Relation between adiposity and disease risk factors in Mexican American children

Anthropometry Versus Imaging for Prediction of Inflammation Among Hispanic Girls

OBJECTIVE

This study aimed to compare total and regional estimates of body composition, by direct and indirect techniques, for the optimal prediction of C-reactive protein (CRP) among young (aged 9-12 years) Hispanic girls (N = 232).

METHODS

Standard anthropometric techniques were used to measure height, weight, and waist circumference. Dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) assessed body composition. Fasting serum CRP was measured by the AU5812 Clinical Chemistry Analyzer (Beckman Coulter, Brea, California). Associations between each total and regional body composition parameter and CRP were tested using linear regression (log-transformed, continuous CRP) and ordinal logistic regression (CRP < 1.0, ≥ 1.0-2.9, and ≥ 3.0 mg/L), controlling for maturation, dietary energy, physical activity, and medications.

RESULTS

All measures of total and regional body fat were positively associated with CRP (P < 0.0001) except for intermuscular fat by pQCT. There were no clinically relevant differences in their association with CRP between anthropometric (BMI; waist circumference) and DXA-derived (total fat and regional fat: trunk, gynoid, android fat, leg) measures of fat.

CONCLUSIONS

Measurement of body habitus in Hispanic girls, by multiple commonly available means, predicts CRP equally well.

Sex Differences in Associations of Adiposity Measures and Insulin Resistance in US Hispanic/Latino Youth: The Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth)

CONTEXT

US Hispanic/Latino youth are disproportionally affected by the obesity and diabetes.

OBJECTIVE

We examined associations of adiposity measures with insulin resistance (IR) and hyperglycemia and the influences of sex and pubertal development on these associations.

DESIGN, SETTING, AND PARTICIPANTS

We performed a cross-sectional analysis of 1223 8- to 16-year-old Hispanic/Latino youth from a community-based study in the United States (SOL Youth).

MAIN OUTCOME MEASURES

We measured IR (≥75th percentile of sex-specific Homeostatic Model Assessment of Insulin Resistance) and hyperglycemia (fasting glucose ≥100 mg/dL or hemoglobin a1c ≥5.7%).

RESULTS

In boys, body mass index (BMI) showed the strongest association with IR [prevalence ratio (PR), 2.10; 95% confidence interval (CI), 1.87 to 2.36 per standard deviation], which was not statistically different compared with body fat percentage (%BF) (PR, 2.03; 95% CI, 1.81 to 2.29) and waist circumference (WC) (PR, 1.89; 95% CI, 1.67 to 2.13) but was significantly stronger compared with fat mass index (FMI) (PR, 1.79; 95% CI, 1.63 to 1.96), waist-to-hip ratio (WHR) (PR, 1.32; 95% CI, 1.21 to 1.44), and waist-to-height ratio (WHtR) (PR, 1.76; 95% CI, 1.54 to 2.01) (P for difference, <0.05). In girls, %BF (PR, 2.73; 95% CI, 2.34 to 3.20) showed a significantly stronger association with IR compared with BMI (PR, 1.48; 95% CI, 1.29 to 1.70), FMI (PR, 1.71; 95% CI, 1.49 to 1.95), WC (PR, 1.96; 95% CI, 1.70 to 2.27), WHR (PR, 1.95; 95% CI, 1.70 to 2.23), and WHtR (PR, 1.79; 95% CI, 1.53 to 2.09) (P for difference, <0.003). Associations between adiposity measures and IR were generally stronger among children in puberty versus those who had completed puberty, with significant interactions for WC and WHtR in boys and for BMI in girls (P for interaction, <0.01). Adiposity measures were modestly associated with hyperglycemia (PR, 1.14 to 1.25), with no interactions with sex or pubertal status.

CONCLUSIONS

Sex and puberty may influence associations between adiposity measures and IR in US Hispanic/Latino youth. Multiple adiposity measures are needed to better assess IR risk between boys and girls according to pubertal status.

Consumption of a high-fat breakfast on consecutive days alters preclinical biomarkers for atherosclerosis

BACKGROUND/OBJECTIVES

Recent research has speculated that the risk of developing atherosclerosis is due to the accumulation of the effects of daily diet choices. The purpose of this study was to examine which of our previously identified preclinical disease risk biomarkers were further elevated when consuming a high-fat (644±50 kcal; 100% recommended dietary allowance for fat), high-calorie (1118±100 kcal; 70% daily caloric needs) breakfast on consecutive days. Young, normal weight females (N=7) participated in this study.

SUBJECTS/METHODS

Blood samples were taken premeal and hourly for 5-h postprandial. Serum biomarkers (C-peptide, eotaxin, gastric inhibitory polypeptide, granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte colony-stimulating factor (GM-CSF), insulin, leptin, monocyte chemoattractant protein 1, pancreatic polypeptide (PPY) and tumor necrosis factor-α), monocyte concentration, and adhesion molecule expression (CD11a, CD18 and CD54) were measured. Area under the curve was calculated for each outcome variable as a function of day and data were analyzed for significance.

RESULTS

We found significant (P<0.05) increases on Day 2 for: GM-CSF (+47%; P=0.041), G-CSF (+31%; P=0.012), PPY (+51%; P=0.049), total monocyte (+110%; P=0.043), pro-inflammatory (PI) monocyte (+60%; P=0.012), PI monocyte CD18 (+960%; P=0.003), PI monocyte CD11a (+230%; P=0.006), and PI monocyte CD54 (+208%; P=0.015).

CONCLUSIONS

To our knowledge, the present study is the first to report changes in selected biomarkers and monocytes following eating a high-fat, high-calorie breakfast on consecutive days in humans. More research is needed to determine how transient the observed changes are and what the long-term implications for disease risk are.

Predictors of screening for hyperlipidemia in an urban pediatric tertiary care center

INTRODUCTION

It is unknown how the conflicting recommendations of the American Academy of Pediatrics and the US Preventive Services Task Force on pediatric hyperlipidemia affect screening.

OBJECTIVES

(a) Identify clinical predictors for screening for hyperlipidemia, (b) assess the adherence to the 2008 American Academy of Pediatrics guidelines, and (c) determine the efficacy of reminder cards in increasing the adherence to the aforementioned guidelines.

METHODS

Retrospective chart review in the resident, attending, and adolescent medicine clinics during a 3-month period. Reminder cards on each patient chart outlining guidelines for lipid screening for the same clinics were inserted and prospectively assessed for adherence during the following 3 months.

RESULTS

Older age and higher body mass index increased likelihood (odds ratio = 1.2 and 12.7, respectively) for lipid screening. Reminder cards improved adherence in the resident clinic only (χ2 P = .016).

CONCLUSIONS

Age and body mass index were the most significant predictors for lipid screening. Reminder cards modestly improved adherence among resident physicians.

Mexican American children have differential elevation of metabolic biomarkers proportional to obesity status

OBJECTIVES

There is a health disparity for obesity among Mexican Americans compared with other racial/ethnic groups. In particular, Mexican American children who are obese are likely to become obese adults. The purpose of this study was to examine traditional and nontraditional risk factors in a subset of Mexican American children before their participation in a larger clinical weight loss study.

METHODS

Venous blood samples were collected from self-identified Mexican American children (12-14 years old) who were assigned to 1 of 3 weight groups based on their standardized body mass index; normal weight (N = 66), overweight (N = 23), or obese (N = 39). Serum was analyzed for interleukin-6, tumor necrosis factor-α, C-peptide, ghrelin, glucagon-like protein, gastric inhibitory polypeptide-1, glucagon, insulin, leptin, macrophage chemoattractant protein 1, and pancreatic polypeptide using a Luminex MagPix-based assay. Total cholesterol, high-density lipoprotein-cholesterol, triglycerides, and glucose were analyzed using enzymatic assays. Data were analyzed for significance using separate analysis of variance tests, with significance set at P < 0.05.

RESULTS

Relative to normal weight and overweight children, obese children had significantly elevated C-peptide (P < 0.0001), insulin (P < 0.0001), leptin (P < 0.0001), macrophage chemoattractant protein 1 (P = 0.005), and tumor necrosis factor-α (P = 0.006).

CONCLUSIONS

We observed that Mexican American children as a function of body weight had elevated serum concentrations of several biomarkers that have been linked to chronic disease development in adults. More research is needed to understand how these differences affect disease risk in adulthood.

Obese Mexican American children have elevated MCP-1, TNF-α, monocyte concentration, and dyslipidemia

BACKGROUND AND OBJECTIVE

Obesity is an independent risk factor for chronic disease. The prevalence of obesity is especially high among Mexican American children. Peripheral blood monocytes are altered with obesity contributing to elevated systemic inflammation and increased risk of chronic disease. In addition, obesity alters the circulating levels of cytokines/chemokines that influence monocyte behavior. The study objective was to investigate alterations in blood monocytes and plasma cytokines/chemokine levels among healthy weight (standardized BMI [zBMI] ≤85th percentile; n = 66), overweight (zBMI 85th-95th percentile; n = 23), and obese (zBMI ≥95th percentile; n = 39) Mexican American children.

METHODS

Blood samples were analyzed for total and subset monocyte concentration via flow cytometry. Serum monocyte chemoattractant protein-1 (MCP-1), fractalkine, interleukin-8, and tumor necrosis factor α (TNF-α) were measured by using a Milliplex MagPix assay. Serum cholesterol, high-density lipoproteins, triglycerides, and glucose were measured by using an enzymatic assay.

RESULTS

Total monocyte concentration (P = .012), classic monocyte concentration (P = .045), MCP-1 (P = .015), and TNF-α (P = .002) were significantly greater in obese children compared with healthy weight children. Also, overweight and obese children had elevated triglycerides (P = .001) and reduced high-density lipoproteins (P = .033) compared with healthy weight children.

CONCLUSIONS

Childhood obesity alters monocytes and circulating chemokines, putting children at a greater risk of developing obesity-related chronic diseases in adulthood. Further characterization of early immune alterations in childhood obesity may provide additional clinical insight into the assessment of obesity-related disease risk.

A one-year school-based diet/exercise intervention improves non-traditional disease biomarkers in Mexican-American children

School-based interventions are an effective way to treat childhood obesity. The purpose of the present study was to biologically validate an established school-based intervention designed to reduce standardised body mass index (zBMI) over a period of 12 months. This intervention focused on a subset of Mexican-American children who were participating in a larger clinical weight loss study. Plasma samples were analysed from self-identified Mexican-American children (12-14 years) who were randomised to either a school-based intervention (IN, n = 152) or self-help control (CN, n = 69). Treatment was 4 days week⁻¹ of exercise (45 min day⁻¹) and 1 day week⁻¹ of nutritional counselling for 6 months. Fasting (>8 h) blood samples were collected at baseline, 6 months (end of active intervention) and 12 months (6 months after the end of the active intervention). Plasma resistin, adiponectin and leptin concentration were measured using a multiplex assay. Separate linear mixed models and a P < 0.05 were used to test for significance. Significant group × time interactions were found for resistin (P < 0.0001), adiponectin (P = 0.001) and leptin (P = 0.013). For resistin, IN was 12% lower at 6 months than CN. Adiponectin concentration in IN was greater at 6 months (26%) and 12 months (8%) than CN. Leptin concentration was 22% lower for IN at 12 months than CN. We have previously reported that our school-based intervention reduced zBMI and now reported alterations in biologically relevant disease biomarkers. Some of the observed changes were only present at the end of the active intervention (resistin), while others persisted until 12 months (leptin and adiponectin). These changes underscore the effectiveness of our school-based intervention at not only improving zBMI but also at reducing disease risk.

Inflammation

Lifestyle interventions show considerable promise in improving levels of inflammation. This review discusses how these improvements in inflammation are consistent with a “small changes” approach.