Obese Latino Adolescents Research Articles

Ambient air pollutants are associated with morning serum cortisol in overweight and obese Latino youth in Los Angeles

BackgroundHypothalamic-pituitary-adrenal (HPA)-axis dysfunction has been associated with a variety of mental health and cardio-metabolic disorders. While causal models of HPA-axis dysregulation have been largely focused on either pre-existing health conditions or psychosocial stress factors, recent evidence suggests a possible role for central nervous system activation via air pollutants, such as nitrogen dioxide (NO2), ozone (O3) and particulate matter (PM). Therefore, in an observational study of Latino youth, we investigated if monthly ambient NO2, O3, and PM with aerodynamic diameter ≤ 2.5 (PM2.5) exposure were associated with morning serum cortisol levels.MethodsIn this cross-sectional study, morning serum cortisol level was assessed after a supervised overnight fast in 203 overweight and obese Latino children and adolescents (female/male: 88/115; mean age: 11.1 ± 1.7 years; pre-pubertal/pubertal/post-pubertal: 85/101/17; BMI z-score: 2.1 ± 0.4). Cumulative concentrations of NO2, O3 and PM2.5 were spatially interpolated at the residential addresses based on measurements from community monitors up to 12 months prior to testing. Single and multi-pollutant linear effects models were used to test the cumulative monthly lag effects of NO2, O3, and PM2.5 on morning serum cortisol levels after adjusting for age, sex, seasonality, social position, pubertal status, and body fat percent by DEXA.ResultsSingle and multi-pollutant models showed that higher O3 exposure (derived from maximum 8-h exposure windows) in the prior 1–7 months was associated with higher serum morning cortisol (p < 0.05) and longer term PM2.5 exposure (4–10 months) was associated with lower serum morning cortisol levels (p < 0.05). Stratification by pubertal status showed associations in pre-pubertal children compared to pubertal and post-pubertal children. Single, but not multi-pollutant, models showed that higher NO2 over the 4–10 month exposure period associated with lower morning serum cortisol (p < 0.05).ConclusionsChronic ambient NO2, O3 and PM2.5 differentially associate with HPA-axis dysfunction, a mechanism that may serve as an explanatory pathway in the relationship between ambient air pollution and metabolic health of youth living in polluted urban environments. Further research that uncovers how ambient air pollutants may differentially contribute to HPA-axis dysfunction are warranted.

1338-P: Lipoprotein Insulin Resistance Scores Decrease after a Lifestyle Intervention among Obese Adolescents with Prediabetes

Introduction: Insulin resistance (IR) is associated with impaired lipid metabolism. The Lipoprotein Insulin Resistance Index (LP-IR) is a novel composite biomarker that estimates IR from lipoprotein particle size and concentration, and prospectively predicts type 2 diabetes (T2D) in adults. Less is known about LP-IR and T2D risk in youth. This study evaluated the effect of a lifestyle intervention on LP-IR scores in obese Latino youths with prediabetes. Methods: Obese Latino adolescents (n=27, 15.5±1.1 years, 13 male/14 female) with prediabetes (defined as a 2-hour, post-challenge glucose ≥120 mg/dL) completed a 12-week intervention including nutrition education (one hour/week) and moderate-to-vigorous physical activity (three hours/week). Measurements at baseline and 12 weeks included anthropometrics, total, large, medium, and small lipoprotein particle concentrations (VLDL and chylomicron, LDL, and HDL), mean lipoprotein particle sizes (VLDL, LDL, HDL), lipid concentrations (total triglyceride, VLDL and chylomicron triglyceride, and HDL cholesterol), and LP-IR scores using nuclear magnetic resonance spectroscopy. Results: After adjusting for body fat and sex, significant reductions in LP-IR scores (63.2±14.4 vs. 59.0±15.5 units, p=0.013), large VLDL and chylomicron particle concentration (9.1±7.8 vs. 7.3±6.2 nmol/L, p=0.004), total HDL particle concentration (30.2±4.3 vs. 28.3±3.9 μmol/L, p=0.013), total triglyceride concentration (144.5±91.9 vs. 122.9±77.9 mg/dL, p=0.002), as well as VLDL and chylomicron triglyceride concentration (117.5±66.7 vs. 102.0±55.7 mg/dL, p=0.020) were observed following lifestyle intervention. Conclusion: Lifestyle intervention significantly reduces LP-IR scores and lipoprotein particle parameters in obese adolescents with prediabetes and may decrease future risk of cardiometabolic disorders through improvements in insulin resistance and lipoprotein metabolism. Disclosure A.M. Renteria-Mexia: None. M. Olson: None. M.A. Connelly: Employee; Self; LabCorp. S. Vega-López: None. A. Williams: None. G.Q. Shaibi: None. Funding National Institute on Minority Health and Health Disparities (P20MD002316, U54MD002316); Programa para el Desarrollo Profesional Docente, para el Tipo Superior, México (to A.M.R-M.)

1327-P: Baseline Characteristics of Latino Youth with Prediabetes: The Preventing Diabetes in Latino Youth Cohort

Background: Latino youth are disproportionately impacted by type 2 diabetes (T2D). Prediabetes is an intermediate stage in the pathogenesis of T2D and represents a critical opportunity for prevention in adults. In youth and adults, prediabetes is identified by HbA1c, fasting glucose, and/or 2-hour glucose (2HrGluc). In youth, it is not well-characterized whether prediabetes by each criterion confers a similar metabolic profile. The objective of this study is to compare baseline characteristics of prediabetic Latino youth enrolled in a randomized, controlled diabetes prevention trial based on hyperglycemic status. Methods: Participants were selected for the following inclusion criteria: 1) Latino ancestry, 2) Age 12-16 years, 3) BMI ≥ 95th percentile for age and sex, and 4) Prediabetes defined as HbA1c ≥ 5.7% and &amp;lt; 6.5%, fasting glucose ≥ 100 and &amp;lt; 126 mg/dL, or 2HrGluc ≥ 120 and &amp;lt; 200 mg/dL after an OGTT. Results: Ninety-four youth (age 13.5±1.4 years, 59 male/35 female) met inclusion criteria with 25% eligible by HbA1c, 45% by 2HrGluc, and 30% based on more than one criterion. No participant met eligibility by fasting glucose alone. Those who met eligibility by more than one criterion were more likely to be exposed to gestational diabetes in utero (19.2%) compared to 2HrGluc (7.9%) or HbA1c (0%) groups, P=0.04. The multiple eligibility group also exhibited higher hepatic fat fraction by MRI (11.9%) compared to 2HrGluc (7.6%) and HbA1c (6.6%) groups, P=0.055. There were no statistically significant differences between eligibility groups in body fat percentage, BMI percentile, diabetes family history, liver enzymes, or lipid profiles. Conclusion: These data suggest that obese Latino adolescents with prediabetes according to more than one criteria were more likely to be exposed to hyperglycemia in utero and exhibit higher liver fat content. Whether prediabetes criteria are associated with a differential response to lifestyle intervention will be tested in this clinical trial. Disclosure M. Olson: None. Y.P. Konopken: None. F.G. Castro: None. H.H. Hu: None. C. Keller: None. D.L. Patrick: None. A. Williams: None. S. Ayers: None. W.C. Knowler: None. J. Pimentel: None. A. Pena: None. E.G. Soltero: None. G.Q. Shaibi: None. Funding National Institutes of Health (R01DK107579P)

Effects of a lifestyle intervention on markers of cardiometabolic risk and oxidized lipoproteins among obese adolescents with prediabetes.

Obesity and hyperglycaemia contribute to the atherosclerotic process in part through oxidative modifications to lipoprotein particles. The present study aimed to evaluate the effects of a lifestyle intervention on markers of oxidized lipoproteins in obese Latino adolescents with prediabetes. Pre-post design. Participants were enrolled into a 12-week lifestyle intervention. Measurements pre- and post-intervention included anthropometrics and body composition, lipid panel, oxidized LDL (oxLDL), oxidized HDL (oxHDL), intake of fresh fruits and vegetables, and cardiorespiratory fitness. Thirty-five obese Latino adolescents (seventeen females, eighteen males; mean age 15·5 (sd 1·0) years; mean BMI percentile 98·5 (sd 1·2)) with prediabetes. Intervention participation resulted in significant reductions in weight (-1·2 %, P = 0·042), BMI and BMI percentile (-2·0 and -0·4 %, respectively, P < 0·001), body fat (-7·0 %, P = 0·025), TAG (-11·8 %, P = 0·032), total cholesterol (-5·0 %, P = 0·002), VLDL-cholesterol (-12·5 %, P = 0·029), and non-HDL-cholesterol (-6·7 %, P = 0·007). Additionally, fitness (6·4 %, P < 0·001) and intake of fruits and vegetables (42·4 %, P = 0·025) increased significantly. OxLDL decreased significantly after the intervention (51·0 (sd 14·0) v. 48·7 (sd 12·8) U/l, P = 0·022), while oxHDL trended towards a significant increase (395·2 (sd 94·6) v. 416·1 (sd 98·4) ng/ml, P = 0·056). These data support the utility of lifestyle intervention to improve the atherogenic phenotype of Latino adolescents who are at high risk for developing premature CVD and type 2 diabetes.

Probiotic supplementation increases obesity with no detectable effects on liver fat or gut microbiota in obese Hispanic adolescents: a 16-week, randomized, placebo-controlled trial.

Numerous studies have shown that there are links between obesity, liver fat and the gut microbiome. However, there are mixed results on whether probiotics could impact the gut microbiome and/or help to decrease liver fat and obesity outcomes. This study aimed to determine whether a probiotic supplement (VSL#3® ) intervention altered gut microbiota and/or gut hormones associated with appetite regulation. The secondary aim of this study was to determine whether VSL#3® altered body composition and liver fat and fibrosis. We conducted a double-blind, randomized placebo-controlled trial in 19 obese Latino adolescents. The intervention consisted of three packets per day of VSL#3® or a matched placebo for 16weeks. Pre-intervention and post-intervention measures included gut microbial abundance, gut appetite regulating hormones, anthropometrics, body composition, liver fat and liver fibrosis. We conducted linear models to determine whether there were any significant differences in the changes in these outcomes following VSL#3® intervention. Compared with placebo, adolescents that received VSL#3 had significant increases in total adiposity (%) (+1.7±0.6 vs. -1.3±0.5, p<0.01) and trunk adiposity (%) (+3.3±0.8 vs. -1.8±0.8, p<0.01) with no significant effects on liver fat/fibrosis, insulin/glucose, gut microbial abundances or gut hormones. VSL#3 supplementation may lead to increased adiposity in obese Latino adolescents with no significant detectable changes in gut microbiota, gut appetite-regulating hormones, liver fat and fibrosis and dietary intake. However, it is important to note that recruitment efforts were terminated early and the sample size fell short of what was planned for this trial.

Preventing diabetes in obese Latino youth with prediabetes: a study protocol for a randomized controlled trial

BackgroundObese Latino adolescents are disproportionately impacted by insulin resistance and type 2 diabetes. Prediabetes is an intermediate stage in the pathogenesis of type 2 diabetes and represents a critical opportunity for intervention. However, to date, no diabetes prevention studies have been conducted in obese Latino youth with prediabetes, a highly vulnerable and underserved group. Therefore, we propose a randomized-controlled trial to test the short-term (6-month) and long-term (12-month) efficacy of a culturally-grounded, lifestyle intervention, as compared to usual care, for improving glucose tolerance and reducing diabetes risk in 120 obese Latino adolescents with prediabetes.MethodsParticipants will be randomized to a lifestyle intervention or usual care group. Participants in the intervention group will attend weekly nutrition and wellness sessions and physical activity sessions twice a week for six months, followed by three months of booster sessions. The overall approach of the intervention is framed within a multilevel Ecodevelopmental model that leverages community, family, peer, and individual factors during the critical transition period of adolescence. The intervention is also guided by Social Cognitive Theory and employs key behavioral modification strategies to enhance self-efficacy and foster social support for making and sustaining healthy behavior changes. We will test intervention effects on quality of life, explore the potential mediating effects of changes in body composition, total, regional, and organ fat on improving glucose tolerance and increasing insulin sensitivity, and estimate the initial incremental cost effectiveness of the intervention as compared with usual care for improving glucose tolerance.DiscussionThe proposed trial builds upon extant collaborations of a transdisciplinary team of investigators working in concert with local community agencies to address critical gaps in how diabetes prevention interventions for obese Latino youth are developed, implemented and evaluated. This innovative approach is an essential step in the development of scalable, cost-effective, solution oriented programs to prevent type 2 diabetes in this and other populations of high-risk youth.Trial RegistrationNCT02615353, registered on June 8, 2016.

Food Insecurity and Quality of Life among Obese Latino Adolescents

ObjectiveTo assess the relationship between quality of life and food insecurity among obese Latino adolescents participating in a diabetes prevention program.MethodsBaseline surveys including the USDA food security screener and the Youth Quality of Life scale were administered to 62 parent‐adolescent (mean age 14.8 yrs) dyads prior to the intervention. Multivariate regressions were used to assess the relationship between youth's quality of life and food insecurity (both household and adolescent's self‐report) , adjusting for parent employment status, household size, and youth's gender and age.ResultsSelf‐reported food insecurity prevalence was high among parents (54.2%) and moderate among youth (19.7%). The odds of a child reporting food insecurity was 3.8 times higher if parents reported food insecurity (p=0.07). The mean adolescent quality of life score was 81.0±11.3. There was no significant relationship between adolescents' quality of life and food insecurity status(β=‐3.67; p=0.33), or in the relationship in adolescents' quality of life and parents' food security status even after adjusting for child food insecurity status (β=‐2.01; p=0.59).ConclusionsParents may protect their children from food insecurity, given the lower relative prevalence of food insecurity in adolescents as compared to parents. Surprisingly, there was no association observed between food security and quality of life; health professionals addressing food insecurity among youth may consider capitalizing on the positive outcomes in overall quality of life when designing interventions.

Effects of a diabetes prevention programme on weight-specific quality of life in Latino youth.

To examine the effects of a diabetes prevention programme on weight-specific Quality of Life (QOL) in obese Latino youth. Fifteen obese Latino adolescents (body mass index % = 96.4 ± 1.2; age = 15.0 ± 1.0) completed a 12-week culturally grounded, community-based intervention designed to improve physical and psychosocial health. Weight-specific QOL was assessed by the Youth Quality of Life-Weight module and compared with age, sex and ethnicity-matched lean youth. At baseline, intervention youth exhibited significantly lower weight-specific QOL compared with lean youth (70.8 ± 5.4 vs. 91.2 ± 2.2, P = 0.002). However, following the intervention, total weight-specific QOL increased by 21.8% among obese youth (70.8 ± 5.4 to 86.2 ± 4.3, P < 0.001) and was no longer different from lean controls. Significant increases in weight-specific QOL were noted across all subdomains including self (45.7%), social (11.9%) and environmental (36.2%) despite the fact that weight did not change (90.6 ± 6.8 to 89.9 ± 7.2, P = 0.44). The improvements in QOL were maintained for up to 12 months after the intervention. Weight-specific QOL among obese Latino youth can be improved through lifestyle interventions to a level similar to lean peers. Further, weight loss may not be necessary to observe improvements in QOL.

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

BackgroundThere 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.MethodsObese (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.ResultsThe 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.ConclusionsThe 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 registrationClinicaltrials.gov Registry #: NCT01895595

Lifestyle intervention improves lipoprotein particle size and distribution without weight loss in obese Latino adolescents

Childhood obesity is associated with a pro-atherogenic phenotype contributing to increased cardiovascular disease (CVD) risk. This single-arm pilot study examined the effects of a lifestyle intervention on lipoprotein particle size and cholesterol distribution in obese Latino adolescents. Fifteen obese Latino adolescents (15.0 ± 1.0 years) completed a 12-week nutrition education and exercise intervention. Low-density lipoprotein (LDL) particle size and distribution of cholesterol in lipoprotein subclasses were determined via polyacrylamide gel electrophoresis. The intervention resulted in increases in mean LDL particle size (269.3 ± 3.4 to 271.6 ± 2.9 Å, P = 0.0003) and cholesterol in large high-density lipoprotein (HDL) subfractions (22.4 ± 11.2 to 26.8 ± 10.6% area, P = 0.007) along with decreases of cholesterol in small LDL (1.6 ± 2.0 to 0.6 ± 1.2% area, P < 0.01) and HDL subfractions (23.2 ± 9.4 to 19.0 ± 6.7% area, P = 0.05). These improvements were observed independent of changes in weight (90.7 ± 26.2 to 89.9 ± 27.8 kg, P > 0.05) and suggest that lifestyle modification in obese youth may reduce cardiovascular risk by shifting lipoprotein particle size and cholesterol distribution to a less atherogenic phenotype.

Effects of a culturally grounded community-based diabetes prevention program for obese Latino adolescents.

The purpose of this study was to test the feasibility and preliminary effects of a culturally grounded, community-based diabetes prevention program among obese Latino adolescents. Fifteen obese Latino adolescents (body mass index [BMI] percentile = 96.3 ± 1.1, age = 15.0 ± 0.9 years) completed a 12-week intervention that included weekly lifestyle education classes delivered by bilingual/bicultural promotoras and three, 60-minute physical activity sessions per week. Participants were assessed for anthropometrics (height, weight, BMI, and waist circumference), cardiorespiratory fitness, physical activity/inactivity, nutrition behaviors, and insulin sensitivity and glucose tolerance by a 2-hour oral glucose tolerance test. The intervention resulted in significant decreases in BMI z score, BMI percentile, and waist circumference; increases in cardiorespiratory fitness; and decreases in physical inactivity and dietary fat consumption. In addition to these changes, the intervention led to significant improvements in insulin sensitivity and reductions in 2-hour glucose levels. These results support the feasibility and efficacy of a community-based diabetes prevention program for high-risk Latino youth. Translational approaches that are both culturally grounded and biologically meaningful represent a novel and innovative strategy for closing the obesity-related health disparities gap.