with peak VO₂ (r=0.90) and linearly associated with each outcome. Comparing extreme quartiles of VO₂ at VT, the HRs (95% CIs) for SCD, fatal CHD, fatal CVD, and all-cause mortality on adjustment for established risk factors were 0.37 (0.18-0.78), 0.32 (0.18-0.57), 0.45 (0.30-0.69), and 0.50 (0.38-0.64) respectively. The HRs were 1.02 (0.36-2.91), 1.43 (0.63-3.25), 1.46 (0.79-2.71), and 1.02 (0.69-1.51) respectively on further adjustment for peak VO₂. Addition of VO₂ at VT to a CVD mortality risk prediction model containing established risk factors significantly improved risk discrimination and reclassification at 25years.

CONCLUSIONS

There are linear and inverse associations of VO2 at VT with fatal cardiovascular and all-cause mortality events, which are dependent on peak VO₂. Inclusion of VO₂ at VT in the standard established risk factors panel significantly improves the prediction and classification of long-term CVD mortality risk.

Cardiovascular and metabolic risk markers are related to parasympathetic indices in pre-pubertal adolescents

OBJECTIVE

To analyse the relationship between different heart rate variability indices, resting heart rate, and cardiovascular markers in adolescents.

METHODS

A cross-sectional study was carried out with information from an ongoing cohort study. The sample was composed of 99 adolescents who complied with the following inclusion criteria: aged between 11 and 14 years; enrolled in a school unit of elementary education; absence of any known diseases; no drug consumption; and a formal consent signed by the parents or legal guardians. Weight, height, heart rate variability, lipid profile, inflammatory markers, blood pressure, resting heart rate, intima-media thickness, blood flow, and trunk fatness were measured. Partial correlation and linear regression (expressed by β and 95% confidence intervals [95%CI]) analyses were used to analyse the relationships between the variables.

RESULTS

In the linear regression analysis, even after adjustments for sex, age, trunk fatness, and somatic maturation, parasympathetic activity presented significant correlations with maximum carotid artery blood flow (β=-0.111 [95%CI=-0.216; -0.007]), systolic blood pressure (β=-0.319 [95%CI=-0.638; -0.001]), and resting heat rate (β=-0.005 [95%CI=-0.009; -0.002]).

CONCLUSION

Parasympathetic activity at rest is inversely related to maximum and minimum blood flow, triacylglycerol levels, and systolic blood pressure. These findings suggest that heart rate variability has the potential to discriminate pre-pubertal adolescents at increased risk.

Effects of Regular Recreational Exercise Training on Serum ANGPTL3-Like Protein and Lipid Profile in Young Healthy Adults

Evidence of the role of ANGPTL3, a liver-secreted glycoprotein, in serum lipid turnover, led us to hypothesize that this protein may be involved in modification of the lipid profile induced by exercise-training. Given the lack of data regarding this issue, the main goal of the present study was to investigate the effects of regular participation in a recreational physical activity program on serum ANGPTL3 and selected lipid profile measures in young, apparently healthy female and male adults. We compared serum ANGPTL3, lipid profile measures, common lipid ratios, the Atherogenic Index of Plasma (AIP) and glucose in fasting blood samples derived from 22 active physical education students including active females (AF, N=6) and males (AM, N=16) with samples from 28 relatively sedentary age-matched peers, including female (SF, N=9) and male (SM, N=19) individuals not involved in any regular physical conditioning program. Despite high inter-individual variability of serum ANGPTL3, there was a general tendency toward higher serum ANGPTL3 and HDL-C in women compared to men, but without significant differences related to their physical activity status. Based on both routine lipid profile measures and lipid ratios, all participants had normal lipid profiles, normal glycemia, as well as favorable anthropometric indices not suggesting increased cardiometabolic risk. However, lower levels of the TG/HDL-C ratio and AIP in physically active compared to relatively sedentary participants, reflecting the predominance of large, buoyant LDL particles, strongly support the view of beneficial health-promoting effects of regular participation in recreational sport activities.

Effects of Exercise Training on Cardiorespiratory Fitness and Biomarkers of Cardiometabolic Health: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Guidelines recommend exercise for cardiovascular health, although evidence from trials linking exercise to cardiovascular health through intermediate biomarkers remains inconsistent. We performed a meta-analysis of randomized controlled trials to quantify the impact of exercise on cardiorespiratory fitness and a variety of conventional and novel cardiometabolic biomarkers in adults without cardiovascular disease.

METHODS AND RESULTS

Two researchers selected 160 randomized controlled trials (7487 participants) based on literature searches of Medline, Embase, and Cochrane Central (January 1965 to March 2014). Data were extracted using a standardized protocol. A random-effects meta-analysis and systematic review was conducted to evaluate the effects of exercise interventions on cardiorespiratory fitness and circulating biomarkers. Exercise significantly raised absolute and relative cardiorespiratory fitness. Lipid profiles were improved in exercise groups, with lower levels of triglycerides and higher levels of high-density lipoprotein cholesterol and apolipoprotein A1. Lower levels of fasting insulin, homeostatic model assessment-insulin resistance, and glycosylated hemoglobin A1c were found in exercise groups. Compared with controls, exercise groups had higher levels of interleukin-18 and lower levels of leptin, fibrinogen, and angiotensin II. In addition, we found that the exercise effects were modified by age, sex, and health status such that people aged <50 years, men, and people with type 2 diabetes, hypertension, dyslipidemia, or metabolic syndrome appeared to benefit more.

CONCLUSIONS

This meta-analysis showed that exercise significantly improved cardiorespiratory fitness and some cardiometabolic biomarkers. The effects of exercise were modified by age, sex, and health status. Findings from this study have significant implications for future design of targeted lifestyle interventions.

The mediating role of physical inactivity on the relationship between inflammation and artery thickness in prepubertal adolescents

OBJECTIVE

To analyze the relationship between inflammatory markers and the lipid profile, blood flow, and artery structure in prepubertal adolescents stratified according to sports practice.

STUDY DESIGN

The sample was composed of 120 adolescents (57 boys and 63 girls) with a mean age of 11.7 ± 0.7 years (ranging from 11 to 13 years). Intima-media thickness (IMT) and blood flow were measured with ultrasonography. The lipid profile and high-sensitivity C-reactive protein were measured after the subjects had fasted for 12 hours overnight. Trunk fatness was measured by dual-energy x-ray absorptiometry. Organized sports participation was analyzed as a categorical variable. Biological maturation was determined via the age at peak height velocity.

RESULTS

In the adjusted model, high-sensitivity C-reactive protein was significantly related to high-density lipoprotein-cholesterol (β = -5.797 [-11.500 to -0.093]), femoral IMT (β = 0.062 [0.008-0.116]), and the sum of femoral and carotid IMT (β = 1.107 [0.223-1.919]), but only in the group without sports participation. Slopes of the crude linear regression were greater in the group without sports participation for femoral IMT (t = 2.621; P = .009) and the sum of femoral and carotid IMT (t = 2.876; P = .004) when compared with the group with sports participation.

CONCLUSION

Independent of body fatness and biological maturation, inflammatory status was related to artery IMT and dyslipidemia in prepubertal adolescents, modulated by sport participation.

Anti-inflammation effect of Exercise and Korean red ginseng in aging model rats with diet-induced atherosclerosis

BACKGROUND/OBJECTIVES

The aim of this study was to investigate the effects of exercise (EX) and Korean red ginseng (KRG) on inflammation mechanism in aging model rats with diet-induced atherosclerosis.

MATERIALS/METHODS

Forty-eight male Sprague-Dawley rats were divided into 6 groups: Young control (Y-C), Aging control (A-C), A-C with HFD (AHF), AHF with EX (AHF-EX), AHF-EX with KRG (AHF-EX+RG), and AHF with KRG (AHF-RG). Aging was induced by D-gal (100mg/kg) and atherosclerosis was induced by HFD (60% fat) for 9 weeks. The experimental rats were performed swimming (60 min/day, 5 days/week) and supplied KRG orally (dose of 200 mg/kg) for 8 weeks. All rat aorta samples were harvested for biochemical and immunohistochemical analyses.

REULTS

The EX and KRG supplementation significantly inhibited body weight and levels of TC, TG, LDL-C, and enhance of HDL-C compared with untreated AHF groups. AHF-EX, AHF-EX+RG, and AHF-RG group showed a decreased plasma CRP and increase plasma NO activities compared to AHF group. In addition, these groups revealed reduced 4-HNE, NF-kB, TNF-α, IL-6, COX-2, ICAM-1, VCAM-1 and enhanced eNOS expression in the aorta.

CONCLUSION

These results suggest that EX alone, KRG alone, and combined treatment of EX and KRG may be an effective anti-inflammatory therapeutic for the atherosclerosis, possibly acting via the decreased of CRP and pro-inflammation proteins and the increased NO and eNOS.

Serum paraoxonase activity and lipid hydroperoxide levels in adult football players after three days football tournament

BACKGROUND

It has been suggested that physical activity is an important factor in the prevention and treatment of cardiovascular diseases. Low serum paraoxononase-1 (PON1) activity is with an associated risk of atherosclerotic disease.

OBJECTIVES

In this study, we aimed to investigate serum PON1 activity and lipid hydroperoxide (LOOH) levels in adult football players after three days football tournament.

METHODS

Twenty-three adult male football players and 23 sedentary male subjects after three days football tournament were enrolled. Serum paraoxonase, arylesterase activities and LOOH levels were determined.

RESULTS

Serum paraoxonase and arylesterase activities were significantly higher in football players than sedentary subjects (all, p<0.05), while LOOH levels were significantly lower (p< 0.05). Serum LOOH levels were inversely correlated with paraoxonase and arylesterase activities (r=-0.552, p<0.001; r=-0.812, p<0.001; respectively) in adult football players.

CONCLUSION

Our data show, for the first time, that physical activity is associated with increased PON1 activity and decreased oxidative stress after three days football tournament. In addition, physical activity for a healthy life is important in increasing serum PON1 activity, and this may play a role in the prevention of atherosclerosis.

Endurance training enhances LXRα gene expression in Wistar male rats

Liver X receptor α (LXRα) is a member of the ligand-activated transcription factor of nuclear hormonal receptor superfamily, whose activation leads to modulation in the expression of genes involved in cholesterol homeostasis including ATP-binding cassette transporter A1 (ABCA1), which plays a crucial role in plasma high-density lipoprotein cholesterol (HDL-C) remodeling. The purpose of this study was to investigate whether endurance training enhanced the expression level of liver LXRα gene. Twelve adult male Wistar rats (200-220 g) were divided into control and training groups. Training group received exercise on a motor-driven treadmill at 28 m/min (0 % grade) for 60 min/day, 5 days/week for 8 weeks. Twenty-four hours after the last exercise session, the rats were killed and blood was taken from the right ventricle of each rat. Plasma was collected for HDL-C, low-density lipoprotein cholesterol (LDL-C), TC and TG measurements. Furthermore, a portion of the liver of each rat was excised and washed in ice-cold saline and frozen in liquid nitrogen for assessment of LXRα and ABCA1 mRNA levels. Data indicated significant increase in both LXRα and ABCA1 mRNA levels in trained rats, compared to control rats. Plasma HDL-C concentration was significantly higher (P < 0.001) in trained rats at the end of treadmill exercise. However, there was a significant decrease in LDL-C (P < 0.003), TG, TC concentration, TC/HDL-C and LDL/HDL-C ratios in trained rats compared with those in the control group (P < 0.001). In conclusion, we found that endurance training induced significant elevation in LXRα gene expression, which correlated with enhanced levels of ABCA1 mRNA and plasma HDL-C concentration.

The relationship between walking speed and changes in cardiovascular risk factors during a 12-day walking tour to Santiago de Compostela: a cohort study

OBJECTIVES

Physical exercise has beneficial effects on cardiovascular risk factors. Knowledge about the effect of exercise intensity, specifically walking speed, on cardiovascular risk factors is limited. We report the relationship between walking speed and changes in cardiovascular risk factors in participants of a 12-day walking tour to Santiago de Compostela.

DESIGN

Prospective cohort study.

SETTING

Single-centre study with healthy middle-aged volunteers.

PARTICIPANTS

Healthy middle-aged men (n=15) and women (n=14). Subjects using lipid-lowering medication were excluded.

INTERVENTION

Participants walked 281±10 km of the classical route to Santiago de Compostela in 12 days in 2009.

PRIMARY AND SECONDARY OUTCOME MEASURES

Walking speed was recorded and blood pressure, weight, waist circumference, lipids and glucose were measured every other day. Changes in risk factors were compared between gender-pooled groups with faster and slower walking speed. Second, the relationship between walking speed and changes in risk factors was quantified using a linear mixed effects model.

RESULTS

In the faster walking speed (4.6±0.2 km/h) group, high-density lipoprotein cholesterol (HDL-c) increased more than in the slower walking speed (4.1±0.2 km/h) group (difference in change between groups: 0.20; 95% CI -0.02 to 0.42 mmol/l), while low-density lipoprotein cholesterol (LDL-c) and total cholesterol decreased more in the slower walking speed group (differences in changes between groups: LDL-c: -0.50; 95% CI -0.88 to -0.12 mmol/l and total cholesterol: -0.75; 95% CI -1.19 to -0.31 mmol/l). A 1 km/h higher walking speed was related to an increase in HDL-c (0.24; 95% CI 0.12 to 0.30 mmol/l), LDL-c (0.18; 95% CI -0.16 to 0.42 mmol/l) and total cholesterol (0.36; 95% CI 0.12 to 0.60 mmol/l), adjusted for age, gender, smoking, body mass index and heart rate, during the whole walking tour.

CONCLUSIONS

Walking the same distance faster improves HDL-c more, while LDL-c and total cholesterol decrease more with lower walking speed independent of changes in body weight in healthy middle-aged subjects.

Combined effects of exercise and soy isoflavone diet on paraoxonase, nitric oxide and aortic apoptosis in ovariectomized rats

Menopause is associated with an increased risk of cardiovascular disease (CVD). Exercise and soy isoflavone diets have been suggested to reduce the risk of CVD in postmenopausal women. We investigated the effects of exercise, or combined exercise and soy isoflavone diet, on plasma lipid profiles, paraoxonase (PON), nitric oxide (NO) and apoptosis in the aorta of ovariectomized (OVX) rats. Thirty-two female Sprague-Dawley rats were divided into four groups: OVX with general diet (OVX-GD), OVX with isoflavone diet (OVX-ISO), OVX-GD with exercise training (OVX-ET) and OVX-ISO with exercise training (OVX-ISO+ET). The experimental rats undertook treadmill training (30 min/day, 4 days/week) and/or were supplied a soy isoflavone diet (added to the experimental diet at 2.39 mg/g protein) for 12 weeks. Body weight and levels of total cholesterol (TC), triglyceride (TG), LDL-cholesterol (LDL-C) increased in the OVX rats and HDL-C decreased. These effects were reduced by exercise and/or soy isoflavone supplementation. PON and NO activities were higher in the OVX-ISO+ET group than in the OVX-GD group. In addition, this group had lower caspase-9 and -3 and higher Bcl-2 expression, and there was less aortic apoptotic cell death. These results suggest that a combination of exercise and a soy isoflavone diet has beneficial effects in terms of protecting against cardiovascular risk factors by controlling lipid profiles and the related enzyme, PON, as well as NO activity and apoptosis of the aorta in OVX rats.

Physiological and physical effects of different milk protein supplements in elite soccer players

Brazilian soccer championships involve a large number of teams and are known to cause stress and loss of muscle mass besides other negative physical consequences. This study was designed to compare the effects produced by three types of protein supplements on body composition, biochemical parameters and performance of a top Brazilian professional soccer team during an actual tournament. Twenty-four athletes assessed as having a normal nutrient intake were divided into three groups according to supplementation. Immediately after each daily training, the athletes received 1 g × kg(-1) of body weight × day(-1) of either whey protein (WP), hydrolyzed whey protein (HWP) or casein (CAS) for eight weeks. Before and after the experimental period, anthropometric characteristics, physical performance by the yo-yo and 3000m tests, and several biochemical variables in blood (uric acid, total cholesterol, HDL-cholesterol, creatinine, glucose) were measured. While no improvement in physical performance was observed with regard to the applied treatments, casein supplementation resulted in muscle mass increase (p<0.039), while WP and HWP favoured the maintenance of the initial muscle mass. Moreover, the eight-week intervention was found to cause no abnormalities in biochemical and anthropometric variables monitored, but instead, the intervention showed to be positive in comparison to the adverse anthropometric changes, when no supplementation was made. It was concluded that supplementation immediately after training sessions with any of the three sources of protein during the competitive period is beneficial and safe, as well as capable of sustaining or even increasing muscle mass.

Exercise enhances whole-body cholesterol turnover in mice

PURPOSE

Regular exercise reduces cardiovascular risk in humans by reducing cholesterol levels, but the underlying mechanisms have not been fully explored. Exercise might provoke changes in cholesterol and bile acid metabolism and thereby reduce cardiovascular risk. We examined whether voluntary wheel running in mice modulates cholesterol and bile acid metabolism.

METHODS

Male mice (10 wk old) were randomly assigned to have access to a voluntary running wheel for 2 wk (RUN group) or remained sedentary (SED group). Running wheel activity was recorded daily. In a first experiment, fecal sterol outputs, fecal bile acid profiles, plasma parameters, and expression levels of genes involved in cholesterol and bile acid metabolism were determined. In a second experiment, bile flow, biliary bile acid profile, and biliary secretion rates of cholesterol, phospholipids, and bile acids were determined.

RESULTS

The RUN group ran an average of 10 km.d and displayed lower plasma cholesterol compared with SED (P = 0.030). Fecal bile acid loss was induced by approximately 30% in running mice compared with SED (P = 0.0012). A approximately 30% increase in fecal cholesterol output in RUN (P = 0.014) was consistent with changes in parameters of cholesterol absorption, such as reduced plasma plant sterol-cholesterol ratio (P = 0.044) and decreased jejunal expression of Npc1l1 (P = 0.013). Supportive of an increased cholesterol synthesis to compensate for fecal sterol loss were increased hepatic mRNA levels of HMGCoA reductase (P = 0.006) and an increased plasma lathosterol-cholesterol ratio (P = 0.0011) in RUN.

CONCLUSIONS

Voluntary wheel running increased cholesterol turnover in healthy mice owing to an increased fecal bile acid excretion and a decreased intestinal cholesterol absorption. Enhanced cholesterol turnover may contribute to the established reduction of cardiovascular risk induced by regular exercise.

Gene activation regresses atherosclerosis, promotes health, and enhances longevity

Background

Lifestyle factors and pharmacological compounds activate genetic mechanisms that influence the development of atherosclerotic and other diseases. This article reviews studies on natural and pharmacological gene activation that promotes health and enhances longevity.

Results

Living habits including healthy diet and regular physical activity, and pharmacotherapy, upregulate genes encoding enzymes and apolipoprotein and ATP-binding cassette transporters, acting in metabolic processes that promote health and increase survival. Cytochrome P450-enzymes, physiological factors in maintaining cholesterol homeostasis, generate oxysterols for the elimination of surplus cholesterol. Hepatic CTP:phosphocholine cytidylyltransferase-α is an important regulator of plasma HDL-C level. Gene-activators produce plasma lipoprotein profile, high HDL-C, HDL₂-C and HDL-C/cholesterol ratio, which is typical of low risk of atherosclerotic disease, and also of exceptional longevity together with reduced prevalence of cardiovascular, metabolic and other diseases. High HDL contributes to protection against inflammation, oxidation and thrombosis, and associates with good cognitive function in very old people. Avoiding unhealthy stress and managing it properly promotes health and increases life expectancy.

Conclusions

Healthy living habits and gene-activating xenobiotics upregulate mechanisms that produce lipoprotein pattern typical of very old people and enhance longevity. Lipoprotein metabolism and large HDL₂ associate with the process of living a very long life. Major future goals for health promotion are the improving of commitment to both wise lifestyle choices and drug therapy, and further the developing of new and more effective and well tolerated drugs and treatments.

Low and moderate, rather than high intensity strength exercise induces benefit regarding plasma lipid profile

BACKGROUND

The effects of chronic aerobic exercise upon lipid profile has been previously demonstrated, but few studies showed this effect under resistance exercise conditions.

OBJECTIVE

The aim of this study was to examine the effects of different resistance exercise loads on blood lipids.

METHODS

Thirty healthy, untrained male volunteers were allocated randomly into four groups based at different percentages of one repetition maximum (1 RM); 50%-1 RM, 75%-1 RM, 90%-1 RM, and 110%-1 RM. The total volume (sets x reps x load) of the exercise was equalized. The lipid profile (Triglycerides [TG], HDL-cholesterol [HDL-c], LDL-cholesterol, and Total cholesterol) was determined at rest and after 1, 24, 48 and 72 h of resistance exercise.

RESULTS

The 75%-1 RM group demonstrated greater TG reduction when compared to other groups (p < 0.05). Additionally, the 110%-1 RM group presented an increased TG concentration when compared to 50% and 75% groups (p = 0.01, p = 0.01, respectively). HDL-c concentration was significantly greater after resistance exercise in 50%-1 RM and 75%-1 RM when compared to 110%-1 RM group (p = 0.004 and p = 0.03, respectively). Accordingly, the 50%-1 RM group had greater HDL-c concentration than 110%-1 RM group after 48 h (p = 0.05) and 72 h (p = 0.004), respectively. Finally, The 50% group has showed lesser LDL-c concentration than 110% group after 24 h (p = 0.007). No significant difference was found in Total Cholesterol concentrations.

CONCLUSION

These results indicate that the acute resistance exercise may induce changes in lipid profile in a specific-intensity manner. Overall, low and moderate exercise intensities appear to be promoting more benefits on lipid profile than high intensity. Long term studies should confirm these findings.

Sedentary subjects have higher PAI-1 and lipoproteins levels than highly trained athletes

Physical exercise protects against the development of cardiovascular disease, partly by lowering plasmatic total cholesterol, LDL-cholesterol and increased HDL-cholesterol levels. In addition, it is now established that reduction plasmatic adiponectin and increased C-reactive protein (CRP) and plasminogen activator inhibitor-1 (PAI-1) levels play a role in the maintenance of an inflammatory state and in the development of cardiovascular disease. This study aimed to examine plasma lipid profile and inflammatory markers levels in individual with sedentary lifestyle and/or highly trained athletes at rest.

METHODS

Fourteen male subjects (sedentary lifestyle n = 7 and highly trained athletes n = 7) were recruited. Blood samples were collected after an overnight fast (approximately 12 h). The plasmatic lipid profile (Triglycerides, HDL-cholesterol, LDL-cholesterol, total cholesterol, LDL-oxidized and total cholesterol/HDL-c ratio), glucose, adiponectin, C - reactive protein and PAI-1 levels were determined.

RESULTS

Total cholesterol, LDL-cholesterol, TG and PAI-1 levels were lower in highly trained athletes group in relation to sedentary subjects (p < 0.01). In addition, we observed a positive correlation between PAI-1 and total cholesterol (r = 0.78; p < 0.0009), PAI-1 and LDL-c (r = 0.69; p < 0.006) and PAI-1 and TG levels (r = 0.56; p < 0.03). The plasma concentration of adiponectin, CRP, glucose, HDL-cholesterol and total cholesterol/HDL-c ratio levels were not different. These results indicate that lifestyle associated with high intensity and high volume exercise induces changes favourable in the lipid profile and PAI-1 levels and may reduce risk cardiovascular diseases.

Randomized trial on the effects of a 7-d low-glycemic diet and exercise intervention on insulin resistance in older obese humans

BACKGROUND

The optimal combination of diet and exercise that produces the greatest reversal of obesity-related insulin resistance is unknown.

OBJECTIVES

We examined the effects of a combined 7-d low-glycemic index (low-GI) diet and exercise training intervention on insulin sensitivity in older obese humans.

DESIGN

Participants [n = 32; mean (+/-SEM) age: 66 +/- 1 y; body mass index (in kg/m(2)): 33.8 +/- 0.7] were randomly assigned to a parallel, double-blind, controlled-feeding trial and underwent supervised aerobic exercise (EX; 60 min/d at 80-85% maximum heart rate) in combination with either a low-GI (LoGI + EX: 41.1 +/- 0.4) or a high-GI (HiGI + EX: 80.9 +/- 0.6) diet. All meals were provided and were isocaloric to individual energy requirements. Insulin sensitivity and hepatic glucose production were assessed with a 40-mU x m(-2) x min(-1) hyperinsulinemic euglycemic clamp combined with a [6,6-(2)H(2)]-glucose infusion.

RESULTS

After the intervention, small decreases were observed in body weight (-1.6 +/- 0.2 kg; P < 0.0001) and fat mass (-1.7 +/- 0.9%; P = 0.004) in both groups. Maximal aerobic capacity ( O(2)max) also improved slightly (0.06 +/- 0.02 L/min; P = 0.004). Resting systolic blood pressure, fasting glucose, insulin, triglycerides, and cholesterol all decreased after the study (all P < 0.05). Larger changes in systolic blood pressure and O(2max) were seen in the LoGI + EX group. Insulin-stimulated glucose disposal (P < 0.001), insulin suppression of hepatic glucose production (P = 0.004), and postabsorptive fat oxidation (P = 0.03) improved equally in both groups after the intervention.

CONCLUSIONS

These findings suggest that the metabolic improvements after short-term exercise training in older obese individuals are dependent on increased physical activity and are not influenced by a low-GI diet. However, a low-GI diet has added benefit in alleviating hypertension, thus reducing the risk of diabetic and vascular complications.

Acute high-intensity exercise with low energy expenditure reduced LDL-c and total cholesterol in men

A reduction in LDL cholesterol and an increase in HDL cholesterol levels are clinically relevant parameters for the treatment of dyslipidaemia, and exercise is often recommended as an intervention. This study aimed to examine the effects of acute, high-intensity exercise ( approximately 90% VO(2max)) and varying carbohydrate levels (control, low and high) on the blood lipid profile. Six male subjects were distributed randomly into exercise groups, based on the carbohydrate diets (control, low and high) to which the subjects were restricted before each exercise session. The lipid profile (triglycerides, VLDL, HDL cholesterol, LDL cholesterol and total cholesterol) was determined at rest, and immediately and 1 h after exercise bouts. There were no changes in the time exhaustion (8.00 +/- 1.83; 7.82 +/- 2.66; and 9.09 +/- 3.51 min) and energy expenditure (496.0 +/- 224.8; 411.5 +/- 223.1; and 592.1 +/- 369.9 kJ) parameters with the three varying carbohydrate intake (control, low and high). Glucose and insulin levels did not show time-dependent changes under the different conditions (P > 0.05). Total cholesterol and LDL cholesterol were reduced after the exhaustion and 1 h recovery periods when compared with rest periods only in the control carbohydrate intake group (P < 0.05), although this relation failed when the diet was manipulated. These results indicate that acute, high-intensity exercise with low energy expenditure induces changes in the cholesterol profile, and that influences of carbohydrate level corresponding to these modifications fail when carbohydrate (low and high) intake is manipulated.

Modulation of paraoxonase 1 and 3 expression after moderate exercise training in the rat

Paraoxonases (PONs) are a small family of antioxidant enzymes whose antiatherogenic activity is well known. The aim of the present study was the evaluation of the effects of moderate aerobic training on their expression using a rat model. In order to discriminate between PON1 and PON3 enzymatic activity, we took advantage of some differences in their substrate preferences. PON1 and PON3 enzymatic activities and their protein levels were analyzed in plasma and in liver microsomes, and their mRNA levels in the liver. Exercise training did not affect PON1 expression or enzymatic activity but increased PON3 mRNA, protein levels, and enzymatic activity. Training also induced variations in plasma membrane composition, including an increase in polyunsaturated and a decrease in mono- and di-unsaturated fatty acids. On the other hand, acute exercise inhibited PON activities while increasing PON3 protein content in liver microsomes and reversing the relative composition in mono-, di-, and poly-unsaturated fatty acids, suggesting that physical stress, by altering membrane composition, may impair PON release from liver membranes. In conclusion, we documented, for the first time, the presence of PON3 in rat serum and, notably, found that the upregulation of PON3, rather than PON1, appears to be associated with physical training.

Aerobic exercise training improves the role of high-density lipoprotein antioxidant and reduces plasma lipid peroxidation in type 2 diabetes mellitus

In this study, we analyzed the effect of aerobic exercise training (AET) and of a single bout of exercise on plasma oxidative stress and on antioxidant defenses in type 2 diabetes mellitus (DM) and in healthy control subjects (C). DM and C did not differ regarding triglycerides, high-density lipoprotein cholesterol (HDL-c), insulin, and HOMA index at baseline and after AET. To measure the lag time for low-density lipoprotein (LDL) oxidation (LAG) and the maximal rate of conjugated diene formation (MCD), participants' plasma HDL(2) and HDL(3) were incubated with LDL from pooled healthy donors' plasma. In the presence of HDL(3), both LAG and MCD were similar in C and DM, but only in DM did AET improve LAG and reduce MCD. In the presence of HDL(2), the lower baseline LAG in DM equaled C after AET. MCD was unchanged in DM after AET, but was lower than C only after AET. Furthermore, after AET plasma thiobarbituric acid-reactive substances were reduced only in DM subjects. Despite not modifying the total plasma antioxidant status and serum paraoxonase-1 activity in both groups, AET lowered the plasma lipid peroxides, corrected the HDL(2), and improved the HDL(3) antioxidant efficiency in DM independent of the changes in blood glucose, insulin, and plasma HDL concentration and composition.

Treadmill exercise enhances ABCA1 expression in rat liver

ATP-binding cassette transporters (ABCs) belong to a large family and include 49 mammalian transmembrane transporters that transfer a variety of substrates across the lipid bilayers in an energy-dependent manner. ABCA1 is a member of this family which plays a crucial role in plasma HDL-C remodeling. The purpose of this study was to investigate liver ABCA1 expression and plasma HDL level in response to treadmill running program in rats. Ten adult Wistar male rats (12-14weeks old, 200-220g) were used for this study. Animals were divided into control (Con, n=5) and Training (TR, n=5) groups. Training group was given exercise on a motor-driven treadmill at 25m/min (0% grade) for 90min/day, 5 days/week for 6 weeks. Rats were sacrificed 24h after the last session of exercise portion of the liver was excised, immediately washed in ice-cold saline, and frozen in liquid nitrogen for extraction of ABCA1 mRNA. Plasma was collected for HDL-C, LDL, TC, TG, and VLDL-C measurements. Liver ABCA1 mRNA expression was significantly (P<0.001) higher in trained rats compared to control rats. Plasma HDL-C, LCAT, pre-beta-HDL concentrations were significantly higher (P<0.01, P<0.001, P<0.028, respectively) in trained rats at the end of treadmill exercise. However, plasma lipids, other lipoproteins and TC/HDL and LDL/HDL ratio were unchanged. In conclusion, a treadmill running-induced elevated plasma HDL-C concentration was accompanied with a higher liver ABCA1 mRNA expression and increased in LCAT and pre-beta-HDL levels.

Influences of Acute and Chronic Aerobic Exercise on the Plasma Homocysteine Level

BACKGROUND AND AIMS

Elevated plasma homocysteine (PH) levels have been identified as a risk factor for cardiovascular diseases. The aims of this study were to investigate the influences of submaximal acute aerobic exercise and aerobic training on PH levels and lipid profiles.

METHODS

69 volunteer subjects (21.12 +/- 2.08 years) were randomized to three groups as acute, training and control groups. Examination and blood samples were collected before and immediately after exercise in the acute group and before and 6 weeks later in the training and control groups.

RESULTS

A significant increase in PH concentration was recorded immediately after aerobic exercise, compared with baseline values (p = 0.001). Although, in the training group, total cholesterol (p = 0.00) and LDL cholesterol (p = 0.001) decreased significantly after training, no significant changes in PH concentration, HDL cholesterol (p = 0.087) and triglyceride (p = 194) levels were found.

CONCLUSIONS

It can be said that the PH level increases following submaximal acute aerobic exercise, but does not alter after submaximal aerobic training due to training duration or intensity. Therefore, submaximal aerobic training decreases lipid profiles independent of the PH level.

Lower HDL-cholesterol among healthy middle-aged Japanese-Brazilians in São Paulo compared to Natives and Japanese-Brazilians in Japan

Blood lipid levels are determined by a combination of genetic and environmental factors. Higher than average values of high-density lipoprotein cholesterol (HDL-cholesterol) have been observed in people of Japanese ethnicity. The aim of this study was to investigate whether Japanese immigrants to Brazil and subsequent generations maintain the protective benefits associated with higher levels of HDL-cholesterol, and to examine the potential associations between HDL-cholesterol and a variety of other blood lipids, anthropometric and lifestyle factors. Healthy men and women aged 35 years and older who were Native Japanese (n = 198) or Japanese-Brazilians (JB) living in São Paulo, Brazil (n = 198) and in some Japanese cities (n = 246) were investigated. Anthropometric variables, blood lipids including HDL-cholesterol, and lifestyle factors were assessed. Serum HDL-cholesterol was observed to be lower for JB in São Paulo (both women and men) compared with Natives and JB in Japan. Among the groups, triglycerides, waist circumference, LDL-cholesterol, meat intake, stress, and smoking were observed to be independently negatively associated with HDL-cholesterol, whereas total cholesterol, fish intake, and physical activity were positively associated. Lower levels of HDL-cholesterol among both men and women of JB in São Paulo compared with both other groups were confirmed even after lifestyle adjustments. Our findings highlight the significantly lower levels of HDL-cholesterol among Japanese-Brazilians living in São Paulo city compared to Japanese-Brazilians and Native Japanese residing in Japan. Although several lifestyle factors were found to be significantly associated with HDL-cholesterol, they cannot adequately explain the role of the Brazilian cultural environment on HDL-cholesterol levels.

Roles of skeletal muscle and peroxisome proliferator-activated receptors in the development and treatment of obesity

Metabolic disturbances associated with alterations in lipid metabolism, such as obesity, type 2 diabetes, and syndrome X, are becoming more and more prominent in Western societies. Despite extensive research in such pathologies and their molecular basis, we are still far from completely understanding how these metabolic perturbations are produced and interrelate and, consequently, how to treat them efficiently. The discovery that adipose tissue is, in fact, an endocrine tissue able to secrete active molecules related to lipid homeostasis--the adipokines--has dramatically changed our understanding of the molecular events that take place in such diseases. This knowledge has been further improved by the discovery of peroxisome proliferator-activated receptors and their ligands, at present commonly used for the clinical treatment of lipid disturbances. However, a key point remains to be solved, and that is the role of muscle lipid metabolism, notably because of the main role played by this tissue in the development of such pathologies. In addition, a reciprocal regulation between adipose tissue and skeletal muscle has been proposed. New discoveries on the role of peroxisome proliferator-activated receptor-delta in skeletal muscle functions as well as the secretory capabilities of muscle, now considered as an endocrine tissue, have changed the general point of view on lipid homeostasis, opening new and promising doors for the treatment of lipid disorders.