Facilitating Growth Mixture Model Convergence in Preventive Interventions.

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.

Organ fat in Latino youth at risk for type 2 diabetes.

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.

Feasibility, Acceptability, and Preliminary Efficacy of an Intensive Clinic-Based Intervention for Children With Poorly Controlled Type 1 Diabetes.

OBJECTIVE: To evaluate the feasibility, acceptability, and preliminary efficacy of a team-based intervention for youth with type 1 diabetes (T1D) with suboptimal glycemia, as detected based on the measurement of hemoglobin A1C (HbA1C). METHODS: Forty participants with T1D for >1 year and an HbA1C level of ≥9.5% (80 mmol/mol) enrolled for a multidisciplinary intervention that included pediatric endocrinologists, pediatric psychologists, and a certified diabetes care and education specialist (CDCES). The CDCES-integrated medical management, while reinforcing physical, emotional, and behavioral health, connected with families to set and monitor goals and reviewed medication adjustments. The feasibility was assessed based on enrollment targets; acceptability based on retention rates; and preliminary efficacy based on changes in HbA1C levels, quality of life, diabetes-related strengths and resilience, hospital admissions, emergency room visits, and missed school days. RESULTS: Of 43 patients and families approached, 40 agreed to participate, 36 completed the 4-month intervention, and 31 completed full 8 months of follow-up data collection. The CDCES coach averaged 6.8 contacts per participant during the 8-month study period. The HbA1C level reduced significantly from baseline to 4 months (12.1% ± 1.6% to 11.0% ± 1.9%, P = .001) and was sustained at 8 months (10.7% ± 1.9%, P < .001). The participants reported significant increases in diabetes-specific quality of life (P < .05) and diabetes-related strength and resilience (P = .003). The missed school days reduced from 7.23 ± 7.5 days to 1.55 ± 1.9 days (P < .001), and the diabetes-related hospitalizations decreased from 0.4 ± 0.6 to 0.1 ± 0.3 (P = .009). CONCLUSION: Preliminary data suggest that a multidisciplinary intervention leveraging a team-based approach with a physician, psychologist, and CDCES can support improvements in glycemic control and psychosocial outcomes among youth with T1D with an HbA1C level above the target.

Increasing access to individualized medicine: a matched-cohort study examining Latino participant experiences of genomic screening.

PURPOSE: Multiple efforts are underway to increase the inclusion of racial minority participants in genomic research and new forms of individualized medicine. These efforts should include studies that characterize how individuals from minority communities experience genomic medicine in diverse health-care settings and how they integrate genetic knowledge into their understandings of health-care needs. METHODS: As part of a large, multisite genomic sequencing study, we surveyed individuals to assess their decision to pursue genomic risk evaluation. Participants included Latino patients recruited at Mountain Park Health Center, a Federally Qualified Health Center in Phoenix, Arizona, and non-Latino patients recruited at a large academic medical center (Mayo Clinic in Rochester, MN). Both groups agreed to receive individualized genomic risk assessments. RESULTS: Comparisons between cohorts showed that Latino respondents had lower levels of decisional conflict about pursuing genomic screening but generally scored lower on genetic knowledge. Latino respondents were also more likely to have concerns about the misuse of genomic information, despite both groups having similar views about the value of genomic risk evaluation. CONCLUSION: Our results highlight the importance of evaluating sociocultural factors that influence minority patient engagement with genomic medicine in diverse health-care settings.

Communicating incidental and reportable findings from research MRIs: considering factors beyond the findings in an underrepresented pediatric population.

BACKGROUND: The application of advanced imaging in pediatric research trials introduces the challenge of how to effectively handle and communicate incidental and reportable findings. This challenge is amplified in underserved populations that experience disparities in access to healthcare as recommendations for follow-up care may be difficult to coordinate. Therefore, the purpose of the present report is to describe the process for identifying and communicating findings from a research MRI to low-income Latino children and families. METHODS: Latino adolescents (n = 86) aged 12-16 years old with obesity and prediabetes underwent a research MRI (3 Tesla Philips Ingenia®) as part of a randomized controlled diabetes prevention trial. The research MRIs were performed at baseline and 6 months to assess changes in whole-abdominal fat distribution and organ fat in response to the intervention. An institutional pathway was developed for identifying and reporting findings to participants and families. The pathway was developed through a collaborative process with hospital administration, research compliance, radiology, and the research team. All research images were reviewed by a board-certified pediatric radiologist who conveyed findings to the study pediatrician for determination of clinical actionability and reportability to children and families. Pediatric sub-specialists were consulted as necessary and a primary care practitioner (PCP) from a free community health clinic agreed to receive referrals for uninsured participants. RESULTS: A total of 139 images (86 pre- and 53 post-intervention) were reviewed with 31 findings identified and 23 deemed clinically actionable and reportable. The only reportable finding was severely elevated liver fat (> 10%, n = 14) with the most common and concerning incidental findings being horseshoe kidney (n = 1) and lung lesion (n = 1). The remainder (n = 7) were less serious. Of youth with a reportable or incidental finding, 18 had a PCP but only 7 scheduled a follow-up appointment. Seven participants without a PCP were referred to a safety-net clinic for follow-up. CONCLUSIONS: With the increased utilization of high-resolution imaging in pediatric research, additional standardization is needed on what, when, and how to return incidental and reportable findings to participants, particularly among historically underrepresented populations that may be underserved in the community. TRIAL REGISTRATION: Preventing Diabetes in Latino Youth, NCT02615353.

Recruitment and retention of underrepresented and vulnerable populations to research.

Per principles outlined in the Belmont Report, research involving human subjects should minimize risks to participants and maximize benefits to participants and society. Recruitment of participants should be equitable. Once enrolled, participants have the right to withdraw at any point. Researchers must balance these principles with pressures to meet enrollment goals and, in the context of repeated-measures designs, retain participants across time. The purpose of this perspective is to describe the approach and corresponding activities for recruiting and retaining underrepresented and vulnerable populations that are the focus of a transdisciplinary academic research center. To this effort, we offer diverse disciplinary backgrounds, experience working with a wide range of populations (from infants to older adults and across multiple health conditions), and spanning a variety of research designs. Effective strategies offered include partnering with community entities, approaching potential participants where they are and at a time of readiness, using population-appropriate modes of communication and data collection, conducting study activities in familiar settings and at convenient times, maintaining frequent contact, and offering meaningful incentives. These strategies are consistent with population-specific reports found in the extant literature and underscore their cross-cutting nature, with adaptations based on participant and community partner needs and preferences.

Returning genomic results in a Federally Qualified Health Center: the intersection of precision medicine and social determinants of health.

PURPOSE: This report describes the return of sequencing results to low-income Latino participants recruited through a Federally Qualified Health Center (FQHC). We describe challenges in returning research results secondary to social determinants of health and present lessons learned to guide future genomic medicine implementation studies in low-resource settings. METHODS: Five hundred Latino adults (76% women) consented to research sequencing for a predetermined panel of actionable genes. Providers and staff from the FQHC were engaged to align processes with the practice and a community advisory board grounded the project in the local community. RESULTS: A pathogenic/likely pathogenic variant was present in 10 participants (2%). Challenges in return of results included the time lag (582 ± 53 days) between enrollment and returning actionable results, difficulty reaching participants, missed appointments, low health literacy, lack of health insurance, and reconciling results with limited information on family history. Return of one actionable result was deferred due to acute emotional distress secondary to recent traumatic life events. CONCLUSION: The social determinants of health influence the implementation of genomic medicine in low-income populations in low-resource settings. Considering nonbiological factors that contribute to disparities will be necessary to better appreciate how genomic medicine may fit within the context of health equity.

Response heterogeneity to lifestyle intervention among Latino adolescents.

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 (ß ± SE, linear 0.52 ± 0.17, P < .001; quadratic -0.03 ± 0.01, P = .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 = .002; quadratic -0.01 ± 0.002, P = .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.

Familism, Self-Esteem, and Weight-Specific Quality of Life Among Latinx Adolescents With Obesity.

OBJECTIVE: Obesity is a critical public health condition affecting Latinx adolescents and contributes to health disparities across the lifespan. Childhood and adolescent obesity is associated with reduced quality of life (QoL) and decreased self-esteem. The purpose of this study is to examine the role of cultural (e.g., familism) and psychosocial (e.g., self-esteem) factors as predictors of weight-specific QoL among Latinx adolescents with obesity. METHODS: Baseline data from 160 Latinx adolescents (ages 14-16 years) with obesity (BMI > 95th percentile for age and sex) who were recruited for a diabetes prevention intervention were used. Structural equation modeling tested the relationships between four latent constructs (familism, positive self-esteem, self-deprecation, and weight-specific QoL). RESULTS: The model tested paths from familism to positive self-esteem, self-deprecation, and weight-specific QoL, and paths from positive self-esteem and self-deprecation to weight-specific QoL. Higher familism was positively associated with positive self-esteem but not self-deprecation. In turn, positive self-esteem was positively associated with higher weight-specific QoL, whereas self-deprecation was negatively associated. Furthermore, there was an indirect effect of familism on QoL via positive self-esteem. CONCLUSIONS: These data shed light into specific cultural and psychosocial constructs that influence QoL among Latinx adolescents with obesity. This study suggests that familism and positive self-esteem can operate as protective factors associated with higher weight-specific QoL in Latinx adolescents with obesity; whereas self-deprecation may operate as a risk factor for lower weight-specific QoL.

Epicardial adipose thickness in youth with type 1 diabetes.

BACKGROUND AND OBJECTIVE: Epicardial adipose thickness (EAT) is increased in adults with type 1 diabetes (T1D) and is thought to contribute to cardiovascular disease (CVD) in this population. Given that CVD risk factors emerge early in life, the purpose of this study was to identify whether EAT is increased in pediatric patients with T1D compared with non-diabetic controls. METHODS: Anthropometric data, blood pressure (BP), and EAT were evaluated in 20 youth with T1D and 20 age, sex, and body mass index (BMI) matched healthy controls between the ages of 5 and 18 years. RESULTS: EAT was 18.5% higher among youth with T1D compared to healthy controls (1.65 ± 0.44 mm vs 1.37 ± 0.27 mm, P = .02). In the entire cohort, EAT was correlated with age (r = 0.71, P < .001), BMI (r = .69, P < .001), waist circumference (r = 0.60, P < .001), systolic BP (r = .34, P = .03), and diastolic BP (r = 0.41, P = .009). Among youth with T1D, there were no significant correlations between EAT and HbA1c (r = -0.16, P = .50), insulin dose (r = .09, P = .71), or duration of disease (r = 0.06, P = .82). CONCLUSIONS: Youth with T1D exhibited significantly higher EAT compared to controls. Increased EAT was associated with adiposity and BP, but not duration of disease, insulin dose, or glycemic control. Increased EAT may represent a pathophysiologic mechanism leading to premature CVD in pediatric patients with T1D.

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

OBJECTIVE: 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. DESIGN: Pre-post design. SETTING: 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. PARTICIPANTS: 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. RESULTS: 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). CONCLUSIONS: 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.

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

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.

Shear-wave ultrasound elastography of the liver in normal-weight and obese children.

Background The identification and subsequent management of liver diseases in children is challenging due to the lack of non-invasive imaging biomarkers. Ultrasound shear-wave elastography (US-SWE) is an emerging imaging technique which can quantitatively assess liver stiffness and may be useful as a tool in the management of liver disease in overweight and obese children. Purpose To evaluate US-SWE velocities of the liver in normal-weight and obese children, to correlate US-SWE findings with age and body-mass-index (BMI), and to compare US-SWE values with qualitative assessment (i.e. normal versus abnormal echogenicity) of the liver by conventional US. Material and Methods A cohort of 300 children (mean age, 9.9 ± 5.3 years; age range, 0.06-18.9 years) were studied, comprising 176 normal-weight and 124 obese participants. In each patient, both US-SWE and conventional US of the liver were obtained. Three pediatric radiologists individually and in consensus determined whether liver parenchyma was of normal or abnormal echogenicity. Results US-SWE velocities differed between normal-weight and obese children (1.08 ± 0.14 versus 1.44 ± 0.39 m/s; P < 0.001), but not by gender. Multivariate linear regression demonstrated US-SWE velocity to be primarily associated with age in normal-weight children ( P < 0.05) and with BMI in obese children ( P < 0.001). In the obese group, mean US-SWE velocity was statistically higher in participants with abnormal echogenic livers than in those with normal-appearing livers (1.53 ± 0.38 vs. 1.17 ± 0.27). The difference was not significant in the normal-weight group. Conclusion US-SWE provides a useful quantitative imaging biomarker for evaluating liver stiffness in children.

Physical activity and FTO genotype by physical activity interactive influences on obesity.

BACKGROUND: Although the effect of the fat mass and obesity-associated (FTO) gene on adiposity is well established, there is a lack of evidence whether physical activity (PA) modifies the effect of FTO variants on obesity in Latino populations. Therefore, the purpose of this study was to examine PA influences and interactive effects between FTO variants and PA on measures of adiposity in Latinos. RESULTS: After controlling for age and sex, participants who did not engage in regular PA exhibited higher BMI, fat mass, HC, and WC with statistical significance (P < 0.001). Although significant associations between the three FTO genotypes and adiposity measures were found, none of the FTO genotype by PA interaction assessments revealed nominally significant associations. However, several of such interactive influences exhibited considerable trend towards association. CONCLUSIONS: These data suggest that adiposity measures are associated with PA and FTO variants in Latinos, but the impact of their interactive influences on these obesity measures appear to be minimal. Future studies with large sample sizes may help to determine whether individuals with specific FTO variants exhibit differential responses to PA interventions.

Exercise for obese youth: refocusing attention from weight loss to health gains.

Despite evidence to the contrary, exercise interventions for obese youth target weight loss as a means of improving health. Using Exercise is Medicine® as a framework, we present a conceptual model for the beneficial effects of exercise independent of weight loss in obese youth and highlight novel biomarkers of cardiometabolic health that could prove useful as interventional targets for this population.

Comparing glycemic indicators of prediabetes: a prospective study of obese Latino Youth.

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.

Perceived health status and cardiometabolic risk among a sample of youth in Mexico.

PURPOSE: To examine differences in self-reported perceived mental and physical health status, as well as known cardiometabolic risk factors in a sample of normal weight, overweight, and obese Mexican youths. METHODS: Cross-sectional analysis of 164 youths aged 11-18 years recruited in Cuernavaca, Mexico. Participants completed a self-administered questionnaire that included measures of generic and weight-specific quality of life, perceived health, physical function, depressive symptoms, and body shape satisfaction. Height, weight, and waist circumference were measured, and body mass index (BMI) was determined. Fasting blood samples from participants yielded levels of glucose, triglycerides, and cholesterol (total, HDL, and LDL). RESULTS: Nearly 50 % of participants were female, 21 % had a normal BMI, 39 % were overweight, and 40 % were obese. Obese youths reported significantly lower measures of perceived health status (PHS) and showed an increase in cardiometabolic risk, compared with normal weight youths. Physical functioning, generic and weight-specific QoL were inversely associated with BMI, waist circumference, and glucose. Depressive symptoms were positively correlated with BMI, waist circumference, glucose levels, and HDL cholesterol. No correlation was found between PHS and cardiometabolic risk measures after controlling for BMI. CONCLUSIONS: In this sample of Mexican youths, obesity was associated with a significantly lower PHS and increased cardiometabolic risk.

Osteocalcin and type 2 diabetes risk in Latinos: a life course approach.

OBJECTIVE: To examine associations between circulating levels of the bone-derived protein osteocalcin (OC) and type 2 diabetes (T2D) risk in Latino children and adults. METHODS: Serum OC was measured in 136 children and 531 adults who had the following T2D risk factors assessed, body mass index (BMI), Hemoglobin A1c (HbA1c), fasting and 2-hour glucose during an oral glucose tolerance test. RESULTS: OC was significantly higher in children than adults (209.0 ± 12.1 vs. 41.0 ± 0.9 ng/ml, p<0.0001). In adults, OC was inversely associated (all p<0.001) with BMI (r=-0.2), HbA1c (r=-0.2), fasting glucose (r=-0.16), and 2-hour glucose (r=-0.21), while there were no significant associations in children. There was a stepwise decrease in OC with increasing dysglycemia in adults, normoglycemic (44.1 ± 1.3 ng/ml), prediabetic (39.3 ± 1.3 ng/ml), and T2D (31.8 ± 1.2 ng/ml), (p<0.0001), whereas there were no differences between normal and prediabetic youth (195.7 ± 16.1 vs. 194.7 ± 25.8 ng/ml, p=0.3). CONCLUSIONS: OC was inversely associated with T2D risk in Latino adults; however, this pattern was not observed in children.

Association of common genetic variants with diabetes and metabolic syndrome related traits in the Arizona Insulin Resistance registry: a focus on Mexican American families in the Southwest.

BACKGROUND/AIMS: The increased occurrence of type 2 diabetes and its clinical correlates is a global public health issue, and there are continued efforts to find its genetic determinant across ethnically diverse populations. The aims of this study were to determine the heritability of diabetes and metabolic syndrome phenotypes in the Arizona Insulin Resistance (AIR) registry and to perform an association analysis of common single nucleotide polymorphisms (SNPs) identified by GWAS with these traits. All study participants were Mexican Americans from the AIR registry. METHODS: Metabolic, anthropometric, demographic and medical history information was obtained on the 667 individuals enrolled in the registry. RESULTS: The heritability estimates were moderate to high in magnitude and significant, indicating that the AIR registry is well suited for the identification of genetic factors contributing to diabetes and the metabolic syndrome. From the 30 GWAS genes selected (some genes were represented by multiple SNPs), 20 SNPs exhibited associations with one or more of the diabetes related traits with nominal significance (p ≤ 0.05). In addition, 25 SNPs were nominally significantly associated with one or more of the metabolic phenotypes tested (p ≤ 0.05). Most notably, 5 SNPs from 5 genes [body mass index (BMI), hip circumference: rs3751812/FTO; fasting plasma glucose, hemoglobin A1c: rs4607517/GCK; very-low-density lipoprotein: rs10830963/MTNR1B; BMI: rs13266634/SLC30A8, and total cholesterol, low-density lipoprotein: rs7578597/THADA] were significantly associated with obesity, glycemic, and lipid phenotypes when using the multiple testing significance threshold of 0.0015. CONCLUSION: These findings extend previous work on Mexican Americans to suggest that metabolic disease is strongly influenced by genetic background in this high-risk population.

Diabetes Prevention for Latino Youth: Unraveling the Intervention "Black Box".

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.