Search

Growth mixture models (GMMs) are applied to intervention studies with repeated measures to explore heterogeneity in the intervention effect. However, traditional GMMs are known to be difficult to estimate, especially at sample sizes common in single-center interventions. Common strategies to coerce GMMs to converge involve post hoc adjustments to the model, particularly constraining covariance parameters to equality across classes. Methodological studies have shown that although convergence is improved with post hoc adjustments, they embed additional tenuous assumptions into the model that can adversely impact key aspects of the model such as number of classes extracted and the estimated growth trajectories in each class. To facilitate convergence without post hoc adjustments, this paper reviews the recent literature on covariance pattern mixture models, which approach GMMs from a marginal modeling tradition rather than the random effect modeling tradition used by traditional GMMs. We discuss how the marginal modeling tradition can avoid complexities in estimation encountered by GMMs that feature random effects, and we use data from a lifestyle intervention for increasing insulin sensitivity (a risk factor for type 2 diabetes) among 90 Latino adolescents with obesity to demonstrate our point. Specifically, GMMs featuring random effects--even with post hoc adjustments--fail to converge due to estimation errors, whereas covariance pattern mixture models following the marginal model tradition encounter no issues with estimation while maintaining the ability to answer all the research questions. [For the corresponding grantee submission, see ED618691.]

Objective: To characterize the heterogeneity in response to lifestyle intervention among Latino adolescents with obesity. Methods: We conducted secondary data analysis of 90 Latino adolescents (age 15.4 ± 0.9 y, female 56.7%) with obesity (BMI% 98.1 ± 1.5%) that were enrolled in a 3 month lifestyle intervention and were followed for a year. Covariance pattern mixture models identified response phenotypes defined by changes in insulin sensitivity as measured using a 2 hour oral glucose tolerance test. Baseline characteristics were compared across response phenotypes using one-way ANOVA and chi-square test. Results: Three distinct response phenotypes (PH1, PH2, PH3) were identified. PH1 exhibited the most robust response defined by the greatest increase in insulin sensitivity over time ([beta] ± SE, linear 0.52 ± 0.17, P < 0.001; quadratic -0.03 ± 0.01, P = 0.001). PH2 showed non-significant changes, while PH3 demonstrated modest short-term increases in insulin sensitivity which were not sustained over time (linear 0.08 ± 0.03, P = 0.002; quadratic -0.01 ± 0.002, P = 0.003). At baseline, PH3 (1.1 ± 0.4) was the most insulin resistant phenotype and exhibited the highest BMI% (98.5 ± 1.1%), 2 hours glucose concentrations (144.0 ± 27.5 mg/dL), and lowest beta-cell function as estimated by the oral disposition index (4.5 ± 2.8). Conclusion: Response to lifestyle intervention varies among Latino youth with obesity and suggests that precision approaches are warranted to meet the prevention needs of high risk youth.

Background: Few studies have examined 24-hour activity and sleep behaviors and their contribution to type 2 diabetes (T2D) in Latino adolescents and young adults with obesity. Aim: This study included quantitative data on T2D risk and 24-hour activity and sleep behaviors and qualitative data on individual, social, and environmental behavioral determinants. Method: A 7 day, 24-hour, wrist-worn accelerometer protocol assessed moderate-to-vigorous physical activity (PA), sedentary behaviors (SB), sleep, and sleep regularity, in adolescents (N = 38; 12-16 years) and young adults (N = 22; 18-22 years). T2D-related outcomes included adiposity (BMI, BF%, waist circumference), fasting, and 2-hour glucose. A subsample of participants (N = 16 adolescents, N = 15 young adults) completed interviews to identify behavioral determinants. Results: High levels of PA were observed among adolescents (M = 103.8 ± 67.5 minutes/day) and young adults (M = 96.8 ± 78.8 minutes/day) as well as high levels of SB across both age groups ([greater than or equal to] 10 hours/day). Sleep regularity was negatively associated with adiposity (all ps < 0.05) in both age groups as well as fasting and 2-hour glucose in young adults (all ps < 0.05). Social support was associated with PA in both age groups as well as SB in younger youth. Auditory noises, lights, and safety inhibited sleep in both age groups. Conclusion: PA is critical for disease reduction, yet reducing SB and improving sleep are also important targets for reducing T2D risk in Hispanic adolescents and young adults. Future health promotion and disease prevention strategies should leverage qualitative findings regarding behavioral determinants.

Purpose: Obesity in youth increases the risk for type 2 diabetes (T2D) and elevated abdominal adipose tissue and organ fat may be particularly deleterious. The purpose of this study was to examine associations among measures of adiposity including total, visceral, and organ fat (hepatic and pancreatic) and whether these measures were independently associated with glycemia in Latino youth at risk for diabetes. Methods: Latino adolescents (47 boys and 32 girls, 13.7 ± 1.4 years) with obesity (BMIz 2.3 ± 0.3) were assessed for total fat by DXA and visceral and organ fat by 3 T magnetic resonance imaging. Glycemic indicators included HbA1c, fasting glucose (FG), and 2‐h glucose (2‐HrG) following an oral glucose tolerance test. Pearson correlations and stepwise linear regression analyses controlling for age and sex were used to examine independent associations between adiposity and glycemia. Results: Total fat was associated with visceral (r = 0.66, p = 0.001) and hepatic fat (r = 0.34, p < 0.01) while visceral fat was associated with hepatic (r = 0.42, p < 0.001) and pancreatic fat (r = 0.36, p < 0.001). In stepwise linear regression analysis, hepatic and pancreatic fat were significant predictors of FG, explaining 4.7% and 5.2% of the variance, respectively (total R2 = 0.14, p = 0.02). Hepatic fat was the only significant predictor of 2‐HrG explaining 9.9% of the variance in the model (total R2 = 0.12, p = 0.03). No measure of adiposity was retained as a significant predictor of HbA1c. Conclusion: Hepatic and pancreatic fat were the only adiposity measures independently associated with glycemia but the small amount of variance explained underscores the need for additional T2D biomarkers in high risk youth. [ABSTRACT FROM AUTHOR]

Summary: Background: Glucose concentrations during an oral glucose tolerance test (OGTT) have been used as biomarkers to differentiate type 2 diabetes risk phenotypes. No studies have examined changes in OGTT‐glucose phenotypes following lifestyle intervention among high‐risk youth. Objective: To examine changes in OGTT‐glucose phenotypes following lifestyle intervention and to explore differences in insulin sensitivity and β‐cell function among post‐intervention phenotypes. Methods: Latino adolescents with obesity (n = 48, age 15.4 ± 1.0, BMI% 98.2 ± 1.4, female 56.3%) completed a 12‐week lifestyle intervention that included weekly nutrition education and physical activity. At baseline and 12 weeks, youth completed a 2‐h OGTT with glucose and insulin concentrations assessed at 0′, 30′, 60′, 90′ and 120′. Glucose concentrations during the OGTT were used to identify biomarkers, 1‐h glucose, glucose response curve and time to glucose peak. Using these respective biomarkers, high‐risk (1‐h glucose ≥ 155 mg/dl, Monophasic, Late Peak) and lower‐risk phenotypes (1‐h glucose < 155 mg/dl, Biphasic, Early Peak) were categorized. Insulin sensitivity was estimated by whole‐body insulin sensitivity index (WBISI) and β‐cell function by oral disposition index (oDI). Results: Following intervention, the prevalence of Monophasic phenotypes decreased from 81% to 67% (p = 0.048) and 1‐h glucose ≥ 155 mg/dl from 38% to 10% (p = 0.054). Although Late Peak phenotypes did not significantly change (from 58% to 29%, p = 0.200), Early Peak phenotypes at post‐intervention demonstrated significantly higher WBISI compared to Late Peak (2.3 ± 0.1 vs 1.7 ± 0.2, p = 0.023). Conclusions: OGTT‐glucose phenotypes improve following lifestyle intervention among high‐risk youth. These findings further support their potential utility as clinical biomarkers to identify diabetes risk and risk reduction in youth. [ABSTRACT FROM AUTHOR]

The ectodysplasin receptor (EDAR) is a tumor necrosis factor receptor (TNF) superfamily member. A substitution in an exon of EDAR at position 370 (EDARV370A) creates a gain of function mutant present at high frequencies in Asian and Indigenous American populations but absent in others. Its frequency is intermediate in populations of Mexican ancestry. EDAR regulates the development of ectodermal tissues, including mammary ducts. Obesity and type 2 diabetes mellitus are prevalent in people with Indigenous and Latino ancestry. Latino patients also have altered prevalence and presentation of breast cancer. It is unknown whether EDARV370A might connect these phenomena. The goals of this study were to determine 1) whether EDARV370A is associated with metabolic phenotypes and 2) if there is altered breast anatomy in women carrying EDARV370A. Participants were from two Latino cohorts, the Arizona Insulin Resistance (AIR) registry and Sangre por Salud (SPS) biobank. The frequency of EDARV370A was 47% in the Latino cohorts. In the AIR registry, carriers of EDARV370A (GG homozygous) had significantly (p < 0.05) higher plasma triglycerides, VLDL, ALT, 2-hour post-challenge glucose, and a higher prevalence of prediabetes/diabetes. In a subset of the AIR registry, serum levels of ectodysplasin A2 (EDA-A2) also were associated with HbA1c and prediabetes (p < 0.05). For the SPS biobank, participants that were carriers of EDARV370A had lower breast density and higher HbA1c (both p < 0.05). The significant associations with measures of glycemia remained when the cohorts were combined. We conclude that EDARV370A is associated with characteristics of the metabolic syndrome and breast density in Latinos. [ABSTRACT FROM AUTHOR]

We examined individual and parental demographics and home environment factors associated with locomotor skills in predominantly Hispanic preschool-aged children. We used questionnaires to survey parents, included inquiries regarding parenting practices, parents' physical activity levels, and home-based physical activity resources; and we administered the Progressive Aerobic Cardiovascular Endurance Run (PACER) and the CHAMPS Motor Skills Protocol (CMSP) to children to measure the quantity and quality of their locomotor skills. Participants were 144 parents and their children (78.9% Hispanic, 49.3% girls) recruited from urban, community-based childcare and education centers. We examined the relationship between survey measures and PACER and CMSP scores with forward-selection stepwise linear regression models. Overall, 142 children completed the PACER, and 91 completed the CMSP. At the individual level, a child's age was positively associated with both PACER and CMSP scores, and girls had lower PACER scores than boys. In the home environment, parental promotion of more screen time was associated with a higher children's PACER score. In addition, higher parent concern for children's safety was associated with a lower PACER score. We identified several physical activity promoting parent practices as new home environment factors related to the preschool-aged children's locomotor development. Additional studies are needed to test new hypotheses generated from these data. ClinicalTrials.gov Identifier: NCT03261492 (date of registration 8/25/17) [ABSTRACT FROM AUTHOR]

Purpose: The aim of the study was to characterize experiences of Latino participants receiving genomic screening results. Methods: Participants were recruited at a federally qualified health center in the USA. In-person, semi-structured interviews were conducted in either Spanish or English by a bilingual, bicultural interviewer. Questions focused on motivations for pursuing genomic sequencing, concerns about receiving genomic screening results, and perceived benefits of receiving genomic information. Interviews were audio-recorded, transcribed, and translated. Results: Fifty individuals completed an interview; 39 were conducted in Spanish. Participants described mixed motivations for pursuing genomic screening. Participants viewed the benefits of genomic screening in relation to not only their personal health but to the health of their families and their communities. Participants tended to have few concerns about genomic screening. Those concerns related to potential loss of privacy, misuses of genomic information, and the possibility of receiving distressing results. Some participants had misunderstandings about the scope of the test and the potential implications of their results. Most felt it was better to know about a genetic predisposition to disease than to remain uninformed. Participants felt that genomic screening was worthwhile. Discussion: This is one of the first studies to examine the experiences of Latino individuals receiving genomic screening results. Our results suggest that many Latino patients in the US see value in genomic screening and have limited concerns about its potential to cause harm. These results inform ongoing efforts to increase the availability of genomic medicine to underrepresented populations and add to our understanding of sociocultural drivers in the adoption of precision medicine. [ABSTRACT FROM AUTHOR]

Summary: Background: Body composition differences between males and females emerge during adolescence and continue throughout adulthood; however, whether sex moderates body composition changes in adolescents with obesity after an intervention is unknown. Objective: To examine sex as a moderator of changes in adiposity following lifestyle intervention. Methods: A total of 136 Latino youth with obesity (BMI% 98.2 ± 1.3) aged 14 to 16 years old were randomized to either a 12‐week lifestyle intervention (27 males/40 females) or control (35 males/34 females) group. The intervention included nutrition education (1 h/wk) and moderate‐to‐vigorous physical activity (3 h/wk). Anthropometric data (body mass index [BMI], BMI%, waist circumference, total body fat, and fat‐free mass) were obtained pre‐ and post‐intervention. Sex differences were examined by general linear models with significance determined at P <.05 for the F‐statistic. Results: Sex did not moderate changes in BMI (F1,115 = 0.01, P =.9), BMI% (F1,115 = 0.14, P =.7), or waist circumference (F1,117 = 1.1, P =.3). Sex significantly moderated changes in body fat percent (F1,117 = 5.3, P =.02), fat mass (F1,116 = 4.5, P =.04), and fat‐free mass (F1,116 = 4.3, P =.04). Intervention males compared with females had greater relative reductions in fat percent (−4.1 ± 0.8% vs −1.2 ± 0.7%, P =.02) and fat mass (−5.0 ± 1.1 kg vs −1.5 ± 0.9 kg, P =.02) and gained more fat free mass (3.6 ± 0.9 kg vs 0.5 ± 0.8 kg, P =.02) when compared with same sex controls. Conclusion: Males and females exhibited a differential response to lifestyle intervention for percent fat, fat mass, and fat‐free mass indicating that sex‐specific improvements in body composition favours males over females. [ABSTRACT FROM AUTHOR]

Background Obese youth with prediabetes are at increased risk for premature morbidity and mortality through multiple mechanisms, including increased systemic inflammation. GlycA is a novel measure of systemic inflammation that predicts type II diabetes, cardiovascular events, and all-cause mortality in adults. Objective The purpose of the present study was to examine changes in GlycA after lifestyle intervention among obese, prediabetic Latino youth. Methods Obese, prediabetic Latino youth (n = 27; 15.5 ± 1.1 years, 13 males/14 females) completed a 12-week lifestyle intervention that included weekly nutrition education and 3 d/wk of moderate to vigorous physical activity. Prediabetes was characterized by an expanded definition of impaired glucose tolerance, using 2-hour glucose ≥120 mg/dL after an oral glucose tolerance test. GlycA was assessed at baseline and 12 weeks using nuclear magnetic resonance spectroscopy. Results After the lifestyle intervention, GlycA was significantly reduced (445.3 ± 51.3 μmol/L to 419.0 ± 50.0 μmol/L, P =.01) (mean ± standard deviation). Additional improvements were observed in multiple cardiovascular risk factors, including body mass index (BMI; 34.8 ± 5.0 kg/m2 to 34.0 ± 5.1 kg/m2, P <.001), total cholesterol (154.1 ± 30.3 mg/dL to 143.3 ± 29.1 mg/dL, P =.003), and 2-hour glucose (141.0 ± 13.2 mg/dL to 115.9 ± 31.4 mg/dL, P <.001). Decreases in GlycA were associated with decreases in 2-hour glucose (r = 0.49, P =.008) and BMI (r = 0.41, P =.03). Conclusion These data are consistent with the hypothesis that lifestyle intervention might improve GlycA levels in obese, prediabetic adolescent Latinos, but randomized trial evidence is needed. Healthy lifestyle modifications among high-risk youth may decrease future risk of cardiometabolic disease through reducing systemic inflammation, in addition to improving traditional cardiovascular risk factors. Highlights • Systemic inflammation predicts incident cardiovascular disease and type II diabetes. • We evaluated effects of a 12-week lifestyle program among obese Latino adolescents. • GlycA levels fell by 6% after lifestyle intervention over 12 weeks, • Improvements in GlycA were associated with improvements in diabetes risk factors. [ABSTRACT FROM AUTHOR]

Objective: This study examined the short- and long-term effects of a community-based lifestyle intervention among Latino youth with obesity.Methods: Latino adolescents (14-16 years old) were randomized to a 3-month lifestyle intervention (n = 67) or comparison control (n = 69) and followed for 12 months. The intervention included weekly nutrition and health classes delivered to groups of families and exercise sessions (3 days/week) delivered to groups of adolescents. Comparison youth received laboratory results and general health information. Primary outcomes included insulin sensitivity and weight-specific quality of life (QoL) with secondary outcomes of BMI percentile (BMI%), waist circumference, and percent body fat.Results: At 3 months, youth in the intervention group exhibited significant increases in insulin sensitivity (P < 0.05) and weight-specific QoL (P < 0.001), as well as reductions in BMI%, waist circumference, and percent body fat compared with controls. Increases in weight-specific QoL and reductions in BMI% and percent body fat remained significant at 12 months (P < 0.001), while changes in insulin sensitivity did not. In a subsample of youth with prediabetes at baseline, insulin sensitivity (P = 0.01), weight-specific QoL (P < 0.001), and BMI% (P < 0.001) significantly improved at 3 months.Conclusions: Lifestyle intervention can improve cardiometabolic and psychosocial health in a vulnerable population of Latino adolescents at high risk for developing type 2 diabetes. [ABSTRACT FROM AUTHOR]

Background: Obese 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.Methods: Participants 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.Discussion: The 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 Registration: NCT02615353, registered on June 8, 2016. [ABSTRACT FROM AUTHOR]

Objective One hour (1-hr) glucose during an oral glucose tolerance test ( OGTT) is an emerging biomarker for type 2 diabetes. We compared the predictive power of 1-hr glucose to traditional glycemic markers for prospectively identifying prediabetes in youth. Research design and methods Obese normoglycemic Latino youth (N = 116) were assessed at baseline for glycated hemoglobin ( HbA1c), fasting, 1-hr, and 2-hr glucose during an OGTT and were followed for up to 8 yr for the development of prediabetes. Receiver operating characteristic ( ROC) curves were used and a multivariable prediction model was developed. Results The area under the 1-hr glucose ROC curve was the most powerful predictor of prediabetes over time [0.73, 95% confidence interval ( CI) = 0.64-0.83]. However, combining all indicators into a single model was superior to individual marker models (0.77, 95% CI = 0.690.86). Conclusions These results further support the utility of 1-hr glucose during an OGTT as a prospective marker of diabetes risk in youth. [ABSTRACT FROM AUTHOR]

The translation of research findings into sustainable health promotion and disease prevention programs in community settings remains a challenge. This report describes the process of substantiating a community-developed diabetes prevention program for Latino youth through research. Included are design considerations, measurement strategies, and the context through which the project is culturally grounded for relevance and fit within a local community. The process included (1) refining the program to include salient, stakeholder-identified behavioral components; (2) refining the collaborative effort to embrace the capacity for facilitating relevant behavior change on targeted health-related outcomes to enhance intervention effectiveness; and (3) including the accurate assessment of intervention efficacy via precise assessment of diabetes-related health outcomes. We explain the process of collaborating with community partners to enhance the cultural relevance and sustainability of intervention effects on both individuals and communities. We discuss the rationale for empirical support for academic–community collaborations that function in both a “top-down” and a “bottom-up” manner to advance the science and practice of sustainable and efficacious community health promotion. [ABSTRACT FROM AUTHOR]

Objective: The soluble receptor for advanced glycation end products (sRAGE) has anti-atherogenic properties in adults, however, little is known about the relationship between sRAGE and cardiometabolic disease risk in pediatric populations. Therefore, the purpose of this investigation is to examine the relationship between sRAGE and cardiometabolic risk factors in Latino youth. Research design and methods: Data from 133 Latino youth (58% female; age 16.3±2.8 yr) enrolled in the Arizona Insulin Resistance Registry were analyzed. Cardiometabolic syndrome was determined using a continuous risk score normalized to the population. Components included waist circumference, high-density lipoprotein cholesterol (HDL-c), triglycerides, mean arterial pressure (MAP), and homeostatic assessment of insulin resistance (HOMA-IR). sRAGE levels were determined from fasting serum using an enzyme-linked immunosorbent assay. Results: In univariate analysis, sRAGE was inversely associated with waist circumference (r=-0.22, p=0.01), MAP (r=-0.15, p=0.09), and HOMA-IR (r=-0.29, p<0.01) and positively associated with HDL-c (r=0.19, p<0.05). In multiple regression analysis with age, sex, and BMI, sRAGE remained an independent predictor of cardiometabolic syndrome risk score (R² =0.55, p<0.001). Conclusions: These data suggest that sRAGE may be an early independent biomarker of cardiometabolic disease risk in youth. Prospective studies are needed to establish the predictive utility of sRAGE for long-term disease outcomes. [ABSTRACT FROM AUTHOR]

Objectives. 1) Examine associations between visceral adipose tissue (VAT), subcutaneous abdominal adipose tissue (SAAT), and anthropometric and demographic variables; 2) generate and cross-validate prediction equations for estimating VAT and SAAT in overweight Latino children. Study design. Cross-sectional. Participants. 196 overweight 8–13-year-old Latino youth. Two-thirds (n&VeryThinSpace;=&VeryThinSpace;131) were randomly assigned to a development group to generate prediction equations for VAT and SAAT; one-third (n&VeryThinSpace;=&VeryThinSpace;65) was used as a cross-validation group. Methods and procedures. Anthropometric measurements (height, weight, skinfold thicknesses, and circumferences) were performed. VAT and SAAT were measured using magnetic resonance imaging (MRI). Results. The strongest univariate correlate for VAT was waist circumference (WC) (r&VeryThinSpace;=&VeryThinSpace;0.65, p&VeryThinSpace;<&VeryThinSpace;0.01) while the strongest correlate for SAAT was hip circumference (r&VeryThinSpace;=&VeryThinSpace;0.88, p&VeryThinSpace;<&VeryThinSpace;0.001). Regression analyses showed &nvsim;50% of the variance in VAT was explained by WC (43.8%), Tanner stage (4.2%) and calf skinfold (1.7%). Variance in the SAAT model was explained by WC (77.8%), triceps skinfold (4.2%) and gender (2.3%). Residual analyses showed no bias in either equation. Though mean differences between measured and predicted VAT and SAAT were small, there was a large degree of variability at the individual level especially for VAT. Conclusions. Both VAT and SAAT prediction equations performed well at the group level, but the relatively high degree of variability suggests limited clinical utility of the VAT equation. MRI is currently required to derive an accurate measure of VAT at the individual level. [ABSTRACT FROM AUTHOR]

Purpose. To examine 1-year changes in insulin dynamics in overweight Hispanic children at high-risk of type 2 diabetes as a function of body composition and pubertal transition. Experimental Design . Longitudinal changes in insulin dynamics, body composition and maturation were determined in 132 Hispanic children (70 boys/62 girls; aged 10.9±1.8 years). Methods. Body composition was determined by dual energy x-ray absorptiometry and Tanner stage by physical examination. Insulin sensitivity (SI), the acute insulin response to glucose (AIR) and the disposition index (DI; an index of beta-cell function) were determined using an insulin modified intravenous glucose tolerance test. These measures were conducted at baseline and 1-year later. Results. Fat mass increased by 13% (3.0 kg) and SI declined by 24%. In repeated measures analysis of variance, the fall in insulin sensitivity over 1 year remained highly significant even after adjusting for baseline fat mass, age, gender and change in fat mass. The fall in SI was not significantly influenced by Tanner stage. However, subjects in earlier maturation showed a compensatory increase in AIR (i.e. appropriate beta-cell compensation), whereas subjects in the latter stages of maturation did not (i.e. poor compensation). Conclusions. These results indicate that failure to increase AIR in response to the fall in SI may be one factor in the pathogenesis of the progression of pediatric type 2 diabetes in this at risk population. [ABSTRACT FROM AUTHOR]

The article reports on the effects of exercise on insulin sensitivity in obese youth. Exercise was thought to reduce the risk of type 2 diabetes in adults but it was said to have an effect to insulin resistance in youth. Resistance training exercise program was conducted to overweight Latino male youth who were at high-risk of developing type 2 diabetes. Strength and body composition were considered and insulin sensitivity was monitored through a frequent glucose tolerance test. Results shows that an increased insulin sensitivity was induced by the training program.

Summary: The whole‐body insulin sensitivity index (WBISI) is a widely used surrogate of insulin sensitivity estimated from glucose and insulin concentrations during an oral glucose tolerance test (OGTT). The original WBISI uses five timepoints but reduced sampling models have been proposed. These reduced models have not been applied to the paediatric population. The purpose of this study is to compare cross‐sectional agreement and changes in response to lifestyle intervention between the original WBISI and the WBISI120 using fasting and 2‐hour glucose and insulin concentrations from OGTT among Latino adolescents with obesity. We also examined the cost‐differential between the two measures. Secondary analyses were conducted with data from Latino adolescents (14‐16 years) with obesity (BMI ≥ 95th percentile) who were recruited for a randomized controlled lifestyle intervention trial. Baseline data in youth (n = 148) who underwent a 2‐hour OGTT was used to analyse agreement between WBISI and WBISI120. Data from 65 participants who completed a 12‐week lifestyle intervention were used to assess changes and the rate of change between WBISI and WBISI120. Research costs to determine both measures were compared. WBISI120 showed good cross‐sectional agreement (ICCagreement = 0.88) with the full WBISI. Following intervention, WBISI120 increased 62.5% (M ± SD, 1.6 ± 1.2 to 2.6 ± 1.7, P <.001) while WBISI increased by 25.0% (1.6 ± 1.0 to 2.0 ± 1.0, P <.001) but the rate of change for WBISI and WBISI120 was not significantly different (P =.11). WBISI120 costs ~70% less than WBISI. WBISI120 may offer a cost‐effective surrogate estimate of insulin sensitivity in Latino youth with obesity. [ABSTRACT FROM AUTHOR]

Latino families are disproportionately affected by type 2 diabetes (T2D) and lifestyle intervention is the first-line approach for preventing T2D. The purpose of this study is to test the efficacy of a culturally-grounded lifestyle intervention that prioritizes health promotion and diabetes prevention for Latino families. The intervention is guided by a novel Family Diabetes Prevention Model, leveraging the family processes of engagement, empowerment, resilience, and cohesion to orient the family system towards health. Latino families (N = 132) will be recruited and assessed for glucose tolerance as measured by an Oral Glucose Tolerance Test (OGTT) and General and Weight-Specific Quality of Life (QoL) at baseline, four months, and 12 months. All members of the household age 10 and over will be invited to participate. Families will be randomized to the intervention group or a control group (2:1). The 16-week intervention includes weekly nutrition and wellness classes delivered by bilingual, bicultural Registered Dietitians and community health educators at a local YMCA along with two days/week of supervised physical activity classes and a third day of unsupervised physical activity. Control families will meet with a physician and a Registered Dietitian to discuss the results of their metabolic testing and recommend lifestyle changes. We will test the efficacy of a family-focused diabetes prevention intervention for improving glucose tolerance and increasing QoL and test for mediators and moderators of long-term changes. This study will provide much needed data on the efficacy of a family-focused Diabetes Prevention Program among high-risk Latino families. [ABSTRACT FROM AUTHOR]