Rapid Decline in β-Cell Function and Increasing Adiposity Are Associated With Conversion to Type 2 Diabetes in At-Risk Latino Youth

Youth-onset type 2 diabetes (T2D) is becoming increasingly prevalent, especially among Latino youth, and there is limited information on its pathophysiology and causative factors. Here, we describe findings from a longitudinal cohort study in 262 Latino children with overweight/obesity at risk of developing T2D with annual measures of oral and intravenous glucose tolerance (IVGTT), body composition, and fat distribution. Logistic binomial regression was used to identify significant predictors in those who developed T2D compared with matched control participants, and mixed-effects growth models were used to compare rates of change in metabolic versus adiposity measures between groups. Overall conversion rate to T2D at year 5 was 2% (n = 6). Rate of decline in disposition index (DI), measured with an IVGTT, over 5 years was three times higher in case patients (-341.7 units per year) compared with the extended cohort (-106.7 units per year) and 20 times higher compared with control participants (-15.2 units per year). Case patients had significantly higher annual increases in fasting glucose, hemoglobin A1c (HbA1c), waist circumference, and trunk fat, and there was an inverse correlation between rate of decline in DI and rates of increase in adiposity measures. T2D development in at-risk Latino youth is associated with a substantial and rapid decrease in DI that is directly correlated with increases in fasting glucose, HbA1c, and adiposity.

ARTICLE HIGHLIGHTS

Youth-onset type 2 diabetes is becoming increasingly prevalent, especially among Latino youth, and there is limited information on its pathophysiology and causative factors. Overall conversion rate to type 2 diabetes over 5 years was 2%. In youth who converted to type 2 diabetes, disposition index decreased rapidly by 85% compared with that in patients who did not convert during the study period. There was an inverse correlation between rate of decline in disposition index and rates of increase in various adiposity measures.

Morning Serum Cortisol Is Uniquely Associated with Cardiometabolic Risk Independent of Body Composition in Latino Adolescents

Background: Alterations in morning serum cortisol (MSC) have been associated with higher cardiometabolic risk. This finding has been documented primarily in populations with overweight or obesity; however, it has not been clearly established if obesity plays a requisite role in this relationship. This study seeks to extend earlier findings by examining whether body composition measures alter the relationship between MSC with glucose and insulin markers, blood pressure, and lipid parameters in Latino youth in middle adolescence. Methods: This cross-sectional study included 196 healthy adolescents (130F/66M; mean age: 16.4 ± 0.6 years; 95% Latino; mean body mass index, BMI: 24.3 ± 5.7) from Los Angeles, California. Morning cortisol, glucose, insulin, glycated hemoglobin, and lipids (triglycerides and high-density lipoprotein cholesterol) were assessed from a fasting blood sample. Sitting systolic and diastolic blood pressure was averaged from duplicate measures. Body composition measures included BMI and waist circumference, which were used as proxies for total body and abdominal adiposity, respectively. Triplicate measurements of weight and height were averaged for calculation of BMI; age- and sex-specific BMI z-score was used to classify into normal BMI or overweight/obese BMI status. Waist circumference was measured in duplicate and the average was used to classify participants into two strata: normal/healthy waist circumference (<90th percentile for age, sex, and ethnicity) and high waist circumference (≥90th percentile). Results: The primary findings were that higher MSC was associated with higher fasting glucose and systolic blood pressure after adjusting for age, sex, and BMI z-score (and/or waist circumference). BMI status or waist circumference status did not alter these relationships. Main Conclusion: Our results suggest that the relationships between hypothalamic-pituitary-adrenal axis function and certain cardiometabolic risk factors may be independent of adiposity. Future research is warranted to discover the contributors and underlying mechanisms of these relationships in adolescent populations. ClinicalTrials.gov identifier: NCT02088294.

Imagine HEALTH: Changes in diurnal salivary cortisol patterns following a 12-week guided imagery RCT lifestyle intervention in predominantly Latino adolescents

OBJECTIVE

Alterations in diurnal salivary cortisol patterns have been linked to adverse metabolic health outcomes. We have previously shown that stress-reduction guided imagery (GI) can reduce salivary cortisol levels acutely. We now ask whether addition of GI into a 12-week lifestyle intervention designed to improve eating and physical activity behaviors can alter diurnal salivary cortisol patterns and perceived stress.

METHODS

232 adolescent participants (ages 14-17 years) were cluster randomized by school into one of four intervention arms: non-intervention Control (C; n = 51), Lifestyle (LS; n=61), Stress-Reduction GI (SRGI; n = 55), and Lifestyle Behavior GI (LBGI; n = 65). LS group received one nutrition and one physical activity class per week after-school for 12 weeks. SRGI and LBGI groups received same LS classes plus an additional weekly GI session. Salivary cortisol was assessed pre- and post-intervention on 3 days, 3 times daily, at awakening, 30-minutes post-awakening, and in the evening to determine Cortisol Awakening Response (CAR) and Diurnal Cortisol Slope (DCS). Perceived Stress Scale (PSS) was administered pre- and post-intervention. Mixed effects modeling was used for intent-to-treat analysis and sensitivity analysis was used for those participants adherent to intervention protocol.

RESULTS

Analysis of 208 subjects with complete data showed a small between-group increase in CAR in LBGI vs C (p = 0.045, d=0.24), with no significant group differences among other intervention arms. There were no between group differences in change in DCS or change in PSS after 12-weeks. Amongst adherent participants, LBGI showed a small-moderate increase in CAR (p = 0.03, d=0.37), and moderate-large reduction in PSS (p = 0.02, d=-0.66) compared to C. There were no other between group differences in CAR, DCS, or PSS.

CONCLUSION

LBGI led to an increase in CAR, and in adherent subjects, a decrease in PSS, suggesting GI may be a mind-body intervention that can affect both objective and subjective measures of the stress response. Whether changes in cortisol patterns in this population affect measures of mental or physical health remains to be determined.

Mind- and Body-Based Interventions Improve Glycemic Control in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

Aims/Hypothesis: Only 51% of patients with type 2 diabetes achieve the hemoglobin A1c (HbA1c) <7% target. Mind and body practices have been increasingly used to improve glycemic control among patients with type 2 diabetes, but studies show inconsistent efficacy. The authors conducted a systematic review and meta-analysis to assess the association between mind and body practices, and mean change in HbA1c and fasting blood glucose (FBG) in patients with type 2 diabetes. Methods: The authors conducted a literature search of Ovid MEDLINE, Embase, and ClinicalTrials.gov seeking through June 10, 2022, published articles on mind and body practices and type 2 diabetes. Two reviewers independently appraised full text of articles. Only intervention studies were included. Reviewers extracted data for meta-analysis. Restricted maximum likelihood random-effects modeling was used to calculate the mean differences and summary effect sizes. The authors assessed heterogeneity using Cochran's Q and I² statistics. Funnel plots were generated for each outcome to gauge publication bias. Weighted linear models were used to conduct study-level meta-regression analyses of practice frequency. Results: The authors identified 587 articles with 28 meeting the inclusion criteria. A statistically significant and clinically relevant mean reduction in HbA1c of -0.84% (95% confidence interval [CI]: -1.10% to -0.58%; p < 0.0001) was estimated. Reduction was observed in all intervention subgroups: mindfulness-based stress reduction: -0.48% (95% CI: -0.72% to -0.23%; p = 0.03), qigong: -0.66% (95% CI: -1.18% to -0.14%; p = 0.01), and yoga: -1.00% (95% CI: -1.38% to -0.63%; p < 0.0001). Meta-regression revealed that for every additional day of yoga practice per week, the raw mean HbA1c differed by -0.22% (95% CI: -0.44% to -0.003%; p = 0.046) over the study period. FBG significantly improved following mind and body practices, with overall mean difference of -22.81 mg/dL (95% CI: -33.07 to -12.55 mg/dL; p < 0.0001). However, no significant association was found between the frequency of weekly yoga practice and change in FBG over the study period. Conclusions/Interpretation: Mind and body practices are strongly associated with improvement in glycemic control in patients with type 2 diabetes. The overall mean reduction in HbA1c and FBG was clinically significant, suggesting that mind and body practices may be an effective, complementary nonpharmacological intervention for type 2 diabetes. Additional analyses revealed that the mean decrease in HbA1c was greater in studies requiring larger number of yoga practice sessions each week.

Effects of Group-delivered Stress-reduction Guided Imagery on Salivary Cortisol, Salivary Amylase, and Stress Mood in Urban, Predominantly Latino Adolescents

Objectives

To determine acute effects of stress-reduction guided imagery delivered in group format on stress biomarkers salivary cortisol and salivary amylase, and on self-reported stress mood, in healthy, predominantly Latino adolescents.

Study Design

111 adolescent participants (94% Latino), a subset from a large, randomized controlled lifestyle intervention to improve obesity-related health behaviors, received either 4 weekly lifestyle education sessions (Lifestyle group; LS) or the same weekly lifestyle education sessions plus an additional weekly stress-reduction guided imagery session delivered in group format (Guided imagery group; GI). Salivary cortisol, salivary amylase, and self-reported stress moods were assessed before and after sessions on intervention weeks 3 and 4. Statistics: Linear mixed effects models examined within- and between-session and group differences in pre- to post-session changes.

Results

Both groups showed decreases in salivary cortisol, 5% decrease in LS group and 32% in GI group (within-group differences all P < .05), with between-group difference in salivary cortisol of moderate size (P = .05; Cohen’s d = .44). Within the GI group alone, salivary cortisol decrease was similar following either the lifestyle or GI sessions (P = .64). There were no statistically significant amylase changes within or between groups. All 5 individual stress moods declined by 27% to 46% in the GI group (all P < .05), while only 1 of the 5 declined in LS group.

Conclusions

Group stress-reduction guided imagery reduces the stress biomarker salivary cortisol, as well as reducing subjective stress mood states, making it a viable modality for large scale stress-reduction interventions.

The Acute Relationship between Affective States and Stress Biomarkers in Ethnic Minority Youths

Background: Whether affective states acutely predict the hypothalamic–pituitary–adrenal (HPA) axis activities and whether energy balance-related behaviors moderate the affect–HPA axis relationship in obese youths are not well-understood. Methods: 87 mostly obese (94.3% obese) minority adolescents (mean: 16.3 ± 1.2 years old; 56.8% Latino and 43.2% African American) participated in a randomized crossover trial in an observation laboratory, where they received either high-sugar/low-fiber (HSLF) or low-sugar/high-fiber (LSHF) meals first and then crossed over in the next visit 2–4 weeks later. During each visit, they rated five affective states and provided a saliva sample every 30 min for the first 5 h and wore a waist-worn accelerometer. The association between the affect ratings and cortisol levels in the subsequent 30 min and the moderation effect of energy balance-related behavior were examined using multilevel models. Results: Within-person negative affect (β = 0.02, p = 0.0343) and feeling of panic (β = 0.007, p = 0.004) were acutely related to the subsequent cortisol level only during the HSLF condition. The time spent in moderate-to-vigorous physical activity did not moderate the acute relationship between affect and the subsequent cortisol level. Conclusions: Negative affect could be acutely related to heightened HPA axis activities in youths, but only when they were exposed to meals with high sugar and low fiber content. These results suggest that the meals’ sugar and fiber content may modulate HPA axis reactivity to negative affect in youths.

The mediating role of emotional eating in the relationship between perceived stress and dietary intake quality in Hispanic/Latino adolescents

Obesity rates have steadily increased over the past three decades, and large racial/ethnic disparities in childhood obesity rates-specifically for Hispanic/Latino youth-highlight the major need for identifying and examining key mechanisms of obesogenic behaviors for this at-risk population. This study investigates the relationship between stress and dietary quality in Hispanic/Latino adolescents and seeks to determine the mediating role of emotional eating as a behavioral mechanism. Baseline data from 169 adolescents enrolled in the Imagine HEALTH trial were used to investigate these relationships. Perceived stress and emotional eating were assessed with age-validated questionnaires, and dietary quality was measured via 24-hour recall dietary assessments (later calculated as individual Healthy Eating Index-2015 scores). Nonparametric bootstrapping was used to test the primary hypothesis that emotional eating partially or fully mediates the relationship between perceived stress and dietary quality in this sample, and to test the significance of the mediating effect. Results indicate that emotional eating partially mediates the relationship between perceived stress and dietary quality. The total effect of perceived stress scores on dietary quality scores was -0.24 (p = .006); the direct effect of perceived stress scores on dietary quality scores (controlling for emotional eating scores) was -0.16 (p = .107), and the mediating (indirect) effect of emotional eating was -0.09 (p = .001). The proportion of mediation was 0.36 (36%) (p = .008). This study identifies an important mechanism of obesogenic behavior and can be used to inform future obesity prevention and intervention strategies tailored for the Hispanic/Latino adolescent population.

Imagine HEALTH: Randomized Controlled Trial of a Guided Imagery Lifestyle Intervention to Improve Obesity-Related Lifestyle Behaviors in Predominantly Latinx Adolescents

Introduction: To determine the effects of a novel lifestyle intervention combining lifestyle behavioral education with the complementary-integrative health modality of guided imagery (GI) on dietary and physical activity behaviors in adolescents. The primary aim of this study was to determine the incremental effects of the lifestyle education, stress reduction GI (SRGI), and lifestyle behavior GI (LBGI) components of the intervention on the primary outcome of physical activity lifestyle behaviors (sedentary behavior, light, moderate, and vigorous physical activity), as well as dietary intake behaviors, at the completion of the 12-week intervention. The authors hypothesized that the intervention would improve obesity-related lifestyle behaviors. Materials and Methods: Two hundred and thirty-two adolescent participants (aged 14-17 years, sophomore or junior year of high school) were cluster randomized by school into one of four intervention arms: nonintervention Control (C), Lifestyle education (LS), SRGI, and LBGI. After-school intervention sessions were held two (LS) or three (SRGI, LBGI) times weekly for 12 weeks. Physical activity (accelerometry) and dietary intake (multiple diet recalls) outcomes were assessed pre- and postintervention. Primary analysis: intention-to-treat (ITT) mixed-effects modeling with diagonal covariance matrices; secondary analysis: ad hoc subgroup sensitivity analysis using only those participants adherent to protocol. Results: ITT analysis showed that the Healthy Eating Index (HEI) increased in the LS group compared with C (p = 0.02), but there was no additional effect of GI. Among adherent participants, sedentary behavior was decreased stepwise relative to C in SRGI (d = -0.73, p = 0.004) > LBGI (d = -0.59, p = 0.04) > LS (d = -0.41, p = 0.07), and moderate + vigorous physical activity was increased in SRGI (d = 0.58, p = 0.001). Among adherent participants, the HEI was increased in LS and SRGI, and glycemic index reduced in LBGI. Conclusions: While ITT analysis was negative, among adherent participants, the Imagine HEALTH lifestyle intervention improved eating habits, reduced sedentary activity, and increased physical activity, suggesting that GI may amplify the role of lifestyle education alone for some key outcomes. CTR #NCT02088294.

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

BACKGROUND

Hypothalamic-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.

METHODS

In 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.

RESULTS

Single 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).

CONCLUSIONS

Chronic 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.

Guided Imagery Council: Feasibility, Acceptability, and Preliminary Effects of a Novel Group-Based Lifestyle Intervention in Predominantly Latino Adolescents

Background

The combination of higher stress and higher obesity rates suggests that Latino youth in the United States may be a population at particular risk for obesity-related adverse health outcomes. The objective of this article is to describe the feasibility, acceptability, and quantitative stress-related outcomes of a 6-week pilot lifestyle intervention using guided imagery (GI) council in order to reduce risk factors for obesity-related disease.

Methods

Seventeen urban, adolescents (12 females/5 males, 16 Latino, age 17 ± 1 years, grades 9–12, body mass index 22 ± 4) participated in the 6-week, after-school pilot intervention. The intervention consisted of three, 75-minute after-school sessions delivered weekly for 6 weeks. The 3 weekly sessions included 1 session each of nutrition education, physical activity education and practice, and GI delivered in council, a facilitated group process based on indigenous practices. Feasibility and acceptability were assessed by attendance and qualitative exit interview. Stress outcomes included salivary cortisol and perceived stress.

Results

The pilot intervention was found to be feasible to deliver in an after-school setting. The GI and council group format were well liked. A 31% reduction in salivary cortisol was observed following the stress-reduction GI sessions. Diurnal cortisol patterns did not change across the intervention, but change in perceived stress was correlated with change in cortisol awakening response.

Conclusions

The intervention was feasible to deliver and highly acceptable. Acute reduction in salivary cortisol was seen following group GI, while no change was seen in daily cortisol patterns. These results support the development of a full 12-week intervention using GI council to reduce obesity-related disease risk.

Protocol for the Imagine HEALTH Study: Guided imagery lifestyle intervention to improve obesity-related behaviors and salivary cortisol patterns in predominantly Latino adolescents

Innovative lifestyle interventions are needed to reduce type 2 diabetes risk in adolescents. This report describes the protocol of the Imagine HEALTH cluster randomized control trial, that tests an intervention based in Self-Determination Theory (SDT) and uses lifestyle education combined with the mind-body, complementary health modality of guided imagery (GI), to address obesity prevention and treatment in predominantly Latino adolescents. The primary aim is to determine the unique effects of each of the three major components of the 12-week lifestyle intervention (lifestyle education, stress reduction guided imagery, and lifestyle behavior guided imagery) compared to control on primary outcomes of physical activity (accelerometry), dietary intake (3-day recall), and stress biomarker levels (salivary cortisol). Secondary aims assess changes compared to controls in psychosocial outcomes (stress, well-being, depression), diabetes-related metabolic outcomes (adiposity, insulin resistance), maintenance of outcome changes for one year post-intervention, and SDT-based mediation of intervention effects. The development and rationale for each of the intervention components, study design, and outcome measurement processes are described. Adolescent participants recruited from four urban schools are cluster randomized by school into one of four arms of the 12-week (3-month) intervention, followed by 6 months of maintenance and 6 months of no contact. Outcome measures are assessed at the end of each period (3-, 9-, and 15-months). Results to date show successful recruitment of 97% of the target study population. Future results will demonstrate the effects of this integrative intervention on primary and secondary outcome measures in adolescents at risk for lifestyle-related metabolic disease.

Diabetes Empowerment Council: Integrative Pilot Intervention for Transitioning Young Adults With Type 1 Diabetes

Background

The transition of young adults with type 1 diabetes (T1D) from pediatric to adult care is challenging and frequently accompanied by worsening of diabetes-related health. To date, there are no reports which prospectively assess the effects of theory-based psycho-behavioral interventions during the transition period neither on glycemic control nor on psychosocial factors that contribute to poor glycemic control. Therefore, the overall aim of this study was to develop and pilot test an integrative group intervention based on the underlying principles of self-determination theory (SDT), in young adults with T1D.

Methods

Fifty-one young adults with T1D participated in an education and case management-based transition program, of which 9 took part in the Diabetes Empowerment Council (DEC), a 12-week holistic, multimodality facilitated group intervention consisting of "council" process based on indigenous community practices, stress-reduction guided imagery, narrative medicine modalities, simple ritual, and other integrative modalities. Feasibility, acceptability, potential mechanism of effects, and bio-behavioral outcomes were determined using mixed qualitative and quantitative methods.

Results

The intervention was highly acceptable to participants, though presented significant feasibility challenges. Participants in DEC showed significant reductions in perceived stress and depression, and increases in general well-being relative to other control participants. Reduction in perceived stress, independent of intervention group, was associated with reductions in hemoglobin A1C. A theoretical model explaining the effects of the intervention included the promotion of relatedness and autonomy support, 2 important aspects of SDT.

Conclusions

The DEC is a promising group intervention for young adults with T1D going through transition to adult care. Future investigations will be necessary to resolve feasibility issues, optimize the multimodality intervention, determine full intervention effects, and fully test the role of the underlying theoretical model of action.ClinicalTrials.gov Registration Number NCT02807155; Registration date: June 15, 2016 (retrospectively registered).

Effects of air pollution exposure on glucose metabolism in Los Angeles minority children

OBJECTIVES

Growing evidence indicates that ambient (AAP: NO₂ , PM_2.5 and O₃ ) and traffic-related air pollutants (TRAP) contribute to metabolic disease risk in adults; however, few studies have examined these relationships in children.

METHODS

Metabolic profiling was performed in 429 overweight and obese African-American and Latino youth living in urban Los Angeles, California. This cross-sectional study estimated individual residential air pollution exposure and used linear regression to examine relationships between air pollution and metabolic outcomes.

RESULTS

AAP and TRAP exposure were associated with adverse effects on glucose metabolism independent of body fat percent. PM_2.5 was associated with 25.0% higher fasting insulin (p < 0.001), 8.3% lower insulin sensitivity (p < 0.001), 14.7% higher acute insulin response to glucose (p = 0.001) and 1.7% higher fasting glucose (p < 0.001). Similar associations were observed for increased NO₂ exposure. TRAP from non-freeway roads was associated with 12.1% higher insulin (p < 0.001), 6.9% lower insulin sensitivity (p = 0.02), 10.8% higher acute insulin response to glucose (p = 0.003) and 0.7% higher fasting glucose (p = 0.047).

CONCLUSIONS

Elevated air pollution exposure was associated with a metabolic profile that is characteristic of increased risk for type 2 diabetes. These results indicate that increased prior year exposure to air pollution may adversely affect type 2 diabetes-related pathophysiology in overweight and obese minority children.

Longitudinal Associations Between Ambient Air Pollution With Insulin Sensitivity, β-Cell Function, and Adiposity in Los Angeles Latino Children

Evidence suggests that ambient air pollution (AAP) exposure may contribute to the development of obesity and type 2 diabetes. The objective of this study was to determine whether exposure to elevated concentrations of nitrogen dioxide (NO₂) and particulate matter with aerodynamic diameter <2.5 (PM_2.5) had adverse effects on longitudinal measures of insulin sensitivity (S_I), β-cell function, and obesity in children at high risk for developing diabetes. Overweight and obese Latino children (8-15 years; n = 314) were enrolled between 2001 and 2012 from Los Angeles, CA, and followed for an average of 3.4 years (SD 3.1 years). Linear mixed-effects models were fitted to assess relationships between AAP exposure and outcomes after adjusting for covariates including body fat percent. Higher NO₂ and PM_2.5 were associated with a faster decline in S_I and a lower S_I at age 18 years, independent of adiposity. NO₂ exposure negatively affected β-cell function, evidenced by a faster decline in disposition index (DI) and a lower DI at age 18 years. Higher NO₂ and PM_2.5 exposures over follow-up were also associated with a higher BMI at age 18 years. AAP exposure may contribute to development of type 2 diabetes through direct effects on S_I and β-cell function.

Clinical and Psychosocial Outcomes of a Structured Transition Program Among Young Adults With Type 1 Diabetes

PURPOSE

We identified and treated young adults with type 1 diabetes who had been lost to follow-up during their transfer from pediatric to adult care, comparing their clinical, psychosocial, and health care utilization outcomes to participants receiving continuous care (CC) throughout the transition to adult care.

METHODS

Individuals in their last year of pediatric care (CC group, n = 51) and individuals lost to follow-up in the transfer to adult care ("lapsed care" [LC] group, n = 24) were followed prospectively for 12 months. All participants were provided developmentally tailored diabetes education, case management, and clinical care through a structured transition program.

RESULTS

At baseline, LC participants reported lapses in care of 11.6 months. Compared with CC participants, they had higher hemoglobin A1C (A1C; p = .005), depressive symptoms (p = .05), incidence of severe hypoglycemia (p = .005), and emergency department visits (p = .004). At 12-month follow-up, CC and LC participants did not differ on the number of diabetes care visits (p = .23), severe hypoglycemia (no events), or emergency department visits (p = .22). Both groups' A1C improved during the study period (CC: p = .03; LC: p = .02). LC participants' depressive symptoms remained elevated (p = .10), and they reported a decline in life satisfaction (p = .007). There was greater loss to follow-up in the LC group (p = .04).

CONCLUSIONS

Our study suggests that, for young adults with a history of lapses in care, a structured transition program is effective in lowering A1C, reducing severe hypoglycemia and emergency department utilization, and improving uptake of routine diabetes care. Loss to follow-up and psychosocial concerns remain significant challenges in this population.

Associations among sugar sweetened beverage intake, visceral fat, and cortisol awakening response in minority youth

CONTEXT

Abdominal adiposity has long been associated with excess caloric intake possibly resulting from increased psychosocial stress and associated cortisol dysfunction. However, the relationship of sugar-sweetened beverage (SSB) intake specifically with cortisol variability and visceral adipose tissue (VAT) is unknown.

OBJECTIVE

To examine the relationships between SSB intake, VAT, and cortisol response in minority youth.

DESIGN

A cross-sectional analysis.

SETTING

The University of Southern California.

PARTICIPANTS

60 overweight/obese Non-Hispanic Black and Hispanic adolescents ages 14-18years.

MAIN OUTCOME MEASURES

VAT via Magnet Resonance Imaging (MRI), cortisol awakening response (CAR) via multiple salivary samples, and SSB intake via multiple 24-hour diet recalls. SSB intake was divided into the following: low SSB consumers (<1 servings per day), medium SSB consumers (≥1-<2 servings per day), high SSB consumers (≥2 servings per day). Analysis of covariance were run with VAT and CAR as dependent variables and SSB intake categories (independent variable) with the following a priori covariates: sex, Tanner stage, ethnicity, caloric intake, and body mass index.

RESULTS

The high SSB intake group exhibited a 7% higher VAT compared to the low SSB intake group (β=0.25, CI:(0.03, 0.33), p=0.02). CAR was associated with VAT (β=0.31, CI:(0.01,0.23), p=0.02). The high SSB intake group exhibited 22% higher CAR compared to the low SSB intake group (β=0.30, CI:(0.02,0.48), p=0.04).

CONCLUSION

This is the first study exploring the relationship between SSB, VAT, and CAR. SSB consumption appears to be independently associated greater abdominal adiposity and higher morning cortisol variability in overweight and obese minority youth. This study highlights potential targets for interventions specifically to reduce SSB intake in a minority youth 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.

Let's Empower and Prepare (LEAP): Evaluation of a Structured Transition Program for Young Adults With Type 1 Diabetes

OBJECTIVE

To evaluate the efficacy of a structured transition program compared with usual care in improving routine follow-up, clinical, and psychosocial outcomes among young adults with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Eighty-one young adults in their last year of pediatric care were recruited from three clinics. Intervention group (IG) participants (n = 51) received a structured transition program incorporating tailored diabetes education, case management, group education classes, and access to a newly developed young adult diabetes clinic and transition website. Control group (CG) participants (n = 30) received usual care. The primary outcome was the number of routine clinic visits. Secondary outcomes included glycemic control, hypoglycemia, health care use, and psychosocial well-being. Assessments were conducted at baseline, and 6 and 12 months.

RESULTS

Limitations in CG follow-up prevented direct comparisons of adult care visits; however, at the 12-month follow-up among IG participants discharged from pediatric care (n = 32), 78% had one or more adult visits. Among IG participants, the total number of clinic visits did not differ between those who transitioned and those who remained in pediatric care (3.0 ± 1.24 vs. 3.11 ± 0.94, P = 0.74). IG compared with CG participants had improved glycemic control (-0.40 ± 1.16% vs. 0.42 ± 1.51% [4.4 ± 12.7 mmol/mol vs. 4.6 ± 16.5 mmol/mol], P = 0.01), incidence of severe hypoglycemia (0.0% vs. 16%, P = 0.02), and global well-being (P = 0.02) at 12 months.

CONCLUSIONS

A structured transition program was successful in facilitating transition to adult care without a decrease in clinical follow-up. Compared with usual care, the transition program facilitated improvements in glycemic control, hypoglycemia, and psychosocial well-being.

Temporal relationships between adipocytokines and diabetes risk in Hispanic adolescents with obesity

OBJECTIVE

Circulating cytokines are frequently cited as contributors to insulin resistance in children with obesity. This study examined whether circulating adipocytokines, independent of adiposity, predicted pubertal changes in insulin sensitivity (SI), insulin secretion (AIR), and β-cell function in high-risk adolescents.

METHODS

158 Hispanic adolescents with overweight or obesity were followed for a median of 4 years. Adipocytokines were measured using Luminex technology. SI, AIR, and the disposition index were derived from an intravenous glucose tolerance test and minimal modeling. Total fat mass was measured by DXA and visceral adipose tissue (VAT) by MRI.

RESULTS

Surprisingly, mean IL-8, IL-1β, IL-6, and TNF-α decreased between 5% and 6.5% per year from baseline (P < 0.001). Despite the general temporal trends, gaining 1-SD of VAT was associated with a 2% and 5% increase in MCP-1 and IL-8 (P < 0.05). In addition, a 1-SD higher MCP-1 or IL-6 concentration at baseline was associated with a 16% and 21% greater decline in SI during puberty vs. prepuberty (P < 0.05).

CONCLUSIONS

Several adipocytokines decreased during adolescence and were weakly associated with VAT and lower SI during puberty. Circulating adipocytokines have relatively limited associations with pubertal changes in diabetes risk; however, the consistent findings with MCP-1 warrant further investigation.

Fasting, post-OGTT challenge, and nocturnal free fatty acids in prediabetic versus normal glucose tolerant overweight and obese Latino adolescents

Type 2 diabetes risk and its relationship to free fatty acid (FFA) exposure and visceral fat by prediabetes status in minority adolescents have yet to be explored. Therefore, the objective of this study was to examine the association of circulating FFA under varying conditions with prediabetes in Latino adolescents and to determine the relative relationships of FFA and visceral adiposity to insulin sensitivity, secretion, and β-cell function. Overweight or obese, but otherwise healthy Latino adolescent males and females (n = 164, 14.2 ± 2.5 years), were recruited for assessment of prediabetes, abdominal fat, and FFA levels taken at a fasting state (FFAF), during an OGTT (FFAOGTT), and overnight (FFANOCTURNAL). Prediabetic adolescents had a higher FFAF than those with normal glucose tolerance when controlling for age, sex, pubertal status, total percent body fat, and visceral fat. FFAOGTT and FFANOCTURNAL did not differ between participants with prediabetes and those with normal glucose tolerance after adjusting for covariates. Visceral fat was independently related to insulin sensitivity and secretion in pubertal adolescents; however, in post-pubertal adolescents, FFAF and visceral fat were both independent and negatively related to β-cell function. These results support a plausible progression of the lipotoxicity theory of diabetes development during the pubertal transition.

Changes in Bone Biomarkers, BMC, and Insulin Resistance Following a 10-Week Whole Body Vibration Exercise Program in Overweight Latino Boys

PURPOSE

With the childhood obesity epidemic, efficient methods of exercise are sought to improve health. We tested whether whole body vibration (WBV) exercise can positively affect bone metabolism and improve insulin/glucose dynamics in sedentary overweight Latino boys.

METHODS

Twenty Latino boys 8-10 years of age were randomly assigned to either a control (CON) or 3 days/wk WBV exercise (VIB) for 10-wk.

RESULTS

Significant increases in BMC (4.5 ± 3.2%; p=0.01) and BMD (1.3 ± 1.3%; p<0.01) were observed for the VIB group when compared to baseline values. For the CON group BMC significantly increased (2.0 ± 2.2%; p=0.02), with no change in BMD (0.8 ± 1.3%; p=0.11). There were no significant between group changes in BMC or BMD. No significant change was observed for osteocalcin and (collagen type I C-telopeptide) CTx for the VIB group. However, osteocalcin showed a decreasing trend (p=0.09) and CTx significantly increased (p<0.03) for the CON group. This increase in CTx was significantly different between groups (p<0.02) and the effect size of between-group difference in change was large (-1.09). There were no significant correlations between osteocalcin and measures of fat mass or insulin resistance for collapsed data.

CONCLUSION

Although bone metabolism was altered by WBV training, no associations were apparent between osteocalcin and insulin resistance. These findings suggest WBV exercise may positively increase BMC and BMD by decreasing bone resorption in overweight Latino boys.

Challenges contributing to disrupted transition from paediatric to adult diabetes care in young adults with type 1 diabetes

AIM

To examine challenges contributing to disruptions in care during the transition from paediatric to adult care among young adults with Type 1 diabetes who are primarily in ethnic minority groups and have low socio-economic status.

METHODS

Participants (n = 20) were newly enrolled patients in a transition clinic for young adults with Type 1 diabetes with a history of loss to medical follow-up. Participants completed qualitative semi-structured interviews detailing their transition experiences in addition to demographic, HbA1c and psychosocial measures. Descriptive statistics were completed for quantitative data, and narrative thematic analysis of interviews was used to identify common themes. A mixed-method analysis was used to identify the associations between stressors identified in interviews and clinical and psychosocial variables.

RESULTS

Three categories of challenges contributing to loss to follow-up were identified: psychosocial challenges, health provider and health system challenges and developmental challenges. Participants experienced a high degree of stressful life circumstances which were associated with higher HbA1c (r = 0.60, P = 0.005), longer duration of loss to follow-up (r = 0.51, P = 0.02), greater emergency department utilization (r = 0.45, P = 0.05), and lower life satisfaction (r = -0.62, P = 0.003).

CONCLUSIONS

A confluence of challenges, including stressful life circumstances, healthcare system barriers and the developmental trajectory of young adulthood, contributes to a high risk of loss to follow-up and poor health in this population of young adults with Type 1 diabetes. An integrated approach to transition addressing medical and psychosocial needs may facilitate improved follow-up and health outcomes in clinical settings.

Double jeopardy: metabolic syndrome leads to increased sedentary behavior in peri-pubertal minority females

While most studies have focused on investigating the preventive effects of physical activity on metabolic risk, the longitudinal impacts of metabolic syndrome (MetS) on activity levels is poorly understood. This study aims to examine the influence of MetS on initial activity levels and the trajectory of activity levels in Latina and African American female children over 12 months (n = 55, 9 ± 1 years). Metabolic measures, including fat and lean tissue mass by BodPod, fasting glucose, lipids, blood pressure, and waist circumference, were collected at baseline. Moderate-to-vigorous physical activity and sedentary behavior by accelerometry were collected on a quarterly basis. There were no significant differences in either initial activity levels by MetS status (Moderate-to-vigorous physical activity: 33 ± 12 mins/day for MetS, 48 ± 28 mins/day for Non-MetS, p = .12; sedentary behavior: 408 ± 57 mins/day for MetS, 421 ± 72 mins/day for Non-MetS, p = .67). Longitudinal declines in moderate-to-vigorous physical activity (p = .038) and increases in sedentary behavior (p = .003) were found. Daily sedentary behavior increased by 82.64 more minutes in youth with MetS than in those without over one year (p = .015). This study yields the first evidence of the adverse effect of MetS on sedentary behavior. Targeted intervention strategies to reduce progressive sedentariness evident in minority youth with MetS are warranted.

"We are all gonna get diabetic these days": the impact of a living legacy of type 2 diabetes on Hispanic young adults' diabetes care

PURPOSE

The purpose of this study was to investigate how an intergenerational legacy of type 2 diabetes affected the knowledge, attitudes, and treatment strategies of Hispanic young adults with diabetes.

METHODS

Eight Hispanic young adults (ages 18-30 years) participated in a series of in-home longitudinal qualitative interviews, and 11 of their family members completed single in-home interviews, regarding their diabetes management practices. Interview transcripts were analyzed thematically by a team of researchers.

RESULTS

Five themes emerged that characterized the influence of an intergenerational legacy of diabetes on young adults: food and family (how meal preparation and eating are shared within families), doing together (activity participation is contingent on others' participation), knowledge and expectations (expectations for the future and understandings of diabetes are shaped by family members), miscarried helping (well-intentioned actions have negative consequences), and reciprocal support (children and parents support each other's diabetes care).

CONCLUSIONS

Hispanic young adults' knowledge, attitudes, and self-care practices related to diabetes are strongly influenced by the diabetes management practices of family members with diabetes, which often depart from current standards of diabetes care. Care providers should consider family members as a potentially significant influence, either positive or negative, on the diabetes self-care practices of this population.

Meal skipping linked to increased visceral adipose tissue and triglycerides in overweight minority youth

OBJECTIVE

To investigate the impact of eating frequency on dietary intake, physical activity (PA), metabolic, and adiposity measures in minority youth.

METHODS

This analysis included 185 overweight (≥85th BMI percentile) Hispanic and African-American youth (8-18 years) with the following cross-sectional measures: height, weight, BMI, dietary intake, body composition, metabolic parameters, PA, visceral adipose tissue (VAT), and subcutaneous adipose tissue. Each eating occasion (EO) was defined as ≥50 calories and ≥15 minutes from any previous EO. Participants were dichotomized based on EOs per 24-h into meal skippers <3 EO (MS; n = 27) or normal/frequent eaters ≥3 EO (NFE; n = 158). ANCOVAs were used to assess dietary intakes, metabolic outcomes, adiposity, and PA between eating frequency groups.

RESULTS

MS compared to NFE consumed 24% fewer calories per 24-h (P ≤ 0.01), 21% more calories per EO (P ≤ 0.01), ate 40% less often (P ≤ 0.01), had 18% higher triglycerides (P = 0.03), and 26% more VAT (P = 0.03), with no differences in PA.

CONCLUSIONS

Although meal skipping was associated with decreased energy intake, it was linked to increased calories per EO and higher triglycerides and VAT, which are strong indicators of deleterious metabolic profiles. These findings elucidate that meal skipping may be associated with increased VAT and related metabolic diseases in high-risk minority youth.

Fast-food restaurants, park access, and insulin resistance among Hispanic youth

BACKGROUND

Evidence of associations between the built environment and obesity risk has been steadily building, yet few studies have focused on the relationship between the built environment and aspects of metabolism related to obesity's most tightly linked comorbidity, type 2 diabetes.

PURPOSE

To examine the relationship between aspects of the neighborhood built environment and insulin resistance using accurate laboratory measures to account for fat distribution and adiposity.

METHODS

Data on 453 Hispanic youth (aged 8-18 years) from 2001 to 2011 were paired with neighborhood built environment and 2000 Census data. Analyses were conducted in 2011. Walking-distance buffers were built around participants' residential locations. Body composition and fat distribution were assessed using dual x-ray absorptiometry and waist circumference. Variables for park space, food access, walkability, and neighborhood sociocultural aspects were entered into a multivariate regression model predicting insulin resistance as determined by the homeostasis model assessment.

RESULTS

Independent of obesity measures, greater fast-food restaurant density was associated with higher insulin resistance. Increased park space and neighborhood linguistic isolation were associated with lower insulin resistance among boys. Among girls, park space was associated with lower insulin resistance, but greater neighborhood linguistic isolation was associated with higher insulin resistance. A significant interaction between waist circumference and neighborhood linguistic isolation indicated that the negative association between neighborhood linguistic isolation and insulin resistance diminished with increased waist circumference.

CONCLUSIONS

Reducing access to fast food and increasing public park space may be valuable to addressing insulin resistance and type 2 diabetes, but effects may vary by gender.

Vegetable consumption is linked to decreased visceral and liver fat and improved insulin resistance in overweight Latino youth

There are limited data on the influence of vegetable consumption on adiposity and metabolic health, specifically nonstarchy vegetables and vegetables that are dark green and deep orange/yellow (also known as nutrient-rich vegetables). Our study examines the relationship between vegetable intake and adiposity, liver fat, and insulin dynamics in overweight Latino youth. This cross-sectional study of 175 overweight (body mass index ≥85th percentile) Latino youth (aged 8 to 18 years), with data collected during 2006-2011, included the following: dietary intake via multiple 24-hour recalls, total body fat via dual-energy x-ray absorptiometry, adipose tissue distribution and liver fat via magnetic resonance imaging, and insulin dynamics via frequently sampled intravenous glucose tolerance test. Linear regression and analysis of covariance were used for analysis, with the following a priori covariates: age, sex, energy intake, and total body fat. Participants who consumed the most nonstarchy vegetables (mean intake=1.7±1.0 servings/day) compared with the least (mean intake=0.1±0.1 servings/day) had 44% less liver fat (10.0%±8.5% vs 5.6%±8.7%; P=0.01). Nutrient-rich vegetable intake was positively correlated with insulin sensitivity (r=0.19; P=0.03). Consumers of nutrient-rich vegetables (mean intake=0.3±0.4 servings/day [n=107]), compared with nonconsumers (n=68), had 31% increased insulin sensitivity (1.6±1.6 vs 2.1±1.3×10(⁻⁴)/min/μU/mL; P=0.03) and 17% less visceral adipose tissue (2.3±0.9 vs 1.9±0.7 L; P=0.01). Consumption of specific vegetable types by overweight Latino youth is associated with positive metabolic outcomes, including reduced visceral and liver fat and risk factors for type 2 diabetes, even when consumed in small quantities. These may be relevant targets for interventions.

Modifying influence of dietary sugar in the relationship between cortisol and visceral adipose tissue in minority youth

OBJECTIVE

Cortisol has been associated with preferential visceral adipose tissue (VAT) deposition; however, findings in humans are mixed, which may be clarified when diet is considered.

DESIGN AND METHODS

Participants included 165 African-American and Latino, overweight adolescents (BMI% 97.2±3.2%, ages 13-18, 67% Latino, 66% female). Body composition was determined by dual energy X-ray absorptiometry, abdominal fat depots [VAT, subcutaneous (SAT)] by multiple-slice MRI, time-controlled serum sample to measure cortisol, and 2-day multi-pass 24-hour dietary recall. Linear regression analysis examined the cross-sectional relationship between cortisol, and the interaction of diet and cortisol on adiposity measures. Sex, race, age, and total body fat were a priori covariates.

RESULTS

There was a significant interaction between cortisol and sugar (total and added) in the prediction of VAT (P(interaction)  ≤ 0.05). Amongst participants with high total or added-sugar intake, cortisol was significantly associated with VAT (ß = 0.031 P < 0.001; ß = 0.026 P < 0.001), with no relationship in low consumers of total or added-sugar.

CONCLUSION

Dietary sugar may play an important role in modifying the relationship between cortisol and VAT, such that cortisol is significantly associated with elevated VAT under conditions of high sugar intake.

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 Imagery^SM (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 > 95^th 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

Temporal relationship between insulin sensitivity and the pubertal decline in physical activity in peripubertal Hispanic and African American females

OBJECTIVE

Little attention has been paid to possible intrinsic biological mechanisms for the decline in physical activity that occurs during puberty. This longitudinal observational study examined the association between baseline insulin sensitivity (SI) and declines in physical activity and increases in sedentary behavior in peripubertal minority females over a year.

RESEARCH DESIGN AND METHODS

Participants were Hispanic and African American girls (n = 55; 76% Hispanic; mean age 9.4 years; 36% obese). SI and other insulin indices were measured at baseline using the frequently sampled intravenous glucose tolerance test. Physical activity was measured on a quarterly basis by accelerometry and self-report.

RESULTS

Physical activity declined by 25% and time spent in sedentary behaviors increased by ∼13% over 1 year. Lower baseline SI predicted the decline in physical activity measured by accelerometry, whereas higher baseline acute insulin response to glucose predicted the decline in physical activity measured by self-report. Time spent in sedentary behavior increased by ~13% over 1 year, and this was predicted by lower baseline SI. All models controlled for adiposity, age, pubertal stage, and ethnicity.

CONCLUSIONS

When evaluated using a longitudinal design with strong outcome measures, this study suggests that lower baseline SI predicts a greater decline in physical activity in peripubertal minority females.

Disclosure of psychosocial stressors affecting diabetes care among uninsured young adults with Type 1 diabetes

AIMS

To determine the disclosure rates of psychosocial issues affecting routine diabetes care.

METHODS

A total of 20 young adults were interviewed regarding the impact of psychosocial stressors on their diabetes care. The interviewer, endocrinologist and case manager reported the prevalence rates of psychosocial stressors. Disclosure rates were compared to determine the prevalence of psychosocial issues and the different patterns of disclosure.

RESULTS

Participants reported a high number of psychosocial stressors, which were associated with poorer glycaemic control (r = 0.60, P = 0.005). Approximately half of all disclosed stressors (50.9%) were identified in routine care; other stressors were identified only through intensive case management and/or in-depth interviews.

CONCLUSIONS

Identifying psychosocial stressors in routine care, and providing referrals to psychological or social services, is a significant unmet need and may improve glycaemic control among certain populations with diabetes. Systematic mechanisms of capturing this information, such as by screening surveys, should be considered.

Liver fat has a stronger association with risk factors for type 2 diabetes in African-American compared with Hispanic adolescents

CONTEXT

Although overweight and obese African-Americans (AAs) have less visceral adipose tissue (VAT) and liver fat (LF) than Hispanics, they have a similar risk for type 2 diabetes.

OBJECTIVE

We examined ethnic differences in the association between VAT and LF with risk factors for type 2 diabetes to help explain this paradox.

DESIGN

We conducted a cross-sectional study in an academic pediatric care facility.

SUBJECTS

Subjects were overweight and obese AA (n = 131; 15.5 ± 3.3 years old) and Hispanic adolescents (n = 227; 14.7 ± 3.0 years old).

MAIN OUTCOME MEASURES

Outcome measures included insulin sensitivity (SI), acute insulin response (AIR), and disposition index (DI) by frequently sampled i.v. glucose tolerance test and minimal modeling.

RESULTS

LF, not VAT, was inversely associated with SI, and the effect of high LF compared with low was more pronounced in AAs (P(interaction) < .05). In Hispanics, high LF was associated with a 24% lower SI (P < .01) and a 31% increase in AIR (P < .01) and was not associated with DI (P = .35). In AAs, high LF was associated with a 49% lower SI (P < .001), was not associated with an increase in AIR (P = .25), and was associated with a 42% lower DI (P < .01), indicating failure of compensatory insulin secretion/clearance in response to insulin resistance. Prediabetes changed the relationship between high/low LF and DI in Hispanics (P(interaction) = .002) but not AAs such that prediabetic Hispanics with high LF had a 43% lower DI (P = .03) with no difference in those without prediabetes (P = .06).

CONCLUSIONS

LF has a stronger effect on SI compared with VAT. Our results suggest that the impact of high LF on poor β-cell compensation is more pronounced in AAs. In Hispanics, the combination of high LF and prediabetes contributes to poor β-cell compensation.

Blunted nocturnal cortisol rise is associated with higher carotid artery intima-media thickness (CIMT) in overweight African American and Latino youth

BACKGROUND

Blunted diurnal cortisol variation has been associated with overt cardiovascular disease in adults. The relationship between the diurnal cortisol variation and subclinical atherosclerosis in youth has yet to be investigated. The objectives of this study were to (1) determine the relationship between overnight cortisol measures and CIMT in overweight and obese, African-American and Latino children; (2) assess ethnic differences in these relationships; and (3) explore whether overnight cortisol and CIMT relationships were independent of inflammatory markers, C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-∝ (TNF-∝).

METHODS

One hundred fifty-six overweight and obese African-American and Latino children (ages 8-17, 86 M/70 F, 55 African-American/101 Latino) underwent measures of CIMT by B-mode ultrasound, nocturnal cortisol rise (NCR = salivary cortisol rise from 2200 h to awakening at 0530 h), cortisol awakening response (CAR = salivary cortisol from time of awakening to 30 min later), fasting serum cortisol and overnight urinary free cortisol.

RESULTS

Using linear regression, salivary cortisol(0530 h) and NCR were negatively associated with CIMT (β(standardized) = -0.215 and -0.220, p < 0.01) independent of age, height, percent body fat, ethnicity and systolic blood pressure. Nocturnal salivary cortisol(2200 h), morning serum cortisol, and overnight urinary free cortisol were not associated with CIMT. Using ANCOVA, participants with LOW NCR (NCR < 0.44 μg/dL, n = 52) had significantly greater CIMT than those with HIGH NCR (NCR ≥ 0.91 μg/dL, n = 52; 0.632 ± 0.008 vs. 0.603 ± 0.008 mm, p=0.01) after controlling for covariates. Ethnicity was independently associated with CIMT, whereby African-American children had greater CIMT than Latino children (-0.028 ± 0.009, p=0.006). The relationships between cortisol measures and CIMT did not differ between the two ethnic groups (all p(interaction) = 0.28-0.97). CRP, IL-6 and TNF-∝ were not associated with CIMT (p > 0.05). IL-6 was inversely related to NCR (r = -0.186, p = 0.03), but it did not explain the relationship between NCR and CIMT.

CONCLUSIONS

Salivary cortisol(0530 h) and NCR, but not CAR, nocturnal salivary cortisol(2200 h), morning serum cortisol or overnight urinary free cortisol were associated with CIMT, independent of relevant covariates, including inflammatory factors. A low awakening salivary cortisol or a blunted NCR may be related to increased atherosclerosis risk in overweight and obese minority youth. These findings support adult studies suggesting flattened daytime diurnal cortisol variation impacts cardiovascular disease risk.

Eating breakfast more frequently is cross-sectionally associated with greater physical activity and lower levels of adiposity in overweight Latina and African American girls

BACKGROUND

Eating breakfast is believed to promote a healthy body weight. Yet, few studies have examined the contribution of energy balance-related behavioral factors to this relation in minority youth.

OBJECTIVE

We assessed the associations between breakfast consumption and dietary intake, physical activity (PA), and adiposity before and after accounting for energy intake and PA in minority girls.

DESIGN

Cross-sectional data were obtained on body mass index (BMI), percentage body fat (measured by BodPod), dietary intake (measured with 3-d dietary records), and PA (measured with 7-d accelerometry) from 87 Latina and African American girls 8-17 y of age (75% Latina, 80% overweight). Dietary records were used to categorize girls as more frequent breakfast eaters (MF; 2 or 3 of 3 d; n = 57) or less frequent breakfast eaters (LF; 0 or 1 of 3 d; n = 30). Chi-square tests, ANCOVA, and multiple regression analyses were conducted. Mediation was assessed with a Sobel test.

RESULTS

Compared with the MF group, the LF group spent 30% less time (12.6 min/d) in moderate-to-vigorous-intensity PA (MVPA; P = 0.004) and had a higher percentage body fat (P = 0.029). MVPA accounted for 25% (95% CI: -8.8%, 58.1%; P = 0.139) of the relation between breakfast consumption and percentage body fat. We were unable to show that energy intake or MVPA was a significant mediator of the relation between breakfast consumption and adiposity in this sample.

CONCLUSIONS

Evidence suggests that among predominantly overweight minority girls, MVPA, but not energy intake, was associated with both breakfast consumption and adiposity; however, a lack of power reduced our ability to detect a significant mediation effect. Other unobserved variables likely contribute to this relation.

One-hour glucose during an oral glucose challenge prospectively predicts β-cell deterioration and prediabetes in obese Hispanic youth

OBJECTIVE

In adults, 1-h glucose during an oral glucose tolerance test (OGTT) predicts the development of type 2 diabetes independent of fasting and 2-h glucose concentrations. The purpose of the current investigation was to examine the utility of elevated 1-h glucose levels to prospectively predict deterioration in β-cell function and the development of prediabetes in high-risk youth.

RESEARCH DESIGN AND METHODS

Obese Latino youth with a family history of type 2 diabetes (133 male and 100 female; age 11.1 ± 1.7 years) completed a baseline OGTT and were divided into two groups based upon a 1-h glucose threshold of 155 mg/dL (<155 mg/dL, n = 151, or ≥ 155 mg/dL, n = 82). Youth were followed annually for up to 8 years for assessment of glucose tolerance, body composition by dual-energy X-ray absorptiometry, and insulin sensitivity, insulin secretion, and the disposition index by the frequently sampled intravenous glucose tolerance test.

RESULTS

Over time, the ≥ 155 mg/dL group exhibited a significantly greater decline in β-cell function compared with youth with a 1-h glucose <155 mg/dL (β = -327.8 ± 126.2, P = 0.01). Moreover, this decline was independent of fasting or 2-h glucose and body composition. When the data were restricted to only participants with normal glucose tolerance at baseline, a 1-h glucose ≥ 155 mg/dL was independently associated with a 2.5 times greater likelihood of developing prediabetes during follow-up (95% CI 1.6-4.1, P = 0.0001).

CONCLUSIONS

These data suggest that a 1-h glucose ≥ 155 mg/dL during an OGTT is an independent predictor of β-cell deterioration and progression to prediabetes among obese Latino youth.

Ectopic fat deposition in prediabetic overweight and obese minority adolescents

CONTEXT

Optimizing effective prevention and treatment of type 2 diabetes in youth is limited by incomplete understanding of its pathophysiology and how this varies across ethnicities with high risk.

OBJECTIVE

The aim of this study was to examine the contribution of visceral adipose tissue (VAT), hepatic fat fraction (HFF), and pancreatic fat fraction (PFF) to prediabetes in overweight/obese African American (AA) and Latino youth.

DESIGN AND SETTING

We conducted a cross-sectional study in an academic pediatric care facility.

SUBJECTS

A total of 148 healthy, overweight/obese adolescents (56 AA, 92 Latino; 72 males, 76 females; age, 15.5 ± 1.2 y; BMI z-score, 2.1 ± 0.5) participated in the study. They were normal glucose tolerant (n = 106) and prediabetic (n = 42), based on fasting glucose of 100-125 mg/dL and/or 2-hour glucose of 140-199 mg/dL, and/or hemoglobin A1C 6.0-6.4%.

MAIN OUTCOME MEASURES

We measured sc abdominal adipose tissue, VAT, HFF, and PFF by 3-Tesla magnetic resonance imaging and measured total body fat by dual-energy x-ray absorptiometry.

RESULTS

Adolescents with prediabetes had 30% higher HFF (P = .001) and 31% higher PFF (P = .042), compared to those with normal glucose tolerance after controlling for age, sex, pubertal stage, ethnicity, total percentage body fat, and VAT. Logistic regression showed that PFF predicted prediabetes in AAs and HFF predicted prediabetes in Latinos, with the odds of having prediabetes increased by 66% for every 1% increase in PFF in African Americans, and increased by 22% for every 1% increase in HFF in Latinos.

CONCLUSION

These data demonstrate that ectopic fat phenotypes associated with prediabetes are established by adolescence. Ethnic differences in the deposition of ectopic fat in adolescents with prediabetes may differ, with pancreatic fat in AAs, vs hepatic fat in Latino adolescents, being associated with diabetes risk.

Leptin predicts a decline in moderate to vigorous physical activity in minority female children at risk for obesity

What is already known about this subject Physical activity declines as children enter puberty. Leptin is cross-sectionally associated with physical activity, but there are conflicting findings on the magnitude and direction of this association. Leptin concentrations fluctuate during puberty, and may impact energy balance. What this study adds Leptin predicts the decline in physical activity during the start of puberty independent of central adiposity. Based on a median split of leptin, girls with low leptin levels have higher levels of physical activity than girls with high leptin levels at the start of puberty. Leptin levels at the start of puberty may provide a biological basis for the age-related physical activity decline in girls.

BACKGROUND

Leptin may influence moderate to vigorous physical activity (MVPA) at the start of puberty. The direction and magnitude of this association are unclear.

OBJECTIVES

To determine the effect of baseline leptin on MVPA over 1 year in minority girls at high risk for obesity.

METHODS

Data came from TRANSITIONS, a longitudinal observational study on the age-related MVPA decline. Fifty peripubertal girls aged 8-11 years at baseline participated. Baseline leptin (ng mL(-1) ) was collected via a duplicated assay using a double antibody radio immune assay. MVPA (min d(-1) ) was measured using accelerometers for at least four 10-h days on a quarterly basis for up to 1 year.

RESULTS

Continuous leptin was negatively related to MVPA (P = 0.001) independent of central adiposity at baseline and predicted the MVPA decline over 1 year (P = 0.002). For descriptive purposes, baseline leptin was dichotomized at the sample median into 'high leptin' and 'low leptin' categories to determine whether MVPA trajectories differed between these groups. Girls with 'low leptin' at baseline had significantly higher levels of MPVA at baseline, visit 1 and visit 2 compared to girls with 'high leptin'.

CONCLUSIONS

High leptin levels predicted nearly a 12.6% decline in MVPA over 1 year. These findings provide support for the biological basis of declining MVPA as girls enter puberty.

Adherence decision making in the everyday lives of emerging adults with type 1 diabetes

PURPOSE

The purpose of this study was to explore motivations underlying nonadherent treatment decisions made by young adults with type 1 diabetes.

METHODS

Eight emerging adults each completed a series of semi-structured interviews concerning their approaches to diabetes care, relationships with clinicians, and everyday activities and routines. A narrative thematic analysis was used to develop initial themes and refine them through continued data collection and review of the research literature.

RESULTS

FIVE THEMES WERE IDENTIFIED AS MOTIVATING NONADHERENCE: (1) efforts to mislead health care providers, (2) adherence to alternative standards, (3) treatment fatigue and burnout, (4) social support problems, and (5) emotional and self-efficacy problems.

CONCLUSION

Instances of nonadherence generally involved a combination of the five identified themes. Participants reporting nonadherence also described difficulties communicating with care providers regarding their treatment. Nonjudgmental communication between providers and emerging adults may be particularly important in promoting positive health outcomes in this population.

Reduction in added sugar intake and improvement in insulin secretion in overweight latina adolescents

BACKGROUND

To date, no study has assessed the effects of modifying carbohydrate intake (specifically decreasing added sugar and increasing fiber) on insulin secretion, nor has any study used an overweight Latino adolescent population. The objective of this study was to examine whether changes in dietary intake, specifically reductions in added sugar and/or increases in fiber, following a 12-week, modified carbohydrate dietary intervention, were associated with changes in insulin secretion and other metabolic risk factors for type 2 diabetes.

METHODS

Participants were 16 overweight (>/=85th percentile BMI) Latina adolescent females (12-17 years) who completed a 12-week modified carbohydrate intervention. Dietary intake was assessed by 3-day diet records, body composition by dual-energy X-ray absorptiometry, and insulin dynamics by an extended 3-hour oral glucose tolerance test (OGTT) at baseline and postintervention.

RESULTS

There was a trend for unadjusted change in reported added sugar intake (% of kcals) to be associated with change in insulin secretion, i.e. IAUC (r = 0.47; p = 0.075), and this relationship became significant after controlling for age, baseline insulin secretion, added sugar and adiposity, and change in adiposity (r = 0.85; p < 0.05). No other changes in dietary variables were related to changes in insulin secretion or other metabolic risk factors for type 2 diabetes.

CONCLUSIONS

Participants with greater reductions in added sugar intake showed significantly greater improvements in insulin secretion following a modified carbohydrate nutrition intervention. These findings suggest that interventions focused on decreasing added sugar intake have the potential to reduce type 2 diabetes risk in overweight youth.

Physical activity is related to insulin sensitivity in children and adolescents, independent of adiposity: a review of the literature

In adults, there is evidence that physical activity effectively improves insulin sensitivity regardless of adiposity. Whether this is also the case in children and adolescents is less clear. Clarifying this matter may help to identify the best outcomes to target in exercise programs for these age groups, where changes in adiposity may not always be desirable or realistic. A review of the literature was conducted on studies that examined the relationships of physical activity, cardiorespiratory fitness and strength with insulin sensitivity independent of adiposity in children and adolescents. Experimental (intervention) and correlational (longitudinal and cross-sectional) studies on participants ages 18 years and younger were identified. A total of 42 studies were included in this review. Sample sizes in the studies ranged from 14 to 4955 participants, with individual ages ranging from 5 to 19 years. A significant relationship with insulin sensitivity existed in 78% of studies on physical activity, 69% of studies on cardiorespiratory fitness and 66% of studies on strength. In studies that examined both physical activity and cardiorespiratory fitness concurrently, evidence suggests that they are both correlated with insulin sensitivity independent of adiposity, especially when physical activity is at higher intensities. However, the strength of this relationship might be influenced by study design, measurement techniques and participant characteristics. This is the first review of its type to take research design into account and to examine study outcomes according to participant ethnicity, gender, age, pubertal status and weight status.

Health-related quality of life in adolescents with or at risk for type 2 diabetes mellitus

OBJECTIVE

To evaluate how adolescents with or at risk for type 2 diabetes mellitus (T2DM) and their parent/guardians (parents) perceive adolescents' health-related quality of life.

STUDY DESIGN

We interviewed overweight/obese, 12- to 18-year-old youth with T2DM, prediabetes, or insulin resistance and one parent from 5 US sites. Assessments included Pediatric Quality of Life Inventory (PedsQL), Health Utilities Index, family conflict, and diabetes burden.

RESULTS

In 108 adolescents, diagnoses included 40.7% with T2DM, 25.0% with prediabetes, and 34.3% with insulin resistance. PedsQL summary score (SS) was higher in adolescents than parents (P=.02). Parents rated physical functioning lower than adolescents (P<.0001), but there were no differences in psychosocial health. Adolescent PedsQL SS did not differ with diagnosis, but was inversely associated with adolescent body mass index z-score (P=.0004) and family conflict (P<.0001) and associated with race/ethnicity (P<.0001). Number of adolescent co-morbidities (P=.007) and burden of diabetes care (P<.05) were inversely associated with parent PedsQL SS. There were no differences in the Health Utilities Index-Mark 3 multi-attribute utility score.

CONCLUSIONS

Parents perceive their adolescents' physical functioning as more impaired than adolescents themselves. Contextual factors including severity of obesity, race/ethnicity, family conflict, and burden of diabetes care influence health-related quality of life. Family-based approaches to treatment and prevention of T2DM may benefit from increased attention to the biopsychosocial context.

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.

CRP is related to higher leptin levels in minority peripubertal females regardless of adiposity levels

Overweight is related to higher levels of C-reactive protein (CRP) and leptin, which have been independently associated with increased risk for diabetes, cardiovascular disease, and the metabolic syndrome. Elevated CRP may trigger leptin resistance by inhibiting the binding of leptin to its receptors. We cross-sectionally examined the relationship between CRP, leptin, BMI z-score, percent body fat (%BF) assessed by air plethysmography (BodPod), and insulin sensitivity (SI) and acute insulin response (AIRg) measured by intravenous glucose tolerance test in 51 Latina and African-American females (77% Latina), mean age 9.2 (±0.9) years, at either Tanner Pubertal Stage (TPS) 1 (n = 25) or TPS 2 (n = 26). Females at TPS 2 had higher BMI z-scores, %BF (23% ± 10.1 vs. 30% ± 10.0, P = 0.02), AIRg (976.7 ± 735.2 vs. 1555.3 ± 1,223 µIU/ml, P = 0.05), fasting insulin (11.0 ± 10.8 vs. 17.2 ± 13.6 µlU/ml, P = 0.00) and leptin levels (11.0 ± 7.1 vs. 19.6 ± 10.9 ng/ml, P < 0.001) than those at TPS 1. There were no ethnic differences in any of the measured variables. CRP was positively correlated with BMI z-score (P = 0.001), %BF (P = 0.006), fasting insulin and AIRg (P = 0.02), and fasting leptin (P = 0.00), and negatively correlated with SI (P = 0.05). A linear regression model showed that CRP independently explained 10% (P = 0.00) of the variance in leptin after adjusting %BF, TPS, ethnicity, habitual physical activity and SI. Hence, low-grade inflammation may contribute to prolonged leptin exposure and leptin resistance, even in healthy children.

Subclinical atherosclerosis in Latino youth: progression of carotid intima-media thickness and its relationship to cardiometabolic risk factors

OBJECTIVE

To assess carotid artery intima-media thickness (CIMT) change over 2 years in overweight Latino adolescents and examine its relationship to cardiometabolic risk.

STUDY DESIGN

Seventy-two healthy overweight male and female Latino adolescents (mean age, 14.5 ± 1.7 years; mean body mass index, 31.5 ± 6.9 kg/m(2)) were evaluated at baseline and 2 years later for CIMT by high-resolution B-mode ultrasound, the metabolic syndrome and its features, body composition by dual-energy x-ray absorptiometry and magnetic resonance imaging, glucose/insulin measures by fasting blood, and oral and intravenous glucose tolerance tests.

RESULTS

Baseline CIMT did not differ from 2-year follow-up; however, 38 participants increased CIMT (0.017 ± 0.003 mm; +2.8%) and 34 decreased or remained the same (-0.019 ± 0.002 mm; -3.1%). ANCOVA analyses showed that participants with CIMT progression had higher baseline low-density lipoprotein (LDL)-cholesterol and total cholesterol (91.3 ± 3.4 and 150.3 ± 3.9 mg/dL) compared with those with CIMT non-progression (78.1 ± 3.6 and 135.6 ± 4.2 mg/dL, P < .05), independent of sex, baseline CIMT, age, and height. In multivariate regression, LDL-cholesterol was the sole predictor of CIMT progression, but the effect was small (odds of CIMT progression increased by 3% for each 1 mg/dL higher baseline LDL-cholesterol; 95% CI, 1.004 to 1.006, P = .03).

CONCLUSIONS

These results indicate a high variability in the magnitude of CIMT change in growing overweight Latino youth and support the use of LDL-cholesterol to assess subclinical atherosclerosis risk in this population.

Relationships between IGF-1 and IGFBP-1 and adiposity in obese African-American and Latino adolescents

The purpose of this study was to examine interrelationships between insulin-like growth factor 1 (IGF-1), IGF binding proteins (IGFBPs), and adiposity in 49 African-American and 77 Latino obese adolescents (15.3 ± 0.1 and 15.4 ± 0.2 years; BMI: 33.0 ± 0.7 and 35.0 ± 1.0 kg/m(2), respectively). Immunoradiometric assays were used to measure IGF-1, IGFBP-1, and IGFBP-3. Total fat and soft lean tissue were measured by dual-energy X-ray absorptiometry and visceral adipose tissue (VAT), subcutaneous abdominal adipose tissue (SAAT), and hepatic fat fraction (HFF) were measured by magnetic resonance imaging. IGF-1 levels were 23.1% higher and IGFBP-1 were 40.4% higher in African Americans compared to Latinos after adjustment for total lean and total fat mass. IGF-1 and IGFBP-1 were inversely correlated with BMI, total fat mass, VAT, and HFF (r = -0.20 to -0.33, P < 0.05) while IGFBP-1 was inversely correlated with SAAT (r = -0.22, P < 0.05). These relationships did not differ by ethnicity, however, the relationship between IGF-1 and SAAT, as well as IGFBP-1 and HFF, differed by ethnicity. Predicted mean IGF-1 levels were 30.7% higher for African Americans at the 75th compared to 25th percentile of SAAT and only 11.7% higher for Latinos. Predicted mean IGFBP-1 levels were 158% higher for African Americans at the 25th compared to the 75th percentile of HFF while IGFBP-1 levels were 1.7% higher for Latinos at the 75th compared to the 25th percentile. These results demonstrate that the relationship between IGF-1 and SAAT as well as IGFBP-1 and HFF are different in African-American and Latino adolescents and may contribute to the higher IGF-1 levels in African-Americans.

Stress and abdominal fat: preliminary evidence of moderation by the cortisol awakening response in Hispanic peripubertal girls

Stress and the cortisol awakening response (CAR) have been independently linked to increases in abdominal fat depots. This cross-sectional study examined the CAR as a moderator of the association between stress, visceral adipose tissue (VAT), and subcutaneous abdominal adipose tissue (SAT) in a sample (N = 23) of female peripubertal Hispanic girls aged from 8 to 11. The study included: (i) monitored salivary cortisol collection, (ii) VAT and SAT obtained by multislice magnetic resonance imaging, and (iii) a stressful life events checklist with four domain-specific subscales: peer, family, personal, and school. Regression analysis indicated an interaction of school-related life events and CAR on VAT and SAT, with greater numbers of school-related events being related to greater VAT and SAT for girls with high CAR, but no association with VAT or SAT for girls with low CAR. Similar to job stress in adults, school-related stress in children may contribute to central adiposity, especially for girls with high CAR.

Fasting indicators of insulin sensitivity: effects of ethnicity and pubertal status

OBJECTIVE

To examine the relationship of fasting indicators of insulin sensitivity with a more invasive measure of insulin sensitivity (frequently sampled intravenous glucose tolerance test [FSIVGTT]) and the effect of Tanner stage and ethnicity on that relationship.

RESEARCH DESIGN AND METHODS

Data were analyzed from 149 overweight girls (97 Hispanic and 52 African American) who were either in the early stages of maturation defined by Tanner stages 1 or 2 (52 Hispanic and 18 African American) or in the later stages of maturation defined by Tanner stages 4 and 5 (45 Hispanic and 34 African American). Fasting indicators of insulin sensitivity (IS) included fasting insulin and glucose and the homeostasis model assessment of insulin resistance (HOMA-IR). IS was derived from an FSIVGTT with minimal modeling.

RESULTS

In Tanner stages 1 and 2, all fasting indicators were significantly associated with IS: (fasting insulin: r = -0.67, P < 0.01; HOMA: r = -0.66, P < 0.01) with no significant influence of ethnicity on these relationships. In Tanner stages 4 and 5, however, all fasting indicators were associated with IS in African American girls (fasting insulin: r = -0.55, P < 0.01; HOMA: r = -0.47, P < 0.01), but none of the indicators were significantly associated with IS in Hispanic girls.

CONCLUSIONS

Fasting indicators were reflective of IS for girls in Tanner stages 1 and 2, regardless of ethnicity and may provide a clinical measure of future risk for type 2 diabetes. In the latter stages of maturation, however, more invasive measures are warranted to adequately determine IS in clinical practice.