Nontraditional risk factors and biomarkers for cardiovascular disease: mechanistic, research, and clinical considerations for youth: a scientific statement from the American Heart Association

The cardio-metabolic risk of moderate and severe obesity in children and adolescents

OBJECTIVE

To compare the cardio-metabolic risk profile between moderately obese and severely obese children and adolescents.

STUDY DESIGN

Cross-sectional study involving 463 obese 6- to 19-year-olds who were referred to an inpatient weight-loss program. Anthropometric data were assessed and fasting blood samples were analyzed for lipid and glucose metabolism, adipokines, and inflammatory markers. Moderately obese individuals (percentiles corresponding to body mass index ≥ 30 to 35 kg/m(2) at age 18 years) and severely obese individuals (percentiles corresponding to body mass index ≥ 35 kg/m(2) at age 18 years) were defined by sex and age-specific cut-offs according to the International Obesity Task Force.

RESULTS

The prevalence of the metabolic syndrome was three times higher in severely obese individuals compared with those who are moderately obese. Mean values for proinsulin, insulin, homeostatic model assessment-insulin resistance, triglycerides, and interleukin-6 were 30%-50% higher in severe obesity compared with moderate obesity. Concentrations of leptin and high-sensitive C-reactive protein were about 1.5-fold higher, adiponectin levels were 12% lower, and resistin levels 10% higher in severely obese individuals compared with moderately obese (all P < .001).

CONCLUSION

Severely obese individuals have a markedly more unfavorable cardio-metabolic risk profile than those who are moderately obese. The results of this study underscore the substantial effect of severe obesity on health and highlights that these children need to receive particular attention regarding obesity treatment.

Relation between adiponectin and brain natriuretic peptide in healthy pediatric subjects: from birth through childhood

BACKGROUND AND AIMS

New biomarkers potentially improve clinical management of cardiovascular disease, but there are gaps in understanding their role during childhood. Adiponectin regulates metabolism and exerts anti-inflammatory/anti-atherogenic effects. The aim of the study was to evaluate circulating levels of adiponectin during postnatal growth and its relationship with Brain Natriuretic Peptide (BNP) in healthy children, a marker of cardiac function known to be increased in childhood.

METHODS AND RESULTS

Plasma adiponectin and BNP were measured in 131 healthy children divided into: 43 newborns (0-3 days), 29 neonates (4-30 days), 25 infants (1-12 months) and 34 children (1-12 years). A group of 33 healthy adult subjects (25-60 years) was also studied. Plasma adiponectin in the 131 children resulted significantly higher compared to adult subjects (p < 0.0001). The time-course of adiponectin suggests the design of three age-based intervals: the first until 1 month of age (median 29.07 μg/mL, 11.61-47.01 μg/mL 5°-95° percentiles), the second between 1 and 12 months of age (21.66 μg/mL, 8.83-59.81 μg/mL) and the third for age up to 12 years (13.81 μg/mL, 4.10-28.57 μg/mL). Both adiponectin and BNP exhibited the same trend of a progressive decrease during growth, showing a significant relationship (Spearman's rho = 0.403, p < 0.0001).

CONCLUSION

Adiponectin plasma levels in a healthy pediatric population vary as a function of age. Three reference intervals for adiponectin in pediatric subjects have been indicated. The relationship between adiponectin and BNP suggests that the age-dependent profile of circulating adiponectin could also be due to BNP.

Matrix metalloproteinase (MMP)-9: a proximal biomarker for cardiac remodeling and a distal biomarker for inflammation

Adverse cardiac remodeling following myocardial infarction (MI) remains a significant cause of congestive heart failure. Additional and novel strategies that improve our ability to predict, diagnose, or treat remodeling are needed. Numerous groups have explored single and multiple biomarker strategies to identify diagnostic prognosticators of remodeling progression, which will improve our ability to promptly and accurately identify high-risk individuals. The identification of better clinical indicators should further lead to more effective prediction and timely treatment. Matrix metalloproteinase (MMP-9) is one potential biomarker for cardiac remodeling, as demonstrated by both animal models and clinical studies. In animal MI models, MMP-9 expression significantly increases and is linked with inflammation, diabetic microvascular complications, extracellular matrix degradation and synthesis, and cardiac dysfunction. Clinical studies have also established a relationship between MMP-9 and post-MI remodeling and mortality, making MMP-9 a viable candidate to add to the multiple biomarker list. By definition, a proximal biomarker shows a close relationship with its target disease, whereas a distal biomarker exhibits non-targeted disease modifying outcomes. In this review, we explore the ability of MMP-9 to serve as a proximal biomarker for cardiac remodeling and a distal biomarker for inflammation. We summarize the current molecular basis and clinical platform that allow us to include MMP-9 as a biomarker in both categories.

Cardiometabolic Risk Factors in Children

Considerable evidence has accrued that cardiovascular disease (CVD) has its beginnings during childhood, with some reports of endothelial damage occurring in early adolescence. Thus, early prevention and intervention on developing cardiometabolic risk factors is important. Presently, diet and exercise are strategic parts of any CVD prevention or treatment program. Although diet is important, the effects of exercise training or regular moderate-to-vigorous intensity physical activity go beyond simply modifying the traditional risk factors. For children, the majority of studies show that regular physical activity can lower elevated blood pressure, positively influence lipid profiles, reduce inflammation, and improve vascular functioning. These changes are most evident in children who exercise and lose weight. Despite these potential benefits of physical activity, not all studies on children have found positive effects of habitual physical activity on CVD risk factors. Reasons for these differences are discussed throughout this review. The literature also suggests that habitual physical activity, although meeting guidelines, may not be sufficient for all individuals to bring about changes; thus, to be an effective modality physical activity needs to increase beyond habitual levels or be of a moderate to vigorous intensity. This review provides recent evidence (since 2008) regarding the influence of physical activity on the cardiometabolic risk factors in children.

Metabolic Syndrome and Cardiovascular Risk Factors in a National Sample of Adolescent Population in the Middle East and North Africa: The CASPIAN III Study

Objective. The present study was designed to investigate the prevalence of different combinations of the metabolic syndrome (MetS) risk factors among a nationally representative sample of adolescents in the Middle East and North Africa (MENA). Methods. The study sample, obtained as part of the third study of the school-based surveillance system entitled CASPIAN III, was representative of the Iranian adolescent population aged from 10 to 18 years. The prevalence of different components of MetS was studied and their discriminative value was assessed by receiver operating characteristic (ROC) curve analysis. Results. The study participants consisted of 5738 students (2875 girls) with mean age of 14.7 ± 2.4 years) living in 23 provinces in Iran; 17.4% of participants were underweight and 17.7% were overweight or obese. Based on the criteria of the International Diabetes Federation for the adolescent age group, 24.2% of participants had one risk factor, 8.0% had two, 2.1% had three, and 0.3% had all the four components of MetS. Low HDL-C was the most common component (43.2% among the overweight/obese versus 34.9% of the normal-weight participants), whereas high blood pressure was the least common component. The prevalence of MetS was 15.4% in the overweight/obese participants, the corresponding figure was 1.8% for the normal-weight students, and 2.5% in the whole population studied. Overweight/obese subjects had a 9.68 increased odds of (95% CI: 6.65-14.09) the MetS compared to their normal-weight counterparts. For all the three risk factors, AUC ranged between 0.84 and 0.88, 0.83 and 0.87, and 0.86 and 0.89 in waist circumference, abdominal obesity, and BMI for boys and between 0.78 and 0.97, 0.67 and 0.93, and 0.82 and 0.96 for girls, respectively. Conclusion. The findings from this study provide alarming evidence-based data on the considerable prevalence of obesity, MetS, and CVD risk factors in the adolescent age group. These results are confirmatory evidence for the necessity of primordial/primary prevention of noncommunicable disease should be considered as a health priority in communities facing a double burden of nutritional disorders.

Oxidative stress and cardiovascular risk in overweight children in an exercise intervention program

BACKGROUND

This study aimed to determine whether oxidative stress was related to cardiovascular risk indices in children, and whether an exercise intervention would reduce oxidative stress.

METHODS

A randomized trial of two different doses of exercise and a no-exercise control group included 112 overweight and obese children, 7-11 years old. Plasma isoprostane levels were obtained at baseline and after the intervention. Cross-sectional analysis of oxidative stress and metabolic markers at baseline was performed. The effect of the exercise training on oxidative stress was tested.

RESULTS

Lower isoprostane levels were observed in blacks. At baseline, isoprostane was positively related to measures of fatness (BMI, waist circumference, percent body fat), insulin resistance and β-cell function (fasting insulin, insulin area under the curve, Matsuda index, disposition index, oral disposition index), and several lipid markers (low-density lipoprotein, triglycerides, total cholesterol), and inversely with fitness [peak oxygen consumption (VO(2))], independent of race, sex, and cohort. No relation was found with visceral fat, blood pressure, or glycemia. Independent of percent body fat, isoprostane predicted triglycerides, β=0.23, total cholesterol-to-high-density lipoprotein (TC/HDL) ratio, β=0.23, and insulin resistance (insulin area under the curve, β=0.24, Matsuda index, β=-0.21, oral disposition index, β=0.33). Exercise did not reduce oxidative stress levels, despite reduced fatness and improved fitness in these children.

CONCLUSIONS

Isoprostane levels were related to several markers of cardiovascular risk at baseline; however, despite reduced fatness and improved fitness, no effect of exercise was observed on isoprostane levels. To our knowledge, this is the first report in children to demonstrate a correlation of oxidative stress with disposition index, fitness, and TC/HDL ratio, the first to test the effect on oxidative stress of an exercise intervention that reduced body fat, and the first such exercise intervention study to include a substantial proportion of black children.

Update in cardiology: Vascular risk and cardiac rehabilitation

Atherosclerotic cardiovascular disease remains the major cause of premature death in developed and developing countries. Nevertheless, surveys show that most patients still do not achieve the lifestyles, risk factor levels, and therapeutic targets recommended in primary and secondary prevention. The present update reflects the most recent novelties in risk classification and estimation of risk and documents the latest changes in fields such as smoking, diet and nutrition, physical activity, lipids, hypertension, diabetes, and cardiovascular rehabilitation, based on experimental trials and population-based observational studies.

Curcumin and obesity

Turmeric has been long recognized for its anti-inflammatory and health-promoting properties. Curcumin is one of the principal anti-inflammatory and healthful components of turmeric comprising 2-8% of most turmeric preparations. Experimental evidence supports the activity of curcumin in promoting weight loss and reducing the incidence of obesity-related diseases. With the discovery that obesity is characterized by chronic low-grade metabolic inflammation, phytochemicals like curcumin which have anti-inflammatory activity are being intensely investigated. Recent scientific research reveals that curcumin directly interacts with white adipose tissue to suppress chronic inflammation. In adipose tissue, curcumin inhibits macrophage infiltration and nuclear factor κB (NF-κB) activation induced by inflammatory agents. Curcumin reduces the expression of the potent proinflammatory adipokines tumor necrosis factor-α (TNFα), monocyte chemoattractant protein-1 (MCP-1), and plasminogen activator inhibitor type-1 (PAI-1), and it induces the expression of adiponectin, the principal anti-inflammatory agent secreted by adipocytes. Curcumin also has effects to inhibit adipocyte differentiation and to promote antioxidant activities. Through these diverse mechanisms curcumin reduces obesity and curtails the adverse health effects of obesity.

Serum resistin and inflammatory and endothelial activation markers in obese adolescents

OBJECTIVES

To assess the level of serum resistin in obese and lean children and to establish a relationship with circulating inflammatory and vascular markers.

STUDY DESIGN

This is a cross-sectional study including 67 obese and 62 lean children (mean age 10.9 ± 2.8 years, age range 5.4-16.6 years). We assessed circulating hormones (insulin, leptin, insulin-like growth factor 1), markers of inflammation (resistin, high sensitivity C-reactive protein, interleukin-6, chemokine ligand 2), and endothelial cell activation (vascular and intercellular adhesion molecules: vascular cell adhesion molecule 1 and intercellular adhesion molecule; E-selectin; P-selectin; endothelin 1).

RESULTS

Body weight, body mass index (BMI), insulin, leptin, high-sensitivity C-reactive protein, vascular adhesion molecule 1, and E-selectin levels were significantly higher in obese than in lean subjects. Resistin was similar among the groups in the prepubertal period, but increased significantly in the obese adolescents (18.6 ± 24.9) compared with lean subjects (7.9 ± 10.7 ng/mL; P = .038). Resistin was not associated with BMI z score (P > .05). Subjects with resistin levels above 9 (ng/mL) had higher concentration of interleukin-6, chemokine ligand 2, endothelin-1, and insulin-like growth factor 1 but not of leptin, insulin, or BMI.

CONCLUSION

Resistin was increased in obese adolescents independently of the quantity of the adipose tissue. In this population, increased resistin levels were related to inflammation and endothelial activation. We may hypothesize that interventions aiming to diminish resistin expression may slow down atherogenesis in adolescents.

Genetic variant SLC2A2 [corrected] Is associated with risk of cardiovascular disease – assessing the individual and cumulative effect of 46 type 2 diabetes related genetic variants

Aim

To assess the individual and combined effect of 46 type 2 diabetes related risk alleles on incidence of a composite CVD endpoint.

Methods

Data from the first Danish MONICA study (N = 3523) and the Inter99 study (N = 6049) was used. Using Cox proportional hazard regression the individual effect of each risk allele on incident CVD was analyzed. Risk was presented as hazard ratios (HR) per risk allele.

Results

During 80,859 person years 1441 incident cases of CVD (fatal and non-fatal) occurred in the MONICA study. In Inter99 942 incident cases were observed during 61,239 person years.

In the Danish MONICA study four gene variants were significantly associated with incident CVD independently of known diabetes status at baseline; SLC2A2 rs11920090 (HR 1.147, 95% CI 1.027–1.283 , P = 0.0154), C2CD4A rs7172432 (1.112, 1.027–1.205 , P = 0.0089), GCKR rs780094 (1.094, 1.007–1.188 , P = 0.0335) and C2CD4B rs11071657 (1.092, 1.007–1.183 , P = 0.0323). The genetic score was significantly associated with increased risk of CVD (1.025, 1.010–1.041, P = 0.0016). In Inter99 two gene variants were associated with risk of CVD independently of diabetes; SLC2A2 (HR 1.180, 95% CI 1.038–1.341 P = 0.0116) and FTO (0.909, 0.827–0.998, P = 0.0463). Analysing the two populations together we found SLC2A2 rs11920090 (HR 1.164, 95% CI 1.070–1.267, P = 0.0004) meeting the Bonferroni corrected threshold for significance. GCKR rs780094 (1.076, 1.010–1.146, P = 0.0229), C2CD4B rs11071657 (1.067, 1.003–1.135, P = 0.0385) and NOTCH2 rs10923931 (1.104 (1.001 ; 1.217 , P = 0.0481) were found associated with CVD without meeting the corrected threshold. The genetic score was significantly associated with increased risk of CVD (1.018, 1.006–1.031, P = 0.0043).

Conclusions

This study showed that out of the 46 genetic variants examined only the minor risk allele of SLC2A2 rs11920090 was significantly (P = 0.0005) associated with a composite endpoint of incident CVD below the threshold for statistical significance corrected for multiple testing. This potential pathway needs further exploration.

Effects of aerobic versus resistance exercise without caloric restriction on abdominal fat, intrahepatic lipid, and insulin sensitivity in obese adolescent boys: a randomized, controlled trial

The optimal exercise modality for reductions of abdominal obesity and risk factors for type 2 diabetes in youth is unknown. We examined the effects of aerobic exercise (AE) versus resistance exercise (RE) without caloric restriction on abdominal adiposity, ectopic fat, and insulin sensitivity and secretion in youth. Forty-five obese adolescent boys were randomly assigned to one of three 3-month interventions: AE, RE, or a nonexercising control. Abdominal fat was assessed by magnetic resonance imaging, and intrahepatic lipid and intramyocellular lipid were assessed by proton magnetic resonance spectroscopy. Insulin sensitivity and secretion were evaluated by a 3-h hyperinsulinemic-euglycemic clamp and a 2-h hyperglycemic clamp. Both AE and RE prevented the significant weight gain that was observed in controls. Compared with controls, significant reductions in total and visceral fat and intrahepatic lipid were observed in both exercise groups. Compared with controls, a significant improvement in insulin sensitivity (27%) was observed in the RE group. Collapsed across groups, changes in visceral fat were associated with changes in intrahepatic lipid (r = 0.72) and insulin sensitivity (r = -0.47). Both AE and RE alone are effective for reducing abdominal fat and intrahepatic lipid in obese adolescent boys. RE but not AE is also associated with significant improvements in insulin sensitivity.

ADRB3 and PPARγ2 gene polymorphisms and their association with cardiovascular disease risk in postmenopausal women

OBJECTIVES

The contribution of heritability to the development of cardiovascular disease (CVD) is of interest as the identification of genes enhancing the susceptibility of individuals to CVD may help the design of clinical interventions optimized for the individual's genome.

METHODS

We studied the associations of polymorphism of ADRB3 and PPARγ2 genes with obesity indices, unfavorable lipid profile parameters and insulin resistance index HOMA in 343 postmenopausal women.

RESULTS

No association was found between tested polymorphisms and CVD risk factors such as total cholesterol ≥ 5.0 mmol/l, high density lipoprotein cholesterol < 1.2 mmol/l, low density lipoprotein cholesterol > 3.0 mmol/l and triacylglycerols > 1.7 mmol/l. The presence of arterial hypertension and HOMA value ≥ 1.95 were also not related to these polymorphisms. A significant association between PPARγ2 gene polymorphism and total body fat mass (odds ratio = 1.90 at p = 0.037) as well as android fat deposit mass (odds ratio = 1.82 at p = 0.048) was found.

CONCLUSIONS

CVD risk factors in postmenopausal women are not directly associated with the polymorphisms of PPARγ2 and ADRB3 genes. We suggest that some indirect link between PPARγ2 gene polymorphism and susceptibility of postmenopausal women to CVD may exist. This suggestion is based on our finding that high total body fat mass and high android fat deposits are associated with the presence of the Pro12Ala allele of the PPARγ2 gene.

A new metabolomic assay to examine inflammation and redox pathways following LPS challenge

BACKGROUND

Shifts in intracellular arginine (Arg) and sulfur amino acid (SAA) redox metabolism modulate macrophage activation, polarization and phenotype. Despite their importance in inflammation and redox regulatory pathways, comprehensive analysis of these metabolic networks was not previously possible with existing analytical methods.

METHODS

The Arg/thiol redox LC-MS/MS metabolomics assay permits simultaneous assessment of amino acids and derivative products generated from Arg and SAA metabolism. Using this assay, LPS-induced changes in macrophage amino acid metabolism were monitored to identify pathway shifts during activation and their linkage to cellular redox regulation.

RESULTS

Metabolite concentrations most significantly changed after treatment of a macrophage-like cell line (RAW) with LPS for 24 hrs were citrulline (Cit) (48-fold increase), ornithine (Orn) (8.5-fold increase), arginine (Arg) (66% decrease), and aspartic acid (Asp) (73% decrease). The ratio Cit + Orn/Arg + Asp (CO/AA) was more sensitive to LPS stimulation than other amino acid ratios commonly used to measure LPS-dependent inflammation (e.g., SAM/SAH, GSH/GSSG) and total media NOx. The CO/AA ratio was also the first ratio to change significantly after LPS treatment (4 hrs). Changes in the overall metabolomic profile over time indicated that metabolic pathways shifted from Arg catabolism to thiol oxidation.

CONCLUSIONS

Simultaneous quantification of Arg and SAA metabolic pathway shifts following LPS challenge of macrophage indicate that, in this system, the Arg-Citrulline/NO cycle and arginase pathways are the amino acid metabolic pathways most sensitive to LPS-challenge. The cellular (Cit + Orn)/(Arg + Asp) ratio, which summarizes this pathway, was more responsive to lower concentrations of LPS and responded earlier than other metabolic biomarkers of macrophage activation including GSH redox. It is suggested that the CO/AA ratio is a redox- independent early biomarker of macrophage activation. The ability to measure both the CO/AA and GSH-redox ratios simultaneously permits quantification of the relative effects of LPS challenge on macrophage inflammation and oxidative stress pathways. The use of this assay in humans is discussed, as are clinical implications.

Size and phospholipid coating of lipid droplets in the diet of young mice modify body fat accumulation in adulthood

BACKGROUND

In addition to contemporary lifestyle factors that contribute to the increased obesity prevalence worldwide, early nutrition is associated with sustained effects on later life obesity. We hypothesized that physical properties of dietary lipids contribute to this nutritional programming. We developed a concept infant formula (IMF) with large, phospholipid-coated lipid droplets (Nuturis; Danone Research, Paris, France) and investigated its programming effect on metabolic phenotype later in life.

METHODS

Male C57Bl/6j mice were fed a control formula (Control IMF) or Nuturis (Concept IMF) diet between postnatal day (PN)16 and PN42. All mice were subsequently fed a Western-style diet (WSD) until PN126. Body composition was monitored repeatedly by dual-energy X-ray absorptiometry between PN42 and PN126.

RESULTS

Concept IMF slightly increased lean body mass as compared with Control IMF at PN42 but did not affect fat mass. Upon 84 d of WSD feeding, the Concept IMF group showed reduced fat accumulation as compared with Control IMF. In addition, fasting plasma leptin, resistin, glucose, and lipids were significantly lower in the Concept IMF group.

CONCLUSION

Large phospholipid-coated lipid droplets in young mice reduced fat accumulation and improved metabolic profile in adulthood. These data emphasize that physical properties of early dietary lipids contribute to metabolic programming.

Elevated C-reactive protein in children from risky neighborhoods: evidence for a stress pathway linking neighborhoods and inflammation in children

BACKGROUND

Childhood socioeconomic status is linked to adult cardiovascular disease and disease risk. One proposed pathway involves inflammation due to exposure to a stress-inducing neighborhood environment. Whether CRP, a marker of systemic inflammation, is associated with stressful neighborhood conditions among children is unknown.

METHODS AND RESULTS

The sample included 385 children 5-18 years of age from 255 households and 101 census tracts. Multilevel logistic regression analyses compared children and adolescents with CRP levels >3 mg/L to those with levels ≤ 3 mg/L across neighborhood environments. Among children living in neighborhoods (census tracts) in the upper tertile of poverty or crime, 18.6% had elevated CRP levels, in contrast to 7.9% of children living in neighborhoods with lower levels of poverty and crime. Children from neighborhoods with the highest levels of either crime or poverty had 2.7 (95% CI: 1.2-6.2) times the odds of having elevated CRP levels when compared to children from other neighborhoods, independent of adiposity, demographic and behavioral differences.

CONCLUSIONS

Children living in neighborhoods with high levels of poverty or crime had elevated CRP levels compared to children from other neighborhoods. This result is consistent with a psychosocial pathway favoring early development of cardiovascular risk that involves chronic stress from exposure to socially- and physically-disordered neighborhoods characteristic of poverty.

[Non-alcoholic fatty liver disease and its association with clinical and biochemical variables in obese children and adolescents: effect of a one-year intervention on lifestyle]

OBJECTIVE

To study the frequency of non-alcoholic fatty liver disease (NAFLD), its relationship to clinical and biochemical variables, and the effect 12-month's lifestyle intervention in obese children and adolescents.

METHODS

Thirty-six obese patients aged 7 to 18 years, 42% female and 58% male, 72.2% prepubertal and 27.8% pubertal, were selected. Anthropometric measurements and glucose, insulin (baseline and after a glucose load), lipid profile, C-reactive protein, and aminotransferase tests were performed before and 12 months after dietary and physical activity intervention. Liver ultrasound was performed to determine the presence of NAFLD.

RESULTS

NAFLD was found in 66.7% (n=24), and was mild in 30.6%, moderate in 27.8%, and severe in 8.3%. Subjects with NAFLD had higher body mass index (BMI, p=0.007), waist (p=0.005), fat area (p=0.002), basal insulin (p=0.01), and HOMA-IR (p=0.008) values and lower QUICKI (p=0.02) values than those with no NAFLD. After intervention, physical activity increased (p=0.0001) and calorie intake remained unchanged. NAFLD disappeared in 9 patients (37.5%, p=0.02) and disease severity decreased in 3 patients (12.5%). In addition, BMI Z-score (p=0.005), fat area (p=0.0001), basal insulin (p<0.05), insulin resistance (p<0.005), lipid profile (p<0.03), and transaminases decreased. Weight loss was the main variable accounting for NAFLD improvement.

CONCLUSION

This group of obese children and adolescents showed a high frequency of NAFLD. The lifestyle intervention with weight reduction is effective for the treatment of NAFLD.

Potential clinical translation of juvenile rodent inactivity models to study the onset of childhood obesity

According to the latest data from the Center for Disease Control and Prevention 17%, or 12.5 million, of children and adolescents aged 2-19 years in the United States are obese. Physical inactivity is designated as one of the actual causes of US deaths and undoubtedly contributes to the obesity epidemic in children and adults. Examining the effects of inactivity on physiological homeostasis during youth is crucial given that 58% of children between the ages 6-11 yr old fail to obtain the recommended 60 min/day of physical activity and 92% of adolescents fail to achieve this goal [Troiano et al. Med Sci Sports Exerc. 40, 2008]. Nonetheless, invasive mechanistic studies in children linking diminished physical activity with metabolic maladies are lacking for obvious ethical reasons. The rodent wheel lock (WL) model was adopted by our laboratory and others to study how different organ systems of juvenile rats respond to a cessation of daily physical activity. Our WL model houses rats in cages equipped with voluntary running wheels starting at 28 days of age. After a certain period of voluntary running (3 to 6 wk), the wheels are locked, thus preventing the rats' primary source of physical activity. The studies discussed herein suggest that obesity-associated maladies including skeletal muscle insulin resistance, hypothalamic leptin resistance, fatty acid oxidation impairments in skeletal muscle and adipose tissue, nonalcoholic fatty liver disease, and endothelial dysfunction are initiated in juvenile animals that are restrained from voluntary exercise via WL. The use of the juvenile rodent WL or other inactivity models will continue to provide a powerful clinical translational tool that can be used for primordial prevention of human childhood obesity.

Prevalence of traditional and novel markers of cardiovascular disease risk in Scottish adolescents: socioeconomic effects

Information on the health status and physical activity of Scottish adolescents is limited. This study examines the prevalence of cardiovascular disease (CVD) risk in Scottish adolescents by socioeconomic status (SES). Participants were recruited from two high schools that differed in the SES of the students in attendance. The sample included 73 boys and 34 girls (16.4 ± 0.6 years). Variables included anthropometry, physical activity, physical fitness, blood pressure, diet, and 11 metabolic markers of CVD risk. Significant sex differences (P ≤ 0.01) were noted for stature, waist circumference, waist-hip ratio, physical activity, cardiorespiratory fitness, muscular power, sprint speed, and several CVD risk factors: high-density lipoprotein (HDL), low-density lipoprotein (LDL), interleukin-6 (IL-6), and C-reactive protein (CRP) levels. Boys from a lower SES had significantly higher levels of glucose and plasminogen activator inhibitor-1 (PAI-1) but lower levels of adiponectin compared with boys from a higher SES. Girls from a lower SES had significantly (P ≤ 0.01) higher glucose and PAI-1 levels but lower levels of insulin and adiponectin than girls from a higher SES. High fat diets, low physical activity levels, and elevated CRP and total cholesterol levels were the CVD risk factors most commonly identified as being at-risk levels in this cohort, regardless of sex or SES. SES differences were not consistently apparent, but several CVD risk factors were identified as elevated in this sample of adolescents, regardless of sex or SES.

Effects of voluntary running on oxygen consumption, RQ, and energy expenditure during primary prevention of diet-induced obesity in C57BL/6N mice

Diet-induced obesity (DIO) in C57BL/6 mice is the standard model for studying obesity in mice. The few reports of DIO utilizing voluntary running provide contradictory results with respect to prevention of obesity. However, total energy expenditures associated with voluntary running during DIO are unknown. We hypothesized that voluntary running would increase the amount of total energy expended during DIO. Female C57BL/6N mice were randomly assigned to one of three experimental groups [high-fat diet with voluntary running (HFRun); high-fat diet without running (HFSed); and low-fat diet without running (LFSed)] for a 10-wk period. We confirmed production of obesity in HFSed, and more importantly demonstrated primary prevention of obesity by voluntary running in a group of cohorts (HFRun). Indirect calorimetry was performed to determine oxygen consumption (Vo(2)) and respiratory quotient (RQ). The following novel mechanisms were identified in female C57BL/6N mice: 1) HFRun showed ∼2 times greater total energy expenditures during a day compared with HFSed and LFSed; 2) HFRun had increased Vo(2) compared with HFSed and LFSed, lower RQ in the light period than HFSed, and lower RQ in both light and dark periods than LFSed; and 3) in the HFRun group, the magnitude of change in Vo(2) and RQ differed in dark and light periods during voluntary running. Our data combined with existing literature point to a potential threshold of physical activity that would prevent DIO in this mouse model. These data give a mechanistic explanation to resolve contradictory reports on whether voluntary running can prevent obesity in the DIO mouse model. In conclusion, voluntary running rescues high-fat fed, female C57BL/6N mice from obesity in DIO by doubling energy expenditure during the dark period and significantly increasing energy expenditure during the light cycle.

Biomarkers of oxidative stress and personalized treatment of pulmonary tuberculosis: emerging role of gamma-glutamyltransferase

Background. The objectives were (i) to evaluate the impact of acute pulmonary tuberculosis (PTB) and anti-TB therapy on the relationship between AST, ALT, and GGT levels in absence of conditions related to hepatotoxicity; (ii) to evaluate the rate and the time of alterations of AST, ALT, and GGT. Design and Methods. A prospective followup of 40 adults (21 males; mean age of 34.7 ± 5.8 years) with active PTB on initial phase and continuation phase anti-TB. Results. Only 3% (n = 1) developed a transient and benign ADR at day 30 without interruption of anti-TB treatment. Within normal ranges, GGT decreased significantly from day 0 to day 60, while AST and ALT increased significantly and respectively. During day 0–day 60, there was a significant, negative, and independent association between GGT and AST. Conclusion. The initial two months led to significant improvement of oxidative stress. Values of oxidative markers in normal ranges might predict low rate of ADR.

E-selectin is elevated in cord blood of South Asian neonates compared with Caucasian neonates

OBJECTIVE

To test the hypothesis that the increased risk of type 2 diabetes mellitus and coronary artery disease in South Asian subjects could be caused by the presence of endothelial dysfunction in early life. We studied markers of endothelial dysfunction in umbilical cord blood of South Asian neonates and compared these with that of Caucasian control subjects.

STUDY DESIGN

From South Asian (n = 57) and Caucasian (n = 21) neonates, cord blood was collected and levels of glucose, insulin, lipids, and markers of endothelial dysfunction (E-selectin, intercellular adhesion molecule 1, vascular cell adhesion molecule 1) and inflammation (C-reactive protein) were measured.

RESULTS

Plasma E-selectin levels were significantly higher in South Asian neonates (46.7 versus 33.5 ng/mL, P < .001), and levels of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 did not differ. Furthermore, South Asian neonates had hyperinsulinemia (P = .043), dyslipidemia (with significantly higher triglyceride and lower high-density lipoprotein cholesterol levels), and higher C-reactive protein levels (75.7 versus 43.8 ng/mL, P = .009).

CONCLUSIONS

South Asian newborns are characterized by elevated E-selectin levels in line with the hypothesis that endothelial dysfunction is present early in life. In addition, hyperinsulinemia, dyslipidemia, and inflammation are present. Because many pathogenic variables for coronary artery disease and type 2 diabetes are already present at birth in South Asian patients, the question arises whether rigorous childhood lifestyle intervention could be beneficial.

Long-term effects of an inpatient weight-loss program in obese children and the role of genetic predisposition-rationale and design of the LOGIC-trial

Background

The prevalence of childhood obesity has increased worldwide, which is a serious concern as obesity is associated with many negative immediate and long-term health consequences. Therefore, the treatment of overweight and obesity in children and adolescents is strongly recommended. Inpatient weight-loss programs have shown to be effective particularly regarding short-term weight-loss, whilst little is known both on the long-term effects of this treatment and the determinants of successful weight-loss and subsequent weight maintenance.

The purpose of this study is to evaluate the short, middle and long-term effects of an inpatient weight-loss program for children and adolescents and to investigate the likely determinants of weight changes, whereby the primary focus lies on the potential role of differences in polymorphisms of adiposity-relevant genes.

Methods/Design

The study involves overweight and obese children and adolescents aged 6 to 19 years, who participate in an inpatient weight-loss program for 4 to 6 weeks. It started in 2006 and it is planned to include 1,500 participants by 2013. The intervention focuses on diet, physical activity and behavior therapy. Measurements are taken at the start and the end of the intervention and comprise blood analyses (DNA, lipid and glucose metabolism, adipokines and inflammatory markers), anthropometry (body weight, height and waist circumference), blood pressure, pubertal stage, and exercise capacity. Physical activity, dietary habits, quality of life, and family background are assessed by questionnaires. Follow-up assessments are performed 6 months, 1, 2, 5 and 10 years after the intervention: Children will complete the same questionnaires at all time points and visit their general practitioner for examination of anthropometric parameters, blood pressure and assessment of pubertal stage. At the 5 and 10 year follow-ups, blood parameters and exercise capacity will be additionally measured.

Discussion

Apart from illustrating the short, middle and long-term effects of an inpatient weight-loss program, this study will contribute to a better understanding of inter-individual differences in the regulation of body weight, taking into account the role of genetic predisposition and lifestyle factors.

Trial Registration

NCT01067157.

Epigenetics: a tool to understand diet-related cardiovascular risk?

Cardiovascular disease (CVD) is a leading cause of mortality and is projected to hold its grim record as developing countries increase their wealth. Since specific nutritional habits are important risk factors for CVD, it is imperative to understand how ingredients of risk-associated diets convert a healthy cellular transcriptional program into a pathological one. Epigenetics has enriched our view of the genome by showing that DNA-associated regulatory proteins and RNAs, together with chemical modifications of the DNA itself, determine which parts of the DNA chain are transcribed or silent in a given phase of a cell's life. This complex biological entity--the epigenome--accounts for the enormous phenotypic diversity within a multicellular organism despite its unicellular origin. Crucially, the epigenome can be modified by diet and other exogenous factors, thus suggesting that epigenetic mechanisms might underlie pathological responses to CVD risk factors. Here, we will review the current knowledge of epigenetic mechanisms in diet-gene interactions and propose ways in which epigenetics might clarify the impact of genetic variants on CVD risk.

Novel risk factors of cardiovascular disease and their associations between obesity, physical activity and physical fitness

The prevalence of cardiovascular disease (CVD) is increasing around the globe and is the leading cause of death around the world. Though once thought of as an adult problem, it is now recognised that the early manifestations of disease may occur during childhood. Numerous risk factors have been linked to CVD with much of the research focusing on understanding the prevalence and relationship of traditional risk factors such as dyslipidemia, smoking, diabetes mellitus, hypertension, obesity, psychosocial stress, poor diet, physical inactivity and alcohol consumption to the early etiology of disease. While this line of investigation has greatly enhanced our understanding of the relationship between these risk factors and disease, they do not fully explain all cardiovascular events. To enhance our understanding and help with the management of CVD, investigations that involve the measurement of traditional as well as novel risk factors may be necessary. Public health strategies that aim to reduce the prevalence of obesity and overweight encourage youth to increase their physical activity levels as a means of protecting against poor cardiometabolic profiles. Interventions that increase physical activity levels and improve cardiorespiratory fitness cause a reduction in certain CVD risk factors but the lack of agreement between findings makes it impossible to give precise recommendations that will ensure CVD risk reduction. Yet it is important that research continues in order to establish the most appropriate means of improving the health and well-being of those at most risk of future CVD.

Early depression of Ankrd2 and Csrp3 mRNAs in the polyribosomal and whole tissue fractions in skeletal muscle with decreased voluntary running

The wheel-lock (WL) model for depressed ambulatory activity in rats has shown metabolic maladies ensuing within 53-173 h after WL begins. We sought to determine if WL beginning after 21-23 days of voluntary running in growing female Wistar rats affected the mRNA profile in the polyribosomal fraction from plantaris muscle shortly following WL. In experiment 1, WL occurred at 0200 and muscles were harvested at 0700 daily at 5 h (WL5h, n = 4), 29 h (WL29h, n = 4), or 53 h (WL53h, n = 4) after WL. Affymetrix Rat Gene 1.0 ST Arrays were used to test the initial question as to whether WL affects mRNA occupancy on skeletal muscle polyribosomes. Using a false discovery rate of 15%, no changes in mRNAs in the polyribosomal fraction were observed at WL29h and eight mRNAs (of over 8,200 identified targets) were altered at WL53h compared with WL5h. Interestingly, two of the six downregulated genes included ankyrin repeat domain 2 (Ankrd2) and cysteine-rich protein 3/muscle LIM protein (Csrp3), both of which encode mechanical stretch sensors and RT-PCR verified their WL-induced decline. In experiment 2, whole muscle mRNA and protein levels were analyzed for Ankrd2 and Csrp3 from the muscles of WL5h (4 original samples + 2 new), WL29h (4 original), WL53h (4 original + 2 new), as well as WL173 h (n = 6 new) and animals that never ran (SED, 4-5 new). Relative to WL5h controls, whole tissue Ankrd2 and Csrp3 mRNAs were lower (P < 0.05) at WL53h, WL173h, and SED; Ankrd2 protein tended to decrease at WL53h (P = 0.054) and Csrp3 protein was less in WL173h and SED rats (P < 0.05). In summary, unique early declines in Ankrd2 and Csrp3 mRNAs were identified with removal of voluntary running, which was subsequently followed by declines in Csrp3 protein levels during longer periods of wheel lock.

Platelet dysfunction in vascular pathologies and how can it be treated

Cardiovascular diseases are one of the leading causes of morbidity and mortality in industrialized countries, and although many processes play a role in the development of vascular disease, thrombosis is the primary event that precipitates stroke and acute coronary syndromes. The blood platelets are of significant importance in medicine. These cells are involved in many physiological processes, particularly haemostasis through their ability to aggregate and form clots in response to activation. In addition, these dynamic cells display activities that extend beyond thrombosis, including an important role in initiating and sustaining vascular inflammation. The expansion of knowledge from basic and clinical research has highlighted the critical position of platelets in several inflammatory diseases such as arthritis and atherosclerosis. Platelets are emerging as important mediators of inflammation and provide important signals to mediate phenotype of other blood and vascular cells. The important role of platelets in arterial thrombosis and the onset of acute myocardial infarction after atherosclerotic plaque rupture make inhibition of platelet aggregation a critical step in preventing thrombotic events associated with stroke, heart attack, and peripheral arterial thrombosis. However, the use of platelet inhibitors for thrombosis prevention must seek a delicate balance between inhibiting platelet activation and an associated increased bleeding risk. The aim of this review is to up-date the knowledge on platelets physiology and dysfunction in pathologies, such as diabetes mellitus, hypercholesterolemia, and hypertension, emphasizing the link between platelets and the inflammation-related atherosclerosis. The review evaluates the opportunities offered by the novel platelet inhibitors to efficiently alleviate the thrombotic events.