Epidemiology of paediatric metabolic syndrome and type 2 diabetes mellitus

The Banishing Obesity and Diabetes in Youth (BODY) Project: description and feasibility of a program to halt obesity-associated disease among urban high school students

Type 2 diabetes (T2DM) and cardiovascular disease (CVD) are rising dramatically in adolescents in parallel with excess weight. The Banishing Obesity and Diabetes in Youth (BODY) Project, is a school-based intervention that medically screens overweight and obese high school students, provides personalized feedback, and connects to appropriate healthcare. Body mass index (BMI) was determined for 1,526 students in one New York City public high school with a school-based health center (SBHC). Overweight and obese students (n = 640) were invited to complete a medical evaluation that included a survey, blood pressure and blood tests. 328/640 (51%) eligible students returned signed parental consent and participated. All participants received a personalized report detailing their results along with specific recommendations on how to improve their health. Parents of participants with results outside healthy ranges (82%; 270/328) were called and mailed referral letters to connect with healthcare services. Project staff reached by telephone 74% (199/270) of those families and 29% (58/199) stated that the report led them to make arrangements to see a healthcare provider. Most students (83%; 273/328) were registered at the SBHC, and we shared their medical results with them so they could follow-up with the students. The BODY Project is a feasible program for urban schools with a SBHC. This may allow effective prevention of T2DM, and CVD from dyslipidemia and hypertension.

Risco cardiovascular e prática de atividade física em crianças e adolescentes de Muzambinho/MG: influência do gênero e da idade

INTRODUÇÃO E OBJETIVO: A doença cardiovascular inicia na infância e está atrelada à presença de fatores de risco cardiovascular (FRC). A prevalência desses fatores varia em diferentes populações brasileiras, tendo sido estudada principalmente em cidades de médio e grande porte. Este estudo avaliou a prevalência dos FRC e da prática de atividade física (AF) em crianças e adolescentes de Muzambinho, uma cidade de pequeno porte. MÉTODO: Foram avaliados 205 sujeitos (entre sete e 18 anos - 108 do gênero masculino). Foram medidos: peso, estatura, glicemia, colesterolemia, pressão arterial (PA) e prática de AF. As comparações foram realizadas pelo teste do Qui-quadrado. RESULTADOS: A prevalência de sobrepeso foi de 19% e de valores alterados de PA, glicemia e colesterolemia foram de, respectivamente, 11, 5 e 15%. Não houve diferença na prevalência dos FRC entre os sexos. O tabagismo, o alcoolismo, a PA alterada e a insuficiência de AF aumentaram com a idade. Setenta e nove por cento dos sujeitos praticavam AF de locomoção, 10% ocupacional, 97% nas aulas de educação física, 72% no recreio e 90% de lazer. Noventa e dois por cento foram considerados ativos. A prática de AF ocupacional foi maior nas meninas e aumentou nos meninos com a idade. A prevalência de AF de lazer e recreio diminuiu com a idade nos dois sexos. CONCLUSÃO: A prevalência de FRC, exceto do sedentarismo, foi expressiva, não diferiu entre os sexos e aumentou com a idade. A prática de AF de todos os tipos foi alta, diferenciou-se entre os sexos e diminuiu com a idade.

Prevalência de alterações metabólicas em crianças e adolescentes com sobrepeso e obesidade: uma revisão sistemática

OBJETIVO: Descrever a prevalência de síndrome metabólica em crianças e adolescentes com sobrepeso ou obesidade bem como os critérios utilizados em sua classificação. FONTES DOS DADOS: Revisão sistemática realizada por meio de busca eletrônica nas bases de dados Pubmed e na Biblioteca Virtual em Saúde. Os critérios de inclusão ado-tados foram apresentar dados de prevalência de síndrome metabólica em crianças e adolescentes com sobrepeso e obesidade, sendo publicados em português, inglês, espanhol e francês. Foram excluídos artigos de revisão, comunica-ção breve e estudos em populações com doenças de base (genética, endócrina, imunológica, hipertensão primária e presença de acantose). SÍNTESE DOS DADOS: Foram levantados 1.226 resumos, sendo selecionados 65 artigos para análise na íntegra, dos quais 46 atendiam os critérios mencionados no período de 2003 a 2009, representando cinco regiões geográficas: América do Norte (33%), América do Sul (20%), América Central (4%), Ásia (30%) e Europa (13%). As prevalências descritas variaram de 2,1 a 58,3%, sendo 31,2% a prevalência mediana. Houve divergência nos critérios, com 26 estudos usando os mesmos componentes (triglicerídeos, HDL, glico-se, circunferência de cintura e pressão arterial), sem consenso nos pontos de corte adotados. Nos demais estudos, houve inclusão de glicemia pós-prandial, índice de massa corporal, colesterol, e índice HOMA-IR. CONCLUSÕES: A prevalência descrita de síndrome metabólica em crianças e adolescentes na literatura apresentou uma ampla variabilidade, ocorrendo heterogeneidade na escolha das variáveis empregadas na definição dos componentes da doença, bem como nos pontos de corte adotados.

[Long term outcome in children of mothers with gestational diabetes]

OBJECTIVES

To appreciate, in epidemiological studies, the impact of fetal exposure to gestational diabetes on the long term outcome of the offspring (type 2 diabetes, overweight and obesity, metabolic syndrome and neurological complications).

METHODS

A systematic search was conducted in Medline between January 1990 and April 2010. Prospective studies (follow-up of the offspring born of mothers with gestational diabetes) and retrospective studies (questionnaire about the parents'history of diabetes in diabetic patients) were searched and analysed.

RESULTS

The fetal exposure to maternal gestational diabetes is a moderate risk factor for metabolic syndrome in the offspring. But some other perinatal risk factors of metabolic syndrome carry a bigger influence. The influence of genetic factors and maternal overweight may not be easily distinguished from the impact of fetal exposure to gestational diabetes.

CONCLUSION

It remains uncertain if the control of maternal glycemia alone may be effective and sufficient to prevent the metabolic syndrome in the adult-aged offspring.

Differences in male and female adolescents from various racial groups in the relationship between insulin resistance-associated parameters with sugar-sweetened beverage intake and physical activity levels

OBJECTIVE

To describe racial and gender differences in insulin resistance-associated parameters due to sugar-sweetened beverage (SSB) intake and physical activity (PA) levels in the adolescent population.

METHODS

Data from individuals aged 12 to 19 years from the National Health and Nutrition Examination Survey during the years 1999-2004 were analyzed. SSB intake and PA levels were evaluated in Non-Hispanic whites, Non-Hispanic blacks, and Mexican Americans. Outcome measures included measurements of insulin sensitivity, lipids, blood pressure, waist circumference, and body mass index.

RESULTS

Multivariate linear regression analyses showed that anthropometric measurements, metabolic parameters, and indices of insulin resistance differed among the racial groups. Moreover, within each of these racial groups, they differed between the sexes.

CONCLUSIONS

The differing relationships between insulin resistance-associated parameters and SSB intake and PA levels among racial groups and between the sexes illustrate the importance of race and gender in the investigation of diseases such as obesity and metabolic syndrome.

Pretransplant risk factors for new-onset diabetes mellitus after transplant in pediatric liver transplant recipients

Our objectives are to examine the incidence of new-onset diabetes mellitus after transplant (NODAT) and to identify its risk factors in pediatric liver transplant recipients using the Organ Procurement and Transplant Network/United Network for Organ Sharing database. Between July 2004 and December 2008, a total of 1214 children (2-20 years old) received their first liver transplant alone, and had at least 1 follow-up report of posttransplant diabetic status. Among these, 1161 recipients were identified as not having diabetes mellitus before transplant. Risk factors for NODAT were examined using classification and regression tree and multivariate Cox regression analysis. Diabetes mellitus was newly reported in 10.1% of the 1161 recipients over the median follow-up time of 770 days. The cumulative incidences of NODAT at 1, 2, and 3 years after transplant were 5.9%, 8.3%, and 11.2%, respectively. More than 50% of recipients with cystic fibrosis developed NODAT. In recipients without cystic fibrosis, independent risk factors for NODAT included increased recipient age (compared to 2-5 years, hazard ratio = 3.09 for 5-13 years, p = 0.02; 7.14 for ≥13 years, p < 0.001), African American race (1.97, p = 0.003), and primary diagnosis of primary sclerosing cholangitis (2.24, p = 0.02) and acute hepatic necrosis (1.89, p = 0.04). In conclusion, NODAT occurred in one-tenth of pediatric liver transplant recipients in the United States during the median follow-up of 2 years. Some of the risk factors for NODAT in pediatric liver transplant recipients are similar to those reported in other solid organ transplants. Underlying liver disease of cystic fibrosis, primary sclerosing cholangitis, and acute hepatic necrosis are independent risk factors for NODAT in pediatric liver transplant recipients.

Targeting the pre-receptor metabolism of cortisol as a novel therapy in obesity and diabetes

Due to its impact upon health and the economy, the mechanisms that contribute to the pathogenesis of obesity and the metabolic syndrome are under intense scrutiny. In addition to understanding the pathogenesis of disease it is important to design and trial novel therapies. Patients with cortisol excess, Cushing's syndrome, have a phenotype similar to that of the metabolic syndrome and as a result there is much interest the manipulation of glucocorticoid (GC) action as a therapeutic strategy. Intracellular GC levels are regulated by 11β-hydroxysteroid dehydrogenase (11β-HSD1) which converts inactive cortisone to cortisol, thereby increasing local GC action. There is an abundance of data implicating 11β-HSD1 in the pathogenesis of obesity, type 2 diabetes and the metabolic syndrome and 11β-HSD1 is an attractive therapeutic target. Selective 11β-HSD1 inhibitors, which do not act upon 11β-HSD2 (which inactivates cortisol to cortisone) are in development. So far studies have primarily been carried out in rodents, with results showing improvements in metabolic profile. Data are now beginning to emerge from human studies and the results are promising.

Peroxisome proliferator-activated receptors, metabolic syndrome and cardiovascular disease

Metabolic syndrome (MetS) is a constellation of risk factors including insulin resistance, central obesity, dyslipidemia and hypertension that markedly increase the risk of Type 2 diabetes (T2DM) and cardiovascular disease (CVD). The peroxisome proliferators-activated receptor (PPAR) isotypes, PPARα, PPARδ/ß and PPARγ are ligand-activated nuclear transcription factors, which modulate the expression of an array of genes that play a central role in regulating glucose, lipid and cholesterol metabolism, where imbalance can lead to obesity, T2DM and CVD. They are also drug targets, and currently, PPARα (fibrates) and PPARγ (thiazolodinediones) agonists are in clinical use for treating dyslipidemia and T2DM, respectively. These metabolic characteristics of the PPARs, coupled with their involvement in metabolic diseases, mean extensive efforts are underway worldwide to develop new and efficacious PPAR-based therapies for the treatment of additional maladies associated with the MetS. This article presents an overview of the functional characteristics of three PPAR isotypes, discusses recent advances in our understanding of the diverse biological actions of PPARs, particularly in the vascular system, and summarizes the developmental status of new single, dual, pan (multiple) and partial PPAR agonists for the clinical management of key components of MetS, T2DM and CVD. It also summarizes the clinical outcomes from various clinical trials aimed at evaluating the atheroprotective actions of currently used fibrates and thiazolodinediones.

Association between serum uric acid levels and cardiometabolic risk factors among Japanese junior high school students

BACKGROUND

The present study was designed to examine whether serum uric acid (SUA) levels were associated with cardiometabolic risk factors and to determine optimal cut-offs for SUA to identify multiple risk factors among Japanese junior high school students.

METHODS AND RESULTS

A total of 958 students (518 boys and 440 girls, aged 12.1-15.0 years) who were enrolled between April 2005 and June 2008 were divided into 4 groups according to SUA quartiles. Compared with the lowest quartile of SUA, prevalence of abdominal obesity, hypertension, and dyslipidemia was significantly increased in the highest quartile in boys and that of abdominal obesity was increased in the highest quartile in girls. The adjusted odds ratios (95% confidence interval) of the highest quartile of SUA for 2 or more cardiometabolic risk factors were 2.59 (1.16-5.79) for boys and 1.54 (0.43-5.56) for girls. Receiver operating characteristic curve analysis demonstrated that the most appropriate cut-offs for SUA to identify multiple cardiometabolic risk factors were 6.4 mg/dl for boys and 4.9 mg/dl for girls.

CONCLUSIONS

SUA was strongly associated with the prevalence of cardiometabolic risk factors among male Japanese junior high school students. The present study may provide insights into the role of SUA in the school screening system for the development of educational programs on prevention of lifestyle-related diseases among school children.

Metabolic syndrome in overweight children from the city of Botucatu - São Paulo State - Brazil: agreement among six diagnostic criteria

BACKGROUND

The metabolic syndrome has been described in children; however, a standard criterion has not been established for its diagnosis. Also, few studies have been conducted to specifically observe the possible existence of agreement among the existing diagnostic criteria. The purpose of the study is to evaluate agreement concerning prevalence rates of the metabolic syndrome diagnosed by six different criteria in overweight schoolchildren in the city of Botucatu - SP -Brazil.

METHODS

This is a cross-sectional study on 128 overweight schoolchildren. Clinical examination included anthropometry, pubertal staging evaluation, and blood pressure. Triacylglycerol, glycemia, HDL-cholesterol, insulin levels, and HOMA-IR were determined. The Kappa index, the Mann-Whitney test and the chi-square test were used for statistical analysis.

RESULTS

The prevalence of the metabolic syndrome varied from 10 to 16.5% according to different diagnostic criteria. Results were similar for boys and girls and pubertal stage. Great agreement was observed among the six different diagnostic criteria for the metabolic syndrome.

CONCLUSIONS

Different diagnostic criteria, when adopted for subjects with similar demographic characteristics, generate similar and compatible prevalence. Results suggest that it is possible to adopt any of the analyzed criteria, and the choice should be according to the components available for each situation.

Dietary patterns and markers for the metabolic syndrome in Australian adolescents

BACKGROUND AND AIMS

Overweight and other risk factors for cardiovascular disease (CVD) as well as their clustering, are increasingly prevalent among adolescents. We examined dietary patterns, CVD risk factors, and the clustering of these risk factors in 1139 14-year-olds living in Western Australia.

METHODS AND RESULTS

Usual dietary intake was assessed using a food frequency questionnaire. Two dietary patterns, 'Western' and 'Healthy', were identified using factor analysis. Associations between these dietary patterns and BMI, waist circumference, systolic blood pressure, fasting levels of serum glucose, insulin, total cholesterol, HDL-C, LDL-C, triglycerides and insulin resistance were assessed using ANOVA. Cluster analysis identified a high risk group (the 'high risk metabolic cluster') with features akin to adult metabolic syndrome. Belonging to the 'high risk metabolic cluster' was examined in relation to dietary patterns using logistic regression, adjusting for aerobic fitness and socio-demographic factors. Higher 'Western' dietary pattern scores were associated with greater odds for the 'high risk metabolic cluster' (p for trend=0.02) and greater mean values for total cholesterol (p for trend=0.03), waist circumference (p for trend=0.03) and BMI (p for trend=0.02) in girls, but not boys. Scores for the 'Healthy' dietary pattern were not related to the 'high risk metabolic cluster' but were inversely associated with serum glucose in boys and girls (p for trend=0.01 and 0.04, respectively) and were positively associated with HDL-C in boys (p for trend=0.02).

CONCLUSIONS

Dietary patterns are associated with CVD risk factors and the clustering of these risk factors in adolescence.

Early overnutrition results in early-onset arcuate leptin resistance and increased sensitivity to high-fat diet

Childhood obesity increases the risk of adult obesity and diabetes, suggesting that early overnutrition permanently programs altered energy and glucose homeostasis. In the present studies, we used a mouse model to investigate whether early overnutrition increases susceptibility to obesity and insulin resistance in response to a high-fat diet (HFD). Litters from Swiss Webster dams were culled to three [chronic postnatal overnutrition (CPO)] or 10 (control) pups and then weaned onto standard chow at postnatal day (P) 23. At 6 wk of age, a subset of mice was placed on HFD, and glucose and insulin tolerance were examined at 16-17 wk of age. Leptin sensitivity was determined by hypothalamic phosphorylated signal transducer and activator of transcription-3 immunoreactivity at P16 and adulthood after ip leptin. CPO mice exhibited accelerated body weight gain and hyperleptinemia during the preweaning period but only a slightly heavier body weight and normal glucose tolerance in adulthood on standard chow diet. Importantly, CPO mice exhibited significant leptin resistance in the arcuate nucleus, demonstrated by reduced activation of phospho-signal transducer and activator of transcription-3, as early as P16 and throughout life, despite normalized leptin levels. In response to HFD, CPO but not control mice displayed insulin resistance in response to an insulin tolerance test. In conclusion, CPO mice exhibited early and persistent leptin resistance in the arcuate nucleus and, in response to HFD, rapid development of obesity and insulin resistance. These studies suggest that early overnutrition can permanently alter energy homeostasis and significantly increase susceptibility to obesity and insulin resistance.

Critical determinants of hypothalamic appetitive neuropeptide development and expression: species considerations

Over the last decade there has been a striking increase in the early onset of metabolic disease, including obesity and diabetes. The regulation of energy homeostasis is complex and involves the intricate integration of peripheral and central systems, including the hypothalamus. This review provides an overview of the development of brain circuitry involved in the regulation of energy homeostasis as well as recent findings related to the impact of both prenatal and postnatal maternal environment on the development of these circuits. There is surprising evidence that both overnutrition and undernutrition impact the development of these circuits in a similar manner as well as having similar consequences of increased obesity and diabetes later in life. There is also a special focus on relevant species differences in the development of hypothalamic circuits. A deeper understanding of the mechanisms involved in the development of brain circuitry is needed to fully understand how the nutritional and/or maternal environments impact the functional circuitry as well as the behavior and physiological outcomes.

Hypoadiponectinemia in overweight children contributes to a negative metabolic risk profile 6 years later

Prognostic biomarkers are needed to identify children at increased cardiometabolic risk. The objective was to study whether markers of metabolism and inflammation, for example, circulating plasma adiponectin, leptin, interleukin-8, and hepatocyte growth factor, are associated with cardiometabolic risk factors in childhood and adolescence. This was a cross-sectional and prospective study, and the setting was the Danish part of the European Youth Heart Studies I and II. Participants were randomly selected girls and boys 8 to 10 years of age with complete baseline data (n = 256) and complete follow-up data 6 years later (n = 169). Cardiometabolic risk profile was calculated using a continuous composite score derived from summing of 6 factors standardized to the sample means (Z scores): body mass index, homeostasis model assessment of insulin resistance, total serum cholesterol to serum high-density lipoprotein cholesterol ratio, serum triglycerides, systolic blood pressure, and the reciprocal value of fitness (maximum watts per kilogram). Overweight was defined using international classification of body mass index cutoff points for children. Plasma adiponectin, leptin, interleukin-8, and hepatocyte growth factor were assessed using immunochemical assays. Linear relationships were found between metabolic risk score and both plasma adiponectin (inverse, P = .02) and plasma leptin (P < .0001) at baseline after adjustment for several confounders. In overweight but not normal-weight children, plasma adiponectin at baseline was inversely associated with metabolic risk score 6 years later (P = .04). In childhood, both hypoadiponectinemia and hyperleptinemia accompany a negative metabolic risk profile. In addition, circulating plasma adiponectin may be a useful biomarker to identify overweight children at greater future risk of the cardiometabolic adverse effects of overweight.

The Influence of Exercise on Metabolic Syndrome in Youth: A Review

The metabolic syndrome (MetS) is a clustering of dyslipidemia, hypertension, glucose intolerance, and central obesity or waist circumference that places individuals at high risk for developing cardiovascular or heart disease. Although first characterized in adults, it has been found in children, but the definition of MetS in children is still controversial. Although MetS is most closely associated with obesity in children, 2 factors believed to affect MetS are physical activity (PA) and aerobic power or fitness. Studies using accelerometry to estimate PA of children have shown that low levels are associated with increased risk of developing MetS. Conversely, high levels of PA at moderate to vigorous intensities reduce the risk. Similarly, low levels of aerobic fitness increase the likelihood of developing MetS. These effects appear to be independent of obesity. Studies have also shown that interventions that increase PA levels and improve aerobic fitness cause a reduction in MetS risk; however, an exact prescription for exercise cannot be presently provided. This review provides an in-depth analysis of what is presently known about the relationship between MetS and PA and aerobic fitness in children. In addition, information is presented regarding potential mechanisms for exercise to affect the major markers of MetS.

Sugar-Sweetened Beverage Intake Trends in US Adolescents and Their Association with Insulin Resistance-Related Parameters

The purpose of this study was to evaluate current sugar-sweetened beverage (SSB) consumption trends and their association with insulin resistance-related metabolic parameters and anthropometric measurements by performing a cross-sectional analysis of the NHANES data during the years 1988–1994 and 1999–2004. Main outcome measures included SSB consumption trends, a homeostasis model assessment of insulin resistance, blood pressure, waist circumference, body mass index, and fasting concentrations of total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides. Although overall SSB consumption has increased, our data suggest that this increase was primarily due to an increase in the amount of SSBs consumed by males in the high-SSB intake group alone. Multivariate linear regression analyses also showed that increased SSB consumption was independently associated with many adverse health parameters. Factors other than SSB consumption must therefore be contributing to the increasing prevalence of obesity and metabolic syndrome in the majority of US children.

Nitric oxide and clustering of metabolic syndrome components in pediatrics

This study was performed to determine the risk factor pattern of the metabolic syndrome (MetS) in association with serum nitric oxide metabolites (NO(x)) in children and adolescents. The study included 851 children and adolescents, aged 4-19 years. The MetS was defined according to modified Adult treatment Panel III criteria. Cluster analysis was performed using principle components analysis with varimax orthogonal rotation to examine the risk factor pattern of the MetS. The prevalence of MetS was 10.8 and 10.0% in males and females, respectively. Age-and sex-adjusted odds ratio of having MetS was significantly higher in the upper quartile of NO(x) compared to the lower quartile (2.2, 95% CI: 1.1-4.7, p = 0.029). In the whole population, three factors were identified including blood pressure/obesity, lipid/obesity, and glucose/NO(x). Stratifying for sex, again three factors were retained; however, in males NO(x) was loaded in two factors. In conclusion, serum NO( x ) was associated and loaded with other MetS components in cluster analysis of metabolic risk factors.

Metformin in combination with structured lifestyle intervention improved body mass index in obese adolescents, but did not improve insulin resistance

This study assessed the efficacy of adding metformin to a structured lifestyle intervention in reducing BMI in obese adolescents with insulin resistance. Obese adolescents (25) aged 10-16 years with a body mass index (BMI) > 95th percentile and insulin resistance (Homeostasis Model Assessment-HOMA) > 3.0 were assessed in a community clinic. A structured lifestyle intervention comprising nutritional and exercise education and motivational support in both individual and group sessions was delivered over 6 months. Subjects were randomized to lifestyle intervention alone or with metformin (1500 g daily). The primary outcome measures were a change in BMI and modification of metabolic risk factors, including insulin resistance, plasma lipids and adipocytokines. Eleven adolescents receiving lifestyle and metformin intervention and 14 receiving lifestyle alone completed the study. BMI decreased by 1.8 kg/m(2) with lifestyle and metformin but did not change with lifestyle alone. HOMA was significantly decreased in the lifestyle intervention group, but not following metformin, while the adiponectin/leptin ratio improved significantly in both groups. Dyslipidemic profiles improved most significantly with metformin. We conclude that metformin in combination with a 6-month structured lifestyle intervention is effective in reducing BMI in obese adolescents but did not improve insulin resistance. Lifestyle intervention, with or without metformin, improved metabolic risk factors such as plasma lipids and adipocytokines.

Endocrine-disrupting chemicals: an Endocrine Society scientific statement

There is growing interest in the possible health threat posed by endocrine-disrupting chemicals (EDCs), which are substances in our environment, food, and consumer products that interfere with hormone biosynthesis, metabolism, or action resulting in a deviation from normal homeostatic control or reproduction. In this first Scientific Statement of The Endocrine Society, we present the evidence that endocrine disruptors have effects on male and female reproduction, breast development and cancer, prostate cancer, neuroendocrinology, thyroid, metabolism and obesity, and cardiovascular endocrinology. Results from animal models, human clinical observations, and epidemiological studies converge to implicate EDCs as a significant concern to public health. The mechanisms of EDCs involve divergent pathways including (but not limited to) estrogenic, antiandrogenic, thyroid, peroxisome proliferator-activated receptor gamma, retinoid, and actions through other nuclear receptors; steroidogenic enzymes; neurotransmitter receptors and systems; and many other pathways that are highly conserved in wildlife and humans, and which can be modeled in laboratory in vitro and in vivo models. Furthermore, EDCs represent a broad class of molecules such as organochlorinated pesticides and industrial chemicals, plastics and plasticizers, fuels, and many other chemicals that are present in the environment or are in widespread use. We make a number of recommendations to increase understanding of effects of EDCs, including enhancing increased basic and clinical research, invoking the precautionary principle, and advocating involvement of individual and scientific society stakeholders in communicating and implementing changes in public policy and awareness.

Relationship between insulin resistance-associated metabolic parameters and anthropometric measurements with sugar-sweetened beverage intake and physical activity levels in US adolescents: findings from the 1999-2004 National Health and Nutrition Examination Survey

OBJECTIVE

To evaluate the relationship between insulin resistance-associated metabolic parameters and anthropometric measurements with sugar-sweetened beverage intake and physical activity levels.

DESIGN

A cross-sectional analysis of the National Health and Nutrition Examination Survey data collected by the National Center for Health Statistics.

SETTING

Nationally representative samples of US adolescents participating in the National Health and Nutrition Examination Survey during the years 1999-2004.

PARTICIPANTS

A total of 6967 adolescents aged 12 to 19 years.

MAIN EXPOSURE

Sugar-sweetened beverage consumption and physical activity levels.

OUTCOME MEASURES

Glucose and insulin concentrations, a homeostasis model assessment of insulin resistance (HOMA-IR), total, high-density lipoprotein, and low-density lipoprotein cholesterol concentrations, triglyceride concentrations, systolic and diastolic blood pressure, waist circumference, and body mass index (calculated as weight in kilograms divided by height in meters squared) percentile for age and sex.

RESULTS

Multivariate linear regression analyses showed that increased sugar-sweetened beverage intake was independently associated with increased HOMA-IR, systolic blood pressure, waist circumference, and body mass index percentile for age and sex and decreased HDL cholesterol concentrations; alternatively, increased physical activity levels were independently associated with decreased HOMA-IR, low-density lipoprotein cholesterol concentrations, and triglyceride concentrations and increased high-density lipoprotein cholesterol concentrations. Furthermore, low sugar-sweetened beverage intake and high physical activity levels appear to modify each others' effects of decreasing HOMA-IR and triglyceride concentrations and increasing high-density lipoprotein cholesterol concentrations.

CONCLUSIONS

Sugar-sweetened beverage intake and physical activity levels are each independently associated with insulin resistance-associated metabolic parameters and anthropometric measurements in adolescents. Moreover, low sugar-sweetened beverage intake and high physical activity levels appear to modify each others' effects on several health-related outcome variables.

Who should be targeted for CKD screening? Impact of diabetes, hypertension, and cardiovascular disease

To address the highly complex interrelated nature of chronic kidney disease (CKD) and diabetes, hypertension, and cardiovascular disease, we examined CKD prevalence by the predictive effect of demographic factors, comorbid conditions, and CKD risk factors by using National Health and Nutrition Examination Survey (NHANES) 1999-2004 data. NHANES is a nationally representative cross-sectional series of surveys with a complex stratified multistage sampling design. NHANES 1999-2004 participants (n = 15,332; age > or = 20 years) were interviewed in their homes and asked to participate in standardized medical examinations in mobile centers and provide samples for laboratory tests. Weighted logistic regression modeling was used to assess the importance of individual CKD risk factors. Multiple logistic regressions were performed on patient cohorts, with increasing levels of CKD severity defined by means of estimated glomerular filtration rate. A branching diagram was constructed to address the distribution of CKD grouped by diabetes, hypertension, and cardiovascular disease status. CKD prevalence increases with age (39.2% for age > or = 60 years). For ages 20 to 59 years, CKD prevalence was greater for participants with diabetes (33.8%) than for those without diabetes (8.2%) and for participants with both diabetes and hypertension (43%) than for diabetic participants without hypertension (25.5%) or nondiabetic participants with hypertension (15.2%). The prevalence was 6.8% for nondiabetic participants without hypertension. Effects of cardiovascular disease are less dramatic when hypertension and diabetes are considered. A CKD screening approach targeting individuals 60 years and older or those with diabetes or hypertension likely would be useful from a public health standpoint.

Objectively measured physical activity in urban alternative high school students

INTRODUCTION

Alternative high school (AHS) students are an underserved population of youth at greater risk for poor health behaviors and outcomes. Little is known about their physical activity patterns.

PURPOSE

: The purpose of this study was to describe 1) physical activity levels of students attending alternative high schools (AHS) in St. Paul/Minneapolis, MN, and 2) compliance with wearing a physical activity accelerometer.

METHODS

Sixty-five students (59% male, 65% <18 yr old, 51% African American, 17% Caucasian, 32% mixed and other) wore an accelerometer during all waking hours for 7 d as part of the baseline assessment for a school-based physical activity and dietary behavior intervention. Accelerometer data were reduced to summary variables using a custom software program. Compliance with wearing the accelerometer was assessed by the number of days with >or=10 h of data. Accelerometer counts per minute and minutes spent in moderate-to-vigorous physical activity (MVPA) were calculated.

RESULTS

Students averaged 323 +/- 143.0 counts min(-1) and 51 +/- 25.5 min d(-1) of MVPA. Minutes of MVPA d(-1) were greater on weekdays compared with the weekend (52 +/- 27.3 vs 43 +/- 39.7 min d(-1), respectively; P = 0.05). However, students wore the accelerometer less on the weekends (weekdays = 17.2 +/- 3.0, weekend = 14.9 +/- 6.8 h d(-1)). Expressing minutes of MVPA as a percentage of the number of minutes of available data, students spent approximately 5% of their time in MVPA on weekdays and weekends. Forty-five percent of students had 7 d of data, 51% had 4-6 d, and 5% had fewer than 4 d. On average, students wore the accelerometer for 17 +/- 3.2 h d(-1) (range = 12.0-23.8 h d(-1)).

CONCLUSION

Compliance was high (95% of students provided at least 4 d of data), and physical activity was relatively low representing a vulnerable population in need of further study and intervention.

Adolescents with metabolic syndrome have a history of low aerobic fitness and physical activity levels

Purpose

Metabolic syndrome (MS) is a clustering of cardiovascular disease risk factors that identifies individuals with the highest risk for heart disease. Two factors that may influence the MS are physical activity and aerobic fitness. This study determined if adolescent with the MS had low levels of aerobic fitness and physical activity as children.

Methods

This longitudinal, exploratory study had 389 participants: 51% girls, 84% Caucasian, 12% African American, 1% Hispanic, and 3% other races, from the State of North Carolina. Habitual physical activity (PA survey), aerobic fitness (VO₂max), body mass index (BMI), blood pressure, and lipids obtained at 7–10 y of age were compared to their results obtained 7 y later at ages 14–17 y.

Results

Eighteen adolescents (4.6%) developed 3 or more characteristics of the MS. Logistic regression, adjusting for BMI percentile, blood pressure, and cholesterol levels, found that adolescents with the MS were 6.08 (95%CI = 1.18–60.08) times more likely to have low aerobic fitness as children and 5.16 (95%CI = 1.06–49.66) times more likely to have low PA levels.

Conclusion

Low levels of childhood physical activity and aerobic fitness are associated with the presence of the metabolic syndrome in adolescents. Thus, efforts need to begin early in childhood to increase exercise.