Imagine HEALTH: results from a randomized pilot lifestyle intervention for obese Latino adolescents using Interactive Guided ImagerySM.

BACKGROUND: There is an urgent need for innovative and developmentally appropriate lifestyle interventions to promote healthy lifestyle behaviors and to prevent the early onset of type 2 diabetes and cardiovascular disease risk in obese Latino adolescents. Guided imagery offers promise to reduce stress and promote lifestyle behavior change to reduce disease risk in obese adolescents. Our objectives were: 1) To pilot test a new 12-wk lifestyle intervention using a randomized trial design in obese Latino adolescents, in order to determine the effects of the mind-body modality of Interactive Guided ImagerySM (IGI), over and above those of a didactic lifestyle education, on insulin resistance, eating and physical activity behaviors, stress and stress biomarkers; and 2) To explore the role of intervention-related changes in stress and stress biomarkers on changes in metabolic outcomes, particularly insulin resistance. METHODS: Obese (BMI > 95th percentile), Latino adolescents (n = 35, age 14-17) were randomized to receive either 12 weekly sessions of a lifestyle education plus guided imagery program (GI), or lifestyle education plus a digital storytelling computer program (DS). Between-group differences in behavioral, biological, and psychological outcomes were assessed using unpaired T-tests and ANCOVA in the 29 subjects who completed the intervention. RESULTS: The GI group demonstrated significant reductions in leisure sedentary behavior (p < .05) and increases in moderate physical activity (p < .05) compared to DS group, and a trend toward reduced caloric intake in GI vs DS (p = .09). Salivary cortisol was acutely reduced by stress-reduction guided imagery (p < .01). There were no group differences in adiposity, insulin resistance, perceived stress, or stress biomarkers across the 12-week intervention, though decrease in serum cortisol over the course of the intervention was associated with improved insulin sensitivity (p = .03) independent of intervention group and other relevant co-variates. CONCLUSIONS: The improvements in physical activity and stress biomarkers following this pilot intervention support the role of guided imagery in promoting healthy lifestyle behavior change and reducing metabolic disease risk in obese Latino adolescent populations. Future investigations will be needed to determine the full effects of the Imagine HEALTH intervention on insulin resistance, stress, and stress biomarkers. TRIAL REGISTRATION: Clinicaltrials.gov Registry #: NCT01895595.

Barriers to physical activity and healthy eating in young breast cancer survivors: modifiable risk factors and associations with body mass index.

Physical activity (PA) and healthy eating (HE) are important behaviors to encourage in breast cancer survivors (BCS). We examined associations between various factors and barriers to PA (BPA) and barriers to HE (BHE), as well as relationships between barriers and body mass index (BMI) in younger BCS. Self-reported data from 162 BCS (mean age 48 years) were used. BPA were assessed with a 21-item scale and BHE with a 19-item scale. Participants were classified as high or low on each scale. Sociodemographic, medical, and psychosocial characteristics were compared by high/low barriers. Correlates of continuous BPA and BHE were assessed as were associations among BHE, BPA, and BMI. 61 % of participants were characterized as having low BHE and low BPA; 12 % were high for both. High BHE/high BPA participants had the least favorable scores for depression, perceived stress, social support, fatigue, bladder control, and weight problems. Factors associated with BHE were lower education, higher perceived stress, and more severe weight problems. Factors associated with BPA were more severe bladder control problems and lower physical well-being. Higher BHE and BPA were significantly and uniquely associated with higher BMI, controlling for covariates. Several biopsychosocial factors (e.g., depression, stress, and fatigue) characterize young BCS who experience barriers to both HE and PA. The correlates of BHE and BPA are distinct. Both BHE and BPA are associated with BMI. These results should be considered in designing interventions for younger women with breast cancer.

Diet, physical, and biochemical characteristics of children and adolescents with type 1 diabetes: relationship between dietary fat and glucose control.

BACKGROUND: Nutritional habits may significantly influence glycemic control and cardiovascular risk factors in youth with type 1 diabetes (T1D). AIMS: To assess dietary intake, cardiovascular risk factors, and the association between diet composition and glycemic control in Italian youth with T1D. METHODS: Subjects included 114 youth aged 6-16 yr with T1D receiving a routine treatment program with nutrition counseling and 448 controls. Cross-sectional measures included dietary intake, anthropometry, blood pressure, lipid profile, and, in children with diabetes, HbA1c. RESULTS: In prepubertal children, BMI, subcutaneous skinfolds, the prevalence of overweight/obesity, and LDL cholesterol (LDL-CH) were significantly lower in patients than in controls, whereas HDL cholesterol (HDL-CH) was higher. Pubertal boys with T1D did not differ significantly from controls in either anthropometry or lipid profile. Pubertal girls with T1D had a higher BMI and higher triceps skinfolds than controls but not significantly different prevalence of overweight/obesity or lipid profile. Compared to controls, participants with T1D had a lower intake of lipids and simple carbohydrates, a higher ratio of unsaturated/saturated fats and fibre, and a dietary intake closer to the National Reference Dietary Intakes (RDIs). The odds of having an HbA1c higher than 7.5, adjusted for BMI, lipid, and fibre intake, increases by 53% for every 1% increase of energy intake from saturated fat in the diet and by 30% for every year of duration of diabetes. CONCLUSIONS: Youth with T1D having regular nutritional counseling had a diet closer to RDIs than controls and not different cardiovascular risk factors. High saturated fatty acid intake was associated with poor blood glucose control.

Impact of progressive familial intrahepatic cholestasis on caregivers: caregiver-reported outcomes from the multinational PICTURE study.

BACKGROUND: Progressive familial intrahepatic cholestasis (PFIC) is a spectrum of rare genetic diseases characterized by inadequate bile secretion that requires substantial ongoing care, though little research is published in this area. We report health-related quality of life (HRQoL) and work productivity outcomes from the retrospective, cross-sectional PICTURE study investigating the burden of PFIC on caregivers. Information from caregivers of patients with PFIC 1 or 2 in Germany, the United Kingdom and the United States from September 2020 to March 2021 was included. RESULTS: The PICTURE study sample comprised HRQoL responses from 22 PFIC caregivers. Patients were on average 8.2 years old; most caregivers were 30-49 years old (68%) and mothers (77%). Median CarerQoL-7D score was 67.7/100; mean CarerQoL-VAS score for general happiness was 5.7/10 (SD 2.1). Most caregivers reported fulfilment in their caregiving responsibilities, but problems with mental and physical health, finances, and relationships. When stratified by patient's PFIC type, mean CarerQoL-7D and CarerQoL-VAS scores suggested worse HRQoL outcomes with PFIC2 versus PFIC1 (59.4 vs. 71.2, and 5.3 vs. 6.5, respectively). Additionally, more caregivers reported impact on sleep in the PFIC2 versus PFIC1 subgroup (93% vs. 75%). When stratified by history of PFIC-related surgeries, mean CarerQoL-7D and VAS scores were higher among those whose children had no specified surgeries (67.7 vs. 59.0/100 and 6.2 vs. 5.2/10, respectively). Nearly all caregivers reported an impact of caregiving responsibilities on sleeping (86%) and on personal relationships (82%). No caregivers reported having formal care support. Most caregivers were employed (73%); a third reported mean productivity loss of 12.9 days (SD 19.3) over the last 3 months, and a mean of 2.8 (SD 9.5) missed years of employment during their career. A higher number of workdays were missed by PFIC 2 caregivers compared to PFIC1 over last 3 months (16 days vs. 3 days). CONCLUSIONS: The PICTURE study has demonstrated the prevalent, comprehensive, and meaningful burden that caring for an individual with PFIC has on caregivers. Despite fulfilment from caregiving, the breadth and depth of these responsibilities reduced caregiver reported HRQoL including mental and physical health, productivity, career prospects, sleep, relationships and finances.

Burden of illness of progressive familial intrahepatic cholestasis in the US, UK, France, and Germany: study rationale and protocol of the PICTURE study.

Background: Progressive familial intrahepatic cholestasis (PFIC) is an ultra-rare disease with a considerable burden on pediatric patients and their caregivers, impacting quality of life (QoL). The mortality rates highlight a significant need for efficacious treatments. Real-world data on associated costs and QoL are needed to gauge the potential impact of new pharmacological treatments.Methods: Clinical and socio-economic burden of PFIC on patients/caregivers, health systems, and society will be assessed. Patient/caregiver- and physician-level retrospective cross-sectional data will be collected from the US, UK, France, and Germany, for PFIC types 1, 2, 3.A representative sample of physicians will provide clinical and resource utilization information using an electronic Case Report Form (eCRF). Patient/caregiver surveys will collect socio-economic and QoL data, enabling assessment of PFIC impact on QoL. Mean costs (direct medical/non-medical, indirect) will be calculated.The study materials were reviewed by medical professionals and patient representatives and received ethical approval from the University of Chester.Discussion: The study aims to reveal the unmet medical need, disease burden, resource utilization, and costs of PFIC, to raise awareness with policymakers and healthcare professionals, and provide support for the patient/caregiver community. As novel PFIC therapies recently emerged, this study will yield quantifiable data for health technology assessments.

Persistence of the metabolic syndrome over 3 annual visits in overweight Hispanic children: association with progressive risk for type 2 diabetes.

OBJECTIVE: To examine an association between persistent metabolic syndrome (MetS) and the risk for type 2 diabetes in overweight Hispanic children. STUDY DESIGN: A total of 73 subjects (mean age, 11.0 +/- 1.7 years) from a longitudinal study were classified as Never (negative for MetS at all 3 annual visits), Intermittent (positive for MetS at 1 or 2 visits), or Persistent (positive for MetS at all 3 visits). Measures included dual-energy x-ray absorptiometry, magnetic resonance imaging, the 2-hour oral glucose tolerance test, and the frequently sampled intravenous glucose tolerance test. RESULTS: The Persistent group had a faster rate of fat mass gain than the Never group (20% vs 15% gain of baseline value; P < .05 for time *group interaction [time = visit]). Independent of body composition, the Persistent group increased by 70% in insulin incremental area under the curve, whereas the other groups decreased (P < .05 for time *group interaction). Despite no time *group interactions for insulin sensitivity, acute insulin response, or disposition index, the Persistent group maintained 43% lower insulin sensitivity (P < .01) and by visit 2 had a 25% lower disposition index (P < .05) compared with the Never group. CONCLUSIONS: Patients with persistent MetS had accelerated fat gain, increased insulin response to oral glucose, and decreased sensitivity and beta cell function, indicators of progressively greater risk for type 2 diabetes.

Dietary intake and the metabolic syndrome in overweight Latino children.

Little is known about the relationship between diet and metabolic health in Latino children, a population at increased risk for diabetes. The present study evaluates diet composition and the metabolic syndrome in a cross-sectional sample of 109 overweight Latino children aged 10 to 17 years with a family history of type 2 diabetes. Dietary intake was assessed by two 24-hour recalls. Associations between nutrients and features of the metabolic syndrome were examined using multiple linear regression and analysis of covariance. Log cholesterol intake was positively associated with log systolic blood pressure (beta=0.034, P=0.017) and log soluble dietary fiber intake was inversely associated with log waist circumference (beta=-0.069, P=0.036). Log soluble fiber intake was significantly higher in participants with 0 features compared to those with 3+ features of the metabolic syndrome (P=0.046), which translates to 5.2 g vs 4.1 g soluble fiber daily. No other significant associations were found between dietary variables and either the individual features of the metabolic syndrome or the clustering of metabolic syndrome components. Increases in soluble fiber through the daily consumption of fruits, vegetables, and beans may improve metabolic health in Latino children.

Adiponectin independently predicts metabolic syndrome in overweight Latino youth.

CONTEXT: Adiponectin may be important in the pathogenesis of insulin resistance and the metabolic syndrome in youth. OBJECTIVE: The objective of the study was to determine the unique effect of adiponectin on the metabolic syndrome in overweight Latino youth. PARTICIPANTS: Participants included 175 overweight children (aged 11.1 +/- 1.7 yr, body mass index percentile 97.3 +/- 2.9) with a family history of type 2 diabetes. METHODS: Metabolic syndrome was defined according to a pediatric adaptation of the Adult Treatment Panel III report and included dyslipidemia, abdominal obesity, elevated blood pressure, and prediabetes (impaired fasting glucose or impaired glucose tolerance from a 2-h oral glucose tolerance test). Body composition was estimated via dual-energy x-ray absorptiometry, insulin sensitivity was quantified by the frequently sampled iv glucose tolerance test, visceral fat was measured using magnetic resonance imaging, and adiponectin was determined in fasting serum. RESULTS: In simple linear regression, adiponectin was significantly and inversely related to systolic blood pressure (P < 0.05), waist circumference (P < 0.001), triglycerides (P < 0.001), and 2-h glucose levels (P < 0.05) and positively related to high-density lipoprotein-cholesterol (P < 0.001). In multiple linear regression, adiponectin was significantly related to triglycerides (P < 0.01) and high-density lipoprotein-cholesterol (P < 0.01) independent of age, gender, Tanner stage, body composition, and insulin sensitivity. Analyses of covariance established that adiponectin levels were approximately 25% higher in healthy overweight youth, compared with those with the metabolic syndrome (12.5 +/- 3.5 vs. 9.4 +/- 2.8 microg/ml; P < 0.05). In multiple logistic regression, adiponectin was a significant independent predictor of the metabolic syndrome, even after adjustment for confounders including insulin sensitivity and visceral fat. CONCLUSIONS: Hypoadiponectinemia is an independent biomarker of the metabolic syndrome, and thus, adiponectin may play a role in the pathophysiology of the disorder in overweight youth.

Associations of dietary sugar and glycemic index with adiposity and insulin dynamics in overweight Latino youth.

BACKGROUND: Few studies have examined the relation between dietary carbohydrate quality, adiposity, and insulin dynamics in children. OBJECTIVE: The objective of the study was to determine which aspects of dietary carbohydrate, specifically dietary sugar, fiber, glycemic index, or glycemic load, are associated with adiposity and insulin dynamics in overweight Latino children. DESIGN: We examined 120 overweight Latino children (10-17 y old) with a family history of type 2 diabetes. Dietary intake was determined by repeated 24-h diet recalls. Adiposity was assessed by using total-body dual-energy X-ray absorptiometry. Insulin dynamics [insulin sensitivity (SI), acute insulin response, and disposition index (an index of beta-cell function)] were measured by using a frequently sampled intravenous-glucose-tolerance test. RESULTS: After adjustment for covariates, total sugar (g/d) was positively correlated with body mass index (BMI; in kg/m(2)), BMI z scores, and total fat mass (r = 0.20, r = 0.22, and r = 21, respectively; P < 0.05) and negatively correlated with SI and disposition index (r = -0.29 and r = -0.24, respectively; P < 0.05). Dietary fiber, glycemic index, and glycemic load were not significantly correlated with adiposity or insulin dynamics before or after control for covariates. Regression analyses showed that total sugar intake explained an additional 3.4%, 4.6%, and 2.4% of the variance in BMI, BMI z scores, and total fat mass, respectively, and an additional 5.6% and 4.8% of the variance in SI and disposition index (P < 0.05), respectively, after control for covariates. CONCLUSION: In this cohort, total sugar intake, rather than glycemic index or glycemic load, was associated with higher adiposity measures, lower SI, and lower measures of insulin secretion.

The relation of sugar intake to beta cell function in overweight Latino children.

BACKGROUND: Few studies have investigated the association between sugar intake and insulin dynamics in children, and none have examined this association in overweight Latino youth. OBJECTIVE: We aimed to examine the relation between dietary components, especially sugar intake, and insulin dynamics in overweight Latino youth. DESIGN: We examined 63 overweight Latino children aged 9-13 y. Dietary intake was determined by 3-d records, and body composition was measured with dual-energy X-ray absorptiometry. Insulin sensitivity (S(I)), acute insulin response (AIR), and disposition index (an index of beta cell function) were measured by using a frequently sampled intravenous-glucose-tolerance test and minimal modeling. Hierarchical regression analysis ascertained the potential independent relation between insulin dynamics and dietary components. RESULTS: The relation between macronutrient intake and any variable related to insulin dynamics was not significant. However, higher total sugar intake, although not related to S(I), was significantly associated with lower AIR (beta = -0.296, P = 0.045) and lower beta cell function (beta = -0.421, P = 0.043), independent of the covariates age, sex, body composition, Tanner stage, and energy intake. Sugar-sweetened beverage intakes trended toward inverse association with lower AIR (beta = -0.219, P = 0.072) and beta cell function (beta = -0.298, P = 0.077). CONCLUSIONS: In overweight Latino children, higher intakes of sugar and sugar-sweetened beverages were associated with lower AIR and disposition index, which suggested that these children already have early signs of poor beta cell function. These results emphasize the need for early nutritional interventions to reduce daily sugar intake in overweight Latino children and potentially reduce their risk for type 2 diabetes.

High fructose corn syrup and diabetes prevalence: a global perspective.

The overall aim of this study was to evaluate, from a global and ecological perspective, the relationships between availability of high fructose corn syrup (HFCS) and prevalence of type 2 diabetes. Using published resources, country-level estimates (n =43 countries) were obtained for: total sugar, HFCS and total calorie availability, obesity, two separate prevalence estimates for diabetes, prevalence estimate for impaired glucose tolerance and fasting plasma glucose. Pearson's correlations and partial correlations were conducted in order to explore associations between dietary availability and obesity and diabetes prevalence. Diabetes prevalence was 20% higher in countries with higher availability of HFCS compared to countries with low availability, and these differences were retained or strengthened after adjusting for country-level estimates of body mass index (BMI), population and gross domestic product (adjusted diabetes prevalence=8.0 vs. 6.7%, p=0.03; fasting plasma glucose=5.34 vs. 5.22 mmol/L, p=0.03) despite similarities in obesity and total sugar and calorie availability. These results suggest that countries with higher availability of HFCS have a higher prevalence of type 2 diabetes independent of obesity.

LA Sprouts: a garden-based nutrition intervention pilot program influences motivation and preferences for fruits and vegetables in Latino youth.

Garden-based approaches to nutrition education may be effective for improving nutrition habits in adolescents. A quasi-experimental, garden-based intervention for Latino youth (LA Sprouts) was piloted and assessed for its influence on behavior associated with dietary intake and psychosocial factors. Study participants were 104 predominately Latino fourth and fifth grade students in Los Angeles (mean age, 9.8±0.7 years; n=70 control subjects, n=34 LA Sprouts participants); more than half (n=61, 59.8%) were overweight or obese (body mass index ≥85th percentile). LA Sprouts participants received an intervention of weekly 90-minute culturally tailored, interactive classes for 12 consecutive weeks at a community garden during the spring of 2010; control participants received an abbreviated delayed intervention. Questionnaire data were obtained before and after the intervention. Compared with control subjects, LA Sprouts participants had an increased preference for vegetables overall, increased preferences for three target fruits and vegetables, as well as improved perceptions that "vegetables from the garden taste better than vegetables from the store." In the overweight/obese subgroup (n=61), LA Sprouts participants had a 16% greater increase in their preference for vegetables compared with control subjects (P=0.009). Results from this pilot study suggest that a cooking, nutrition, and gardening after-school program in a garden-based setting can improve attitudes and preferences for fruits and vegetables in Latino youth, which may lead to improved nutritional habits and dietary intake and reduced health disparities.

Randomized controlled trial to improve adiposity, inflammation, and insulin resistance in obese African-American and Latino youth.

The purpose of this study was to examine ethnic differences in the metabolic responses to a 16-week intervention designed to improve insulin sensitivity (SI), adiposity, and inflammation in obese African-American and Latino adolescents. A total of 100 participants (African Americans: n = 48, Latino: n = 52; age: 15.4 ± 1.1 years, BMI percentile: 97.3 ± 3.3) were randomly assigned to interventions: control (C; n = 30), nutrition (N; n = 39, 1×/week focused on decreasing sugar and increasing fiber intake), or nutrition + strength training (N+ST; n = 31, 2×/week). The following were measured at pre- and postintervention: strength, dietary intake, body composition (dual-energy X-ray absorptiometry/magnetic resonance imaging) and glucose/insulin indexes (oral glucose tolerance test (OGTT)/intravenous glucose tolerance test (IVGTT)) and inflammatory markers. Overall, N compared to C and N+ST reported significant improvements in SI (+16.5% vs. -32.3% vs. -6.9% respectively, P < 0.01) and disposition index (DI: +15.5% vs. -14.2% vs. -13.7% respectively, P < 0.01). N+ST compared to C and N reported significant reductions in hepatic fat fraction (HFF: -27.3% vs. -4.3% vs. 0% respectively, P < 0.01). Compared to N, N+ST reported reductions in plasminogen activator inhibitor-1 (PAI-1) (-38.3% vs. +1.0%, P < 0.01) and resistin (-18.7% vs. +11.3%, P = 0.02). There were no intervention effects for all other measures of adiposity or inflammation. Significant intervention by ethnicity interactions were found for African Americans in the N group who reported increases in total fat mass, 2-h glucose and glucose incremental areas under the curve (IAUC) compared to Latinos (P's < 0.05). These interventions yielded differential effects with N reporting favorable improvements in SI and DI and N+ST reporting marked reductions in HFF and inflammation. Both ethnic groups had significant improvements in metabolic health; however some improvements were not seen in African Americans.

Sugar content of popular sweetened beverages based on objective laboratory analysis: focus on fructose content.

The consumption of fructose, largely in the form of high fructose corn syrup (HFCS), has risen over the past several decades and is thought to contribute negatively to metabolic health. However, the fructose content of foods and beverages produced with HFCS is not disclosed and estimates of fructose content are based on the common assumption that the HFCS used contains 55% fructose. The objective of this study was to conduct an objective laboratory analysis of the sugar content and composition in popular sugar-sweetened beverages with a particular focus on fructose content. Twenty-three sugar-sweetened beverages along with four standard solutions were analyzed for sugar profiles using high-performance liquid chromatography (HPLC) in an independent, certified laboratory. Total sugar content was calculated as well as percent fructose in the beverages that use HFCS as the sole source of fructose. Results showed that the total sugar content of the beverages ranged from 85 to 128% of what was listed on the food label. The mean fructose content in the HFCS used was 59% (range 47-65%) and several major brands appear to be produced with HFCS that is 65% fructose. Finally, the sugar profile analyses detected forms of sugar that were inconsistent with what was listed on the food labels. This analysis revealed significant deviations in sugar amount and composition relative to disclosures from producers. In addition, the tendency for use of HFCS that is higher in fructose could be contributing to higher fructose consumption than would otherwise be assumed.

LA Sprouts: a gardening, nutrition, and cooking intervention for Latino youth improves diet and reduces obesity.

Evidence demonstrates that a gardening and nutrition intervention improves dietary intake in children, although no study has evaluated the effect of this type of intervention on obesity measures. The objective of this pilot study was to develop and test the effects of a 12-week, after-school gardening, nutrition, and cooking program (called LA Sprouts) on dietary intake and obesity risk in Latino fourth- and fifth-grade students in Los Angeles, CA. One hundred four primarily Latino children (mean age 9.8±0.7 years), 52% boys and 59% overweight, completed the program (n=70 controls, n=34 LA Sprouts participants). Weight, height, body mass index, waist circumference, body fat (via bioelectrical impendence), blood pressure, and dietary intake (via food frequency screener) were obtained at baseline and postintervention. LA Sprouts participants received weekly 90-minute, culturally tailored, interactive classes for 12 consecutive weeks during spring 2010 at a nearby community garden, whereas control participants received an abbreviated delayed intervention. Compared to subjects in the control group, LA Sprouts participants had increased dietary fiber intake (+22% vs -12%; P=0.04) and decreased diastolic blood pressure (-5% vs -3%; P=0.04). For the overweight subsample, LA Sprouts participants had a significant change in dietary fiber intake (0% vs -29%; P=0.01), reduction in body mass index (-1% vs +1%; P=0.04) and less weight gain (+1% vs +4%; P=0.03) compared to those in the control group. We conclude that a gardening, nutrition, and cooking intervention is a promising approach to improve dietary intake and attenuate weight gain in Latino children, particularly in those who are overweight.

Ethnic differences in pancreatic fat accumulation and its relationship with other fat depots and inflammatory markers.

OBJECTIVE: Visceral adipose tissue (VAT) and hepatic fat are associated with insulin resistance and vary by sex and ethnicity. Recently, pancreatic fat fraction (PFF) has also been linked with increasing obesity. Our aim was to assess ethnic and sex differences in PFF and its relationship to other fat depots, circulating free fatty acids (FFA), insulin secretion and sensitivity, and inflammation in obese adolescents and young adults. RESEARCH DESIGN AND METHODS: We examined 138 (40 males, 98 females) obese Hispanics and African Americans (13-25 years). Subcutaneous adipose tissue and VAT volumes, hepatic fat fraction (HFF), and PFF were determined by magnetic resonance imaging. Insulin sensitivity and ß-cell function were assessed during an intravenous glucose tolerance test. RESULTS: Hispanics had higher PFF than African Americans (7.3 ± 3.8 vs. 6.2 ± 2.6%, P = 0.03); this ethnic difference was higher in young adults compared with children and adolescents (ethnicity × age: P = 0.01). Males had higher PFF than females (P < 0.0001). PFF was positively correlated with VAT (r = 0.45, P < 0.0001), HFF (r = 0.29, P < 0.0001), and FFA (r = 0.32, P = 0.001). PFF positively correlated with inflammatory markers but lost significance when adjusted for VAT. In multiple stepwise regression analysis, VAT and FFA were the best predictors of PFF (adjusted R(2) = 0.40). There were no significant correlations between PFF and markers of insulin sensitivity or ß-cell function. CONCLUSIONS: PFF is higher in Hispanics than African Americans, and this difference increases with age. In young obese individuals, PFF is related to VAT, HFF, and circulating FFA, thus possibly contributing to their increased risk for type 2 diabetes and related metabolic disorders.

Physical activity, sedentary behavior, and the metabolic syndrome in minority youth.

PURPOSE: This study aimed to determine the associations among physical activity, sedentary behavior, and the metabolic syndrome (MetS) in Latino and African American youth using both subjective and objective measures of activity levels. METHODS: Cross-sectional data from 105 participants from three pediatric obesity studies that share a core set of methods and measures (Latino 74%, female 75%, mean age = 13 ± 3 yr) were used. Measures included moderate-to-vigorous physical activity and sedentary behavior by accelerometry and 3-Day Physical Activity Recall (3DPAR), fat and lean tissue mass by BodPod™, fasting glucose, lipids, blood pressure, and waist circumference. Associations between physical activity, sedentary behavior, and MetS were examined using ANCOVA, Pearson correlations, partial correlations, and logistic regressions with adjustments for age, sex, ethnicity, fat and lean mass, and pubertal Tanner stage. RESULTS: Accelerometry data showed that greater time engaging in moderate-to-vigorous physical activity was related to lower odds of the MetS (odds ratio = 0.49, 95% confidence interval = 0.25-0.98), independent of sedentary behavior and covariates, and inversely correlated with fasting glucose (r = -0.21, P = 0.03) and systolic blood pressure (r = -0.25, P = 0.01), adjusting for covariates. Data from the 3DPAR showed that higher levels of sedentary behavior were related to higher odds of the MetS (odds ratio = 4.44, 95% confidence interval = 1.33-14.79), independent of moderate-to-vigorous physical activity and covariates, negatively correlated with HDL-cholesterol (r = -0.21, P = 0.04) and positively correlated systolic blood pressure (r = 0.26, P = 0.009), adjusting for covariates. CONCLUSIONS: Future interventions aiming to improve metabolic health in youth should target both the promotion of physical activity and the reduction of sedentary behavior. Subjective and objective measures should be used in conjunction to better capture activity behaviors.

Cortisol is negatively associated with insulin sensitivity in overweight Latino youth.

CONTEXT AND OBJECTIVE: The purpose of the present study was to investigate the cross-sectional and longitudinal associations of serum morning cortisol and aspects of insulin action in Latino children and adolescents (8-13 yr) at risk for type 2 diabetes. DESIGN AND PARTICIPANTS: The present study includes a cross-sectional analysis in 211 participants and a longitudinal analysis in a subset of 143 participants. RESULTS: At baseline, cortisol was negatively associated with fasting glucose (r = 0.23; P < 0.01), ß-cell function (disposition index, r = -0.24; P < 0.05), and acute insulin response to glucose (r = -0.27; P < 0.05). Baseline cortisol was also significantly related to the change in insulin sensitivity over 1 yr (r = -0.23; P < 0.05). These results did not differ by Tanner stage or sex. CONCLUSIONS: Cortisol contributes to the reduction in insulin sensitivity at an early age in Latino children and adolescents. Specifically, cortisol is negatively associated with potential compensatory mechanisms for insulin resistance, such as increased ß-cell function and increased insulin release to a glucose challenge, by exacerbating the progression toward insulin resistance in this population. The results underline the relevance of glucocorticoid reduction for the prevention of metabolic disease in Latino children and adolescents.

Increased physical activity and reduced adiposity in overweight Hispanic adolescents.

PURPOSE: The objectives of this study were to examine 1) whether changes in total physical activity (PA; counts per minute, cpm) and time spent in moderate to vigorous PA (MVPA) are associated with changes in adiposity and 2) whether energy intake influences the relationship between changes in PA and changes in adiposity in overweight Hispanic adolescents. METHODS: Analysis included 38 overweight (body mass index, >85th percentile) Hispanic adolescents with complete pretest and posttest data on relevant variables after participating in a 16-wk intervention. The intervention treatment did not influence PA, so the sample was combined and the randomization group was adjusted for in the analysis. Body composition by dual-energy x-ray absorptiometry, 7-d PA by accelerometry, and dietary intake by 3-d diet records were assessed before and after intervention. RESULTS: Within individuals, the mean increase of PA (n = 19) and mean decrease of PA (n = 19) was approximately 105 cpm. A 100-cpm increase in total PA was associated with a decrease of 1.3 kg of fat mass and 0.8% body fat after adjusting for pretest adiposity, PA, age, sex, and treatment (P < 0.05). Controlling for energy intake modestly strengthened the relationships between total PA and fat mass and percent body fat. Changes in MVPA were not related to changes in adiposity after controlling for total PA (P > 0.05). CONCLUSIONS: Increasing total PA by 28% (100 cpm) was associated with a decrease of 1.4 kg of fat mass and 1% body fat for 16 wk in overweight Hispanic adolescents independent of intervention group assignment. Increases in total PA, compared with MVPA, may be sufficient to improve body composition in overweight Hispanic adolescents.

Ethnic differences in insulin action in obese African-American and Latino adolescents.

INTRODUCTION: African-American children have a greater acute insulin response to iv glucose (AIR) compared with Latino children despite a similar degree of insulin resistance and body composition. It is unclear whether African-Americans demonstrate an exaggerated insulin response to an oral glucose challenge and whether any differences are seen in more obese children in advanced pubertal development. PURPOSE: Our objective was to compare glucose and insulin indices derived from an oral glucose tolerance test (OGTT) and iv glucose tolerance test (IVGTT) in sedentary, obese African-American (n=59) and Latino (n=83) adolescents. METHODS: Glucose and insulin incremental area under the curve was measured during an OGTT, and AIR, insulin sensitivity, disposition index, and glucose effectiveness were assessed during an IVGTT. Body composition was assessed via dual-energy x-ray absorptiometry and magnetic resonance imaging. RESULTS: From the OGTT, glucose and insulin IAUC were 29.1 and 22.5% lower (P=0.01) in African-Americans compared with Latino adolescents. From the IVGTT, insulin sensitivity and glucose effectiveness were 41.7% (P<0.01) and 50.0% (P=0.02) lower in African-Americans compared to Latinos. AIR (P=0.001) and disposition index (P=0.02) were 63.0 and 48.8% higher in African-Americans, respectively, compared with Latinos. These findings persisted after controlling for body composition and fat distribution. CONCLUSIONS: There were marked differences in glucose and insulin indices derived from the OGTT and IVGTT. African-Americans were more insulin resistant as measured by the IVGTT compared with the Latino adolescents. However, the well-described hyperinsulinemia in response to iv glucose was not observed after oral glucose in African-American adolescents.