Frequency of abnormal carbohydrate metabolism and diabetes in a population-based screening of adolescents

Gender differences in the relationships among obesity, adiponectin and brachial artery distensibility in adolescents and young adults

BACKGROUND

Obesity-related cardiovascular diseases (CVDs) are a major cause of cardiovascular (CV) mortality. Obesity-related reduction in vascular protective adipose-derived proteins, such as adiponectin (APN), has an important role.

METHODS

We compared brachial artery distensibility (BrachD) with APN, the level of adiposity and other CV risk factors (CVRFs) in 431 post-pubertal subjects (mean 17.9 years). Gender differences in average values were examined by t-tests. Correlations among BrachD, obesity and other CVRFs were examined. Regression analysis was performed to determine whether APN provided an independent contribution to BrachD, while controlling for obesity and other CVRFs.

RESULTS

Male subjects had lower BrachD (5.72+/-1.37 vs 6.45+/-1.60% change per mm Hg, P<0.0001) and lower APN (10.50+/-4.65 vs 13.20+/-6.53; all P<0.04) than female subjects. BrachD correlated with APN (r=0.25, P< 0.0001). Both BrachD and APN correlated with measures of body size, including height, weight and body mass index (BMI). Both correlated with higher systolic blood pressure, glucose, insulin and lower high-density lipoprotein cholesterol (all P<0.01). In multivariate analysis, APN, gender, APN*gender and BMI z-score predicted BrachD (r(2)=0.305). On the basis of gender difference, only BMI z-score was significant for male subjects (r(2)=0.080), whereas APN and BMI z-score contributed for female subjects (r(2)=0.242, all P<0.0001).

CONCLUSIONS

BrachD is independently influenced by obesity in both male and female subjects. In female subjects, APN exerts an additional independent effect even after adjusting for blood pressure (BP), lipid levels and insulin. Differences in the effect of the APN-adiposity relationship on obesity-related vascular disease may be one reason for gender differences in the development and progression of atherosclerosis.

Risk factors for type 2 diabetes in a sixth- grade multiracial cohort: the HEALTHY study

OBJECTIVE

HEALTHY is a 3-year middle school intervention program designed to reduce risk factors for type 2 diabetes. The prevalence of diabetes risk factors at baseline in a cohort of 6,358 sixth-grade students is reported.

RESEARCH DESIGN AND METHODS

Forty-two schools at seven U.S. sites were randomly assigned to intervention or control. Students participated in baseline data collection during fall of 2006.

RESULTS

Overall, 49.3% of children had BMI >or=85th percentile, 16.0% had fasting blood glucose >or=100 mg/dl (<1% had fasting blood glucose >or=126 mg/dl), and 6.8% had fasting insulin >or=30 microU/ml. Hispanic youth were more likely to have BMI, glucose, and insulin levels above these thresholds than blacks and whites.

CONCLUSIONS

Sixth-grade students in schools with large minority populations have high levels of risk factors for type 2 diabetes. The HEALTHY intervention was designed to modify these risk factors to reduce diabetes incidence.

Prevalence of pre-diabetes and its association with clustering of cardiometabolic risk factors and hyperinsulinemia among U.S. adolescents: National Health and Nutrition Examination Survey 2005-2006

OBJECTIVE

Impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) are considered to constitute "pre-diabetes." We estimated the prevalence of IFG, IGT, and pre-diabetes among U.S. adolescents using data from a nationally representative sample.

RESEARCH DESIGN AND METHODS

We analyzed data from participants aged 12-19 years in the National Health and Nutrition Examination Survey 2005-2006. We used fasting plasma glucose and 2-h glucose during an oral glucose tolerance test to assess the prevalence of IFG, IGT, and pre-diabetes and used the log-binomial model to estimate the prevalence ratios (PRs) and 95% CIs.

RESULTS

The unadjusted prevalences of IFG, IGT, and pre-diabetes were 13.1, 3.4, and 16.1%, respectively. Boys had a 2.4-fold higher prevalence of pre-diabetes than girls (95% CI 1.3-4.3). Non-Hispanic blacks had a lower rate than non-Hispanic whites (PR 0.6, 95% CI 0.4-0.9). Adolescents aged 16-19 years had a lower rate than those aged 12-15 years (0.6, 0.4-0.9). Overweight adolescents had a 2.6-fold higher rate than those with normal weight (1.3-5.1). Adolescents with two or more cardiometabolic risk factors had a 2.7-fold higher rate than those with none (1.5-4.8). Adolescents with hyperinsulinemia had a fourfold higher prevalence (2.2-7.4) than those without. Neither overweight nor number of cardiometabolic risk factors was significantly associated with pre-diabetes after adjustment for hyperinsulinemia.

CONCLUSIONS

Pre-diabetes was highly prevalent among adolescents. Hyperinsulinemia was independently associated with pre-diabetes and may account for the association of overweight and clustering of cardiometabolic risk factors with pre-diabetes.

Pubarche as well as thelarche may be a marker for the onset of puberty

STUDY OBJECTIVE

To define anthropometric and hormonal differences in a group of black and white girls who began puberty with breast development alone ("thelarche" pathway) compared to those who began with pubic hair development alone ("pubarche" pathway), and test the hypothesis that pubarche may represent true pubertal development.

DESIGN

Longitudinal cohort seen annually for ten years.

SETTING

Recruited through elementary schools in Cincinnati, OH, and Richmond, CA; through HMO in Washington, DC.

PARTICIPANTS

9 years old, either Black or White, in the National Heart, Lung, and Blood Institute Growth and Health Study.

INTERVENTIONS

None; observational study.

MAIN OUTCOME MEASURES

Initial secondary sexual characteristic at onset of puberty; anthropometric measures; hormone measures.

RESULTS

478 of 1155 girls matured through a defined pathway. Age at onset of secondary sexual characteristics was similar between pathways, although girls in the thelarche pathway had puberty at a somewhat younger age, and black participants entered at a significantly younger age. Height velocity was the same in both pathways, and in the pubertal range. DHEA-S levels at onset of puberty were significantly greater in girls in the pubarche pathway, but levels of estradiol and testosterone were not different. Age of menarche was different by race (younger in blacks) and pathway (younger in thelarche pathway).

CONCLUSIONS

Given similar age and height velocities at onset of secondary sexual characteristics, these results suggest that pubarche, the development of pubic hair without breast development, may represent true pubertal maturation.

Prevalence of cardiometabolic risk factors by weight status in a population-based sample of Quebec children and adolescents

BACKGROUND

There are few data on the prevalence of cardiometabolic risk factors in population-based samples of overweight and obese youth.

OBJECTIVES

To compare the prevalence of individual and multiple cardiometabolic risk factors across body mass index (BMI) categories in a population-based sample of youth.

METHODS

In 1999, a school-based survey of a provincially representative sample of youth nine, 13 and 16 years of age was conducted in Quebec (1778 boys, 1835 girls). Overweight was defined as BMI in the 85th percentile or higher and lower than the 95th percentile of the Centers for Disease Control and Prevention 2000 growth charts, and obesity was defined as BMI in the 95th percentile or higher. Levels of total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, high-density lipoprotein cholesterol, triglycerides, insulin, glucose, C-reactive protein and systolic blood pressure were categorized as desirable, borderline or unfavourable.

RESULTS

The proportions of overweight and obese participants were 14% and 10% in boys, and 14% and 7% in girls, respectively. With the exception of total cholesterol and low-density lipoprotein cholesterol in girls, and glucose in both sexes, the prevalence of all investigated risk factors (borderline or unfavourable) was significantly higher among overweight and obese participants. Almost one-third of obese participants had unfavourable levels of at least two of seven risk factors (apolipoprotein B, high-density lipoprotein cholesterol, triglycerides, insulin, glucose, C-reactive protein and systolic blood pressure) compared with 3% of normal weight participants (adjusted OR 15 and 18 in boys and girls, respectively). Thirty-four per cent of obese youth did not have unfavourable levels of any risk factor.

CONCLUSION

There is marked heterogeneity in the association between excess weight and cardiometabolic risk factors. Nonetheless, the present study highlights a high prevalence of multiple risk factors in a population-based sample of overweight and obese youth.

Breastfeeding helps explain racial and socioeconomic status disparities in adolescent adiposity

OBJECTIVES

Studies suggest that breastfeeding is protective for later obesity; however, this association has not held among all racial and socioeconomic status groups. Racial and socioeconomic status differences in breastfeeding behavior have also been noted. In this study, we formally test whether breastfeeding mediates the relationship between race and socioeconomic status with adolescent adiposity.

METHODS

Data were analyzed from 739 black and white 10- to 19-year-old adolescents who participated in a large, school-based study. Parents provided information on parental education, used to measure socioeconomic status, and whether the child was breastfed as an infant. BMI was used to measure adolescent adiposity and was analyzed as a continuous measure (BMI z score) using linear regression and categorically (BMI > or = 85th and > or = 95th percentile) using logistic regression.

RESULTS

Black adolescents and those without a college-educated parent were less likely to have been breastfed for > 4 months. Race and parental education were each independent predictors of BMI z score and of having BMI > or = 85th percentile or BMI > or = 95th percentile. When added to the model, being breastfed for > 4 months was also independently associated with lower BMI z score and lower odds of having BMI > or = 85th percentile or BMI > or = 95th percentile. Inclusion of being breastfed for > 4 months resulted in a 25% decrease in racial and parental education differences in adolescent BMI z score, supporting partial mediation. CONCLUSIONS; Having been breastfed for > 4 months was associated with lower adolescent BMI z score and lower odds of having a BMI > or = 85th percentile or BMI > or = 95th percentile, independent of race or parental education. Furthermore, these analyses suggest that being breastfed for > 4 months partially explains the relationship between social disadvantage and increased adiposity. Increasing breastfeeding duration could result in lower adolescent adiposity for all racial and socioeconomic status groups and potentially minimize socioeconomic disparities in adiposity.

Management approaches for pediatric obesity

Childhood obesity is a worldwide problem that has reached epidemic proportions, resulting in an increased prevalence of premature obesity-related morbidities, and, thus, probable increased health-care costs to treat children. The development of viable approaches to manage this epidemic is crucial. Most experts in the field of childhood obesity agree that the prevention of obesity in children should be the first line of management. Pediatricians must be adept at recognizing children at risk of obesity, calculating and plotting the BMI at all visits, using a change in the BMI to identify excessive weight gain, and monitoring for comorbidities associated with obesity. If obesity is present, the cornerstone of treatment is modification of dietary and exercise habits. Practice-based counseling and community-based programs that support and encourage lifestyle modifications have yielded promising short-term results. Children with severe comorbidities who are unable to achieve lifestyle modifications can be considered for either pharmacologic therapy or surgery, but these options should be considered as a last resort. Early intervention and prevention strategies are the most cost-effective methods of dealing with this issue.

Metabolic syndrome rates in United States adolescents, from the National Health and Nutrition Examination Survey, 1999-2002

OBJECTIVE

To report the prevalence rates of the metabolic syndrome in a nationally representative sample of adolescents in the United States using 4 previously reported definitions of the syndrome.

STUDY DESIGN

Data from 12- to 19-year-old adolescents included in the National Health and Nutrition Examination Survey from 1999 to 2002 (NHANES 99-02) were analyzed by cross-sectional methods, by using 4 definitions of the metabolic syndrome previously applied to adolescents.

RESULTS

In NHANES 99-02, the prevalence of the metabolic syndrome in all teens varied from 2.0% to 9.4% of teens in the United States, depending on the definition used. In obese teens, these prevalence rates varied from 12.4% to 44.2%. In the group of obese teens, application of the definition by Cruz produced a metabolic syndrome prevalence rate of 12.4%; that of Caprio produced a rate of 14.1%. However, none of the normal weight or overweight teens met either definition. Application of the definition by Cook produced a prevalence rate of 7.8% in overweight teens and 44% in obese teens. The adult definition of metabolic syndrome produced a prevalence rate of 16% in overweight teens and 26% in obese teens.

CONCLUSIONS

In the period between 1999 and 2002, the prevalence rate of metabolic syndrome varied from just >9% to as low as 2% of adolescents overall. Different definitions of metabolic syndrome generated prevalence rates in obese adolescents that varied widely from 12% to 44%. For this syndrome to be a useful construct, a more standardized set of criteria may be needed.

Epidemiology of childhood type 2 diabetes and obesity

Over the last decade, it has become apparent that type 2 diabetes extends not only into the young adult population but is also found in adolescents and even, occasionally, in children. The limited data that are currently available present a rather uncertain picture, with a rather wide range of prevalences and incidences of type 2 diabetes in children and adolescents. Not surprisingly, the majority of the cases, and the highest prevalences, have been found among ethnic groups known to be at high risk of adult type 2 diabetes. Nevertheless, even in European populations, where the prevalence of type 2 diabetes remains very low among children and adolescents and certainly is considerably smaller than type 1 diabetes, there are several cases reported. The risk factors for type 2 diabetes in children and adolescents are, as expected, similar to those seen in adults, with obesity being almost always present. In utero exposure to hyperglycemia now appears to be an additional risk factor to having a family history of diabetes and suggests that better management of diabetes in pregnancy and prevention of gestational diabetes may reduce the risk of diabetes developing in the offspring.

Prevalence of glucose intolerance in school age children. Population based cross-sectional study

AIM

The aim of the study was to determine the prevalence of glucose intolerance among school children in south-eastern Poland.

METHODS

Schools were randomly selected in the area and the entire school population was studied. We examined 1083 children (510 boys and 573 girls) in the mean age 14.49 years (age range: 7.9-19 years). Their weight and height were measured and body mass index (BMI) was calculated. Patients were classified as overweight or obese based on International Obesity Task Force (IOTF) criteria. We tested fasting glucose level in randomly selected children with normal weight (N=83) in all overweight and obese subjects (N=229). In children with fasting blood glucose level higher than 5.5 mmol/L (100 mg/dL) oral glucose tolerance test (OGTT) was performed.

RESULTS

About 17.8% of children were overweight and 4.6% obese. Fasting hyperglycemia was found in 16.7% obese children. The calculated prevalence of fasting hyperglycemia for entire population was 6.7/1000. Impaired glucose tolerance (IGT) was found only in obese children. The prevalence of glucose intolerance in obese children was 7.1%, in contrast the calculated prevalence of glucose intolerance for the entire population was 3.0/1000 (95% confidence interval: 0-8.4/1000).

CONCLUSION

Despite relatively high number of obese children, the prevalence of IGT among schoolchildren of south-eastern Poland remains low.

Stability of adolescent body mass index during three years of follow-up

OBJECTIVE

A 4-year longitudinal study was conducted to determine the prevalence of overweight, detect shifts in body mass index (BMI) distribution, and determine which adolescents were at risk for pathologic weight gain.

STUDY DESIGN

BMI was analyzed in 1746 adolescents in years 1 (2001-2002) through 4 (2004-2005) of a school-based study. Changes in BMI-Z according to baseline BMI category were examined with general linear modeling.

RESULTS

In year 1, the prevalence of at risk for overweight (BMI = 85th-95th percentile) and overweight (BMI > or = 95th percentile) was 19.1% and 18.1%, respectively. Between years 1 and 4, the cohort exhibited no increase in the prevalence of at risk for overweight (19.1% versus 17.2%) or overweight (18.2% versus 18.8%; P > .5). The mean BMI Z-score (BMI-Z) for the cohort was identical in years 1 and 4 (0.66 +/- 1.0 Z-score units). Although the overall cohort exhibited stability in BMI-Z, individuals at the lowest categories of BMI-Z (year 1 BMI Z-score < 0) exhibited significant increases in BMI Z-score by year 4 (P < .01), with lean girls gaining more than lean boys (P for difference < .007).

CONCLUSION

The study cohort exhibited stability in adiposity during 3 years of follow-up. However, lean adolescents, particularly girls, experienced significant increases in BMI-Z, beyond that expected for age- and sex-related growth.

Fatness, fitness, and insulin sensitivity among 7- to 9-year-old children

OBJECTIVE

The purpose of this study was to examine the relationships among fatness and aerobic fitness on indices of insulin resistance and sensitivity in children.

RESEARCH DESIGN AND METHODS

A total of 375 children (193 girls and 182 boys) 7 to 9 years of age were categorized by weight as normal-weight, overweight, or obese and by aerobic fitness based on a submaximal physical working capacity test (PWC). Fasting blood glucose (GLU) and insulin (INS) were used to calculate various indices of insulin sensitivity (GLU/INS), the homeostasis model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI). Surrogate measures of pancreatic beta cell function included the insulinogenic index (INS/GLU) and the HOMA estimate of pancreatic beta-cell function (HOMA %B).

RESULTS

Insulin sensitivity and secretion variables were significantly different between the normal-weight children and the overweight and obese subjects. Fasting insulin (FI), HOMA, QUICKI, and INS/GLU were significantly different between the overweight and obese subjects. Likewise, the high fitness group possessed a better insulin sensitivity profile. In general, the normal-weight-high fit group possessed the best insulin sensitivity profile and the obese-unfit group possessed the worst insulin sensitivity profile. Several significant differences existed among the six fat-fit groups. Of particular note are the differences within BMI groups by fitness level and the comparison of values between the normal-weight-unfit subjects and the overweight and obese subjects with high fitness.

CONCLUSIONS

The results indicate that aerobic fitness attenuates the difference in insulin sensitivity within BMI categories, thus emphasizing the role of fitness even among overweight and obese children.

Adiponectin receptor 1 variants associated with lower insulin resistance in African Americans

Adiponectin has been shown to have a role in insulin resistance. However, little is known about the contribution of genetic variation in the adiponectin receptor 1 gene (ADIPOR1) in this regard. We hypothesized that variation in ADIPOR1 would be associated with significant changes in insulin resistance and tested this hypothesis in a cohort of 483 African-American adolescents. Seven single nucleotide polymorphisms (SNPs) of ADIPOR1 spanning from the promoter to the 3'-untranslated region were genotyped. We analyzed single SNPs and haplotypes for associations with insulin resistance [homeostasis model assessment of insulin resistance (HOMA-IR)] in the full cohort as well as lean (BMI < 85%) and non-lean (BMI >or= 85%) subsets. There was no evidence of ADIPOR1 variant effects on HOMA-IR in the full cohort or in the lean subset. However, in the non-lean subset, SNP +5843 (A allele), and haplotypes including SNPs -8505/-5692/+3002/+5843 (ATTA and AGTG) showed significant associations with decreased HOMA-IR after adjustment for sex, puberty, adiponectin, and waist z-score. Our findings suggest not only that ADIPOR1 variants influence insulin resistance in the presence of adiposity, but also that these variants and haplotypes are protective in African Americans.

Cardiovascular risk reduction in high-risk pediatric patients: a scientific statement from the American Heart Association Expert Panel on Population and Prevention Science; the Councils on Cardiovascular Disease in the Young, Epidemiology and Prevention, Nutrition, Physical Activity and Metabolism, High Blood Pressure Research, Cardiovascular Nursing, and the Kidney in Heart Disease; and the Interdisciplinary Working Group on Quality of Care and Outcomes Research

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

Instability in the diagnosis of metabolic syndrome in adolescents

BACKGROUND

Factor analyses suggest that the structure underlying metabolic syndrome is similar in adolescents and adults. However, adolescence is a period of intense physiological change, and therefore stability of the underlying metabolic structure and clinical categorization based on metabolic risk is uncertain.

METHODS AND RESULTS

We analyzed data from 1098 participants in the Princeton School District Study, a school-based study begun in 2001-2002, who were followed up for 3 years. We performed factor analyses of 8 metabolic risks at baseline and follow-up to assess stability of factor patterns and clinical categorization of metabolic syndrome. Metabolic syndrome was defined using the current American Heart Association/National Heart, Lung, and Blood Institute definition for adults (AHA), a modified AHA definition used in prior pediatric metabolic syndrome studies (pediatric AHA), and the International Diabetes Federation (IDF) guidelines. We found that factor structures were essentially identical at both time points. However, clinical categorization was not stable. Approximately half of adolescents with baseline metabolic syndrome lost the diagnosis at follow-up regardless of the definitions used: pediatric AHA=56% (95% confidence interval [CI], 42% to 69%), AHA=49% (95% CI, 32% to 66%), IDF=53% (95% CI, 38% to 68%). In addition to loss of the diagnosis, new cases were identified. Cumulative incidence rates were as follows: pediatric AHA=3.8% (95% CI, 2.8% to 5.2%); AHA=4.4% (95% CI, 3.3% to 5.9%); IDF=5.2% (95% CI, 4.0% to 6.8%).

CONCLUSIONS

During adolescence, metabolic risk factor clustering is consistent. However, marked instability exists in the categorical diagnosis of metabolic syndrome. This instability, which includes both gain and loss of the diagnosis, suggests that the syndrome has reduced clinical utility in adolescence and that metabolic syndrome-specific pharmacotherapy for youth may be premature.

Socioeconomic disparities in insulin resistance: results from the Princeton School District Study

OBJECTIVES

The objectives of this study were to determine whether lower socioeconomic status (SES) is associated with changes in insulin resistance in adolescents over a 3-year period and explore moderators of this effect.

METHODS

A total of 1167 healthy non-Hispanic black and white participants in the Princeton School District Study, a longitudinal study of fifth to 12th graders in a suburban Midwestern public school district were included in this study. Inclusion criteria were a) physical examination and fasting morning blood draw at baseline and 3 years later, b) younger than 20 years old at follow up, and c) information available on SES provided by a parent. The influence of SES on insulin resistance and change in insulin resistance over time was examined using general linear models adjusting for multiple covariates. Models also assessed if race or baseline weight status changed the SES-insulin resistance relationship and explored the role of perceived stress.

RESULTS

Blacks and lower SES youth had higher body mass index z score and increased insulin resistance (p < .001). In multivariable models, lower parent education, but not household income, was associated with higher baseline insulin resistance (F = 7.84, p < .001) and worsening insulin resistance over time (F = 18.86, p < .001). Parent education's effect on change in insulin resistance was more pronounced for obese youth compared with nonobese (F interaction = 10.12, p < .001) even with adjustment for multiple covariates. Perceived stress did not alter these relationships.

CONCLUSIONS

Lower parent education appears to be related to increased insulin resistance both cross-sectionally and over time in black and white adolescents. Worsening insulin resistance is especially problematic for obese adolescents from families with low parent education.

Cardiovascular Risk Reduction in High-Risk Pediatric Patients

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

The burden of diabetes mellitus among US youth: prevalence estimates from the SEARCH for Diabetes in Youth Study

OBJECTIVE

Our goal was to estimate the prevalence of diabetes mellitus in youth <20 years of age in 2001 in the United States, according to age, gender, race/ethnicity, and diabetes type.

METHODS

The SEARCH for Diabetes in Youth Study is a 6-center observational study conducting population-based ascertainment of physician-diagnosed diabetes in youth. Census-based denominators for 4 geographically based centers and enrollment data for 2 health plan-based centers were used to calculate prevalence. Age-, gender-, and racial/ethnic group-specific prevalence rates were multiplied by US population counts to estimate the total number of US youth with diabetes.

RESULTS

We identified 6379 US youth with diabetes in 2001, in a population of approximately 3.5 million. Crude prevalence was estimated as 1.82 cases per 1000 youth, being much lower for youth 0 to 9 years of age (0.79 cases per 1000 youth) than for those 10 to 19 years of age (2.80 cases per 1000 youth). Non-Hispanic white youth had the highest prevalence (1.06 cases per 1000 youth) in the younger group. Among 10- to 19-year-old youth, black youth (3.22 cases per 1000 youth) and non-Hispanic white youth (3.18 cases per 1000 youth) had the highest rates, followed by American Indian youth (2.28 cases per 1000 youth), Hispanic youth (2.18 cases per 1000 youth), and Asian/Pacific Islander youth (1.34 cases per 1000 youth). Among younger children, type 1 diabetes accounted for > or = 80% of diabetes; among older youth, the proportion of type 2 diabetes ranged from 6% (0.19 cases per 1000 youth for non-Hispanic white youth) to 76% (1.74 cases per 1000 youth for American Indian youth). We estimated that 154,369 youth had physician-diagnosed diabetes in 2001 in the United States.

CONCLUSIONS

The overall prevalence estimate for diabetes in children and adolescents was approximately 0.18%. Type 2 diabetes was found in all racial/ethnic groups but generally was less common than type 1, except in American Indian youth.

Presence of diabetes risk factors in a large U.S. eighth-grade cohort

OBJECTIVE

The study was conducted in 12 middle schools to determine the prevalence of diabetes, pre-diabetes, and diabetes risk factors in eighth-grade students who were predominantly minority and evaluate the feasibility of collecting physical and laboratory data in schools.

RESEARCH DESIGN AND METHODS

Anthropometric measurements and fasting and 2-h post-glucose load blood draws were obtained from approximately 1,740 eighth-grade students.

RESULTS

Mean recruitment rate was 50% per school, 49% had BMI > or = 85th percentile, 40.5% had fasting glucose > or = 100 mg/dl, 0.4% had fasting glucose > or = 126 mg/dl, and 2.0% had 2-h glucose > or = 140 mg/dl and 0.1% > or = 200 mg/dl. Mean fasting insulin value was 30.1 microU/ml, 36.2% had fasting insulin > or = 30 microU/ml, and 2-h mean insulin was 102.1 microU/ml. Fasting and 2-h glucose and insulin values increased across BMI percentiles, and fasting glucose was highest in Hispanic and Native American students.

CONCLUSIONS

There was a high prevalence of risk factors for diabetes, including impaired fasting glucose (> or =100 mg/dl), hyperinsulinism suggestive of insulin resistance (fasting insulin > or = 30 microU/ml), and BMI > or = 85th percentile. These data suggest that middle schools are appropriate targets for population-based efforts to decrease overweight and diabetes risk.

Interactions between noncontiguous haplotypes in the adiponectin gene ACDC are associated with plasma adiponectin

Adiponectin, an adipocyte protein important in insulin sensitization and cardioprotection, has a strong genetic component. We hypothesized that variants in the adiponectin gene (adipocyte collagen-domain containing [ACDC]) contribute to adiponectin levels in a biracial adolescent cohort. We genotyped 11 ACDC single nucleotide polymorphisms (SNPs) in 631 non-Hispanic white and 553 African-American unrelated adolescents in grades 5-12 randomly selected from the Princeton School District Study. ACDC SNPs -11,391 (A allele), -10,068 (G allele), and +276 (T allele) were associated with higher adiponectin, adjusting for sex, puberty stage, BMI Z score, and waist Z score. Contiguous two-SNP haplotypes of promoter variants -11,391/-10,068 were significantly associated with adiponectin levels in whites and African Americans (P < 0.0001 and 0.03, respectively). Extended haplotypes from the promoter through the second intron (-11,391 to +349) strongly associated with adiponectin in whites (P = 6 x 10(-11)) and African Americans (P = 0.004), but haplotypes of first intron SNPs -4,521 to -657 did not (P > 0.2). Noncontiguous haplotypes or interactions between two-SNP (-11,391/-10,068) and three-SNP (+45, +276, and +349) haplotypes predicted adiponectin better than either region alone. Variants of ACDC are associated with adiponectin levels in whites and African Americans. Interactions between noncontiguous ACDC haplotypes strongly influence adiponectin levels, suggesting nonadditive and potentially cis relationships between these regions.

The relationships of adiponectin with insulin and lipids are strengthened with increasing adiposity

CONTEXT

Adipose tissue inflammation has been implicated in the pathogenesis of obesity-related comorbidities. Adiponectin, an antiinflammatory protein, improves insulin sensitivity and lipid levels systemically. Because adiponectin is secreted by adipocytes, it may also act locally to counteract insulin resistance and dyslipidemia worsened by inflammation.

OBJECTIVE

The aim of this study was to determine whether associations between adiponectin and insulin sensitivity and lipids are stronger with increasing adiposity.

DESIGN

This cross-sectional study involved participants in The Princeton School District Study.

SETTING

The study was conducted in the Princeton City schools (Cincinnati, OH) during the 2001-2002 school year.

PARTICIPANTS

A total of 1196 non-Hispanic White and Black students in grades 5-12 participated.

MAIN OUTCOME MEASURE

The relationships between adiponectin and high-density lipoprotein, triglycerides, and insulin were measured. To test our hypothesis, we: 1) compared correlation and regression coefficients of lean and nonlean individuals, and 2) incorporated an adiponectin by adiposity interaction in regression models.

RESULTS

For high-density lipoprotein and triglycerides, the relationship with adiponectin, although present among lean adolescents, strengthened with increasing adiposity. However, with insulin, a relationship with adiponectin was only present among nonlean adolescents.

CONCLUSIONS

These analyses suggest that adiponectin's relationship with insulin and lipids strengthens with increasing adiposity, such that heavier adolescents have a greater benefit from high levels of adiponectin than their lean counterparts.