High-sensitive C-reactive protein, tumor necrosis factor alpha, and cardiovascular risk factors before and after weight loss in obese children

Obesity, inflammation and the immune system

Obesity shares with most chronic diseases the presence of an inflammatory component, which accounts for the development of metabolic disease and other associated health alterations. This inflammatory state is reflected in increased circulating levels of pro-inflammatory proteins, and it occurs not only in adults but also in adolescents and children. The chronic inflammatory response has its origin in the links existing between the adipose tissue and the immune system. Obesity, like other states of malnutrition, is known to impair the immune function, altering leucocyte counts as well as cell-mediated immune responses. In addition, evidence has arisen that an altered immune function contributes to the pathogenesis of obesity. This review attempts to briefly comment on the various plausible explanations that have been proposed for the phenomenon: (1) the obesity-associated increase in the production of leptin (pro-inflammatory) and the reduction in adiponectin (anti-inflammatory) seem to affect the activation of immune cells; (2) NEFA can induce inflammation through various mechanisms (such as modulation of adipokine production or activation of Toll-like receptors); (3) nutrient excess and adipocyte expansion trigger endoplasmic reticulum stress; and (4) hypoxia occurring in hypertrophied adipose tissue stimulates the expression of inflammatory genes and activates immune cells. Interestingly, data suggest a greater impact of visceral adipose tissue and central obesity, rather than total body fat, on the inflammatory process. In summary, there is a positive feedback loop between local inflammation in adipose tissue and altered immune response in obesity, both contributing to the development of related metabolic complications.

Long-term effect of lifestyle intervention on adiposity, metabolic parameters, inflammation and physical fitness in obese children: a randomized controlled trial

Background:

Behavioral lifestyle intervention, combined with parental involvement, is preferred over standard care or self-help in childhood obesity. The short-term results of such interventions are promising, but long-term follow-up results are equivocal.

Objective:

The objective of the present study was the short (3 months) and long-term (1 and 2 years follow-up) effect evaluation of a family-based multidisciplinary cognitive behavioral lifestyle intervention on markers of adiposity, metabolism, inflammation and physical fitness compared with standard care in children with obesity. Also the association between these outcome variables was determined.

Methods:

In this prospective longitudinal clinical trial, obese children were randomly assigned to a 3-month family-based cognitive behavioral multidisciplinary lifestyle treatment (n=40; body mass index-standard deviation score (BMI-SDS) 4.2±0.7; age; 13.3±2.0 years) or to a control group receiving an initial advice on physical activity and nutrition (n=39; BMI-SDS 4.3±0.6; age 13.1±1.9 years). Anthropometric data, physical fitness, metabolic parameters and inflammatory state were evaluated at baseline, after intervention (at 3 months) and at 1-year follow-up. At 2-year follow-up, anthropometric data and physical fitness were measured in the intervention group.

Results:

An intervention effect after 1 year was found for adiposity (P=0.02 for BMI-SDS, P=0.03 for waist circumference (WC)-SDS), physical fitness (absolute measured peak value of oxygen uptake (ml min⁻¹), standardized for age and gender (VO_2peak-SDS), P<0.01) and insulin resistance (HOMA-SDS, P=0.04). No significant intervention effect was found for serum lipid profile, high-sensitive C-reactive protein or for adiponectin. At 2-year follow-up, BMI-SDS in the intervention group (n=31) was 3.8±1.2 SDS, significantly less than at baseline (P=0.02).

Conclusion:

A positive 1-year follow-up treatment effect was found for adiposity, physical fitness and glucose homeostasis, but not for inflammatory markers. There was a significant long-term treatment effect on adiposity, although almost all children remained obese.

The obesity phenotype in children with asthma

Asthma and obesity have been increasing in prevalence internationally among children. Evidence points to an association between these chronic morbidities, suggesting the development of an 'obese asthma' phenotype in childhood. This review summarises the evidence that the proinflammatory environment created by excess adiposity may provide a mechanism leading to obese asthma in children and adolescents. Weight loss studies conducted in children without asthma have demonstrated a reduction in systemic inflammation. However, the impact of weight loss in the obese paediatric population with asthma has not been investigated. The paucity of information highlights the need for high quality randomised controlled trials of weight loss in this population that include assessment of systemic and airway inflammation, and clinical asthma outcomes. This will lead to refinements in management approaches for these patients.

Changes in cardiometabolic risk factors, appetite-controlling hormones and cytokines after a treatment program in overweight adolescents: preliminary findings from the EVASYON study

OBJECTIVE

We investigated the effects of the EVASYON program on body fatness, cardiometabolic risk factors, gut appetite-controlling hormones and serum levels of cytokines in adolescents with overweight or obesity (OW/OB).

METHODS

This study comprised 13 boys (10 obese) and 12 girls (8 obese), aged 13-16 years, from a Madrid Hospital. The EVASYON program was based on a calorie-restricted diet (10-40%), increased physical activity (at least 60 min/day 5 days a week), psychological therapy and nutritional education for 13 months. Anthropometric and blood pressure measurements were measured before and after intervention. Serum glucose, total cholesterol, high-density lipoprotein cholesterol, triglycerides, leptin, total peptide YY and insulin levels were determined before and after intervention. Serum levels of cytokines IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, and TNF-α were also assessed before and after intervention.

RESULTS

A decrease in body mass index (BMI), BMI z-score, skinfolds (triceps, biceps, subscapular, thigh, and calf), sum of six skinfolds and body circumferences (arm relaxed and flexed, waist, hip, and proximal thigh) values were observed after the intervention program (all p < 0.05). In addition, diastolic blood pressure also decreased (p < 0.05). A decrease in serum leptin levels (-48.4%, p < 0.001) was observed after intervention without changes in total peptide YY and insulin levels. Levels of IL-8, IL-10, and TNF-α also decreased (all p < 0.05) after the intervention program.

CONCLUSIONS

These preliminary results evidence that the EVASYON program may improve body fat, leptin, and some pro-inflammatory cytokines in adolescents with OW/OB.

Reduction in BMI z-score and improvement in cardiometabolic risk factors in obese children and adolescents. The Oslo Adiposity Intervention Study - a hospital/public health nurse combined treatment

BACKGROUND

Weight loss and increased physical fitness are established approaches to reduce cardiovascular risk factors. We studied the reduction in BMI z-score associated with improvement in cardiometabolic risk factors in overweight and obese children and adolescents treated with a combined hospital/public health nurse model. We also examined how aerobic fitness influenced the results.

METHODS

From 2004-2007, 307 overweight and obese children and adolescents aged 7-17 years were referred to an outpatient hospital pediatrics clinic and evaluated by a multidisciplinary team. Together with family members, they were counseled regarding diet and physical activity at biannual clinic visits. Visits with the public health nurse at local schools or at maternal and child health centres were scheduled between the hospital consultations. Fasting blood samples were taken at baseline and after one year, and aerobic fitness (VO2peak) was measured. In the analyses, 230 subjects completing one year of follow-up by December 2008 were divided into four groups according to changes in BMI z-score: Group 1: decrease in BMI z-score≥0.23, Group 2: decrease in BMI z-score≥0.1-< 0.23, Group 3: decrease in/stable BMI z-score≥0.0-< 0.1, Group 4: increase in BMI z-score (>0.00-0.55).

RESULTS

230 participants were included in the analyses (75%). Mean (SD) BMI z-score was reduced from 2.18 (0.30) to 2.05 (0.39) (p < 0.001) in the group as a whole. After adjustment for BMI z-score, waist circumference and gender, the three groups with reduced BMI z-score had a significantly greater reduction in HOMA-IR, insulin, total cholesterol, LDL cholesterol and total/HDL cholesterol ratio than the group with increased BMI z-score. Adding change in aerobic fitness to the model had little influence on the results. Even a very small reduction in BMI z-score (group 3) was associated with significantly lower insulin, total cholesterol, LDL and total/HDL cholesterol ratio. The group with the largest reduction in BMI z-score had improvements in HOMA-IR and aerobic fitness as well. An increase in BMI z-score was associated with worsening of C-peptide and total/HDL cholesterol ratio.

CONCLUSIONS

Even a modest reduction in BMI z-score after one year of combined hospital/and public health nurse intervention was associated with improvement in several cardiovascular risk factors.

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

The rapid increase in the prevalence and severity of obesity in children is likely to lower the age of onset and increase the incidence of cardiovascular disease worldwide. Understanding the pathophysiology and improving the clinical management of cardiovascular disease involve a knowledge of novel risk factors and biomarkers. The clinical and mechanistic roles of these novel biological factors during childhood are currently being investigated. The goals of this scientific statement are to present the existing knowledge and theoretical framework of nontraditional risk factors for cardiovascular disease as they relate to children and adolescents, to describe the relevance and weight of available experimental and clinical evidence and the therapeutic implications pertaining to nontraditional risk factors in the pediatric population, and to stimulate further research with a goal of developing valid and reliable approaches to identify and validate novel risk factors that will aid in the clinical evaluation and perhaps prediction of cardiovascular disease in the pediatric population. Although several biomarkers are promising, substantial research is required before nontraditional risk factors can be used to identify and reduce cardiovascular disease risk in children and adolescents.

The effect of family-based multidisciplinary cognitive behavioral treatment in children with obesity: study protocol for a randomized controlled trial

BACKGROUND

The prevalence of childhood obesity has increased rapidly during the last three decades in the Netherlands. It is assumed that mainly environmental factors have contributed to this trend. Parental overweight and low social economic status are risk factors for childhood obesity. Childhood obesity affects self-esteem and has negative consequences on cognitive and social development. Obese children tend to become obese adults, which increases the risk for developing cardiovascular complications, type 2 diabetes mellitus, and psychosocial problems. Additionally, the secretion of several gastrointestinal hormones, responsible for appetite and food intake, is impaired in obese subjects. Weight reduction through lifestyle changes in order to change health risks is, until now, suggested as the preferred treatment for childhood obesity.The objective of this study is the effect evaluation of a family-based cognitive behavioral multidisciplinary lifestyle treatment. The intervention aims to establish long-term weight reduction and stabilization, reduction of obesity-related health consequences and improvement of self-image by change of lifestyle and learning cognitive behavioral techniques.

STUDY DESIGN/METHODS

In this randomized clinical trial newly presented children with obesity (8-17 years old) are divided, by randomization, in an intervention and control group, both consisting of 40 obese children. The intervention is carried out in groups of 8-11 children, and consists of respectively 7 and 5 separate group meetings for the children and their parents and 1 joint group meeting of 2 ½ hours. Main topics are education on nutrition, self-control techniques, social skills, physical activity and improvement of self-esteem. The control group is given advice on physical activity and nutrition. For normal data comparison, data were collected of 40 normal-weight children, 8-17 years old.

DISCUSSION

Because of the increasing prevalence of childhood obesity and the impact on the individual as well as on society, prevention and treatment of obesity in children is of great importance. For evaluation of short- and long-term effects of the treatment, measurements are taken before and after 3 months of treatment, and after 12 and 24 months follow-up. During these visits clinical and biochemical data are determined, cardiovascular fitness tests are performed and quality of life questionnaires are completed.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Register ISRCTN36146436

C-reactive protein levels are associated with adiposity and a high inflammatory foods index in mountainous Cypriot children

BACKGROUND & AIMS

Inflammatory marker levels have long been associated with obesity status in adult populations, but relevant data are scarce in children, especially in diverse races. The aim of this study was thus to examine the association between overall and central obesity and C-reactive protein (CRP) levels in Cypriot children of Greek ancestry.

METHODS

Eighty three children (9.2 ± 1.7 years) were studied. Body mass index (BMI) was calculated according to the age-sex specific International Obesity Task Force (IOTF) criteria while body fat percentage (BF%) was measured via leg-to-leg bioelectric impedance (BIA). Central obesity was defined as waist circumference ≥ 75 th percentile. Physical activity was assessed using a pedometer and diet quality was evaluated by applying the KIDMED index. An inflammatory foods' index, composed of nine foods/food groups, was also calculated. CRP levels were measured using a high-sensitivity (hs) immunoassay.

RESULTS

Obese children, children with excess BF% and children with WC ≥ 75 th percentile were 7.35, 6.84 and 7.81 times (P < 0.05) respectively more likely to have hs-CRP levels ≥ 0.10 mg/dL; a high score of the dietary inflammation index was positively associated with CRP levels.

CONCLUSIONS

Obesity is associated with increased hs-CRP levels in 6-12 year-old children, a finding that supports the inflammation-obesity hypothesis at an early stage of life. Furthermore, frequent consumption of inflammatory foods is positively related to CRP levels.

Insulin sensitivity, serum lipids, and systemic inflammatory markers in school-aged obese and nonobese children

The impact of obesity as a systemic low-grade inflammatory process has only partially been explored. To this effect, 704 community-based school-aged children (354 obese children and 350 age-, gender-, and ethnicity-matched controls) were recruited and underwent assessment of plasma levels of fasting insulin and glucose, lipids, and a variety of proinflammatory mediators that are associated with cardiometabolic dysfunction. Obese children were at higher risk for abnormal HOMA and cholesterol levels. Furthermore, BMI z score, HOMA, and LDL/HDL ratio strongly correlated with levels of certain inflammatory mediators. Taken together, obesity in children is not only associated with insulin resistance and hyperlipidemia, but is accompanied by increased, yet variable, expression of markers of systemic inflammation. Future community-based intervention and phenotype correlational studies on childhood obesity will require inclusion of expanded panels of inflammatory biomarkers to provide a comprehensive assessment of risk on specific obesity-related morbidities.

AMPK as Target for Intervention in Childhood and Adolescent Obesity

Childhood obesity is a major worldwide health problem. Intervention programs to ameliorate the rate of obesity have been designed and implemented; yet the epidemic has no end near in sight. AMP-activated protein kinase (AMPK) has become one of the most important key elements in energy control, appetite regulation, myogenesis, adipocyte differentiation, and cellular stress management. Obesity is a multifactorial disease, which has a very strong genetic component, especially epigenetic factors. The intrauterine milieu has a determinant impact on adult life, since the measures taken for survival are kept throughout life thanks to epigenetic modification. Nutrigenomics studies the influence of certain food molecules on the metabolome profile, raising the question of an individualized obesity therapy according to metabolic (and probably) genetic features. Metformin, an insulin sensitizing agent, its known to lower insulin resistance and enhance metabolic profile, with an additional weight reduction capacity, via activation of AMPK. Exercise is coadjutant for lifestyle modifications, which also activates AMPK in several ways contributing to glucose and fat oxidation. The following review examines AMPK's role in obesity, applying its use as a tool for childhood and adolescent obesity.

Leukocyte Count versus C-Reactive Protein Levels in Obese Portuguese Patients Aged 6-12 Years Old

Objectives:

to evaluate whether total and differential WBC counts are altered in young obese patients (aged 6-12 years) and if a relationship exists between WBC counts and the severity of obesity as well as with CRP level.

Materials and Methods:

a group of 77 obese patients [32 males and 45 females] and 19 controls [7 males and 12 females] were studied. Total WBC count was performed by using an automatic blood cell counter. Blood cell morphology and WBC differential count were evaluated in Wright stained blood films. The plasma levels of CRP were evaluated by immunoturbidimetry.

Results:

obese participants presented with a statistically significant higher neutrophil percentage and CRP levels when compared to controls; the median CRP value was about 5 times higher than that observed in controls. Absolute neutrophil count and neutrophil/lymphocyte ratio were also higher in patients, though without statistical significance. The parameters that were statistically significant related with adiposity markers were neutrophil count and CRP levels. The neutrophil count was positively and statistically correlated with body mass index (BMI), BMI z-score, waist circumference and waist/height ratio, and also with CRP levels. In multiple regression analysis, the only variable that remained statistically associated with neutrophil count was CRP (neutrophil count = 2.612 + 0.439lnCRP; standardised coefficient/beta: 0.384, P=0.001). When performing multiple regression without CRP, the only variable that remained statistically associated with neutrophil count was BMI.

Conclusions:

our results demonstrated in obese patients aged 6-12 years, a significant change in the differential leukocyte count towards neutrophilia, together with a significant higher CRP concentration, and that absolute neutrophil count correlates with obesity markers and with CRP levels. Our data also indicate that neutrophil count, a current clinically used low-cost parameter, may be used as an obesity-related inflammatory marker in young obese patients.

Stunting, adiposity, and low-grade inflammation in African adolescents from a township high school

OBJECTIVE

The objective of this study was to compare the inflammatory status of children with differences in nutritional status.

METHODS

This was a cross-sectional study of 184 African children aged 13-18 y from a low socioeconomic background that compared stunted with non-stunted and lean with over-fat (percentage of body fat above normal cutoff points) children. Fasting serum tumor necrosis factor-alpha, interleukin-6, C-reactive protein, and insulin were measured using high-sensitivity methods. Body composition was assessed using anthropometry and air-displacement plethysmography. T tests for parametric data and the Mann-Whitney test for non-parametric data were used to compare groups. Regression analyses and principal components analyses were done to assess relations between body composition and biochemical variables.

RESULTS

Of all participants 18% were stunted. Serum tumor necrosis factor-alpha of stunted girls was higher than in non-stunted girls. More of the stunted boys were over-fat compared with their non-stunted counterparts. Regression analyses showed that insulin resistance, diastolic blood pressure, and C-reactive protein contributed significantly to interleukin-6 in boys. Serum C-reactive protein, waist circumference, and body mass index clustered together in factor analysis in boys. Serum interleukin-6, waist-hip ratio, and tumor necrosis factor-alpha clustered together in factor analysis in girls.

CONCLUSION

An association between adiposity and stunting and between adiposity low-grade inflammation was found in this study. Interventions for stunted children focus mainly on correction of undernutrition by providing feeding schemes. Attention should, however, also be paid to changes in body composition over time to prevent excessive abdominal fat accumulation and risk for cardiovascular diseases later in life.

Obesity is the major contributor to vascular dysfunction and inflammation in high-fat diet hypertensive rats

Obesity and hypertension are the two major risk factors that contribute to the progression of end-stage renal disease. To examine whether hypertension further exacerbates oxidative stress and vascular dysfunction and inflammation in obese rats, four groups of male Sprague-Dawley rats were fed either a normal (7% fat) or high-fat (36% fat) diet for 6 weeks and osmotic pumps were implanted to deliver ANG (angiotensin II) or vehicle for an additional 4 weeks.Treatment with the high-fat diet did not alter ANG-induced hypertension compared with the normal diet (174 +/- 6 compared with 170 +/- 5 mmHg respectively). Treatment with the high-fat diet increased body weight gain and plasma leptin levels and induced insulin resistance in normotensive and ANG-induced hypertensive rats. Plasma TBARS (thiobarbituric acid-reacting substances), a measure of oxidative stress, were elevated in high-fat diet-fed rats compared with controls (11.2 +/-1 compared with 8.4 +/- nmol/ml respectively) and was increased further in ANG-induced hypertensive rats fed a high-fat diet (18.8 +/-2.2 nmol/ml). Urinary nitrite excretion was also decreased in rats fed a high-fat diet without or with ANG infusion compared with controls. Afferent arteriolar relaxation to acetylcholine was impaired in rats fed the high-fat diet without or with ANG infusion. Renal cortical TNF-alpha(tumour necrosis factor-alpha), COX-2(cyclo-oxygenase-2) and phospho-IKK (inhibitor of nuclear factor k B kinase) expression increased in high-fat diet-fed rats compared with normal diet-fed rats. The increases in phospho-IKK and COX-2 expression were elevated further in ANG-induced hypertensive rats fed the high-fat diet.These results suggest that ANG-induced hypertension exacerbates oxidative stress and renal inflammation without further impairment in vascular dysfunction in high-fat diet-induced obesity.

Obesity and low-grade inflammation: a paediatric perspective

Childhood obesity is a major public health problem. Low-grade inflammation, a hallmark characterizing adult obesity, may be a pivotal mechanism linking obesity to its numerous systemic complications, with adipose tissue depots secreting and producing inflammatory mediators and visceral fat displaying an increased inflammatory profile. While knowledge is relatively scarce regarding the importance of the adipose tissue inflammation process in children, identifying its contribution in childhood obesity and the associated influences of age, sex, weight status, growth, and adipose depot phenotypes are crucial for understanding physiopathology and implementing early intervention strategies. We review the latest research linking obesity and inflammation in childhood focusing on serum inflammatory markers and the effectiveness of lifestyle interventions in improving systemic inflammation. Generally, there are significant correlations between body mass index and increased c-reactive protein and decreased adiponectin levels in children; these levels tend to be improved in interventions resulting in approximately 5% weight loss, regardless of the type or length of intervention. There is a need for further research measuring other inflammatory mediators (e.g. tumour necrosis factor (TNF)-alpha, IL-6, IL-8) and histological studies examining immune cell infiltration in adipose tissue depots in obese children.

Relation between adiposity and disease risk factors in Mexican American children

OBJECTIVE

Excess adiposity is associated with systemic low-grade inflammation, which has been implicated in the pathophysiology of various diseases. The purpose of this study was to examine the relation between measures of adiposity and disease risk factors in Mexican American children participating in a weight loss intervention.

SUBJECTS AND METHODS

Boys and girls (N=170; 13.3+/-0.1 year) volunteered for additional testing from a larger study that demonstrated significant reduction in standardized body mass index. Insulin, C-reactive protein, soluble cluster of differentiation 14, glucose, and cholesterol profile were assessed.

RESULTS

Linear mixed models regression showed that changes in adiposity (standardized body mass index and triceps skinfold) were significantly related with changes in total cholesterol (P=0.01), triglycerides (P<0.001), C-reactive protein (P<0.001), insulin (P<0.001), Homeostasis model assessment of insulin resistance (P<0.001), and high-density lipoprotein (P<0.001).

CONCLUSIONS

The relation between measures of adiposity and disease risk factors was stable over time in children participating in an exercise/weight loss intervention. Also, our findings indicate that reducing adiposity results in an improvement of blood disease risk factors in Mexican American children.

Dietary determinants of subclinical inflammation, dyslipidemia and components of the metabolic syndrome in overweight children: a review

OBJECTIVE

To review and summarize the dietary determinants of the metabolic syndrome, subclinical inflammation and dyslipidemia in overweight children.

DESIGN

Review of the current literature, focusing on pediatric studies.

PARTICIPANTS

Normal weight, overweight, or obese children and adolescents.

RESULTS

There is a growing literature on the metabolic effects of excess body fat during childhood. However, few pediatric studies have examined the dietary determinants of obesity-related metabolic disturbances. From the available data, it appears that dietary factors are not only important environmental determinants of adiposity, but also may affect components of the metabolic syndrome and modulate the actions of adipokines. Dietary total fat and saturated fat are associated with insulin resistance and high blood pressure, as well as obesity-related inflammation. In contrast to studies in adults, resistin and adiponectin do not appear to be closely linked to insulin resistance or dyslipidemia in childhood. However, circulating leptin and retinol-binding protein (RBP) 4 correlate well with obesity, central obesity and the metabolic syndrome in children. Intakes of antioxidant vitamins tend to be low in obese children and may be predictors of subclinical inflammation. Higher fructose intake from sweets and sweetened drinks in overweight children has been linked to decreased low-density lipoprotein (LDL) particle size.

CONCLUSIONS

Dietary interventions aimed at reducing intakes of total fat, saturated fat and free fructose, whereas increasing antioxidant vitamin intake may be beneficial in overweight children. More research on the relationships between dietary factors and the metabolic changes of pediatric obesity may help to identify the dietary changes to reduce health risks.

Changes in body mass index are associated with changes in inflammatory and endothelial dysfunction biomarkers in obese prepubertal children after 9 months of body mass index SD score loss

The metabolic syndrome is associated with insulin resistance, a systemic low-grade inflammatory state, and endothelial dysfunction. These disorders may arise at a very early age in obese children. The aim of this study was to confirm changes in endothelial dysfunction and inflammatory biomarkers in obese prepubertal children and to evaluate the effect of body mass index (BMI) modification on these biomarkers. Biomarkers for inflammation, endothelial dysfunction, and insulin resistance were measured in obese children (47) and healthy controls (47). Baseline pretreatment levels of insulin (P = .019), homeostasis model assessment of insulin resistance (P = .004), soluble intercellular adhesion molecule (sICAM) (P = .003), and C-reactive protein (CRP) (P < .001) were significantly higher in obese children than in controls. After 9 months of treatment, obese children with lowered BMI SD score (SDS-BMI) displayed a significant decrease in insulin (P = .011), homeostasis model assessment of insulin resistance (P = .012), CRP (P = .006), and interleukin-6 (IL-6) (P = .045) levels compared with obese children with stable SDS-BMI; they also displayed a nonsignificant drop in sICAM levels. Similarly, obese children with lowered SDS-BMI displayed a decrease in CRP (P = .005) and IL-6 (P = .065) compared with baseline levels before treatment. In the total obese group, changes in SDS-BMI correlated positively with changes in CRP (P = .035), IL-6 (P = .027), and sICAM-1 (P = .038) levels. Only SDS-BMI was an independent predictive factor for CRP (P = .031), IL-6 (P = .027), and sICAM-1 (P = .033). Prepubertal obese children displayed alterations indicative of endothelial dysfunction, insulin resistance, and inflammatory state. Lowering of the SDS-BMI after 9 months of treatment was associated with an improvement in these variables compared with those in obese children with stable SDS-BMI status.

Inflammatory Disease Processes and Interactions with Nutrition

Inflammation is a stereotypical physiological response to infections and tissue injury; it initiates pathogen killing as well as tissue repair processes and helps to restore homeostasis at infected or damaged sites. Acute inflammatory reactions are usually self-limiting and resolve rapidly, due to the involvement of negative feedback mechanisms. Thus, regulated inflammatory responses are essential to remain healthy and maintain homeostasis. However, inflammatory responses that fail to regulate themselves can become chronic and contribute to the perpetuation and progression of disease. Characteristics typical of chronic inflammatory responses underlying the pathophysiology of several disorders include loss of barrier function, responsiveness to a normally benign stimulus, infiltration of inflammatory cells into compartments where they are not normally found in such high numbers, and overproduction of oxidants, cytokines, chemokines, eicosanoids and matrix metalloproteinases. The levels of these mediators amplify the inflammatory response, are destructive and contribute to the clinical symptoms. Various dietary components including long chain ω-3 fatty acids, antioxidant vitamins, plant flavonoids, prebiotics and probiotics have the potential to modulate predisposition to chronic inflammatory conditions and may have a role in their therapy. These components act through a variety of mechanisms including decreasing inflammatory mediator production through effects on cell signaling and gene expression (ω-3 fatty acids, vitamin E, plant flavonoids), reducing the production of damaging oxidants (vitamin E and other antioxidants), and promoting gut barrier function and anti-inflammatory responses (prebiotics and probiotics). However, in general really strong evidence of benefit to human health through anti-inflammatory actions is lacking for most of these dietary components. Thus, further studies addressing efficacy in humans linked to studies providing greater understanding of the mechanisms of action involved are required.

Effect of obesity on response to cardiovascular drugs in pediatric patients with renal disease

Obesity is associated with an increased concentration of inflammatory mediators, which in turn, in adults, reduces the response to calcium channel blockers (CCBs). We reviewed the medical charts of 263 pediatric nephrology patients with renal conditions, with the aim of studying the effect of obesity on the response to L-type CCBs, angiotensin interrupting agents (ANGIs), or a combination of the two. Forty-eight patients were ultimately enrolled in the study: 25 obese and 23 non-obese patients. The effect of the treatments on lowering the blood pressure was compared in obese versus non-obese patients. The systolic response to CCBs, measured as at least a 10% reduction from the baseline, was significantly lower in the obese (12.5%) patients than in the non-obese (52.9%) ones. The differences in diastolic response (58.8 and 25% for non-obese and obese patients, respectively) did not reach significance. The percentage response to CCBs, however, was significantly less in the obese patients than in the non-obese patients for both systolic and diastolic blood pressure. Corticosteroids also significantly influenced the response to CCBs in terms of diastolic pressure (62.9 and 25% for non-obese and obese patients, respectively). None of the tested covariates, including obesity, was found to significantly influence the response to ANGIs alone or in various combinations with CCBs. In conclusion, obesity and corticosteroid therapy should be considered when initiating antihypertensive drug treatment in children with kidney disease as both may contribute to a reduced efficacy of the antihypertensive therapy.

Fasting and postprandial markers of inflammation in lean and overweight children

BACKGROUND

Overweight children have greater circulating concentrations of markers of inflammation (MOI) than do lean children. Whether adiposity influences the postprandial MOI response is unknown.

OBJECTIVE

We aimed to evaluate the relations of fasting and postprandial MOI with total and regional adiposity and insulin sensitivity in children.

DESIGN

Fifty-nine children aged 7-12 y were assessed for C-reactive protein (CRP), interleukin-6 (IL-6), and soluble tumor necrosis factor receptor-2 (sTNF-R2) in the fasted state and after a mixed meal. Insulin sensitivity, body composition, and abdominal adipose tissue distribution were assessed with a frequently sampled intravenous-glucose-tolerance test, dual-energy X-ray absorptiometry, and computed tomography, respectively.

RESULTS

Central adipose measures were not independently associated with fasting MOI, although they were independently inversely associated with the postprandial sTNF-R2 response (r = -0.30 to -0.37, P = 0.02-0.006). The inverse association between intraabdominal adipose tissue and the postprandial CRP response was nearly significant (r = -0.27, P = 0.05). Insulin sensitivity was not associated with fasting or postprandial CRP or sTNF-R2; however, there was a positive relation between insulin sensitivity and fasting IL-6 (r = 0.27, P = 0.03), which was attenuated after adjustment for lean body mass (r = 0.25, P = 0.08).

CONCLUSIONS

Excess adiposity is associated with both fasting and postprandial MOI. The postprandial MOI response may be influenced by central adiposity in children. The positive association of insulin sensitivity with IL-6 warrants further study.

Impaired glucose regulation and type 2 diabetes in children and adolescents

Diabetes mellitus in paediatric patients used to be almost exclusively type 1, but in recent years, case series as well as hospital-based and population-based studies indicated that the number of children and adolescents with type 2 diabetes (T2DM) has been increasing. This development is alarming since T2DM in youth is usually not an isolated condition, but accompanied by other cardiovascular risk factors such as obesity, dyslipidaemia, hypertension and low-grade inflammation. In adults, numerous studies provided detailed data on prevalence, incidence and risk factors for the development of T2DM, but for children and adolescents clinical and experimental data are still rather limited. This review provides an overview about the epidemiology and pathogenesis of T2DM in youth and about impaired glucose regulation as major risk factor for diabetes development with a special focus on the recent literature on clinical and lifestyle-related risk factors. Differences in incidence and prevalence across different populations indicate that ethnic background and genetic pre-disposition may be important risk determinants. In addition, epigenetic factors and foetal programming appear to confer additional risk before birth. Among the environmental and lifestyle-related risk factors there is evidence that obesity, hypercaloric diet, physical inactivity, socio-economic position (SEP), smoking, low-grade inflammation, psychosocial stress and sleeping patterns contribute to the risk for T2DM. However, the assessment of the relevance of risk factors and of incidence or prevalence estimates in youth is complicated by methodological issues that are also discussed.

Five-year alterations in BMI are associated with clustering of changes in cardiovascular risk factors in a gender-dependant way: the Stanislas study

OBJECTIVE

The purpose of the present longitudinal study was to describe the associations between the 5-year changes in body mass index (BMI) and alterations in the clusters of metabolic syndrome (MS)-related factors.

METHODS

The study population comprised 1099 middle-aged adults drawn from the Stanislas study. Individuals were stratified into four groups according to the 5-year changes in BMI (weight loss (<0 kg/m(2)), and weight gain (0-1, 1-2 and >2 kg/m(2))). Changes in various MS-related variables and clusters were compared between groups: anthropometric indices, blood pressure, lipid and inflammatory markers, liver enzymes, uric acid and the five summary factors extracted by using factor analysis ('risk lipids', 'liver enzymes', 'inflammation', 'protective lipids' and 'blood pressure').

RESULTS

There was a strong linear trend between increasing BMI and worsening of risk lipids and blood pressure factors for both men and women (P<or=0.001). In men only, liver enzymes and protective lipids factors were significantly related to the 5-year gain of BMI (P<or=0.001), whereas inflammation factor positively increased across the four BMI-change groups, in women only. Interaction terms for sex were statistically significant for inflammation and liver enzymes clusters.

CONCLUSION

In our population, there was a strong linear trend between increasing BMI and worsening of various MS-related variables. More interestingly, the identification of five factors associated with BMI changes dependent to gender, support the hypothesis that weight gain, and probably obesity, trigger metabolic mechanisms that differ between men and women.

Insulin sensitivity is correlated with subcutaneous but not visceral body fat in overweight and obese prepubertal children

AIM

Our aim was to explore the relationship between insulin sensitivity, body fat distribution, ectopic (liver and skeletal muscle) fat deposition, adipokines (leptin and adiponectin), and inflammation markers (highly sensitive C-reactive protein, IL-6, IL-10, and TNF-alpha) in prepubertal children.

SUBJECTS AND METHODS

Thirty overweight and obese children (16 males and 14 females with body mass index z-score range of 1.1-3.2) were recruited. Body fat distribution and fat accumulation in liver and skeletal muscle were measured using magnetic resonance imaging. Insulin sensitivity was assessed by iv glucose tolerance test.

RESULTS

Insulin sensitivity was associated with sc abdominal adipose tissue (SAT) (r = -0.52; P < 0.01) and liver fat content (r = -0.44; P < 0.02) but not with visceral abdominal adipose tissue (VAT) (r = -0.193; P value not significant) and fat accumulation in skeletal muscle (r = -0.210; P value not significant). Adipokines, but not inflammation markers, were significantly correlated to insulin sensitivity. VAT correlated with C-reactive protein (r = 0.55; P < 0.01) as well as adiponectin (r = -0.53; P <0.01). Multiple regression analysis showed that only SAT and liver fat content were independently correlated to insulin sensitivity (P < 0.01; 20 and 16% of explained variance, respectively).

CONCLUSIONS

In overweight and moderately obese prepubertal children, insulin sensitivity was negatively correlated with SAT and liver fat content. Furthermore, contrary to adults, VAT and inflammation markers were not correlated with insulin sensitivity in children.

Low-grade inflammation and the metabolic syndrome in children and adolescents

PURPOSE OF REVIEW

The prevalence of overweight and the metabolic syndrome is increasing in young people. This review aims to summarize current research in children and adolescents on inflammatory markers related to components of the metabolic syndrome.

RECENT FINDINGS

Obesity is characterized by a state of low-grade inflammation at all ages. Body fat has been shown to correlate with the various components of the metabolic syndrome. There is evidence to show that chronic subclinical inflammation in childhood and adolescence is associated with metabolic dysfunction, which can lead to insulin resistance and the metabolic syndrome.

SUMMARY

The results presented in this review highlight the underlying inflammatory mechanisms of the early stages of metabolic disorders related to obesity. The preclinical phases of diabetes and cardiovascular disease last many decades, and this feature of the diseases provides an opportunity for the early identification of target groups and the use of appropriate prevention strategies while the pathological processes are still completely reversible.

Obesity reduces the bioavailability of nitric oxide in juveniles

OBJECTIVE

There is growing evidence that nitric oxide (NO) is critically involved in obesity and its clinical consequences like cardiovascular disease, hypertension and diabetes. We hypothesize that NO is already involved in the pathophysiology of juvenile obesity. We here determined the role of NO, its metabolites arginine and citrulline in obese and normal weight children.

DESIGN

We investigated 57 obese and 57 normal weight age- and gender-matched juveniles. Various clinical parameters as well as body measurements and intima media thickness were determined.

RESULTS

Obese juveniles revealed highly significant alterations in the NO pathway. NOX and citrulline were decreased in obese compared to normal weight juveniles and negatively correlated with body weight. Arginine was increased in obese juveniles and positively correlated with body weight. We found a significant negative correlation between NOX and oxidized low-density lipoprotein. Analysis of gamma-aminobutyric acid (GABA) revealed correlations with the NO pathway as NOX and citrulline were negatively correlated with GABA and arginine showed a positive correlation.

CONCLUSION

We show here that NO and its metabolites arginine and citrulline are already involved in juvenile obesity that may contribute to atherogenesis via reduced bioavailability of NO. Moreover, we identify GABA as a new parameter in the mechanism of obesity-related NO reduction.

Low-grade inflammation, obesity, and insulin resistance in adolescents

CONTEXT

Low-grade inflammation is associated with insulin resistance and precedes the onset of type 2 diabetes mellitus in adults, but there are no comparable data in youth.

OBJECTIVE

The objective of the study was to characterize the pattern of subclinical immune activation that is associated with indices of obesity and insulin resistance in youth and analyze whether this association is explained by obesity.

DESIGN

This was a cross-sectional study.

SETTING

Medical check-up of schoolchildren was conducted by the Public Health Office in Düsseldorf (Germany).

PARTICIPANTS

Participants included 519 adolescents (mean age 15.5 +/- 0.8 yr).

MAIN OUTCOME MEASURES

Measures included body mass index (BMI) and waist circumference (WC) as indices of obesity; fasting glucose, insulin, and homeostasis model assessment of insulin resistance; serum concentrations of TNFalpha, IL-6, IL-8, IL-18, monocyte chemoattractant protein-1, interferon-gamma-inducible protein (IP)-10 and adiponectin as immunological variables.

RESULTS

In age-, sex-, and lipid-adjusted analyses, IL-6, IL-18, IP-10, and adiponectin (inversely) were associated with both BMI and WC (all P <or= 0.002). None of the immune markers was related to glucose, but IL-6, IL-18, and adiponectin (inversely) were associated with insulin and homeostasis model assessment of insulin resistance in age- and sex-adjusted models. Adjustment for BMI or WC indicated that a considerable proportion of these associations may be mediated by obesity.

CONCLUSIONS

We found that a differential low-grade immune activation is associated with parameters of obesity in adolescents. Moreover, there is evidence that IL-6, IL-18, IP-10, and adiponectin (inversely) are associated with insulin resistance and that these associations can mainly be attributed to obesity.

Fat cell size, insulin sensitivity, and inflammation in obese children

OBJECTIVE

To assess the association between adiposity indexes (body mass index [BMI], fat mass, adipocyte size) and circulating inflammation markers with known metabolic relevance or insulin sensitivity in overweight/obese children.

STUDY DESIGN

Twenty-eight children (males/females: 13/15) with different degrees of overweight (BMI z-score: 1.64-3.1; fat mass: 14.1-49.8 kg) were studied. BMI, body composition (dual-energy x-ray absorptiometry scanning), subcutaneous adipocyte diameter (needle biopsy of subcutaneous abdominal fat), blood tumor necrosis factor-alpha and interleukin-6 concentrations and insulin sensitivity (frequently sampled intravenous glucose tolerance test) were assessed.

RESULTS

Adipocyte diameter, more than BMI and fat mass, was significantly associated with interleukin-6 (r = 0.62, P < .001) and tumor necrosis factor-alpha (r = 0.61, P < .001). Moreover adipocyte size was associated with insulin sensitivity (R2 = 0.15, F = 4.69, P = .04) independently from fat mass.

CONCLUSIONS

Adipocyte size is a factor linked to both inflammation and insulin resistance in overweight/obese children. This is similar to the findings in adults and lends support to the tenet that the earlier obesity ensues, the more severe the biologic consequences may be.

Lifestyle-related determinants of inflammation in adolescence

Inflammatory processes are involved in the pathogenesis of the most common chronic non-communicable diseases and may also play an important initiating role in their development. Only recently have inflammatory markers been included in epidemiological studies focusing on nutritional status, body composition and physical activity. We are just starting to understand how different lifestyles can determine basal levels of inflammatory biomarkers in early ages. This review aims to summarise what is known about the relationships between lifestyle-related determinants (focusing on overweight, physical activity and dietary habits) and inflammatory markers in apparently healthy young populations. Obesity is the most widely studied determinant. Several large-scale studies have now demonstrated that healthy young subjects with more body fat or higher BMI have moderately higher concentrations of inflammatory markers than their leaner peers, supporting the idea that obesity should be considered as a state of chronic low-grade inflammation. Less data is available to allow us to elucidate how physical activity/fitness or dietary patterns may have a direct effect on inflammation in apparently healthy, disease-free young populations.

Elevated total and central adiposity and low physical activity are associated with insulin resistance in children

The aim of this study was 2-fold: (1) to examine insulin resistance, blood lipid levels, and inflammatory markers in 9- to 11.5-year-old obese and lean children and (2) to identify factors that influence insulin resistance in this cohort of youths. Body mass index, skinfold thickness, waist circumference, physical activity (4-day triaxial accelerometer), cardiorespiratory fitness (submaximal bicycle ergometer test), and dietary intake (3-day food records) were evaluated in 27 obese and 27 lean boys and girls. Fasting blood samples were analyzed for insulin, glucose, lipids and lipoproteins, C-reactive protein (CRP), interleukin 6, soluble intercellular adhesion molecule, and soluble vascular cell adhesion molecule. Homeostasis model assessment (HOMA) was used to evaluate insulin resistance (HOMA-IR). Obese children presented higher HOMA-IR, CRP, and blood lipid levels (all P < .01) compared with lean children. Total body fat and waist circumference were positively associated with fasting insulin (r > or = 0.51), HOMA-IR (r > or = 0.56), CRP (r > or = 0.51), and blood triacylglycerol (r > or = 0.38), and were inversely correlated with high-density lipoprotein cholesterol (r > or = -0.39; all P < .01). Cardiorespiratory fitness was inversely associated with HOMA-IR (r = -0.24; P < .05), but this association disappeared when adjusted for age, sex, and fat mass. Waist circumference and total daily physical activity explained 49% of the variance in HOMA-IR in these children. In conclusion, these findings suggest that total and central adiposity are positively associated and physical activity is negatively associated with insulin resistance in children. Interventions to improve glucose metabolism in youth should target at reducing total body and abdominal fat and increasing physical activity. The lack of association between inflammatory markers and HOMA-IR suggests that obesity may precede the elevation of these markers in the evolution of insulin resistance in youth.

Relative contribution of body composition to bone mineral density at different sites in men and women of South Korea

We examined the relative contribution of body composition to bone mineral density (BMD) at various sites in 1406 Korean rural men and women, aged 19-80 years, from July to August 2004. The BMD was measured at peripheral (distal forearm and calcaneus) and central (lumbar spine at L1-L4, femoral neck, trochanter, and Ward's triangle) using dual-energy X-ray absorptiometry. In multivariate analyses, the linear regression models were adjusted for relevant covariates. In premenopausal women, only lean mass had a significant positive correlation with BMD at all sites. In postmenopausal women, fat mass was significantly positively correlated with BMD at all sites, except the Ward's triangle; fat mass was the only determinant of BMD at the lumbar, distal forearm, and calcaneus sites, whereas both lean and fat mass contributed to BMD at the hip, with the effect of lean mass being slightly greater than that of fat mass. In younger men, lean mass had a significant positive contribution to BMD at all sites, whereas fat mass appeared to contribute negatively to BMD at all sites, except the calcaneus. In older men, lean mass made a significant positive contribution to the BMD at all sites; fat mass also made a significant positive contribution to the BMD at the forearm and calcaneus. These data indicate that in the Korean rural population, lean mass may be an important determinant of the BMD, whereas fat mass may contribute positively to BMD only in postmenopausal women and older men.

Obesity and inflammation in children

Systemic inflammation is present in children and adults with obesity. Inflammation associated with obesity appears to be central to the development of insulin resistance and atherosclerosis and may be important in the pathogenesis of other comorbid conditions. Although generally considered an inert energy storage tissue, white adipose tissue is a metabolically active organ. It produces a number of inflammatory cytokines and acute-phase reactants. Inflammation associated with obesity declines after weight loss and with exercise. It may also be possible to modify obesity-associated inflammation with medications, reducing comorbidities without weight loss. The study of inflammation in the context of excessive adipose tissue is central to understanding obesity and modifying its impact on patients.

Relationship between low-grade inflammation and arterial stiffness in patients with essential hypertension

BACKGROUND

Arterial stiffness is an independent cardiovascular risk factor in hypertensive individuals. Inflammation is associated with increased arterial stiffness and is implicated in the pathogenesis of hypertension.

OBJECTIVES

To examine whether low-grade inflammation contributes to arterial stiffness and wave reflections independently of blood pressure, in patients with essential hypertension and in controls.

METHODS

We studied 235 consecutive patients with uncomplicated, never-treated essential hypertension and 103 sex- and age-matched controls. The level of inflammation was evaluated with high-sensitivity C-reactive protein (hsCRP) and serum amyloid A (SAA). Arterial stiffness was assessed with carotid-femoral (c-f) and carotid-radial (c-r) pulse wave velocity (PWV), and wave reflections with augmentation index (AIx).

RESULTS

In the hypertensive group, in multiple regression analysis, both PWVc-f and PWVc-r were independently correlated with log hsCRP (beta = 0.56, P = 0.006 and beta = 0.45, P = 0.016, respectively), whereas no correlation was found between PWV and log SAA (P = NS). No significant correlation was observed between heart-rate-corrected AIx and log hsCRP (P = NS) and log SAA (P = 0.07) in the same group. Similarly, in the control group, an independent association was observed between PWVc-f and PWVc-r with log hsCRP (beta = 0.68, P = 0.05 and beta = 0.74, P = 0.05 respectively), but not with log SAA (P = NS). Furthermore, no significant association was shown between heart-rate-corrected AIx and log hsCRP or log SAA (P = NS) in the control group.

CONCLUSIONS

In hypertensive individuals, hsCRP is related to PWV, a direct marker of arterial stiffness, but not to AIx, a measure of wave reflections. Whether inflammation might act as a pathogenetic or modulating factor in arterial stiffening in chronic hypertension has to be confirmed.

Dietary intakes of fat and antioxidant vitamins are predictors of subclinical inflammation in overweight Swiss children

BACKGROUND

In obese children, subclinical inflammation is often present and is correlated with the metabolic syndrome. Dietary factors, such as fatty acids and antioxidants, potentially modulate the association between adiposity and subclinical inflammation, but few data are available in children.

OBJECTIVE

The aim of the study was to determine whether dietary fat or antioxidant intakes influence circulating tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), C-reactive protein (CRP), and leptin concentrations in overweight children.

DESIGN

In a cross-sectional study of 6-14-y-old normal-weight (n = 33), overweight (n = 19), and obese (n = 27) Swiss children, nutritional intakes were assessed from two 24-h dietary recalls and a 1-d dietary record. Percentage body fat from skinfold thicknesses, waist-hip ratio, and blood pressure were measured. Fasting blood samples were collected for the measurement of insulin, glucose, HDL-cholesterol, triacylglycerol, CRP, IL-6, TNF-alpha, and leptin concentrations.

RESULTS

CRP, IL-6, and leptin increased significantly (P < 0.02) with increasing adiposity, independent of age; TNF-alpha did not increase. Total dietary fat and the percentage of energy from fat were significant predictors of CRP concentration, independent of body mass index (P < 0.05). Meat intake was a significant predictor of IL-6 and leptin, independent of body mass index (P < 0.05). Intakes of antioxidant vitamins (vitamins E and C and beta-carotene) were significant predictors of leptin (P < 0.05) but not of CRP, IL-6, or TNF-alpha.

CONCLUSIONS

Overweight Swiss children as young as 6 y have elevated concentrations of inflammatory markers. Intakes of total fat and antioxidant vitamins are determinants of subclinical inflammation in this age group.

Intima media thickness in childhood obesity: relations to inflammatory marker, glucose metabolism, and blood pressure

Obesity in childhood is discussed to be associated with hypertension, dyslipidemia, impaired glucose metabolism, and chronic inflammation. It has not yet been studied in obese children which of these cardiovascular risk factors are related to intima media thickness (IMT), a noninvasive marker for early atherosclerotic changes. We collected the clinical data (age, sex, pubertal stage, percentage of body fat, SD score of body mass index [SDS-BMI]) and measured systolic blood pressure [SBP] and diastolic blood pressure [DBP], triglycerides [TGs], high- and low-density lipoprotein cholesterol, glucose, insulin, and high-sensitivity C-reactive protein [hsCRP]) in 96 obese children (median age, 11 years). The control group was composed of 25 nonobese children of the same age, sex, and pubertal stage. We determined the carotid IMT of all the patients by B-mode ultrasound with a 14-MHz linear transducer. Obese children demonstrated a significantly (P < .001) thicker intima media (median, 0.6 mm) as compared with the control group (median IMT, 0.4 mm). IMT was significantly correlated to the SDS-BMI (r = 0.38, P < .001), percentage of body fat (r = 0.39, P < .001), SBP (r = 0.39, P < .001) and DBP (r = 0.29, P = .002), glucose (r = 0.30, P = .001), and hsCRP levels (r = 0.29, P = .002). In stepwise backward multiple linear regression analysis, IMT correlated significantly to BMI (r2 = 0.05, P = .044), SBP (r2 = 0.15, P = .013), glucose (r2 = 0.05, P = .028), and hsCRP (r2 = 0.07, P = .005). Because IMT is increased in obese children, vascular changes in obesity seem to occur already in childhood. These changes are related to the cardiovascular risk factors of obesity, especially hypertension, chronic inflammation, and impaired glucose metabolism.