Risk of colonic cancer is not higher in the obese Lep(ob) mouse model compared to lean littermates.

Epidemiological data suggest that obesity increases the risk of colorectal cancer in humans. Given that diet-induced obesity mouse models verified the epidemiological data, the present study aimed to determine whether obese C57BL/6J-Lep(ob) male mice (a different obesity in vivo model) were at greater risk of colonic cancer than their lean male littermates. Risk of colonic tumorigenesis was assessed by numbers of aberrant crypts, aberrant crypt foci and colonic tumors.

Diet induced obesity increases the risk of colonic tumorigenesis in mice.

A large body of epidemiological data indicates that obesity increases the risk of colon cancer in humans. There are limited studies using rodent models where the relationship between obesity and colon cancer has been studied. In this study, wild-type diet-induced obese (DIO) mice and lean wild-type controls were used to investigate the influence of obesity on the risk of colon cancer.

Use of HbA(1C) testing to diagnose pre-diabetes in high risk African American children: a comparison with fasting glucose and HOMA-IR.

Objective: This study aimed to compare the discriminating power of HbA(1C) with other pre-diabetes diagnostic tests specifically in high-risk African American children.

Research Design And Methods: A cross-sectional analysis was performed on a sample of 172 children (70 boys and 102 girls) aged 9-11 years with BMI's above the 85th percentile. Fasting glucose, insulin and HbA(1C) were analyzed from the plasma samples.

Influence of body dissatisfaction on 1-year change in nutrient intake of overweight and obese inner-city African American children.

This analysis aimed to examine the relationship of baseline body dissatisfaction with 1-year change in nutrient intake of inner-city, overweight and obese, African American children. This is a secondary analysis of 1-year pre-post data available for a convenience sample of 88 children. After adjusting for baseline intake of dietary variables and intervention group status, baseline body dissatisfaction was associated with 1-year increases in intake of energy, and all macronutrients in girls, but not in boys.

One-year change in energy and macronutrient intakes of overweight and obese inner-city African American children: effect of community-based Taking Action Together type 2 diabetes prevention program.

Taking Action Together (TAT) was a controlled community-based intervention protocol developed to reduce risk of T2DM among low-income, high BMI, 9-10 year old African American children. A secondary hypothesis of this study was that there would be greater improvements in the treatment group in dietary intakes and physical activity. To evaluate the primary study objectives, multiple linear regression models were employed, with 1 year change in dietary variables as dependent variables.

Lp(a)-cholesterol is associated with HDL-cholesterol in overweight and obese African American children and is not an independent risk factor for CVD.

Background: The role of lipoprotein (a) cholesterol {Lp(a)-C}as an additional and/or independent risk factor for cardiovascular disease (CVD) is not clear. We evaluated the associations between Lp(a)-C and other CVD risk factors including plasma lipoprotein concentrations and body fatness in overweight and obese African American children.

Methods: A cross-sectional analysis was carried out using data from a sample of 121 African American children aged 9-11 years with body mass index (BMI)'s greater than the 85th percentile.

Accuracy of multisensor activity monitors in normal versus high BMI African American children.

Background: Overweight children show different movement patterns during walking than normal-weight children, suggesting the accuracy of multisensory activity monitors may differ in these groups.

Methods: Eleven normal and 15 high BMI African American children walked at 2, 4, 5, and 6 km/h on a treadmill wearing the Intelligent Device for Energy Expenditure and Activity (IDEEA) and SenseWear (SW). Accuracy was determined using indirect calorimetry and manually counted steps as references.

Relationship of insulin resistance to psychobehavioral characteristics of overweight and obese African American children.

Objectives: The objective of this study was to evaluate the relationships of insulin resistance to positive as well as negative dimensions of the child's emotions, behavior and personality (hereafter referred to as "psychobehavioral characteristics") in a convenience sample of inner-city, overweight and obese, African American children.

Methods: A secondary analysis was performed on a sample of 127 children ages 9-12 yr old who were participating in a community-based, Type 2 diabetes prevention program. Psychobehavioral characteristics of children were assessed using both child and parent ratings derived from the Behavioral Assessment for Children, 2nd edition (BASC-2).

Accelerometer response to physical activity intensity in normal-weight versus overweight African American children.

Background: Different movement efficiency in overweight children may affect accelerometer output data. The purpose was to investigate the ability of accelerometers to assess physical activity intensity and number of steps in normal-weight compared with overweight children.

Methods: Eleven normal-weight and 14 overweight African American children walked at 2, 4, 5, and 6 km/h on a treadmill wearing Lifecorder, ActiGraph, RT3, and Biotrainer.

Dietary intakes of urban, high body mass index, African American children: family and child dietary attributes predict child intakes.

Objective: To identify family and child nutrition and dietary attributes related to children's dietary intakes.

Design: African American children (ages 8-11 years, n = 156), body mass index > 85th percentile, from urban, low-income neighborhoods. Baseline, cross-sectional data collected as part of an ongoing diabetes prevention intervention.

Identifying metabolic syndrome in African American children using fasting HOMA-IR in place of glucose.

Introduction: Metabolic syndrome (MetS) is increasing among young people. We compared the use of homeostasis model assessment of insulin resistance (HOMA-IR) with the use of fasting blood glucose to identify MetS in African American children.

Methods: We performed a cross-sectional analysis of data from a sample of 105 children (45 boys, 60 girls) aged 9 to 13 years with body mass indexes at or above the 85th percentile for age and sex.

Insulin resistance and self-perceived scholastic competence in inner-city, overweight and obese, African American children.

Purpose: scholastic competence is a predictor of future achievement, yet there is little research about health factors that influence the development of self-perceived scholastic competence (SPSC). This study examined the relationship of insulin resistance and body fatness with SPSC in low-income, overweight and obese, African American children.

Methods: data were analyzed from a convenience sample of 9-10years old African American children (89 boys and 113 girls) enrolled in a type 2 diabetes prevention study.

Taking Action Together: a YMCA-based protocol to prevent type-2 diabetes in high-BMI inner-city African American children.

Background: Associated with a tripling in obesity since 1970, type 2 diabetes mellitus (T2DM) in children has risen 9-10 fold. There is a critical need of protocols for trials to prevent T2DM in children.

Methods/design: This protocol includes the theory, development, evaluation components and lessons learned from a novel YMCA-based T2DM prevention intervention designed specifically for high-BMI African American children from disadvantaged, inner-city neighborhoods of Oakland, California.

Insulin resistance is improved in overweight African American boys but not in girls following a one-year multidisciplinary community intervention program.

Aim: To assess potential for effectiveness, in a non-randomized pilot study, of a community-based lifestyle intervention program to reduce the risk for type 2 diabetes mellitus in overweight African American (AA) children.

Research Design: Sample of 165 9-11 year-old AA children with body mass index (BMI) >85th percentile were recruited from local recreational sites, schools and churches. Participants self-selected to attend one of two study sites, blinded to the specifics of the intervention administered at each site.

Accuracy of self-assessed Tanner staging against hormonal assessment of sexual maturation in overweight African-American children.

Aim: To evaluate the accuracy of self-reported Tanner (SRT) staging against a proxy method of physician's assessment of sexual maturation, using pubertal hormones in overweight African-American (AA) children.

Methods: Cross-sectional data from 196 children (113 girls, 83 boys) aged 9-11 years, who were 'overweight' (>85th and <95th percentile for age- and gender-matched BMI; n = 43) or 'obese' (>95th percentile; n = 153) were used. Children assessed their breast or genital and pubic hair development using standardized Tanner drawings representing different stages of sexual maturity.

Baseline correlates of insulin resistance in inner city high-BMI African-American children.

To characterize the influence of diet-, physical activity-, and self-esteem-related factors on insulin resistance in 8- 10-year-old African-American (AA) children with BMI greater than the 85th percentile who were screened to participate in a community-based type 2 diabetes mellitus (T2DM) prevention trial. In 165 subjects, fasting glucose- and insulin-derived values for homeostasis model assessment of insulin resistance (HOMA-IR) assessed insulin resistance. Body fatness was calculated following bioelectrical impedance analysis, and fitness was measured using laps from a 20-m shuttle run.

Acetylation of histones associated with the p21WAF1/CIP1 gene by butyrate is not sufficient for p21WAF1/CIP1 gene transcription in human colorectal adenocarcinoma cells.

Butyric acid is well recognized as a histone deacetylase (HDAC) inhibitor, and changes in histone acetylation are thought to alter gene expression. The mechanism by which sodium butyrate (NaB) induces p21WAF1/CIP1, a critical gene involved in the antiproliferative effect of NaB, was studied at the chromatin level. Using chromatin immunoprecipitation (ChIP) assay, acetylation of histone H3 was observed at the proximal region of the promoter within 30 min of NaB exposure and this extended to the distal region within 2 hr.

Sodium butyrate inhibits cell growth and stimulates p21WAF1/CIP1 protein in human colonic adenocarcinoma cells independently of p53 status.

Butyric acid, one of the short-chain fatty acids produced by microbial fermentation in the colon, exhibits antiproliferative activities in various cancer cell lines. The initial objective of the study was to assess whether the effect of sodium butyrate (NaB) on cell growth differed by p53 status of the cells. Four human colorectal adenocarcinoma cell lines were used: HT29 (p53 point mutation), Caco2 (p53 truncation), LS513 (p53 wild type), and Lovo (p53 wild type).

Acetate and butyrate are the major substrates for de novo lipogenesis in rat colonic epithelial cells.

The objective of these experiments was to investigate the source of substrates used for lipid synthesis and the pathways of substrate incorporation into lipids by epithelial cells of the colon. Within replicates, cells were exposed to all treatments evaluated in that experiment. By comparing the relative incorporation rates of several 14C-labeled substrates into lipids, acetate made a significantly larger carbon contribution to lipids than propionate, butyrate, glucose or glutamine under the in vitro conditions utilized in this study.

Glucose alleviates ammonia-induced inhibition of short-chain fatty acid metabolism in rat colonic epithelial cells.

Ammonia decreased metabolism by rat colonic epithelial cells of butyrate and acetate to CO2 and ketones but increased oxidation of glucose and glutamine. Ammonia decreased cellular concentrations of oxaloacetate for all substrates evaluated. The extent to which butyrate carbon was oxidized to CO2 after entering the tricarboxylic acid (TCA) cycle was not significantly influenced by ammonia, suggesting there was no major shift toward efflux of carbon from the TCA cycle.