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

The Metabolic Syndrome, a Human Disease

This review focuses on the question of metabolic syndrome (MS) being a complex, but essentially monophyletic, galaxy of associated diseases/disorders, or just a syndrome of related but rather independent pathologies. The human nature of MS (its exceptionality in Nature and its close interdependence with human action and evolution) is presented and discussed. The text also describes the close interdependence of its components, with special emphasis on the description of their interrelations (including their syndromic development and recruitment), as well as their consequences upon energy handling and partition. The main theories on MS's origin and development are presented in relation to hepatic steatosis, type 2 diabetes, and obesity, but encompass most of the MS components described so far. The differential effects of sex and its biological consequences are considered under the light of human social needs and evolution, which are also directly related to MS epidemiology, severity, and relations with senescence. The triggering and maintenance factors of MS are discussed, with especial emphasis on inflammation, a complex process affecting different levels of organization and which is a critical element for MS development. Inflammation is also related to the operation of connective tissue (including the adipose organ) and the widely studied and acknowledged influence of diet. The role of diet composition, including the transcendence of the anaplerotic maintenance of the Krebs cycle from dietary amino acid supply (and its timing), is developed in the context of testosterone and β-estradiol control of the insulin-glycaemia hepatic core system of carbohydrate-triacylglycerol energy handling. The high probability of MS acting as a unique complex biological control system (essentially monophyletic) is presented, together with additional perspectives/considerations on the treatment of this 'very' human disease.

Harnessing the power of nutritional antioxidants against adrenal hormone imbalance-associated oxidative stress

Oxidative stress, resulting from dysregulation in the secretion of adrenal hormones, represents a major concern in human health. The present review comprehensively examines various categories of endocrine dysregulation within the adrenal glands, encompassing glucocorticoids, mineralocorticoids, and androgens. Additionally, a comprehensive account of adrenal hormone disorders, including adrenal insufficiency, Cushing's syndrome, and adrenal tumors, is presented, with particular emphasis on their intricate association with oxidative stress. The review also delves into an examination of various nutritional antioxidants, namely vitamin C, vitamin E, carotenoids, selenium, zinc, polyphenols, coenzyme Q10, and probiotics, and elucidates their role in mitigating the adverse effects of oxidative stress arising from imbalances in adrenal hormone levels. In conclusion, harnessing the power of nutritional antioxidants has the potential to help with oxidative stress caused by an imbalance in adrenal hormones. This could lead to new research and therapeutic interventions.

Changes in insulin resistance, body mass index and degree of obesity among junior high school students: A comparison before and after the outbreak of the COVID-19 pandemic

This study aimed to investigate how the COVID-19 pandemic since 2020 has affected the homeostasis model assessment of insulin resistance (HOMA-IR), body mass index (BMI) and degree of obesity among Japanese children. HOMA-IR, BMI and degree of obesity were calculated for 378 children 14-15 years old (boys/girls, 208/170) who underwent checkups during 2015-2021. Changes in these parameters over time and correlations between parameters were assessed, and the proportions of participants with IR (HOMA-IR ≥2.5) were compared. HOMA-IR values increased significantly over the study period (p < 0.001), with a significantly large proportion of participants with IR in 2020-2021 (p < 0.001). Conversely, BMI and degree of obesity did not change significantly. HOMA-IR did not correlate with BMI or degree of obesity during 2020-2021. In conclusion, the COVID-19 pandemic may have had an impact on the increase in the proportion of children with IR, regardless of BMI or degree of obesity.

The protective role of nutritional antioxidants against oxidative stress in thyroid disorders

An imbalance between pro-oxidative and antioxidative cellular mechanisms is oxidative stress (OxS) which may be systemic or organ-specific. Although OxS is a consequence of normal body and organ physiology, severely impaired oxidative homeostasis results in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells' function and viability. The thyroid gland is an organ that exhibits both oxidative and antioxidative processes. In terms of OxS severity, the thyroid gland's response could be physiological (i.e. hormone production and secretion) or pathological (i.e. development of diseases, such as goitre, thyroid cancer, or thyroiditis). Protective nutritional antioxidants may benefit defensive antioxidative systems in resolving pro-oxidative dominance and redox imbalance, preventing or delaying chronic thyroid diseases. This review provides information on nutritional antioxidants and their protective roles against impaired redox homeostasis in various thyroid pathologies. We also review novel findings related to the connection between the thyroid gland and gut microbiome and analyze the effects of probiotics with antioxidant properties on thyroid diseases.

Implication of saturated fats in the aetiology of childhood attention deficit/hyperactivity disorder - A narrative review

Attention Deficit/Hyperactivity Disorder (ADHD) is the most common mental health disorder in the paediatric population. ADHD is highly comorbid with obesity, and has also been associated with poor dietary patterns such as increased consumption of refined carbohydrates and saturated fats. Although ADHD in children was associated with high consumption of saturated fats, so far there has been no evidence-based attempt to integrate dietary strategies controlling for intake of saturated fats into the etiological framework of the disorder. Evidence from human studies and animal models has shown that diets high in saturated fats are detrimental for the development of dopaminergic neurocircuitries, synthesis of neurofactors (e.g. brain derived neurotrophic factor) and may promote brain inflammatory processes. Notably, animal models provide evidence that early life consumption of a high saturated fats diet may impair the development of central dopamine pathways. In the present paper, we review the impact of high saturated fats diets on neurobiological processes in human studies and animal models, and how these associations may be relevant to the neuropathophysiology of ADHD in children. The validation of this relationship and its underlying mechanisms through future investigative studies could have implications for the prevention or exacerbation of ADHD symptoms, improve the understanding of the pathogenesis of the disorder, and help design future dietary studies in patients with ADHD.

Association of dietary antioxidant index with body mass index in adolescents

Background

Dietary antioxidants may decrease body fat through reduction of oxidative stress. This study aimed to examine the association between dietary antioxidant index (DAI) and body mass index (BMI) in adolescent boys.

Methods

In this cross-sectional study, 593 adolescent boys aged 12-16 years were randomly selected and were divided into two groups of overweight and non-overweight individuals. Data on physical activity and anthropometric measurements were collected. Dietary intake was assessed using 168-item semi quantitative food frequency questionnaire and the DAI score was calculated to measure the antioxidant capacity of the diet.

Results

The overweight adolescents had higher intake of energy (2490.55 ± 632.49 vs. 2354.33 ± 632.64 kcal/d, p = 0.01), carbohydrate (290.21 ± 71.41 vs. 272.93 ± 79.22 g/d, p = 0.01), fat (111.51 ± 40.76 vs. 104.51 ± 35.56 g/d, p = 0.04), calcium (811.70 ± 283.70 vs. 741.06 ± 251.17 g/d, p = 0.003), and vitamin D (1.41 ± 1.17 vs. 1.18 ± 1.19 μg/d, p = 0.031) in comparison with normal weight adolescents. The DAI had an inverse association with BMI after adjustment for age and caloric intake (OR: 0.85, 95% CI: 0.76-0.96, p = 0.009). Additional adjustment for dietary intake of vitamin A, vitamin E, vitamin C, zinc, manganese, and selenium did not change the results.

Conclusion

The results of the study showed that following a diet rich in antioxidants may be effective in preventing obesity in adolescent boys. Further longitudinal studies are needed to confirm these finding and to determine the underlying mechanisms.

Association of Serum Retinol Concentrations With Metabolic Syndrome Components in Iranian Children and Adolescents: The CASPIAN-V Study

Background

As a fat-soluble vitamin, vitamin A plays a crucial role in adipogenesis, lipolysis, insulin resistance, and obesity. However, it is still unclear whether they are associated with cardiometabolic risk factors in children and adolescents. The current study aimed to determine the association between serum retinol concentration and the cluster of metabolic syndrome components among children and adolescents.

Methods

This nationwide cross-sectional study was performed on 2,518 students aged 7–18 years from the Childhood and Adolescence Surveillance and Prevention of Adult Non- communicable disease (CASPIAN-V) study. Students were selected via multistage cluster sampling method from 30 provinces of Iran in 2015. Multivariable logistic regression was used to assess the association of serum retinol concentration with metabolic syndrome (MetS) components.

Results

Overall, the mean (SD) age of study participants was 12.16 (3.04) years, and 44.9% (n = 1,166) of them were girls. The mean serum retinol concentration was 1.48 ± 1.55 μmol/L and vitamin A deficiency was observed among 19.7% (95% CI: 18.2–21.3) of study subjects. The results of the logistic regression analysis showed that increasing serum retinol concentrations were associated with an increased likelihood of developing obesity (OR: 1.12, 95% CI: 1.04, 1.20), abdominal obesity (OR: 1.07, 95% CI: 1.01, 1.14), low high-density lipoprotein cholesterol (HDL-C) (OR: 1.10, 95% CI: 1.04, 1.16) and high fasting blood glucose (FBG) (OR: 1.21, 95% CI: 1.10, 1.35), whereas it was associated with a decreased odds of developing high blood pressure (OR: 0.82, 95% CI: 0.73, 0.93). Nevertheless, there was no statistically significant association between metabolic syndrome itself and retinol concentration (OR: 1.02, 95% CI: 0.88, 1.18).

Conclusion

We found that serum retinol concentration was positively associated with metabolic syndrome components such as obesity, low HDL-C, and high FBG, but not with metabolic syndrome itself.

Effect of Vitamin D and Docosahexaenoic Acid Co-Supplementation on Vitamin D Status, Body Composition, and Metabolic Markers in Obese Children: A Randomized, Double Blind, Controlled Study

Obese children are at high risk of developing vitamin D deficiency. Omega-3 polyunsaturated fatty acids and their derivatives might have a beneficial effect on vitamin D status of obese children, due to their anti-inflammatory action, and increasing its absorption. This multicenter, randomized, double-blind controlled study aims to investigate the effect of vitamin D and docosahexaenoic acid (DHA) co-supplementation for six months on vitamin D status, body composition, and metabolic markers of obese children with vitamin D deficiency. A total of 108 children were enrolled and 73 children completed the study: 33 were supplemented with an oral dose of 500 mg of DHA and 1200 IU/day of vitamin D3 and 41 were supplemented with 1200 IU/day of vitamin D3 + wheat germ oil. At the end of the study, more than 50% of the subjects improved their vitamin D status. However, co-supplementation was not more effective than vitamin D plus wheat germ oil. Fat mass percentage was significantly reduced, and body mass index improved in both groups, even if all the subjects were still obese at the end of the study. Children receiving both vitamin D and DHA presented a higher increase of DHA levels that could be relevant to prevent inflammatory-associated complications of obesity, but they had no effect on vitamin D levels.

Association between Dietary Antioxidant Quality Score and Anthropometric Measurements in Children and Adolescents: The Weight Disorders Survey of the CASPIAN-IV Study

BACKGROUND

Limited experience exists on the relationship between anthropometric measures and dietary antioxidant intake in the pediatric age group. We aimed to investigate the association of dietary antioxidants intake and anthropometric measurement in children and adolescents.

METHODS

This nationwide study was conducted in 4270 children and adolescents, aged 6-18 years. Demographic and anthropometric data were assessed. Children and adolescents were classified as underweight, healthy weight or overweight/obese based on body mass index percentiles. Dietary intake was obtained by a 168-item semi-quantitative validated food frequency questionnaire. Energy and nutrients intake was estimated using the Nutritionist IV software. Dietary antioxidant quality score (DAQS) was calculated based on the daily dietary intake of selenium, zinc, vitamin A, vitamin C and vitamin E compared with daily recommended intake.

RESULTS

After adjustment for age, gender, living area (rural or urban), energy intake and physical activity level, DAQS was positively associated with waist circumference (WC), hip circumference and waist-to-height ratio (WHtR) in under-weight children and adolescents (B = 1.614, 1.634 and 0.01, respectively; all ps < 0.05). Increased DAQS was significantly associated with higher WC and WHtR in normal-weight children and adolescents (B = 0.536 and 0.003, respectively; all ps <0.05).

CONCLUSION

Dietary intakes of some antioxidants were higher in children and adolescents with excess weight. DAQS was correlated with some anthropometric measurements in under-weight and normal-weight subjects. It can provide a novel approach to assess the role of antioxidant intake on health promotion and diet-based therapies in under-weight and normal-weight children and adolescents.

Associations of Dietary Intake on Biological Markers of Inflammation in Children and Adolescents: A Systematic Review

BACKGROUND

In children and adolescents, chronic low-grade inflammation has been implicated in the pathogenesis of co- and multi-morbid conditions to mental health disorders. Diet quality is a potential mechanism of action that can exacerbate or ameliorate low-grade inflammation; however, the exact way dietary intake can regulate the immune response in children and adolescents is still to be fully understood.

METHODS

Studies that measured dietary intake (patterns of diet, indices, food groups, nutrients) and any inflammatory biomarkers in children and adolescents aged 2 to19 years and published until November 2020 were included in this systematic review, and were selected in line with PRISMA guidelines through the following databases: Academic Search Complete, CINAHL, Global Health, Medline COMPLETE and Web of Science-Core Collection. A total of 53 articles were identified.

RESULTS

Results show that adequate adherence to healthful dietary patterns such as the Mediterranean diet, or food groups such as vegetables and fruit, or macro/micro nutrients such as fibre or vitamin C and E, are associated with decreased levels of pro-inflammatory biomarkers, mainly c-reactive protein (CRP), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), whereas adherence to a Western dietary pattern, as well as intake of food groups such as added sugars, macro-nutrients such as saturated fatty acids or ultra-processed foods, is associated with higher levels of the same pro-inflammatory biomarkers.

CONCLUSIONS

This is the first systematic review examining dietary intake and biological markers of inflammation in both children and adolescents. A good quality diet, high in vegetable and fruit intake, wholegrains, fibre and healthy fats ameliorates low-grade inflammation, and therefore represents a promising therapeutic approach, as well as an important element for disease prevention in both children and adolescents.

Inhibition of γ-secretase in adipocytes leads to altered IL-6 secretion and adipose inflammation

Adipocyte-mediated inflammatory signalling has been proposed to alter adipose physiology in obesity and Type 2 diabetes mellitus. Novel targets for alteration of inflammatory signalling are needed to improve obesity-related outcomes. The γ-secretase enzyme complex has been suggested to play a role both in adipocyte function as well as in immune regulation. We hypothesized that adipocyte-specific γ-secretase inhibition could alter the inflammatory makeup of adipose tissue. We found that genetic blockade of γ-secretase in adipocytes leads to a decrease in EMR1 (F4/80) expression, as a marker of macrophage presence, in adipose tissue without changes in expression of markers of other inflammatory cell types. To explore the mechanism by which adipocytes can alter macrophage function in vitro, fully differentiated 3T3-L1 adipocytes were treated with a γ-secretase inhibitor in the presence of lipopolysaccharide (LPS) and transcription of IL6 and ccl2 (MCP1) were quantified. IL-6 expression and secretion were significantly inhibited by γ-secretase blockade, with little effect on MCP1. Preconditioned media from 3T3-L1 adipocytes treated with a γ-secretase inhibitor also alters macrophage activation but did not affect macrophage translocation in vitro. Therefore, γ-secretase inhibition in fully differentiated adipocytes can alter IL-6 signalling to macrophages, consistent with our hypothesis that that γ-secretase is involved in adipocyte-initiated inflammatory signalling cascades.

Carotenoids, vitamin A, and their association with the metabolic syndrome: a systematic review and meta-analysis

Context

Modifiable factors that reduce the burden of the metabolic syndrome (MetS), particularly plant-derived biomarkers, have been a recent focus of rising interest.

Objective

This systematic review and meta-analysis, which follows PRISMA guidelines, evaluates evidence from a period of 20 years that links vitamin A and carotenoids with the occurrence of MetS and following the PRISMA guidelines.

Data Sources

PubMed and Cochrane databases (January 1997 through March 2017) were systematically assessed for studies, including case-control, cross-sectional, and cohort studies, that evaluated the associations of MetS with carotenoids and retinyl esters and retinol (vitamin A).

Data Extraction

Key measures of associations were harmonized into odds ratios (ORs) and 95% confidence intervals (95%CI) of MetS per 1 standard deviation (SD) of exposure using forest plots and random effects models that pooled data points from 11 cross-sectional studies. Begg's funnel and harvest plots were constructed.

Results

An inverse association between total carotenoids and MetS was found [ORpooled, 0.66; 95%CI, 0.56-0.78; 1 SD ∼ 0.82 µmol/L; n = 5 studies]. This association was the strongest for β-carotene, followed by α-carotene and β-crypotoxanthin. No association was detected between retinol and MetS (ORpooled, 1.00; 95%CI, 0.88-1.13; 1 SD ∼ 2.14 µmol/L; n = 6 studies). Publication bias was absent, and harvest plots indicated consistency upon replication for β-carotene and total carotenoid exposures.

Conclusions

This review and meta-analysis suggests that, unlike retinol, total and individual carotenoids were inversely related to MetS.

Salusin-α levels are negatively correlated with diastolic blood pressure in children with obesity

Salusins have emerged as a new biomarker that reflects an increased inflammatory state, which is associated with cardiovascular risk. We investigated the predictive value and usefulness of salusins as an inflammatory biomarker in obese children. This prospective cohort study included 75 obese children and 101 healthy children (as a control group). Salusin-α, Salusin-β, and various cardiovascular parameters were assessed in both groups. Correlation analyses of Salusin-α and Salusin-β with body mass index standard deviation scores and inflammatory and cardiovascular markers were performed. The mean patient age was 11.9±2.4 years for the obese group and 12.5±2.1 years for the control group. The obese children had a significantly higher heart rate, systolic blood pressure, diastolic blood pressure, epicardial adipose tissue thickness, and left ventricular mass than did the children in the control group. There was no significant correlation between Salusin-α and Salusin-β and body mass index; however, there was a negative correlation between Salusin- α and diastolic blood pressure (r = 0.277, p = 0.004). Overall, there was no significant difference in the Salusin-α and Salusin-β levels between obese and healthy children. However, a negative correlation was found between Salusin-α and diastolic blood pressure. Although this result suggests that Salusin-α might be an early marker of cardiovascular involvement in obese children, further studies are needed to demonstrate the predictive value of salusins.

Changes in leukocyte profile and C-reactive protein concentration in overweight and obese adolescents after reduction of body weight

Aim of the study

To assess the changes in the leukocyte profile and C-reactive protein (CRP) concentration in adolescents with excess fat mass after 6-12 months of dietary intervention.

Material and methods

The retrospective study included 99 overweight and obese adolescents, aged from 10.0 to 17.5 years, 82 of whom were re-hospitalized 6 to 12 months after dietary counseling. The control group consisted of 42 normal weight peers. Anthropometric measurements and laboratory tests were performed, homeostasis model assessment – insulin resistance (HOMA-IR) and triglycerides/high-density lipoprotein cholesterol (TG/HDL-C) ratio were calculated.

Results

Obese and overweight adolescents had higher white blood cells (WBC), neutrophil, monocyte counts and CRP concentration. In the backward stepwise regression analysis, body mass index standard deviation score (BMI SDS) and fasting insulin concentration were independent predictors of WBC and neutrophil counts at the baseline. At the follow-up visit in 45 (54.8%) children, who had lost weight, decreases in WBC, neutrophil and monocyte counts and CRP, fasting insulin, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) concentrations were observed. Changes in WBC and neutrophil counts were dependent on changes in HOMA-IR and TG/HDL ratio. Changes in HOMA-IR had a significant impact on changes in the monocyte count.

Conclusions

Adipose tissue promotes systemic inflammation and its intensity depends on the degree of obesity and insulin resistance. This state is reversible. Changes in HOMA-IR were independent predictors of changes in WBC, neutrophil and monocyte counts after reduction of body weight.

Predictors of Subclinical Inflammatory Obesity: Plasma Levels of Leptin, Very Low-Density Lipoprotein Cholesterol and CD14 Expression of CD16+ Monocytes

OBJECTIVE

Predictors of subclinical inflammatory obesity (SIO) can be important tools for early therapeutic interventions in obesity-related comorbidities. Waist circumference (WC) and BMI have different SIO sensitivity. We aimed to i) identify SIO predictors and ii) investigate whether CD16+ monocytes are associated with BMI- (generally) or WC-defined (centrally) obesity.

METHODS

Anthropometric and metabolic/endocrine (namely catecholamines, adrenaline and noradrenaline) parameters were evaluated, and CD16+ monocytes were studied by flow cytometry in the peripheral blood from 63 blood donors, and compared and correlated to each other. Multiple linear regression analysis was performed to identify variables that best predict SIO.

RESULTS

CD16+ monocyte counts were similar in BMI and WC groups. CD16+ monocytes from centrally obese (CO) showed a more inflammatory pattern, as compared to non-CO subjects. WC was sensitive to lipidemia and, in CO subjects, lipidemia was associated with a more inflammatory phenotype of CD16+ monocytes. These differences were not noticed between BMI groups. Adrenaline was correlated with CD16+ monocyte expansion with a lower inflammatory pattern. Leptin, very low-density lipoprotein cholesterol (VLDL-C), and CD14 expression of CD16+ monocytes were found to be CO predictors.

CONCLUSIONS

WC-, but not BMI-defined obesity, was associated with a more inflammatory pattern of CD16+ monocytes, without monocyte expansion, suggesting that a monocyte maturation process rather than an independent arise of CD16+ monocytes occurs in CO. Thus, in a population with low cardiovascular risk, leptin, VLDL-C, and CD14 expression of CD16+ monocytes predict CO, constituting a putative tool for screening of SIO.

White adipose tissue urea cycle activity is not affected by one-month treatment with a hyperlipidic diet in female rats

Under high-energy diets, amino acid N is difficult to dispose of, as a consequence of the availability of alternative substrates. We found, recently, that WAT contains a complete functional urea cycle, we analyzed the possible overall changes in the WAT urea cycle (and other-related amino acid metabolism gene expressions) in rats subjected to a cafeteria diet. Adult female Wistar rats were fed control or simplified cafeteria diets. Samples of WAT sites: mesenteric, periovaric, retroperitoneal and subcutaneous, were used for the estimation of all urea cycle enzyme activities and gene expressions. Other key amino acid metabolism gene expressions, and lactate dehydrogenase were also measured. Subcutaneous WAT showed a differentiated amino acid metabolism profile, since its cumulative (whole site) activity for most enzymes was higher than the activities of the other sites studied. After one month of eating an energy-rich cafeteria diet, and in spite of doubling the size of WAT, the transforming capacity of most amino acid metabolism enzymes remained practically unchanged in the tissue. This was not only due to limited changes in the overall enzyme activity, but also a consequence of a relative decrease in the expression of the corresponding genes. Overall, the results of this study support the consideration of WAT as an organ, disperse but under uniform control. The metabolic peculiarities between its different sites, and their ability to adapt to different energy availability conditions only add to the variable nature of adipose tissue. We have presented additional evidence of the significant role of WAT in amino acid metabolism.

Longitudinal associations of lifestyle factors and weight status with insulin resistance (HOMA-IR) in preadolescent children: the large prospective cohort study IDEFICS

Background

This study investigates prospective associations of anthropometrical and lifestyle indices with insulin resistance (IR) in European children from the IDEFICS cohort. Insulin resistance (IR) is a growing concern in childhood obesity and a central aspect of the metabolic syndrome (MS). It most likely represents the link between obesity and type 2 diabetes.

Methods

This longitudinal study included 3348 preadolescent children aged 3 to 10.9 years from 8 European countries who were observed from 2007/2008 to 2009/2010. The main outcome measure in the present analysis is HOMA-IR (homeostasis model assessment as a common proxy indicator to quantify IR) at follow-up and in its longitudinal development. Anthropometrical measures and lifestyle indices, including objectively determined physical activity, were considered, among others factors, as determinants of IR. Prospective associations between IR at follow-up and anthropometrical and lifestyle indices were estimated by logistic regression models.

Results

Country-specific prevalence rates of IR in the IDEFICS cohort of European children showed a positive trend with weight category. Prospective multivariate analyses showed the strongest positive associations of IR with BMI z-score (OR = 2.6 for unit change from the mean, 95 % CI 2.1–3.1) and z-score of waist circumference (OR = 2.2 for unit change from the mean, 95 % CI 1.9–2.6), which were analysed in separate models, but also for sex (OR = 2.2 for girls vs. boys, 95 % CI 1.5–3.1 up to OR 2.5, 95 % CI 1.8–3.6 depending on the model), audio-visual media time (OR = 1.2 for an additional hour per day, 95 % CI 1.0–1.4 in both models) and an inverse association of objectively determined physical activity (OR = 0.5 for 3^rd compared to 1^st quartile, 95 % CI 0.3–0.9 in both models). A longitudinal reduction of HOMA-IR was accompanied with a parallel decline in BMI.

Conclusions

This study is, to our knowledge, the first prospective study on IR in a preadolescent children’s population. It supports the common hypothesis that overweight and obesity are the main determinants of IR. Our data also indicate that physical inactivity and a sedentary lifestyle are likewise associated with the development of IR, independent of weight status. The promotion of physical activity should thus be considered as an equal option to dietary intervention for the treatment of IR in the paediatric practice.

Thyroid Hormones, Oxidative Stress, and Inflammation

Inflammation and oxidative stress (OS) are closely related processes, as well exemplified in obesity and cardiovascular diseases. OS is also related to hormonal derangement in a reciprocal way. Among the various hormonal influences that operate on the antioxidant balance, thyroid hormones play particularly important roles, since both hyperthyroidism and hypothyroidism have been shown to be associated with OS in animals and humans. In this context, the nonthyroidal illness syndrome (NTIS) that typically manifests as reduced conversion of thyroxine (T₄) to triiodothyronine (T₃) in different acute and chronic systemic conditions is still a debated topic. The pathophysiological mechanisms of this syndrome are reviewed, together with the roles of deiodinases, the enzymes responsible for the conversion of T₄ to T₃, in both physiological and pathological situations. The presence of OS indexes in NTIS supports the hypothesis that it represents a condition of hypothyroidism at the tissue level and not only an adaptive mechanism to diseases.

Obesity and inflammation markers in relation to leukocyte telomere length in a cross-sectional study of persons with Barrett's esophagus

BACKGROUND

Telomere shortening is associated with increasing age, male gender and lifestyle factors such as obesity and smoking. Inflammation has also been implicated in cellular senescence and may promote telomere shortening in chronic conditions such as obesity and diabetes. However, little is known about the relationship between markers of obesity and inflammation, and leukocyte telomere length (LTL).

METHODS

LTL was measured using quantitative polymerase chain reaction in peripheral leukocytes from 295 individuals diagnosed with Barrett's esophagus (BE) between 1995 and 2009. Data on lifestyle variables including obesity and smoking were collected at in-person interviews. Biomarkers of obesity (leptin, adiponectin), diabetes (glucose, insulin), inflammation (C-reactive protein, Interleukin-6, surface tumor necrosis factor receptor (sTNFR) I & II) and oxidative stress (F2-isoprostanes) were measured in stored blood samples. We examined associations between these covariates and LTL in a cross-sectional analysis using linear and logistic regression models, adjusting for possible confounders.

RESULTS

LTL was significantly associated with age (r = -0.30, p < 0.001), gender (r = 0.14 for females, p = 0.01) and inversely associated with cigarette pack-years (r = -0.11, p = 0.04). Odds of having short LTL were significantly higher for participants in the highest tertile for sTNF-RI (Odds ratio adjusted for age, gender, smoking, and obesity = 2.19; 95 % CI 1.00-4.85, p-trend = 0.02). LTL was not significantly associated with any other lifestyle factors, including smoking or obesity, or other inflammation-, obesity-/diabetes-related biomarkers measured.

CONCLUSIONS

Increasing age, male gender, smoking history, and sTNF-RI levels were associated with short LTL among persons with BE but no correlations were observed between LTL and other inflammatory markers or measures of obesity. Larger longitudinal studies are necessary in order to further establish the potential relationships between obesity, inflammation markers and LTL.

Correlation of Childhood Obesity and Related Insulin Resistance with Leptin and Retinol Binding Protein 4

OBJECTIVES

To study the correlation of obesity with various metabolic parameters and correlation between insulin resistance and leptin and retinol binding protein 4 (RBP4) levels.

METHODS

This is a cross sectional study in a tertiary care children's hospital wherein 98 obese children were included and their metabolic parameters analysed with regards to insulin resistance and RBP4 levels.

RESULTS

Leptin levels were abnormal for all children and high RBP4 levels were observed in 69.6 %. There was no significant association between insulin resistance and RBP4 levels (p 0.8).

CONCLUSIONS

RBP4, the sole retinol transporter in blood, secreted from adipocytes and liver has been implicated in insulin resistance. The index study however, did not show a significant positive association.

Circulating profiling reveals the effect of a polyunsaturated fatty acid-enriched diet on common microRNAs

BACKGROUND

Consumption of long-chain polyunsaturated fatty acids (PUFAs), which are abundant in seafood and nuts, ameliorates components of the metabolic syndrome. Circulating microRNAs (miRNAs) have demonstrated to be valuable biomarkers of metabolic diseases. Here, we investigated whether a sustained nuts-enriched diet can lead to changes in circulating miRNAs, in parallel to the dietary modification of fatty acids (FAs).

METHODS AND RESULTS

The profile of 192 common miRNAs was assessed (TaqMan low-density arrays) in plasma from 10 healthy women before and after an 8-week trial with a normocaloric diet enriched with PUFAs (30 g/day of almonds and walnuts). The most relevant miRNAs were validated in an extended sample of 30 participants (8 men and 22 women). Adiponectin was measured by immunoassay and FAs by gas liquid chromatography coupled to mass spectrometry. The percentage of both ω-3 (P=.01) and ω-6 (P=.029) PUFAs of dietary origin (as inferred from plasma FA concentrations) increased, whereas saturated FAs decreased (P=.0008). Concomitantly with changes in circulating FAs, several miRNAs were modified by treatment, including decreased miR-328, miR-330-3p, miR-221 and miR-125a-5p, and increased miR-192, miR-486-5p, miR-19b, miR-106a, miR-769-5p, miR-130b and miR-18a. Interestingly, miR-106a variations in plasma correlated with changes in PUFAs, while miR-130b (r=0.58, P=.003) and miR-221 (r=0.46, P=.03) reflected changes in C-reactive protein. The dietary modulation of miR-125a-5p mirrored changes in fasting triglycerides (r=-0.44, P=.019) and increased adiponectin (r=0.43, P=.026).

CONCLUSION

Dietary FAs (as inferred from plasma FA concentration) are linked to changes in circulating miRNAs, which may be modified by a PUFAs-enriched diet.

Development and evaluation of a stand-alone index for the assessment of small children’s diet quality

Objective

To construct and evaluate an independent Children’s Index of Diet Quality (CIDQ).

Design

A food consumption questionnaire, which contained twenty-five multiple-item questions on eating and food intake, was formulated and evaluated against 7 d food records. Key questions that best reflected a healthy diet, defined in criteria set by the nutrient recommendations, were searched and validated by correlation and analyses of receiver-operating characteristic curves.

Settings

A cohort of a young population of South-West Finland.

Subjects

Participants (n 400) were 2–6-year-old children.

Results

Fifteen questions were identified to best depict the children’s diet quality in reference to the recommendations. These questions were scored, summarized and further constructed into a three-class index (good, moderate and poor dietary quality) where higher scores depicted better diet quality. The CIDQ cut-off score of 14 points for good dietary quality had a sensitivity of 0·59 and a specificity of 0·82 and the cut-off score of 10 points, for at least moderate dietary quality, had a sensitivity of 0·77 and a specificity of 0·69. Higher index scores were related to higher dietary intakes of several vitamins, lower dietary intakes of SFA and cholesterol, and further with lower serum cholesterol and higher serum vitamin C concentrations.

Conclusions

The three-class food index was found to represent diet quality as defined in recommendations and evaluated against nutrient intakes from food diaries and biochemical markers. This self-standing index could provide an effective and low-burden method to obtain information about diet quality and guide future recommendations.

Adolescents in southern regions of Italy adhere to the Mediterranean diet more than those in the northern regions

There is a large amount of literature regarding the benefits of the Mediterranean diet in the adult population; however, there is growing curiosity about the individuals who naturally adhere to those principles early in life. The "Evaluation of Dietary Habits in Adolescents," carried out by the National Research Council of Italy in 2009, is a survey that aimed to assess the dietary habits and lifestyles of Italian adolescents and their adherence to the Mediterranean diet. We hypothesized that there would be differences across regions, with a higher adherence in Southern Italy compared with Northern Italy based on geography. The survey was conducted in 3 different geographic locations in Italy and included a convenience sample of adolescents who attended either a middle or high school. The participants were asked to fill out a questionnaire concerning demographic data, lifestyle factors, and eating patterns, and scores were assigned according to adherence to the Mediterranean diet, as calculated using Trichopoulou's Mediterranean diet scale. The final sample included 565 adolescents, between 12 and 19 years old, who attended school in the northeastern, northwestern, or southern regions of Italy in 2009. According to the findings, 38.6% of the respondents had scores indicating a low adherence to the Mediterranean diet, whereas only 14% had scores showing a high adherence. Teenagers from the Southern region showed the highest adherence. Those with a high adherence to the Mediterranean diet consumed higher quantities of fiber, iron, vitamin B6, vitamin C, folic acid, vitamin A, vitamin D, and monounsaturated fats.

Effects of a 1-year exercise and lifestyle intervention on irisin, adipokines, and inflammatory markers in obese children

OBJECTIVE

Exercise improves weight status and metabolism. Irisin, a novel myokine, may be involved in the regulation of metabolic function. The effect of an exercise and dietary lifestyle intervention for 1-year on irisin, adipokines (leptin, adiponectin, resistin) and inflammatory markers (C-reactive protein (CRP), soluble tumor necrosis factor receptor II (sTNFR-II) was evaluated, and predictors of irisin levels were characterized in obese children.

METHODS

Parameters were assessed at baseline and at follow-up for 65 obese children who completed the program (7-18 years, 54%boys). Their relation to weight status and metabolic risk was analyzed.

RESULTS

Anthropometric and metabolic parameters improved after completion of the program. Circulating irisin levels at baseline were 111.0 ± 8.0 ng ml(-1) and increased after the intervention by 12% [6%, 17%], P = 0.00003. There was no evidence for differences in irisin levels between genders and across age. Moreover, changes in irisin did not correlate with those in BMI-SDS, adipokines or inflammatory markers. Leptin decreased after the intervention (Δ5.3 ng ml(-1) , [3.2, 6.3], P = 10(-7) ). Anthropometric measures were significantly associated with leptin and inflammatory markers.

CONCLUSIONS

A 1-year long lifestyle intervention program is associated with improvement in anthropometric and metabolic parameters and leads to an elevation in irisin levels in obese children.

Subclinical inflammatory status in Rett syndrome

Inflammation has been advocated as a possible common central mechanism for developmental cognitive impairment. Rett syndrome (RTT) is a devastating neurodevelopmental disorder, mainly caused by de novo loss-of-function mutations in the gene encoding MeCP2. Here, we investigated plasma acute phase response (APR) in stage II (i.e., “pseudo-autistic”) RTT patients by routine haematology/clinical chemistry and proteomic 2-DE/MALDI-TOF analyses as a function of four major MECP2 gene mutation types (R306C, T158M, R168X, and large deletions). Elevated erythrocyte sedimentation rate values (median 33.0 mm/h versus 8.0 mm/h, P < 0.0001) were detectable in RTT, whereas C-reactive protein levels were unchanged (P = 0.63). The 2-DE analysis identified significant changes for a total of 17 proteins, the majority of which were categorized as APR proteins, either positive (n = 6 spots) or negative (n = 9 spots), and to a lesser extent as proteins involved in the immune system (n = 2 spots), with some proteins having overlapping functions on metabolism (n = 7 spots). The number of protein changes was proportional to the severity of the mutation. Our findings reveal for the first time the presence of a subclinical chronic inflammatory status related to the “pseudo-autistic” phase of RTT, which is related to the severity carried by the MECP2 gene mutation.

Variation in access to sugar-sweetened beverages in vending machines across rural, town and urban high schools

OBJECTIVES

The 2010 Dietary Guidelines for Americans include reducing consumption of sugar-sweetened beverages. Among the many possible routes of access for youth, school vending machines provide ready availability of sugar-sweetened beverages. The purpose of this study was to determine variation in high school student access to sugar-sweetened beverages through vending machines by geographic location - urban, town or rural - and to offer an approach for analysing school vending machine content.

STUDY DESIGN

Cross-sectional observational study.

METHODS

Between October 2007 and May 2008, trained coders recorded beverage vending machine content and machine-front advertising in 113 machines across 26 schools in New Hampshire and Vermont, USA.

RESULTS

Compared with town schools, urban schools were significantly less likely to offer sugar-sweetened beverages (P = 0.002). Rural schools also offered more sugar-sweetened beverages than urban schools, but this difference was not significant. Advertisements for sugar-sweetened beverages were highly prevalent in town schools.

CONCLUSIONS

High school students have ready access to sugar-sweetened beverages through their school vending machines. Town schools offer the highest risk of exposure; school vending machines located in towns offer up to twice as much access to sugar-sweetened beverages in both content and advertising compared with urban locations. Variation by geographic region suggests that healthier environments are possible and some schools can lead as inspirational role models.

Regulation of adipose tissue energy availability through blood flow control in the metabolic syndrome

Maintenance of blood flow rate is a critical factor for tissue oxygen and substrate supply. The potentially large mass of adipose tissue deeply influences the body distribution of blood flow. This is due to increased peripheral resistance in obesity and the role of this tissue as the ultimate destination of unused excess of dietary energy. However, adipose tissue cannot grow indefinitely, and the tissue must defend itself against the avalanche of nutrients provoking inordinate growth and inflammation. In the obese, large adipose tissue masses show lower blood flow, limiting the access of excess circulating substrates. Blood flow restriction is achieved by vasoconstriction, despite increased production of nitric oxide, the vasodilatation effects of which are overridden by catecholamines (and probably also by angiotensin II and endothelin). Decreased blood flow reduces the availability of oxygen, provoking massive glycolysis (hyperglycemic conditions), which results in the production of lactate, exported to the liver for processing. However, this produces local acidosis, which elicits the rapid dissociation of oxyhemoglobin, freeing bursts of oxygen in localized zones of the tissue. The excess of oxygen (and of nitric oxide) induces the production of reactive oxygen species, which deeply affect the endothelial, blood, and adipose cells, inducing oxidative and nitrosative damage and eliciting an increased immune response, which translates into inflammation. The result of the defense mechanism for adipose tissue, localized vasoconstriction, may thus help develop a more generalized pathologic response within the metabolic syndrome parameters, extending its effects to the whole body.

Eating behaviour, insulin resistance and cluster of metabolic risk factors in European adolescents. The HELENA study

The present study examined the associations of food behaviours and preferences with markers of insulin resistance and clustered metabolic risk factors score after controlling for potential confounders, including body fat in European adolescents. A cross-sectional study "Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study" of 3546 European adolescents aged 12.5-17.5 years was conducted, using a complete dataset on at least glucose, insulin and "Food Choice Questionnaire". Results indicated skipping breakfast, as well as the preference of some foods such as nuts, chocolate, burgers and pizzas, soft drinks or juices, explain part of homeostasis model assessment index variance. In addition, snacking regularly during school day is associated with higher metabolic risk score in females. In conclusion, the present findings suggest that intervention studies aimed to prevent insulin resistance and metabolic risk factors in youth should focus not only in influencing food and drink preferences, but also to ensure healthy food behaviour in adolescents. The harmful consequences in the choice of certain foods or drinks and food habits can be countered with proper planning and intervention programs to prevent insulin resistance and metabolic risk factors.

Do the interactions between glucocorticoids and sex hormones regulate the development of the metabolic syndrome?

The metabolic syndrome is basically a maturity-onset disease. Typically, its manifestations begin to flourish years after the initial dietary or environmental aggression began. Since most hormonal, metabolic, or defense responses are practically immediate, the procrastinated response do not seem justified. Only in childhood, the damages of the metabolic syndrome appear with minimal delay. Sex affects the incidence of the metabolic syndrome, but this is more an effect of timing than absolute gender differences, females holding better than males up to menopause, when the differences between sexes tend to disappear. The metabolic syndrome is related to an immune response, countered by a permanent increase in glucocorticoids, which keep the immune system at bay but also induce insulin resistance, alter the lipid metabolism, favor fat deposition, mobilize protein, and decrease androgen synthesis. Androgens limit the operation of glucocorticoids, which is also partly blocked by estrogens, since they decrease inflammation (which enhances glucocorticoid release). These facts suggest that the appearance of the metabolic syndrome symptoms depends on the strength (i.e., levels) of androgens and estrogens. The predominance of glucocorticoids and the full manifestation of the syndrome in men are favored by decreased androgen activity. Low androgens can be found in infancy, maturity, advanced age, or because of their inhibition by glucocorticoids (inflammation, stress, medical treatment). Estrogens decrease inflammation and reduce the glucocorticoid response. Low estrogen (infancy, menopause) again allow the predominance of glucocorticoids and the manifestation of the metabolic syndrome. It is postulated that the equilibrium between sex hormones and glucocorticoids may be a critical element in the timing of the manifestation of metabolic syndrome-related pathologies.

Inflammation in depression: is adiposity a cause?

Mounting evidence indicates that inflammation may play a significant role in the development of depression. Patients with depression exhibit increased inflammatory markers, and administration of cytokines and other inflammatory stimuli can induce depressive symptoms. Mechanisms by which cytokines access the brain and influence neurotransmitter systems relevant to depression have also been described, as have preliminary findings indicating that antagonizing inflammatory pathways may improve depressive symptoms. One primary source of inflammation in depression appears to be adiposity. Adipose tissue is a rich source of inflammatory factors including adipokines, chemokines, and cytokines, and a bidirectional relationship between adiposity and depression has been revealed. Adiposity is associated with the development of depression, and depression is associated with adiposity, reflecting a potentional vicious cycle between these two conditions which appears to center around inflammation. Treatments targeting this vicious cycle may be especially relevant for the treatment and prevention of depression as well as its multiple comorbid disorders such as cardiovascular disease, diabetes, and cancer, all of which have also been associated with both depression and inflammation.

Obesity and obstructive sleep apnea syndrome in children: a tale of inflammatory cascades

Obesity has emerged as one of the most prevalent diseases in the western hemisphere, and its prevalence continues to increase. Obese children are at increased risk for several disorders, particularly affecting the cardiovascular and metabolic systems. The mechanisms leading to obesity-related morbidities are likely multifactorial, and include activation of inflammatory pathways ultimately leading to end-organ injury. Furthermore, the concurrent presence of obesity and other diseases facilitated by increased fat deposition poses a theoretical risk of accentuating obesity-related complications. One of the conditions whose prevalence is increased by obesity in childhood is the obstructive sleep apnea syndrome (OSAS). OSAS in non-obese children may lead to co-morbidities that are not only remarkably similar to those associated with obesity but recruit similar inflammatory mechanisms as those activated by obesity, suggesting that the two disorders may amplify each other and synergistically augment the magnitude of their respective adverse consequences. The objective of this review is to critically review the effects of both obesity and OSAS in inducing systemic inflammation in children and will examine the latest evidence pertaining to the up-regulation of specific inflammatory mediators.

Evidence-based review on the effect of normal dietary consumption of fructose on blood lipids and body weight of overweight and obese individuals

Although some investigators have hypothesized that ingestion of fructose from foods and beverages is responsible for the development of hyperlipidemia or obesity, a recent evidence-based review demonstrated that there was no relationship between the consumption of fructose in a normal dietary manner and the development of hyperlipidemia or increased weight in normal weight individuals. Because overweight and obese individuals may exhibit metabolic abnormalities such as insulin resistance, impaired glucose tolerance, hyperlipedemia, and/or alterations in gut hormones involved in appetite regulation, the findings of fructose studies performed in normal weight subjects may not be particularly relevant for overweight or obese subjects. A systematic assessment of the strength and quality of the studies and their relevance for overweight or obese humans ingesting fructose in a normal dietary manner has not been performed. The purpose of this review was to critically evaluate the existing database for a causal relationship between the ingestion of fructose in a normal, dietary manner and the development of hyperlipidemia or increased body weight in overweight or obese humans, using an evidence-based approach. The results of the analysis indicate that there is no evidence which shows that the consumption of fructose at normal levels of intake causes biologically relevant changes in triglycerides (TG) or body weight in overweight or obese individuals.

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.

Adiposity and insulin resistance correlate with telomere length in middle-aged Arabs: the influence of circulating adiponectin

OBJECTIVE

Studies in obesity have implicated adipocytokines in the development of insulin resistance, which in turn may lead to accelerated aging. In this study, we determined associations of chromosomal telomere length (TL) to markers of obesity and insulin resistance in middle-aged adult male and female Arabs with and without diabetes mellitus type 2 (DMT2).

DESIGN AND METHODS

One hundred and ninety-three non-diabetic and DMT2 subjects without complications (97 males and 96 females) participated in this cross-sectional study. Clinical data, as well as fasting blood samples, were collected. Serum glucose and lipid profile were determined using routine laboratory methods. Serum insulin, leptin, adiponectin, resistin, tumor necrosis factor-α, and PAI-1 were quantified using customized multiplex assay kits. High sensitive C-reactive protein (hsCRP) and angiotensin II (ANG II) were measured using ELISAs. Circulating leukocyte TL was examined by quantitative real-time PCR.

RESULTS

Circulating chromosomal leukocyte TL had significant inverse associations with body mass index (BMI), systolic blood pressure, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), low-density lipoprotein (LDL)- and total cholesterol, ANG II and hsCRP levels. Adiponectin, BMI, systolic blood pressure, and LDL cholesterol predicted 47% of the variance in TL (P<0.0001). HOMA-IR was the most significant predictor for TL in males, explaining 35% of the variance (P=0.01). In females, adiponectin accounted for 28% of the variance in TL (P=0.01).

CONCLUSION

Obesity and insulin resistance are associated with chromosomal TL among adult Arabs. Evidence of causal relations needs further investigation. The positive association of adiponectin to TL has clinical implications as to the possible protective effects of this hormone from accelerated aging.

Chronic inflammation in obesity and the metabolic syndrome

The increasing incidence of obesity and the metabolic syndrome is disturbing. The activation of inflammatory pathways, used normally as host defence, reminds the seriousness of this condition. There is probably more than one cause for activation of inflammation. Apparently, metabolic overload evokes stress reactions, such as oxidative, inflammatory, organelle and cell hypertrophy, generating vicious cycles. Adipocyte hypertrophy, through physical reasons, facilitates cell rupture, what will evoke an inflammatory reaction. Inability of adipose tissue development to engulf incoming fat leads to deposition in other organs, mainly in the liver, with consequences on insulin resistance. The oxidative stress which accompanies feeding, particularly when there is excessive ingestion of fat and/or other macronutrients without concomitant ingestion of antioxidant-rich foods/beverages, may contribute to inflammation attributed to obesity. Moreover, data on the interaction of microbiota with food and obesity brought new hypothesis for the obesity/fat diet relationship with inflammation. Beyond these, other phenomena, for instance psychological and/or circadian rhythm disturbances, may likewise contribute to oxidative/inflammatory status. The difficulty in the management of obesity/metabolic syndrome is linked to their multifactorial nature where environmental, genetic and psychosocial factors interact through complex networks.