Fat distribution and storage: how much, where, and how?

Mechanisms and risk factors of metabolic syndrome in children and adolescents

Metabolic syndrome (MetS) is a complex disorder characterized by abdominal obesity, elevated blood pressure, hyperlipidemia, and elevated fasting blood glucose levels. The diagnostic criteria for MetS in adults are well-established, but there is currently no consensus on the definition in children and adolescents. The etiology of MetS is believed to involve a complex interplay between genetic predisposition and environmental factors. While genetic predisposition explains only a small part of MetS pathogenesis, modifiable environmental risk factors play a significant role. Factors such as maternal weight during pregnancy, children's lifestyle, sedentariness, high-fat diet, fructose and branched-chain amino acid consumption, vitamin D deficiency, and sleep disturbances contribute to the development of MetS. Early identification and treatment of MetS in children and adolescents is crucial to prevent the development of chronic diseases later in life. In this review we discuss the latest research on factors contributing to the pathogenesis of MetS in children, focusing on non-modifiable and modifiable risk factors, including genetics, dysbiosis and chronic low-grade inflammation.

Adipose Tissue Insulin Resistance Is Not Associated With Changes in the Degree of Obesity in Children and Adolescents

CONTEXT

The "carbohydrate-insulin model" claims that adipose tissue insulin sensitivity explains development of obesity via adipocyte energy storage and/or low postprandial metabolic fuel levels.

OBJECTIVE

We tested whether adipose tissue insulin sensitivity predicts changes in the degree of obesity over time.

METHODS

This secondary analysis of an observational study of youth with obesity included 213 youths at a pediatric weight management clinic. Adipose tissue insulin sensitivity/resistance and whole-body insulin sensitivity were evaluated using oral glucose tolerance test (OGTT)-derived surrogates in the face of changes in the degree of obesity over time. The main outcome measure was change in body mass index (BMI) z score.

RESULTS

Mean BMI z change was 0.05 ± 0.28 (range, -1.15 to 1.19), representing a broad distribution of changes in the degree of obesity over a follow-up period of 1.88 ± 1.27 years. Adipose tissue insulin resistance was not associated with changes in the degree of obesity in univariate or multivariate analyses (adjusted for baseline age, BMI z score, sex, ethnicity, and time of follow-up). Low postprandial free fatty acid concentrations or their suppression during the OGTT were not associated with changes in the degree of obesity in univariate or multivariate analyses. Whole-body insulin sensitivity was not associated with changes in the degree of obesity in univariate or multivariate analyses.

CONCLUSION

In this secondary analysis, in youth with obesity, adipose tissue insulin resistance is not protective from increases of the degree of obesity and skeletal muscle insulin resistance is not associated with increases of the degree of obesity.The analysis was performed using data derived from NCT00000112 and NCT00536250.

Inflammaging: The ground for sarcopenia?

Sarcopenia is a progressive skeletal muscle disease that occurs most commonly in the elderly population, contributing to increased costs and hospitalization. Exercise and nutritional therapy have been proven to be effective for sarcopenia, and some drugs can also alleviate declines in muscle mass and function due to sarcopenia. However, there is no specific pharmacological treatment for sarcopenia at present. This review will mainly discuss the relationship between inflammaging and sarcopenia. The increased secretion of proinflammatory cytokines with aging may be because of cellular senescence, immunosenescence, alterations in adipose tissue, damage-associated molecular patterns (DAMPs), and gut microbes due to aging. These sources of inflammaging can impact the sarcopenia process through direct or indirect pathways. Conversely, sarcopenia can also aggravate the process of inflammaging, creating a vicious cycle. Targeting sources of inflammaging can influence muscle function, which could be considered a therapeutic target for sarcopenia. Moreover, not only proinflammatory cytokines but also anti-inflammatory cytokines can influence muscle and inflammation and participate in the progression of sarcopenia. This review focuses on the effects of TNF-α, IL-6, and IL-10, which can be detected in plasma. Therefore, clearing chronic inflammation by targeting proinflammatory cytokines (TNF-α, IL-1, IL-6) and the inflammatory pathway (JAK/STAT, autophagy, NF-κB) may be effective in treating sarcopenia.

CIDEA expression in SAT from adolescent girls with obesity and unfavorable patterns of abdominal fat distribution

OBJECTIVE

This study investigated whether variations in cell death-inducing DNA fragmentation factor alpha subunit-like effector A (CIDEA) mRNA expression and protein levels are modulated by the pattern of abdominal fat distribution in adolescent girls with obesity.

METHODS

This study recruited 35 adolescent girls with obesity and characterized their abdominal fat distribution by magnetic resonance imaging. Participants had only a periumbilical/abdominal (n = 14) or a paired abdominal and gluteal subcutaneous adipose tissue (SAT) biopsy (n = 21). CIDEA expression was determined by reverse transcription-polymerase chain reaction, CIDEA protein level by Western blot, and the turnover of adipose lipids and adipocytes by 2 H2 O labeling. In six girls, a second abdominal SAT biopsy was performed (after ~34.2 months) to explore the weight gain effect on CIDEA expression in abdominal SAT.

RESULTS

CIDEA expression decreased in abdominal SAT from participants with high visceral adipose tissue (VAT)/(VAT+SAT); CIDEA inversely correlated with number of small adipocytes, with the increase in preadipocyte proliferation, and with adipogenesis. A strong inverse correlation was found between CIDEA protein level with the newly synthetized glycerol (r = -0.839, p = 0.0047). Following weight gain, an increase in adipocytes' cell diameter with a decrease in CIDEA expression and RNA-sequencing transcriptomic profile typical of adipocyte dysfunction was observed.

CONCLUSIONS

Reduced expression of CIDEA in girls with high VAT/(VAT+SAT) is associated with adipocyte hypertrophy and insulin resistance.

Relation of glomerular filtration to insulin resistance and related risk factors in obese children

BACKGROUND AND OBJECTIVE

Childhood obesity is associated with later development of significant renal morbidity. We evaluated the impact of the degree of insulin sensitivity on estimated glomerular filtration rate (eGFR) and determined the factors associated with eGFR in obese children. We further tested the relation of eGFR to clinical outcomes such as blood pressure and microalbuminuria.

MATERIALS AND METHODS

We evaluated the relation of whole body insulin sensitivity and estimated glomerular filtration rate (eGFR) across the spectrum of obesity in children and adolescents. eGFR was calculated using the iCARE formula, which has been validated in obese children with varying glucose tolerance.

RESULTS

1080 children and adolescents with overweight and obesity (701 females and 379 males) participated. Insulin sensitivity was a strongly negatively associated with (B = -2.72, p < 0.001) eGFR), even after adjustment for potential confounders. Male sex emerged to be significantly associated with eGFR with boys having greater values than girls (B = 18.82, p < 0.001). Age was a positively associated (B = 2.86, p < 0.001) with eGFR. Whole body and hepatic insulin sensitivity decreased across eGFR quartiles. Adjusted eGFR was tightly positively associated with systolic blood pressure (B = 0.09, p = 0.003) and negatively associated with the presence of microalbuminuria (B = -2.18, p = 0.04).

CONCLUSIONS

eGFR tends to increase with greater degrees of insulin resistance in children and adolescents representing hyperfiltration and is associated with cardiovascular risk factors. Longitudinal studies are needed to determine the natural history of childhood insulin resistance related hyperfiltration in regards to future kidney disease.

Associations of fitness and physical activity with specific abdominal fat depots in children with overweight/obesity

OBJECTIVES

To examine the relationship between physical fitness and physical activity (PA) with specific abdominal fat depots and their potential implications for cardiometabolic risk and insulin resistance (IR) in children with overweight/obesity.

MATERIALS AND METHODS

A total of 116 children with overweight/obesity (10.7 ± 1.1 year, 54% girls) participated in the study. Abdominal visceral (VAT), subcutaneous (ASAT), and intermuscular abdominal adipose tissue (IMAAT) were assessed by magnetic resonance imaging. The cardiometabolic risk (MetS) score and the insulin resistance homeostasis model assessment (HOMA-IR) were calculated. Health-related physical fitness components (treadmill test, and 20 m shuttle run, handgrip, standing broad jump and 4 × 10 m tests) were evaluated, and PA was measured (accelerometry). Children were categorized as fit or unfit for each specific fitness test, and as active or inactive.

RESULTS

Higher VAT, ASAT, and IMAAT were associated with higher MetS score and HOMA-IR (all p < 0.02). A better performance in all fitness tests and total and vigorous PA were strongly associated with lower VAT (all p < 0.04), ASAT (all p < 0.005), and IMAAT (all p < 0.005). Fit or active children had lower VAT, ASAT, and IMAAT (all p < 0.03) than their unfit or inactive counterparts.

CONCLUSION

These results reinforce the importance of having adequate fitness and PA levels to reduce abdominal fat accumulation in children. Given that VAT, ASAT, and IMAAT are associated with higher risk of developing cardiovascular diseases and type 2 diabetes, the improvement of physical fitness by the promotion of PA should be goals of lifestyle interventions for improving health in children with overweight/obesity.

Comparison of cardiovascular risk factors between children and adolescents with classes III and IV obesity: findings from the APV cohort

Objective

Obesity is associated with many cardiovascular risk factors (CVRF) in childhood. There is an ongoing discussion whether there is a linear relationship between degree of overweight and deterioration of CVRFs justifying body mass index (BMI) cut-offs for treatment decisions.

Methods

We studied the impact of BMI-SDS on blood pressure, lipids, and glucose metabolism in 76,660 children (aged 5–25 years) subdivided in five groups: overweight (BMI-SDS 1.3 to <1.8), obesity class I (BMI-SDS 1.8 to <2.3), class II (BMI-SDS 2.3–2.8), class III (BMI-SDS > 2.8–3.3), and class IV (BMI-SDS > 3.3). Analyses were stratified by age and sex.

Results

We found a relationship between BMI-SDS and blood pressure, triglycerides, HDL cholesterol, liver enzymes, and the triglycerides–HDL-cholesterol ratio at any age and sex. Many of these associations lost significance when comparing children with obesity classes III and IV: In females < 14 years and males < 12 years triglycerides and glucose parameters did not differ significantly between classes IV and III obesity. Prevalence of dyslipidemia was significantly higher in class IV compared to class III obesity only in females ≥ 14 years and males ≥ 12 years but not in younger children. In girls < 14 years and in boys of any age, the prevalences of type 2 diabetes mellitus did not differ between classes III and IV obesity.

Conclusions

Since a BMI above the highest BMI cut-off was not associated consistently with dyslipidemia and disturbed glucose metabolism in every age group both in boys and girls, measurements of CVRFs instead of BMI cut-off seem preferable to guide different treatment approaches in obesity such as medications or bariatric surgery.

Association of Serum Calcium Level with Waist Circumference and Other Biochemical Health-care Predictors among Patients with Type 2 Diabetes

INTRODUCTION

This study aimed to find the association of serum calcium level with abdominal obesity according to the waist circumference (WC) and the associated factors.

MATERIALS AND METHODS

A cross-sectional study was carried out at private health-care center. A total of 291 patients, aged 18 years and above, with type 2 diabetes mellitus who attended the clinic from May 2017 through March 2018 were included. Sociodemographic, clinical, and laboratory data were obtained from the medical records of patients. Statistical analysis was carried out using the Statistical Package for the Social Sciences software (SPSS, version 23). Abdominal obesity was defined by WC ≥ 80cm in women and ≥94cm in men.

RESULTS

A total number of 291 participants participated in the study. Among these participants, 42.6% (n = 124) were male and 57.4% (n = 167) were female. The average age of respondents was 55.99 ± 9.81 years. Among the male participants, 90 (72.6%) (95% confidence interval [CI]: 64.6%-80.5%) were abdominally obese as were 154 participants (92.2%) (95% CI: 88.1%-96.3%) among females. Overall, 244 participants (83.8%) (95% CI: 79.6%-88.1%) were abdominally obese. The results of statistical modeling showed that gender, smoking status, physical activity, and serum calcium are strong determinants of abdominal obesity.

CONCLUSION

This study revealed a significant association of abdominal obesity and serum calcium level among patients with diabetes.

Altered In Vivo Lipid Fluxes and Cell Dynamics in Subcutaneous Adipose Tissues Are Associated With the Unfavorable Pattern of Fat Distribution in Obese Adolescent Girls

Patterns of abdominal fat distribution (for example, a high vs. low visceral adipose tissue [VAT]/[VAT + subcutaneous adipose tissue (SAT)] ratio), independent of obesity, during adolescence carry a high risk for insulin resistance and type 2 diabetes. Longitudinal follow-up of a cohort of obese adolescents has recently revealed that a high ratio (high VAT/[VAT + SAT]) is a major determinant of fatty liver and metabolic impairment over time, with these effects being more pronounced in girls than in boys. To unravel the underlying metabolic alterations associated with the unfavorable VAT/(VAT + SAT) phenotype, we used the 2H2O labeling method to measure the turnover of adipose lipids and cells in the subcutaneous abdominal and gluteal/femoral adipose tissue (SAT) of weight-stable obese adolescent girls with a similar level of obesity but discordant VAT/(VAT + SAT) ratios. Girls with the unfavorable (high VAT/[VAT + SAT]) phenotype exhibited higher in vivo rates of triglyceride (TG) turnover (representing both lipolysis and synthesis at steady state), without significant differences in de novo lipogenesis in both abdominal and gluteal depots, compared with obese girls with the favorable phenotype. Moreover, mature adipocytes had higher turnover, with no difference in stromal vascular cell proliferation in both depots in the metabolically unfavorable phenotype. The higher TG turnover rates were significantly correlated with higher intrahepatic fat stores. These findings are contrary to the hypothesis that impaired capacity to deposit TGs or proliferation of new mature adipocytes are potential mechanisms for ectopic fat distribution in this setting. In summary, these results suggest that increased turnover of TGs (lipolysis) and of mature adipocytes in both abdominal and gluteal SAT may contribute to metabolic impairment and the development of fatty liver, even at this very early stage of disease.

Obesity as the Main Risk Factor for Metabolic Syndrome in Children

Obesity in childhood is the main determinant of whole body reduced insulin sensitivity. This association has been demonstrated in multiple adult and pediatric cohorts. The mechanistic link explaining this association is the pattern of lipid partitioning in the face of excess calories and energy surplus. A tight relation exists between typical lipid deposition patterns, specifically within the skeletal muscle and liver, as well as the intra-abdominal compartment and whole body insulin sensitivity. The impact of lipid deposition within insulin responsive tissues such as the liver and skeletal muscle relates to the ability of fatty acid derivates to inhibit elements of the insulin signal transduction pathway. Strengthening the relation of obesity and reduced insulin sensitivity are the observations that weight gain reduces insulin sensitivity while weight loss increases it. This manifests as the appearance of cardiovascular risk factor clustering with weight gain and its recovery in the face of weight loss. Both obesity per se, via the adipocytokine profile it induces, and low insulin sensitivity, are independent determinants of the adverse metabolic phenotype characteristic of the metabolic syndrome.

PEDIATRIC VISCERAL ADIPOSITY INDEX ADAPTATION CORRELATES WITH HOMA-IR, MATSUDA, AND TRANSAMINASES

OBJECTIVE

Visceral adiposity index (VAI) is a mathematical model associated with cardiometabolic risk in adults, but studies on children failed to support this association. Our group has proposed a pediatric VAI model using pediatric ranges, but it has not yet been evaluated and needs further adjustments. The objective of this study was to further adjust the proposed pediatric VAI by age, creating a new pediatric metabolic index (PMI), and assess the correlation of the PMI with insulin resistance indexes and hepatic enzymes.

METHODS

A cross-sectional design with data from 396 children (age 5 to 17 years) was analyzed with a generalized linear model to find the coefficients for triglycerides, high-density-lipoprotein cholesterol, and waist circumference-body mass index quotient. The model was constructed according to sex and age and designated PMI. A cross-validation analysis was performed and a receiver operating characteristic curve was used to determine cut-off points.

RESULTS

Significant moderate correlation was found between PMI and homeostatic model assessment of insulin resistance (HOMA-IR) ( r = 0.452; P = .003), Matsuda ( r = -0.366; P = .019), alanine aminotransferase ( r = 0.315, P = .045), and γ-glutamyltransferase ( r = 0.397; P = .010). A PMI score >1.7 was considered as risk.

CONCLUSION

PMI correlates with HOMA-IR, Matsuda, and hepatic enzymes. It could be helpful for identifying children at risk for cardiometabolic diseases.

ABBREVIATIONS

ALT = alanine transaminase BMI = body mass index GGT = γ-glutamyltransferase HDL-C = high-density-lipoprotein cholesterol HOMA-IR = homeostatic model assessment of insulin resistance hs-CRP = high sensitivity C-reactive protein ISI = insulin sensitivity index NAFLD = nonalcoholic fatty liver disease PMI = pediatric metabolic index QUICKI = quantitative insulin sensitivity check index ROC = receiver operating characteristic TG = triglyceride TNF-α = tumor necrosis factor-alpha VAI = visceral adiposity index VAT = visceral adipose tissue WC = waist circumference.

Impact of Severe Obesity on Cardiovascular Risk Factors in Youth

OBJECTIVE

To compare cardiovascular risk factor clustering (CVRFC) in severely obese youth with those with lower degrees of obesity.

STUDY DESIGN

We divided a childhood obesity clinic derived cohort into the degrees of obesity (class I, II, and III) and added a "class IV" category corresponding to >160% of the 95th centile of body mass index (BMI) for age and sex. In a cross-sectional analysis, we investigated the presence of CVRFC in 2244 participants; in 621 who were followed longitudinally, we investigated the determinants of endpoint CVRFC.

RESULTS

Class IV obesity was associated with increased risk for CVRFC compared with overweight (OR = 17.26, P < .001) at a similar magnitude to class III obesity (OR = 17.26, P < .001). Male children were at greater risk for presence of CVRFC (OR = 1.57, P = .03) compared with female children. Adiponectin (OR = 0.90, P < .001) and leptin levels (OR = 0.98, P = .008) were protective, independent of degree of obesity. Baseline class IV obesity was associated with increased risk compared with overweight of having CVRFC at follow-up (OR = 5.76, P = .001), to a similar extent as class III obesity (OR = 5.36, P = .001). Changes in the degree of obesity were significant predictors of CVRFC on follow-up (OR = 1.04, P < .01 per percent BMI change).

CONCLUSIONS

The metabolic risk associated with obesity in childhood is conferred prior to reaching class IV obesity. An individualized risk stratification approach in children with severe obesity should be based on presence of complications rather than simple BMI cutoffs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01967849.

Marrow adipose tissue spectrum in obesity and type 2 diabetes mellitus

OBJECTIVE

To assess the association of bone mass and marrow adipose tissue (MAT) with other fat depots, insulin resistance, bone remodeling markers, adipokines and glucose control in type 2 diabetes and obesity.

DESIGN AND METHODS

The study groups comprised 24 controls (C), 26 obese (O) and 28 type 2 diabetes. Dual-energy X-ray absorptiometry was used to determine bone mineral density (BMD). Blood samples were collected for biochemical measurements. ¹H Magnetic resonance spectroscopy was used to assess MAT in the L3 vertebra, and abdominal magnetic resonance imaging was used to assess intrahepatic lipids in visceral (VAT) and subcutaneous adipose tissue. Regression analysis models were used to test the association between parameters.

RESULTS

At all sites tested, BMD was higher in type 2 diabetes than in O and C subjects. The C group showed lower VAT values than the type 2 diabetes group and lower IHL than the O and type 2 diabetes groups. However, MAT was similar in the 3 groups. Osteocalcin and C-terminal telopeptide of type 1 collagen were lower in type 2 diabetes than those in C and O subjects. Moreover, at all sites, BMD was negatively associated with osteocalcin. No association was observed between MAT and VAT. No relationship was observed among MAT and HOMA-IR, leptin, adiponectin or Pref-1, but MAT was positively associated with glycated hemoglobin.

CONCLUSIONS

MAT is not a niche for fat accumulation under conditions of energy surplus and type 2 diabetes, also is not associated with VAT or insulin resistance. MAT is associated with glycated hemoglobin.

Anthocyanin Rich-Black Soybean Testa Improved Visceral Fat and Plasma Lipid Profiles in Overweight/Obese Korean Adults: A Randomized Controlled Trial

Anthocyanin-rich black soybeans have been used in traditional East Asian medicine to cure diseases related to oxidative stress and carcinogens, but not obesity. Our objective was to investigate the effects of anthocyanin-rich black soybean testa extracts (BBT), Glycine max (Chongja No. 3), on obesity. In total, 63 participants defined as overweight or obese by their body mass index (BMI >23) or waist circumference (WC >90 cm for males, >85 cm for females) were sorted into two groups: 32 receiving the trial medication (BBT, 2.5 g/d) and 31 receiving the placebo (starch, 2.5 g/d). Participants completed an 8-week, randomized, double-blinded, and placebo-controlled clinical trial. There were no significant differences between the two groups at the beginning of the trial, and both required the same safety assessments. Significant decreases in abdominal fat, described according to WC and hip circumference, and lipid profiles such as triacylglycerols (TG), low density lipoprotein cholesterol (LDLc), and non-high density lipoprotein cholesterol (non-HDLc) were observed in the BBT group at the conclusion of the clinical trial. The indicators for arteriosclerosis such as total cholesterol (TC)/HDLc and LDLc/HDLc were significantly decreased in the BBT group, but had not changed in the placebo group. With no difference between the two groups in energy-adjusted dietary intakes and physical activity, BBT was shown to strongly improve plasma lipid profiles, related to the reduction of WC (an indicator of abdominal fat) as long as high dietary fiber and low cholesterol diets were maintained. In conclusion, BBT can potentially be developed as a functional food for preventing abdominal obesity with high fiber and low cholesterol diets.

The Association of Body Fat and Leisure Time Physical Activity Called into Question for Asian Indians

OBJECTIVE

Thrifty genotypes may predispose to type 2 diabetes and body fat (%BF) excess through a differentiated relationship between physical activity and body fat. We explored this hypothesis in Asian Indians, a population thought to be thrifty.

METHODS

Three hundred and nine Guadeloupian adolescents responded to the modifiable activity questionnaire. Their body fat was assessed by bioimpedancemetry. We first studied the relationship between %BF and leisure time physical activity (LTPA). We then explored the associations of ethnicity with this relationship in a subgroup of 93 Asian Indians matched with 93 controls for age, sex, and LTPA class. The alpha risk retained was .05.

RESULTS

The analyses showed that Asian Indians had higher %BF even when matched with controls for age, sex and LTPA quartile, and the relationship between LTPA and %BF observed in controls was not evidenced in Asian Indians.

CONCLUSIONS

The higher %BF in Asian Indians remained significant even when they were matched with controls for age, sex and LTPA quartile, and their LTPA was not associated ‒ or was at least less robustly associated ‒ with %BF. These findings are consistent with the hypothesis of thriftiness in Asian Indians, with the weaker relationship of high LTPA and low %BF a possible path to thriftiness.

Obesity, Oxidative Stress, Adipose Tissue Dysfunction, and the Associated Health Risks: Causes and Therapeutic Strategies

Obesity is gaining acceptance as a serious primary health burden that impairs the quality of life because of its associated complications, including diabetes, cardiovascular diseases, cancer, asthma, sleep disorders, hepatic dysfunction, renal dysfunction, and infertility. It is a complex metabolic disorder with a multifactorial origin. Growing evidence suggests that oxidative stress plays a role as the critical factor linking obesity with its associated complications. Obesity per se can induce systemic oxidative stress through various biochemical mechanisms, such as superoxide generation from NADPH oxidases, oxidative phosphorylation, glyceraldehyde auto-oxidation, protein kinase C activation, and polyol and hexosamine pathways. Other factors that also contribute to oxidative stress in obesity include hyperleptinemia, low antioxidant defense, chronic inflammation, and postprandial reactive oxygen species generation. In addition, recent studies suggest that adipose tissue plays a critical role in regulating the pathophysiological mechanisms of obesity and its related co-morbidities. To establish an adequate platform for the prevention of obesity and its associated health risks, understanding the factors that contribute to the cause of obesity is necessary. The most current list of obesity determinants includes genetic factors, dietary intake, physical activity, environmental and socioeconomic factors, eating disorders, and societal influences. On the basis of the currently identified predominant determinants of obesity, a broad range of strategies have been recommended to reduce the prevalence of obesity, such as regular physical activity, ad libitum food intake limiting to certain micronutrients, increased dietary intake of fruits and vegetables, and meal replacements. This review aims to highlight recent findings regarding the role of oxidative stress in the pathogenesis of obesity and its associated risk factors, the role of dysfunctional adipose tissue in development of these risk factors, and potential strategies to regulate body weight loss/gain for better health benefits.

Comparative Effect of Insulin Sensitizers and Statin on Metabolic Profile and Ultrasonographical Score in Non Alcoholic Fatty Liver Disease

INTRODUCTION

Non Alcoholic Fatty Liver Disease (NAFLD) is a metabolic disorder involving fat accumulation in the liver. The initial management for patients with NAFLD includes lifestyle modification and weight loss in overweight or obese patients.

AIM

The present study was conducted to compare the efficacy of insulin sensitizers and statin in the patients of NAFLD.

MATERIALS AND METHODS

The study included 98 patients diagnosed with NAFLD on USG (Ultrasonography) abdomen, divided into three Groups randomly and administered Metformin (Group I), Rosuvastatin (Group II) or Pioglitazone (Group III) along with dietary intervention and lifestyle modification. Their Body Mass Index (BMI), liver function tests, fasting lipid profile, USG scores for fatty liver were done and followed up at 4 weeks, 12 weeks and 24 week for change in above parameters.

RESULTS

Out of the three Groups, Group II showed a maximum improvements in usg scores for NAFLD (p<0.001) and fasting lipid profile. Group II also showed maximum derangement of liver enzymes at 24 weeks though none of the subjects had more than three times elevation of liver enzymes.

CONCLUSION

Rosuvastatin may be an effective therapy as add on treatment to dietary and lifestyle intervention in patients of NAFLD. As an add-on treatment Rosuvastatin was superior to Pioglitazone or Metformin and acute decompensation is unlikely with this drug. Metformin was not effective as add on therapy for NAFLD, rather rapid weight loss in short period of time resulted in worsening of hepatic steatosis.

Adipose Insulin Resistance in Obese Adolescents Across the Spectrum of Glucose Tolerance

CONTEXT

Adipocytes represent an important insulin-responsive tissue taking an active part in glucose metabolism.

OBJECTIVE

This study sought to assess adipose tissue insulin resistance (IR) across the spectrum of glucose tolerance and to test its relation with free fatty acid (FFA) suppression during an oral glucose tolerance test (OGTT).

DESIGN AND SETTING

A cross-sectional analysis of a pediatric clinic-derived cohort of obese adolescents.

PATIENTS OR OTHER PARTICIPANTS

Participants age 7-20 y with a body mass index that exceeded the 95th percentile for their age and sex.

INTERVENTION(S)

A standard oral glucose tolerance test.

MAIN OUTCOME MEASURES

The adipose tissue insulin resistance index (calculated as the product of fasting insulin and FFA concentrations) (Adipose IR) and the area under curve of FFAs during the OGTT were compared between glucose tolerance categories.

RESULTS

A total of 962 obese children and adolescents participated in this study. Adipose IR significantly increased across glucose tolerance categories (P for trend < .001). Within the normal glucose tolerance participants, an increase in adipose IR was observed related to an increase in 2-hr glucose levels. In a subsample of participants who underwent abdominal imaging for determination of lipid partitioning (n = 115), a tight relation of visceral fat (r = 0.34; P < .001) and the visceral/sc fat ratio (r = 0.55; P < .001) with the Adipose IR index was evident. Greater area under the curve FFAs (lower FFA suppression) during the OGTT was evident with worsening glucose tolerance (P for trend < .001). Glucose tolerance category, degree of obesity (body mass index-z score), IL-6, and low adiponectin emerged as significant predictors of the Adipose IR.

CONCLUSIONS

Adipose IR is associated with reduced suppression of FFAs during the OGTT and with an altered adipocytokine profile. The negative relation with insulin secretion deserves further longitudinal investigation in the context of deteriorating glucose tolerance.

Differences in the triglyceride to HDL-cholesterol ratio between Palestinian and Israeli adults

Aims

To evaluate differences in the triglyceride to HDL-cholesterol ratio (TG/HDL), thought to be a proxy measure of insulin resistance, between Palestinian and Israeli adults in view of the greater incidence of coronary heart disease and high prevalence of diabetes in Palestinian Arabs.

Research Methods

A population-based observational prevalence study of cardiovascular and diabetes risk factors in Jerusalem. Participants (968 Palestinians, 707 Israelis, sampled at ages 25-74 years) underwent fasting and 2h post-75g oral challenge plasma glucose determinations. Metabolic risk was assessed using the surrogate index TG/HDL. Sex-specific comparisons were stratified by categories of body mass index and sex-specific waist circumference quartiles, adjusted by regression for age, glucose tolerance status and use of statins.

Results

Prevalence of overweight and obesity was substantially larger in Palestinians (p = 0.005). Prevalence of diabetes was 2.4 and 4 fold higher among Palestinian men and women, respectively (p<0.001). Adjusted TG/HDL was higher in Palestinians than Israelis across BMI and waist circumference categories (p<0.001 for both). Higher TG/HDL in Palestinians persisted in analyses restricted to participants with normal glucose tolerance and off statins. Notably, higher TG/HDL among Palestinians prevailed at a young age (25-44 years) and in normal weight individuals of both sexes.

Conclusions

Palestinians have a higher TG/HDL ratio than Israelis. Notably, this is evident also in young, healthy and normal weight participants. These findings indicate the need to study the determinants of this biomarker and other measures of insulin resistance in urban Arab populations and to focus research attention on earlier ages: childhood and prenatal stages of development.

Improving the spectral resolution and spectral fitting of (1) H MRSI data from human calf muscle by the SPREAD technique

Proton magnetic resonance spectroscopic imaging ((1) H MRSI) has been used for the in vivo measurement of intramyocellular lipids (IMCLs) in human calf muscle for almost two decades, but the low spectral resolution between extramyocellular lipids (EMCLs) and IMCLs, partially caused by the magnetic field inhomogeneity, has hindered the accuracy of spectral fitting. The purpose of this paper was to enhance the spectral resolution of (1) H MRSI data from human calf muscle using the SPREAD (spectral resolution amelioration by deconvolution) technique and to assess the influence of improved spectral resolution on the accuracy of spectral fitting and on in vivo measurement of IMCLs. We acquired MRI and (1) H MRSI data from calf muscles of three healthy volunteers. We reconstructed spectral lineshapes of the (1) H MRSI data based on field maps and used the lineshapes to deconvolve the measured MRS spectra, thereby eliminating the line broadening caused by field inhomogeneities and improving the spectral resolution of the (1) H MRSI data. We employed Monte Carlo (MC) simulations with 200 noise realizations to measure the variations of spectral fitting parameters and used an F-test to evaluate the significance of the differences of the variations between the spectra before SPREAD and after SPREAD. We also used Cramer-Rao lower bounds (CRLBs) to assess the improvements of spectral fitting after SPREAD. The use of SPREAD enhanced the separation between EMCL and IMCL peaks in (1) H MRSI spectra from human calf muscle. MC simulations and F-tests showed that the use of SPREAD significantly reduced the standard deviations of the estimated IMCL peak areas (p < 10(-8) ), and the CRLBs were strongly reduced (by ~37%).

Effect of fish and krill oil supplementation on glucose tolerance in rabbits with experimentally induced obesity

PURPOSE

This study was conducted to investigate the effect of fish oil (FO) and krill oil (KO) supplementation on glucose tolerance in obese New Zealand white rabbits.

METHODS

The experiments were carried out with 24 male rabbits randomly divided into four groups: KO-castrated, treated with KO; FO-castrated, treated with FO; C-castrated, non-treated; NC-non-castrated, non-treated. At the end of treatment period (2 months), an intravenous glucose tolerance test (IVGTT) was performed in all rabbits.

RESULTS

Fasting blood glucose concentrations in FO and KO animals were significantly lower than in group C. The blood glucose concentrations in FO- and KO-treated animals returned to initial values after 30 and 60 min of IVGTT, respectively. In liver, carnitine palmitoyltransferase 2 (Cpt2) and 3-hydroxy-3-methyl-glutaryl-CoA synthase 2 (Hmgcs2) genes were significantly increased in FO-fed rabbits compared with the C group. Acetyl-CoA carboxylase alpha (Acaca) expression was significantly reduced in both KO- and FO-fed rabbits. In skeletal muscle, Hmgcs2 and Cd36 were significantly higher in KO-fed rabbits compared with the C group. Acaca expression was significantly lower in KO- and FO-fed rabbits compared with the C group.

CONCLUSION

The present results indicate that FO and KO supplementation decreases fasting blood glucose and improves glucose tolerance in obese New Zealand white rabbits. This could be ascribed to the ameliorated insulin sensitivity and insulin secretion and modified gene expressions of some key enzymes involved in β-oxidation and lipogenesis in liver and skeletal muscle.

Metabolic syndrome in pediatrics

The ever growing prevalence of childhood obesity is being accompanied by an increase in the pediatric population of diseases once believed to be exclusive of the adulthood such as the metabolic syndrome (MS). The MS has been defined as the link between insulin resistance, hypertension, dyslipidemia, impaired glucose tolerance, and other metabolic abnormalities associated with an increased risk of atherosclerotic cardiovascular diseases in adults. In this review, we will discuss the peculiar aspects of the pediatric MS and the role of novel molecules and biomarkers in its pathogenesis.

The "New Deadly Quartet" for cardiovascular disease in the 21st century: obesity, metabolic syndrome, inflammation and climate change: how does statin therapy fit into this equation?

Despite population-based improvements in cardiovascular risk factors, such as blood pressure, cholesterol and smoking, cardiovascular disease still remains the number-one cause of mortality in the United States. In 1989, Kaplan coined the term "Deadly Quartet" to represent a combination of risk factors that included upper body obesity, glucose intolerance, hypertriglyceridemia and hypertension [Kaplan in Arch Int Med 7:1514-1520, 1989]. In 2002, the third report of the National Cholesterol Education Program Adult Treatment Panel (NCEP-ATP III) essentially added low HDL-C criteria and renamed this the "metabolic syndrome." [The National Cholesterol Education Program (NCEP) in JAMA 285:2486-2497, 2001] However, often forgotten was that a pro-inflammatory state and pro-thrombotic state were also considered components of the syndrome, albeit the panel did not find enough evidence at the time to recommend routine screening for these risk factors [The National Cholesterol Education Program (NCEP) in JAMA 285:2486-2497, 2001]. Now over a decade later, it may be time to reconsider this deadly quartet by reevaluating the roles of obesity and subclinical inflammation as they relate to the metabolic syndrome. To complete this new quartet, the addition of increased exposure to elevated levels of particulate matter in the atmosphere may help elucidate why this cardiovascular pandemic continues, despite our concerted efforts. In this article, we will summarize the evidence, focusing on how statin therapy may further impact this new version of the "deadly quartet".

Ectopic fat in youth: the contribution of hepatic and pancreatic fat to metabolic disturbances

OBJECTIVE

To study the relationships between parameters of glucose and insulin metabolism and visceral and abdominal ectopic fat in youth.

METHODS

A cross sectional study of 50 children (24 females), 8-18 years old. Anthropometrics, body composition, blood-work and visceral and ectopic fat by magnetic resonance imaging were assessed. Insulin secretion, insulin sensitivity and beta cell function were calculated from an oral glucose tolerance test.

RESULTS

BMI z-scores ranged between -1.3 and 4.5. The hepatic fat fraction (HFF) ranged between 0 and 36% and pancreatic fat fraction (PFF) between 0 and 14%. Visceral fat, HFF and PFF were associated with clinical and biochemical metabolic abnormalities, and correlated with markers of insulin sensitivity (r = -0.60, P < 0.01; r = -0.64, P < 0.01; r = -0.48, P < 0.01, respectively) insulin secretion (r = 0.55, P < 0.01; r = 0.57, P < 0.01; r = 0.41, P < 0.01, respectively), and beta cell function (r = -0.49, P < 0.01; r = -0.59, P < 0.01; r = -0.39, P < 0.01, respectively).

CONCLUSIONS

Accumulations of pancreatic and hepatic fat have complementary clinical consequences in youth. While visceral and hepatic fat demonstrated a dominant effect, even relatively small degrees of pancreatic fat deposition may contribute to metabolic alterations.

Validation of the measurement of intra-abdominal fat between ultrasound and CT scan in women with obesity and infertility

OBJECTIVE

To compare the means and changes over time of intra-abdominal fat (IAF) and subcutaneous abdominal fat (SAF) measured by abdominal ultrasound (US) and computerized tomography (CT).

DESIGN AND METHODS

Prospective cohort study of 53 women with obesity and infertility undergoing a lifestyle program.

RESULTS

The Pearson's correlation between IAF measurement by US compared to CT was good at baseline, month 3 and 6 (all r ≥ 0.72). The correlation of SAF measurement by US compared to CT was reasonable at baseline (r = 0.54; 95%CI 0.30-0.78) and weak at month 3 and 6 (all r ≤ 0.39). The correlation between the changes in IAF over 3 and 6 months by US compared to CT was reasonable and significant respectively (all r > 0.48). US could not measure the changes of SAF over time. The Bland-Altman plot showed good agreement between US and CT for IAF measurements (-1.1 [95%CI -3.9-1.6] cm lower mean in US) at baseline. For changes of IAF over time, mean estimates were in agreement.

CONCLUSION

In women with obesity and infertility, measuring IAF by US is in good agreement with the CT scan methodology but the measurement of SAF by US is unreliable.

Significantly fewer protein functional changing variants for lipid metabolism in Africans than in Europeans

Background

The disorders in metabolism of energy substances are usually related to some diseases, such as obesity, diabetes and cancer, etc. However, the genetic background for these disorders has not been well understood. In this study, we explored the genetic risk differences among human populations in metabolism (catabolism and biosynthesis) of energy substances, including lipids, carbohydrates and amino acids.

Results

Two genotype datasets (Hapmap and 1000 Genome) were used for this study. The genetic risks of protein functional changing variants (PFCVs) on genes involved in lipid, carbohydrate and amino acid metabolism were calculated using two genetic risk indices: the total number of PFCVs (Num) and the total possibly harmful score of PFCVs (R). Observations in these two genotype datasets consistently showed that Africans had lower genetic risk in lipid metabolism (both catabolic and biosynthetic processes) compared to Europeans. However this relationship was not observed in carbohydrate and amino acid metabolism.

Conclusions

Our results suggested that Africans had higher efficiency of utilizing lipids as energy substances than Europeans. In other words, lipids might be more preferred as energy substances in Africans than in Europeans.

Prospective histopathologic evaluation of lifestyle modification in nonalcoholic fatty liver disease: a randomized trial

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is now recognized as part of the metabolic syndrome, and is specifically related to obesity and insulin resistance. Lifestyle modification is advocated for the treatment of NAFLD, but few studies have evaluated its impact on liver histology. The purpose of this study was to investigate which, if any, specific diet and exercise recommendations are associated with histopathologic changes.

METHODS

A total of 56 participants were randomly assigned to 1 of 4 lifestyle modification subgroups for 6 months: standard care, low-fat diet and moderate exercise, moderate-fat/low-processed-carbohydrate diet and moderate exercise, or moderate exercise only. All subjects had biopsy-proven NAFLD, to include nonalcoholic steatohepatitis (NASH), and received a repeat 6-month biopsy to detect histopathologic changes. Other measures included blood assay of liver enzymes (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase), fasting glucose, serum insulin, lipid panel, body weight, dietary intake, fat mass, and fitness level.

RESULTS

Among the 41 participants who completed the study (88% with NASH), a significant change was found in pre- to post-NAFLD activity score in the group as a whole (p < 0.001) with no difference detected between subgroups (p = 0.31). Our results confirm that lifestyle modification is effective in improving NAFLD and NASH.

CONCLUSIONS

Regardless of intervention group, lifestyle modification improved liver histology, as verified by repeat biopsy, after a 6-month intervention. This study reinforces the importance of lifestyle modification as the primary treatment strategy for patients with NAFLD.

Metabolic syndrome in youth: current insights and novel serum biomarkers

Paralleling the worldwide epidemic in childhood obesity, in the last decade we have observed a rise in the prevalence of metabolic syndrome (MetS) in pediatrics. The MetS comprises a cluster of cardiovascular risk factors. Multiple definitions have been proposed for the syndrome in the pediatric age group, but they are very difficult to test and validate. Thus, in this paper we will discuss the current knowledge in pediatric MetS and the potential role of novel biomarkers in the pathogenesis and diagnosis of MetS.

A consideration of biomarkers to be used for evaluation of inflammation in human nutritional studies

To monitor inflammation in a meaningful way, the markers used must be valid: they must reflect the inflammatory process under study and they must be predictive of future health status. In 2009, the Nutrition and Immunity Task Force of the International Life Sciences Institute, European Branch, organized an expert group to attempt to identify robust and predictive markers, or patterns or clusters of markers, which can be used to assess inflammation in human nutrition studies in the general population. Inflammation is a normal process and there are a number of cells and mediators involved. These markers are involved in, or are produced as a result of, the inflammatory process irrespective of its trigger and its location and are common to all inflammatory situations. Currently, there is no consensus as to which markers of inflammation best represent low-grade inflammation or differentiate between acute and chronic inflammation or between the various phases of inflammatory responses. There are a number of modifying factors that affect the concentration of an inflammatory marker at a given time, including age, diet and body fatness, among others. Measuring the concentration of inflammatory markers in the bloodstream under basal conditions is probably less informative compared with data related to the concentration change in response to a challenge. A number of inflammatory challenges have been described. However, many of these challenges are poorly standardised. Patterns and clusters may be important as robust biomarkers of inflammation. Therefore, it is likely that a combination of multiple inflammatory markers and integrated readouts based upon kinetic analysis following defined challenges will be the most informative biomarker of inflammation.

Ethnic differences in the accumulation of fat and lean mass in late gestation

OBJECTIVES

Lower birth weight within the normal range predicts adult chronic diseases, but the same birth weight in different ethnic groups may reflect different patterns of tissue development. Neonatal body composition was investigated among non-Hispanic Caucasians and African Americans, taking advantage of variability in gestational duration to understand growth during late gestation.

METHODS

Air displacement plethysmography assessed fat and lean body mass among 220 non-Hispanic Caucasian and 93 non-Hispanic African American neonates. The two ethnic groups were compared using linear regression.

RESULTS

At 36 weeks of gestation, the average lean mass of Caucasian neonates was 2,515 g vs. that of 2,319 g of African American neonates (difference, P = 0.02). The corresponding figures for fat mass were 231 and 278 g, respectively (difference, P = 0.24). At 41 weeks, the Caucasians were 319 g heavier in lean body mass (P < 0.001) but were also 123 g heavier in fat mass (P = 0.001). The slopes for lean mass vs. gestational week were similar, but the slope of fat mass was 5.8 times greater (P = 0.009) for Caucasian (41.0 g/week) than for African American neonates (7.0 g/week).

CONCLUSIONS

By 36 weeks of gestation, the African American fetus developed similar fat mass and less lean mass compared with the Caucasian fetus. Thereafter, changes in lean mass among the African American fetus with increasing gestational age at birth were similar to the Caucasian fetus, but fat accumulated more slowly. We hypothesize that different ethnic fetal growth strategies involving body composition may contribute to ethnic health disparities in later life.

Efeito de dietas hiperlipídicas com extrato de baru e chocolate sobre a área de adipócitos de ratos submetidos ao exercício físico

INTRODUÇÃO: O acúmulo de tecido adiposo provoca uma série de distúrbios metabólicos, os quais poderiam ser atenuados pela modulação dietética e prática de exercícios físicos. OBJETIVO: Avaliar os efeitos de dietas hipercalóricas/hiperlipídicas com extrato de baru e chocolate associadas ao exercício aeróbio sobre a área de adipócitos e triglicérides hepáticos (TGLhep) de ratos. MÉTODOS: Após o desmame, ratos da linhagem Wistar, com exceção dos controles (dieta Nuvilab®; 3,48kcal/g), foram alimentados com dieta à base de chocolate (4,17kcal/g), por dois meses, para indução da obesidade. Feito isso, os animais foram distribuídos em seis grupos: controle sedentários (CS), controle exercitados (CE), baru sedentários (BS), baru exercitados (BE), chocolate sedentários (CHOS), chocolate exercitados (CHOE), de acordo com a introdução da dieta com extrato de baru e treinamento de natação (2% do peso corporal., 8 sem., 5x/semana, 1h/sessão). Após a morte dos animais, o conteúdo de TGLhep foi determinado e os tecidos adiposos retroperitoneal, inguinal e omental foram removidos, pesados e submetidos à avaliação da área de adipócitos. RESULTADOS: As dietas hipercalóricas aumentaram o peso e a área de células do tecido retroperitoneal em relação à dieta controle (p < 0,05). O exercício reduziu a área de células do tecido omental (CHOE: 6.370,91 ± 7.776,13 < CHOS: 7.341,28 ± 5.862,24µm²) e inguinal (CHOE: 5.147,49 ± 5.712,71 < CHOS: 7.083,11 ± 7.682,40µm²) do grupo chocolate e inguinal do controle (CE: 2.212,87 ± 1.920,34 < CS: 3.386,11 ± 3.973,09µm²). O conteúdo de TGLhep dos animais sedentários apresentou-se mais elevado em relação aos animais exercitados e alimentados com as dietas hipercalóricas (BS: 1,36 ± 0,50 > BE: 0,88 ± 0,43mg.100mg-1; CHOS: 1,77 ± 0,64 > CHOE: 0,86 ± 0,41mg.100mg-1). CONCLUSÃO: O treinamento físico em intensidade leve à moderada reduziu significativamente os depósitos adiposos omental (visceral) e inguinal dos animais alimentados com dieta controle e chocolate. Esse mesmo comportamento não foi reproduzido com a dieta à base de extrato de baru. Os animais exercitados apresentaram menor conteúdo de TGLhep, mesmo na persistência das dietas hiperlipídicas/hipercalóricas.

The relationship between indices of iron status and selected anthropometric cardiovascular disease risk markers in an African population: the THUSA study

There is evidence that certain indices of iron status are associated with anthropometric measures, which are used independently as markers of cardiovascular disease (CVD) risk. This study examined whether this association exists in an African population. The study was a cross-sectional comparative study that examined a total of 1 854 African participants. Ferritin was positively associated with body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), percentage body fat and subscapular skinfold thickness. Serum ferritin concentration was higher in the high-WHR category than the normal-WHR category for both genders. Additionally, WC and WHR increased with increasing ferritin concentrations in both genders. Serum iron was lower in the obese than the normal-weight and pre-obese women only. In this population-based study, increased serum ferritin concentrations associated positively with increased WHR and WC, indicating that individuals or populations at risk of iron overload as defined by high serum ferritin concentrations may be at a greater risk of developing CVD.

Postmenopausal obesity promotes tumor angiogenesis and breast cancer progression in mice

Obese postmenopausal women have a 50% higher risk of breast cancer than non-obese women. There is not an animal model that mimics postmenopausal obesity related to breast cancer progression. Using age-relevant C57BL/6 mice, this study determined whether postmenopausal obesity increases VEGF expression, tumor angiogenesis, and breast tumor growth. Ovariectomy (OVX) was performed in 12 sixty week-old female mice, then followed by a low-fat (5%, LF, n=6) or a high-fat (60%, HF, n=6) diet for 12 weeks. In the eighth week of the dietary program, 10(6) E0771 (mouse breast cancer) cells were injected in the left fourth mammary gland. Tumor size was monitored for 4 weeks. Body weights were monitored weekly. At the end of the experiment, blood samples, visceral fat and tumors were collected for measuring VEGF expression using ELISA and intratumoral microvessel density (IMD) using CD31 immunochemistry. Body weight was significantly increased in OVX/HF mice, compared to OVX/LF group (55.3±1.7 vs. 41.5±1.5 g; p < 0.01). There was a two-fold increase in the ratio of visceral fat/BW in OVX/HF mice, compared to those in OVX/LF group (0.062±0.005 vs. 0.032±0.003; p < 0.01). Postmenopausal obesity significantly increased breast tumor weight over the control (4.62±0.63 vs. 1.98±0.27 g; p < 0.01) and IMD (173±3.7 vs. 139±4.3 IM#/mm^2; p < 0.01). Tumor VEGF levels were higher in OVX/HF mice, compared to OVX/LF group (73.3±3.8 vs. 49.5±4.3 pg/mg protein; p < 0.01). Plasma VEGF levels (69±7.1 vs. 48±3.5 pg/ml) and visceral fat VEGF levels (424.4±39.5 vs. 208.5±22.4 pg/mg protein) were significantly increased in OVX/HF mice, compared to OVX/LF group, respectively (n=6; p < 0.01). Interestingly, adipose tissue primary culture showed that subcutaneous fat released more VEGF, compared to visceral fat (6.77±1.14 vs. 0.94±0.16 pg/mg tissue; n=6; p < 0.01). These findings support the hypothesis that postmenopausal obesity promotes tumor angiogenesis and breast cancer progression, possibly through increased adipose tissue mass and adipokines such as VEGF that could systemically and locally affect breast cancer progression.

Metabolic effects of obesity causing disease in childhood

PURPOSE OF REVIEW

Childhood obesity is rising to epidemic proportions throughout the world, and much emphasis has been placed on the long-term consequences that can result later, in adulthood. This article reviews the metabolic consequences of obesity that can manifest as disease during the childhood years.

RECENT FINDINGS

Obese children suffer from many disease processes once thought to affect only adults. They can have type 2 diabetes mellitus, and potentially early β cell failure with rapid progression to an insulin requirement. There is a high prevalence of fatty liver disease in obese children, and complications such as steatohepatitis and even cirrhosis can develop during childhood. Visceral fat has been shown to have many different properties than subcutaneous fat, and children with central adiposity can develop the metabolic syndrome with insulin resistance, hypertension, and dyslipidemia. Hyperandrogenism, sleep disturbances, and many types of orthopedic complications can also develop in young children.

SUMMARY

Physicians should not only warn obese children and their families about the long-term consequences of obesity for which they are at risk in adulthood, they should also screen for the many diseases that may already be present.

Associação entre variáveis antropométricas, perfil glicêmico e lipídico em mulheres idosas

OBJETIVO: Estudo transversal com o objetivo de associar variáveis antropométricas, perfil lipídico e glicêmico em 102 idosas de três centros de convivência para idosos do município de Cuiabá-MT, Brasil, com idade entre 60 e 84 anos. MÉTODOS: Avaliaram-se índice de massa corporal, relação cintura/quadril, circunferência abdominal, percentual de gordura, glicemia em jejum, glicemia pós-prandial, hemoglobina glicada, triglicérides, colesterol total, HDL-c e LDL-c. RESULTADOS: Houve associação significativa no grupo 60-69 anos, entre o IMC e glicemia de jejum; relação cintura-quadril e glicemia de jejum e glicemia pós-prandial; circunferência abdominal e glicemia de jejum e glicemia pós-prandial; para o grupo >70 anos, entre o percentual de gordura e colesterol total e a circunferência abdominal e glicemia pós-prandial. Regressão múltipla houve significância somente para o grupos >70anos: IMC e colesterol total; relação cintura-quadril com triglicérides e com colesterol total; circunferência abdominal com glicemia de jejum, com triglicérides, com colesterol total e com LDL-c. CONCLUSÃO: As variáveis antropométricas apresentam fragilidade para associação com a bioquímica sanguínea de idosas. Entretanto, os marcadores de gordura corporal parecem estar associados à piora bioquímica, sendo a circunferência da cintura a que mais se associa especialmente em relação às mais idosas.

Pioglitazone, but not metformin, reduces liver fat in Type-2 diabetes mellitus independent of weight changes

BACKGROUND

Pioglitazone (Pio) treatment induces weight gain in Type 2 diabetes mellitus (T2DM), which could worsen hepatic lipid accumulation, and alter adiponectin and high-sensitivity C-reactive protein (hs-CRP).

OBJECTIVE

To compare changes in hepatic lipid, serum adiponectin and hs-CRP in diabetics treated with Pio (with and without weight gain) against metformin (Met) treatment, which produces weight loss.

DESIGN

Fifty-one men and women with T2DM, naive to thiazolidinediones, entered a 16-week, open-label, parallel arm study, where participants were randomized to one of three groups: (1) Pio plus the American Diabetes Association diet (Pio+ADA); (2) Pio plus a portion control weight loss diet (Pio+PC), or (3) metformin plus ADA diet (Met+ADA).

METHODS

Hepatic lipid was assessed with abdominal computed tomography (CT) and the serum adiponectin and hs-CRP by enzyme-linked immunosorbent assay at baseline and study end.

RESULTS

Forty-eight subjects completed the study. The Pio+ADA group gained (mean+/-S.E.M.) 2.15+/-1.09 kg, while Pio+PC and Met+ADA group lost -2.59+/-1.25 and -3.21+/-0.7 kg, respectively. Pio-treated groups (Pio+ADA and Pio+PC) significantly decreased hepatic fat as indicated by increased liver density on CT scan [10.1+/-2.4: 11.4+/-1.0 Hounsfield units (HU)], compared with Met+ADA group (-2.4+/-3.1 HU). The Pio groups demonstrated significantly increased serum adiponectin, (8.6+/-1.5; 7.4+/-1.6 microg/ml) independent of weight change, compared to Met+ADA (-0.14+/-0.6 microgm/ml) group which lost weight. Serum hs-CRP decreased in groups showing weight loss (Pio+PC, -3.1+/-1.7 mg/l; Met+ADA, -1.5+/-1.2 mg/l) compared to Pio+ADA (1.8+/-3.0 mg/l) group that gained weight.

CONCLUSIONS

Pio treatment in T2DM significantly reduced hepatic lipid and increased adiponectin independent of weight change, while decreasing hs-CRP with weight loss.

Change in waist circumference over 11 years and current waist circumference independently predict elevated CRP in Filipino women

C-reactive protein, a marker of chronic, low-grade inflammation, is strongly associated with current central adiposity, and has been linked to elevated risk of cardiovascular disease. Less is known about the contribution of longitudinal change in waist circumference to current inflammation. We evaluated the extent to which current waist circumference and change over an 11-year interval contribute independently to low-grade systemic inflammation measured in a group of 1,294 women, 35-69 years, participating in the Cebu Longitudinal Nutrition and Health Survey in the Philippines. Waist circumference was measured at the time of blood draw for CRP analysis in 2005 and during an earlier survey in 1994. A waist circumference delta variable was constructed by subtracting current circumference from past circumference. We used logistic regression models to predict having an elevated plasma CRP concentration (3 mg L(-1) < CRP < 10 mg L(-1)). Waist circumference in 2005 was a strong predictor of elevated CRP (OR 1.10, 95% CI = 1.08, 1.12, P < 0.001). In combined models, increase in circumference over 11 years was a significant and independent predictor of elevated CRP risk (OR = 1.023, 95% CI = 1.00, 1.05, P < 0.05). Considering the average increase over time, the cumulative risk of elevated CRP due to increased central adiposity was 25.7%. However, women who reduced their waist circumference between 1994 and 2005 had greatly reduced risk (6.2%), suggesting that even long-term inflammatory burden can be reversed by weight loss. Although current waist circumference is an important contributor to risk of elevated systemic inflammation in this as in other populations, history of central adiposity may be an independent phenomenon.

Effects of castration-induced visceral obesity and antioxidant treatment on lipid profile and insulin sensitivity in New Zealand white rabbits

Molecular mechanisms, responsible for the impaired insulin-sensitivity state due to the obesity are not fully understood in both humans and animals. The purpose of this study was to investigate the effects of castration-induced visceral obesity and the influence of two antioxidants on constituents of blood lipid profile and insulin sensitivity in New Zealand white rabbits. Twenty-six clinically healthy male New Zealand white rabbits were used in the experiment and were divided into 3 groups: first group (CI, n=7) - castrated-obese and treated with antioxidants "Immunoprotect" for 2months; second group (CO, n=7) - castrated-obese; third group (NC, n=12) - control group (non-castrated, non-obese). At the end of the follow-up period of 2months after castration an intravenous glucose tolerance test (IVGTT) was performed after a 12-h fasting period as the blood samples for determination of glucose and insulin and their kinetic parameters were obtained at 5 and 0min before and at 5, 10, 30, 60 and 120min after the infusion of the glucose. The constituents of lipid profile, triglycerides (TG), total cholesterol (TC) and HDL-cholesterol (HDL-C) were also assessed in the overnight fasting blood samples. The body weight (BW), body mass index (BMI), amount of the visceral fat (VF) and VF/BW ratio were both measured and calculated before the IVGTT and at the end of the experimental period. All measured markers of obesity (BW, BMI, VF, VF/BW) were significantly higher in both groups of castrated rabbits than in the control group. Apart HDL-C, the plasma concentrations of all constituents of lipid profile (TG, TC, HDL-C) were the highest in CO group. There were generally no differences between CI and NC groups for the same traits. After glucose injection blood glucose concentrations and glucose and insulin kinetic parameters were considerably higher (except of glucose elimination rate) in CO rabbits than in NC ones. Castrated rabbits treated with "Immunoprotect" showed lower fasting plasma insulin and improved glucose kinetics dynamics than CO rabbits, but commensurable values of glucose and insulin kinetics parameters than NC group. The results of the current study clearly indicated that castration-induced visceral obesity affected negatively the lipid profile and insulin sensitivity and/or responsiveness. Treatment with antioxidant supplementation, consisted of d-limonene and vitamin E, improved blood lipid profile, fatty liver, glucose homeostasis and insulin sensitivity in obese rabbits. In addition, based on our results we may suggest that castrated male New Zealand white rabbits might be considered as an appropriate animal model to study various metabolic abnormalities related to visceral obesity, such as dyslipidemia and impaired insulin sensitivity.

High fat diet induces ceramide and sphingomyelin formation in rat's liver nuclei

Obesity increases the risk for hepatic steatosis. Recent studies have demonstrated that high fat diet (HFD) may affect sphingolipid formation in skeletal muscles, heart, and other tissues. In this work we sought to investigate whether HFD feeding provokes changes in content and fatty acids (FAs) composition of sphingomyelin and ceramide at the level of liver and hepatic nuclei. Furthermore, we investigated whether the ceramide formation is related to the activity of either neutral sphingomyelinase (N-SMase) or acidic sphingomyelinase (A-SMase). Three weeks of HFD provision induced pronounced ceramide and sphingomyelin accumulation in both liver and hepatic nuclei, accompanied by increased activity of N-SMase but not A-SMase. Furthermore, a shift toward greater FAs saturation status in these sphingolipids was also observed. These findings support the conclusion that HFD has a major impact on sphingolipid metabolism not only in the liver, but also in hepatic nuclei.

Leptin intake during the suckling period improves the metabolic response of adipose tissue to a high-fat diet

BACKGROUND

The intake of leptin during the suckling period protects against obesity and improves insulin and central leptin sensitivity in adult rats.

OBJECTIVE

We analyzed whether leptin treatment to neonates may also improve later peripheral leptin sensitivity in adipose tissue under high-fat (HF) diet conditions.

DESIGN

Male rats were supplemented with a daily oral dose of leptin or the vehicle (controls) during the suckling period. After weaning, animals were fed a normal-fat or an HF diet until the age of 6 months. At this age, mRNA and protein levels of the long-form leptin receptor (OB-Rb) and the expression of other genes related with energy metabolism were measured in various adipose depots (inguinal, mesenteric and retroperitoneal).

RESULTS

HF-diet feeding resulted in lower OB-Rb mRNA and protein levels in internal depots in controls but not in leptin-treated animals; these animals maintained OB-Rb mRNA and protein levels under HF-diet conditions in these depots, particularly in the mesenteric one, and this was accompanied by increased expression of genes related with energy uptake (GLUT4, CD36), fatty acid oxidation (peroxisome proliferator activated receptor-alpha (PPARalpha), CPT1, UCP3) and lipogenesis (PPARgamma, GPAT). Leptin-treatment also ameliorated HF-diet-induced hepatic fat accumulation occurring in control animals.

CONCLUSION

Leptin treatment during the suckling period may improve the lasting effects of HF-diet feeding on leptin receptor abundance in the adipose tissue and increase its oxidative capacity, resulting in a better handling and partitioning of excess fuel. This, together with the described improvement of central leptin sensitivity, may explain why these animals are more protected against diet-induced obesity and its metabolic-related disorders.

[Metabolic syndrome and aging]

In recent years, the current "obesity epidemic" and its correlate, metabolic syndrome, have been related not only to cardiovascular disease but also to the presence of multiple chronic diseases and even to the development of disability. Therefore, it has been hypothesized that this situation of risk and that of frailty, which has aroused such interest in geriatrics, could share common physiopathologic mechanisms. These mechanisms are reviewed in the present article.

Short-term dynamics and metabolic impact of abdominal fat depots after bariatric surgery

OBJECTIVE

Bariatric surgery is gaining acceptance as an efficient treatment modality for obese patients. Mechanistic explanations regarding the effects of bariatric surgery on body composition and fat distribution are still limited.

RESEARCH DESIGN AND METHODS

Intra-abdominal and subcutaneous fat depots were evaluated using computed tomography in 27 obese patients prior to and 6 months following bariatric surgery. Associations with anthropometric and clinical changes were evaluated.

RESULTS

Excess weight loss 6 months following surgery was 47% in male and 42.6% in female subjects. Visceral fat and subcutaneous fat were reduced by 35% and 32%, respectively, in both sexes, thus the visceral-to-subcutaneous fat ratio remained stable. The strongest relation between absolute and relative changes in visceral and subcutaneous fat was demonstrated for the excess weight loss following the operations (r approximately 0.6-0.7), and these relations were strengthened further following adjustments for sex, baseline BMI, and fat mass. Changes in waist circumference and fat mass had no relation to changes in abdominal fat depots. All participants met the criteria of the metabolic syndrome at baseline, and 18 lost the diagnosis on follow-up. A lower baseline visceral-to-subcutaneous fat ratio (0.43 +/- 0.15 vs. 0.61 +/- 0.21, P = 0.02) was associated with clinical resolution of metabolic syndrome parameters.

CONCLUSIONS

The ratio between visceral and subcutaneous abdominal fat remains fairly constant 6 months following bariatric procedures regardless of sex, procedure performed, or presence of metabolic complications. A lower baseline visceral-to-abdominal fat ratio is associated with improvement in metabolic parameters.

High-speed vibrational imaging and spectral analysis of lipid bodies by compound Raman microscopy

Cells store excess energy in the form of cytoplasmic lipid droplets. At present, it is unclear how different types of fatty acids contribute to the formation of lipid droplets. We describe a compound Raman microscope capable of both high-speed chemical imaging and quantitative spectral analysis on the same platform. We used a picosecond laser source to perform coherent Raman scattering imaging of a biological sample and confocal Raman spectral analysis at points of interest. The potential of the compound Raman microscope was evaluated on lipid bodies of cultured cells and live animals. Our data indicate that the in vivo fat contains much more unsaturated fatty acids (FAs) than the fat formed via de novo synthesis in 3T3-L1 cells. Furthermore, in vivo analysis of subcutaneous adipocytes and glands revealed a dramatic difference not only in the unsaturation level but also in the thermodynamic state of FAs inside their lipid bodies. Additionally, the compound Raman microscope allows tracking of the cellular uptake of a specific fatty acid and its abundance in nascent cytoplasmic lipid droplets. The high-speed vibrational imaging and spectral analysis capability renders compound Raman microscopy an indispensible analytical tool for the study of lipid-droplet biology.