Genetic variation in six genes has been associated with elevated liver fat and nonalcoholic fatty liver disease in adults. We sought to determine the influence of these genes on liver fat and whether a genetic risk score (GRS) would improve upon the ability of common clinical risk factors to predict elevated liver fat content (ELF) in Hispanic children.
Design and Methods
223 obese Hispanic children were genotyped for six SNPs. MRI was used to measure liver fat. A GRS was tested for association with ELF using multivariate linear regression. Predictors were assessed via ROC curves and pair-wise analysis was used to determine significance alone and combined with clinical markers.
Only variants in PNPLA3 and APOC3 genes were associated with liver fat (p<0.001, p=0.01, respectively). Subjects with a GRS=4 had ~3-fold higher liver fat content than subjects with GRS of 0 (15.1±12.7% vs. 5.1±3.7%, p=0.03). While the addition of the GRS to a model containing BMI and liver enzymes increased ROC AUC from 0.83 to 0.85 [95% CI, 0.79-0.89], (p=0.01), it does not improve detection of ELF from a clinical perspective.
Only PNPLA3 and APOC3 were related to ELF and a GRS comprised of these susceptibility alleles did not add to the discriminatory power of traditional biomarkers for clinical assessment of liver fat.
NAFLD; liver fat; Hispanic; obesity; genetic risk
Background and Aims
Recent work has studied multiple addictions using a matrix measure, which taps multiple addictions through single responses for each type.
The present study investigated use of a matrix measure approach among former alternative high school youth (average age = 19.8 years) at risk for addictions. Lifetime and last 30-day prevalence of one or more of 11 addictions reviewed in other work (Sussman, Lisha & Griffiths, 2011) was the primary focus (i.e., cigarettes, alcohol, other/hard drugs, eating, gambling, Internet, shopping, love, sex, exercise, and work). Also, the co-occurrence of two or more of these 11 addictive behaviors was investigated. Finally, the latent class structure of these addictions, and their associations with other measures, was examined.
We found that ever and last 30-day prevalence of one or more of these addictions was 79.2% and 61.5%, respectively. Ever and last 30-day co-occurrence of two or more of these addictions was 61.5% and 37.7%, respectively. Latent Class Analysis suggested two groups: a generally Non-addicted Group (67.2% of the sample) and a “Work Hard, Play Hard”-addicted Group that was particularly invested in addiction to love, sex, exercise, the Internet, and work. Supplementary analyses suggested that the single-response type self-reports may be measuring the addictions they intend to measure.
Discussion and Conclusions
We suggest implications of these results for future studies and the development of prevention and treatment programs, though much more validation research is needed on the use of this type of measure.
multiple addictions; prevalence; co-occurrence; latent class analysis; addiction groups; convergent validity
The current study examines the psychometric properties of the Eating in Emotional Situations Questionnaire (EESQ) and the frequency of eating in emotional situations among 159 low-income Latino fourth graders. The EESQ assesses eating in emotional situations that are emotion-driven (“I eat when I am lonely”) and context-driven (“I eat when I get a really bad grade”). Internal consistencies for the EESQ subscales and total scale ranged from .70 to .86. Criterion validity of the EESQ was established by statistically significant correlations between the EESQ subscales and total scale, and uncontrollable eating, external eating, and junk food intake. Eating in emotional situations was common in the sample; almost one-half reported eating in at least 3 of the 11 types of emotional situations (e.g. when stressed, sad, bored) and 28% reported eating in at least 6 types. Overall, these findings provide support for the internal consistency and validity of the EESQ in low-income Latino children, and suggest that eating in emotional situations is moderately present in this demographic. Future studies are needed to validate the EESQ in other ethnic groups and examine the longitudinal tracking of eating in emotional situations among Latino youth.
Eating in Emotional Situations Questionnaire (EESQ); emotional eating; children; Latino; Hispanic
Parental factors may play an important role in influencing children’s physical activity levels.
This cross-sectional study sought to describe the locations of joint physical activity among parents and children.
Parent-child pairs (N = 291) wore an Actigraph GT2M accelerometer and GlobalSat BT-335 Global Positioning Systems (GPS) device over the same 7-day period. Children were ages 8–14 years. Joint behavior was defined by a linear separation distance of less than 50m between parent and child. Land use classifications were assigned to GPS data points.
Joint physical activity was spread across residential locations (35%), and commercial venues (24%), and open spaces/parks (20%). Obese children and parents performed less joint physical activity in open spaces/parks than under/normal weight children and parents (p’s < .01).
Understanding where joint parent-child physical activity naturally occurs may inform location-based interventions to promote these behaviors.
moderate-to-vigorous physical activity; sedentary behavior; parents; children; global positioning systems; environments
There is an urgent need for innovative and developmentally appropriate lifestyle interventions to promote healthy lifestyle behaviors and to prevent the early onset of type 2 diabetes and cardiovascular disease risk in obese Latino adolescents. Guided imagery offers promise to reduce stress and promote lifestyle behavior change to reduce disease risk in obese adolescents. Our objectives were: 1) To pilot test a new 12-wk lifestyle intervention using a randomized trial design in obese Latino adolescents, in order to determine the effects of the mind-body modality of Interactive Guided ImagerySM (IGI), over and above those of a didactic lifestyle education, on insulin resistance, eating and physical activity behaviors, stress and stress biomarkers; and 2) To explore the role of intervention-related changes in stress and stress biomarkers on changes in metabolic outcomes, particularly insulin resistance.
Obese (BMI > 95th percentile), Latino adolescents (n = 35, age 14-17) were randomized to receive either 12 weekly sessions of a lifestyle education plus guided imagery program (GI), or lifestyle education plus a digital storytelling computer program (DS). Between-group differences in behavioral, biological, and psychological outcomes were assessed using unpaired T-tests and ANCOVA in the 29 subjects who completed the intervention.
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.
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.
Clinicaltrials.gov Registry #: NCT01895595
Guided imagery; Obesity; Childhood; Latino; Adolescents; Lifestyle; Diabetes
It is now presumed that youth do not move directly from adolescence to adulthood, but rather pass through a transitional period, “emerging adulthood.” The Revised Inventory of the Dimensions of Emerging Adulthood (IDEA-R) is a self-report instrument developed to examine the attributes of this period. “At-risk” youth appear to enter emerging adulthood developmental tasks at a slightly earlier age than general population youth. In the present study, a 21-item version of the IDEA was administered to a sample of 1676 “at-risk” continuation (alternative) high school students in Southern California. Principal component factor analysis with orthogonal rotation revealed three factors the authors labeled “Identity Exploration,” “Experimentation/Possibilities,” and “Independence.” Overall, the measure demonstrated high internal consistency. Construct validity analyses indicated that the measure was correlated with demographics, risk behaviors, and psychological measures. The authors conclude that the IDEA-R is a useful instrument for measuring emerging adulthood in at-risk populations.
emerging adulthood; continuation high school; at-risk youth; inventory of the dimensions of emerging adulthood (IDEA); psychometrics
Motivational Interviewing (MI) is a widely-used approach for addressing adolescent substance use. Recent meta-analytic findings show small but consistent effect sizes. However, differences in intervention format and intervention design, as well as possible mediators of change, have never been reviewed. This review of the literature summarizes the most up-to-date MI interventions with adolescents, looks at differences between intervention format and design, and discusses possible theory-based mechanisms of change. Of the 39 studies included in this review, 67% reported statistically significant improved substance use outcomes. Chi square results show no significant difference between interventions using feedback or not, or interventions combined with other treatment versus MI alone. The need for systematic investigation in theory-based mechanisms of change is presented.
Motivational Interviewing; Adolescent; Substance Use; Alcohol; Tobacco; Marijuana
Childhood obesity continues to be a significant public health issue. mHealth systems offer state-of-the-art approaches to intervention design, delivery, and diffusion of treatment and prevention efforts. Benefits include cost effectiveness, potential for real-time data collection, feedback capability, minimized participant burden, relevance to multiple types of populations, and increased dissemination capability. However, these advantages are coupled with unique challenges. This commentary discusses challenges with using mHealth strategies for child obesity prevention, such as lack of scientific evidence base describing effectiveness of commercially available applications; relatively slower speed of technology development in academic research settings as compared with industry; data security, and patient privacy; potentially adverse consequences of increased sedentary screen time, and decreased focused attention due to technology use. Implications for researchers include development of more nuanced measures of screen time and other technology-related activities, and partnering with industry for developing healthier technologies. Implications for health practitioners include monitoring, assessing, and providing feedback to child obesity program designers about users' data transfer issues, perceived security and privacy, sedentary behavior, focused attention, and maintenance of behavior change. Implications for policy makers include regulation of claims and quality of apps (especially those aimed at children), supporting standardized data encryption and secure open architecture, and resources for research–industry partnerships that improve the look and feel of technology. Partnerships between academia and industry may promote solutions, as discussed in this commentary.
Childhood; Obesity; Mobile technology; mHealth; Screen time; Focused attention; Sedentary behavior
Research examined joint physical activity and sedentary behavior among 291 parent-child pairs who both wore an accelerometer and global positioning systems (GPS) device over the same 7-day period.
Children were 52.2% female, 8-14 years, and 43.0% Hispanic. Parents were 87.6% female. An Actigraph GT2M accelerometer and GlobalSat BT-335 GPS device collected activity and global positioning data, respectively. Linear distance between the parent and child for each 30-sec. epoch was calculated using geographic coordinates from the GPS. Joint behavior was defined as a separation distance less than 50m between parents and children.
On average during non-school waking hours, parents and children spent 2.4 min. (SD = 4.1) per day performing moderate-to-vigorous physical activity (MVPA) together and 92.9 min. (SD = 40.1) per day in sedentary behavior together. Children engaged in an average of 10 min. per day of MVPA during non-school waking hours when their parent was nearby but not engaging in MVPA. During this same period, parents engaged in 4.6 min. per day of MVPA when their child was nearby but not engaging in MVPA. Household income level and the child’s age were negatively associated with joint MVPA. Girls engaged in a greater percentage of their total MVPA together with their parent than boys. Girls and older children engaged in more sedentary behavior together with their parent than boys and younger children. Older parents engaged in a greater percentage of their sedentary behavior together with their children than younger parents.
Replacing the time that parents and children spend together in sedentary pursuits with joint physical activity could have health benefits, especially for girls, older children, older parents, and higher income families.
moderate-to-vigorous physical activity; accelerometer; global positioning systems; age; sex
The current article reports a large scale study of the prediction of marijuana use cessation among individuals attending alternative high schools who were regular users at baseline. Based on the Triadic Influence Theory, predictors of marijuana use cessation at 1-year follow-up were organized by type of influence (e.g., interpersonal, cultural and attitudinal, and intrapersonal) and level of influence (e.g., distal and ultimate). Among the 522 students who were past 30-day marijuana users at baseline, quitting was defined as having not used marijuana in the last 30 days at 1-year follow-up (43% of baseline users). To account for the level of influence we employed a theory-based analytic strategy, hierarchical regression. In the final multivariate model, lower level of baseline marijuana use and less of a likelihood to endorse pro-drug-use myths remained predictors of marijuana use cessation 1-year later. Implications of these findings include the need to develop cessation programs that reduce psychological dependence on marijuana use, and correct cognitive misperceptions about drug use in order to help adolescents make decisions that lead to health-promoting behaviors.
marijuana; cessation; adolescents; youth; cannabis; self-initiated; predictors
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 has been less clear. 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 and younger were identified. A total of 42 studies were included in this review. Sample sizes in the studies ranged from 14 to 4,955 participants, with individual ages ranging from 5 to 19 years. A significant relationship with SI 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.
The present study tested the efficacy of motivational interviewing-based booster sessions for Project Towards No Drug Abuse (TND), a 12-session school-based curriculum targeting youth at risk for drug abuse. In addition, generalization of effects to risky sexual behavior was assessed. The one-year outcomes evaluation of the project is presented.
A total of 24 schools were randomized to one of three conditions: Standard Care Control (SCC), TND classroom program only (TND-only), and TND plus Motivational Interviewing booster (TND+MI). A total of 1186 participants completed baseline and one-year follow-up surveys. Following the classroom program, youth in the TND+MI condition received up to three sessions of MI in person or by telephone. Effects were examined on 30-day cigarette, alcohol, marijuana, and hard drug use, as well as measures of risky sexual behavior (number of sex partners, condom use, having sex while using drugs or alcohol).
Collapsed across the two program conditions, results showed significant reductions in alcohol, hard drug use, and cigarette smoking, relative to controls. These effects held for an overall substance use index. The MI booster component failed to achieve significant incremental effects above and beyond the TND classroom program. No effects were found on risky sexual behavior.
While the program effects of previous studies were replicated, the study failed to demonstrate that an adequately implemented MI booster was of incremental value at one-year follow-up.
one-year follow-up; drug prevention; continuation high schools; Motivational Interviewing; boosters
This study assessed the changes in time spent in moderate to vigorous physical activity (MVPA) on fat depots, insulin action, and inflammation. Longitudinal data were generated from 66 Hispanic adolescents (15.6±1.1 yr; BMI percentile 97.1±3.0) who participated in a 16-wk nutrition or nutrition+exercise intervention. There were no effects of the intervention on PA, but there were inter-individual changes in PA. For purposes of this analysis, all intervention groups were combined to assess how changes in PA during 16 wk affected changes in adiposity, insulin action, and markers of inflammation. MVPA was assessed by 7-day accelerometry, total body fat via DXA, liver fat by MRI, and insulin, glucose and HOMA-IR via a fasting blood draw. A repeated measures ANCOVA was used to assess the effect of MVPA on fat depots, insulin action, and inflammatory markers. Sixty-two percent of participants increased MVPA (mean increase, 19.7±16.5 min/day) and 38% decreased MVPA (mean decrease, 10.7±10.1 min/day). Those who increased MVPA by as little as 20 min per day over 16 wk, compared to those who decreased MVPA, had significant reductions in liver fat (−13% vs. +3%; P=0.01), leptin levels (−18% vs. +4%; P=0.02), and fasting insulin (−23% vs. +5%; P=0.05). These findings indicate that a modest increase in MVPA can improve metabolic health in sedentary overweight Hispanic adolescents.
Moderate-to-Vigorous Physical Activity; Obesity
Purpose. It is unclear whether sociocultural and socioeconomic factors are directly linked to type 2 diabetes risk in overweight/obese ethnic minority children and adolescents. This study examines the relationships between sociocultural orientation, household social position, and type 2 diabetes risk in overweight/obese African-American (n = 43) and Latino-American (n = 113) children and adolescents. Methods. Sociocultural orientation was assessed using the Acculturation, Habits, and Interests Multicultural Scale for Adolescents (AHIMSA) questionnaire. Household social position was calculated using the Hollingshead Two-Factor Index of Social Position. Insulin sensitivity (SI), acute insulin response (AIRG) and disposition index (DI) were derived from a frequently sampled intravenous glucose tolerance test (FSIGT). The relationships between AHIMSA subscales (i.e., integration, assimilation, separation, and marginalization), household social position and FSIGT parameters were assessed using multiple linear regression. Results. For African-Americans, integration (integrating their family's culture with those of mainstream white-American culture) was positively associated with AIRG (β = 0.27 ± 0.09, r = 0.48, P < 0.01) and DI (β = 0.28 ± 0.09, r = 0.55, P < 0.01). For Latino-Americans, household social position was inversely associated with AIRG (β = −0.010 ± 0.004, r = −0.19, P = 0.02) and DI (β = −20.44 ± 7.50, r = −0.27, P < 0.01). Conclusions. Sociocultural orientation and household social position play distinct and opposing roles in shaping type 2 diabetes risk in African-American and Latino-American children and adolescents.
To assess the effects of a maintenance program (monthly newsletters versus monthly group classes and telephone behavioral sessions) on obesity and metabolic disease risk at one year in overweight minority adolescents.
After a 4-month nutrition and strength training intervention, 53 overweight Latino and African American adolescents (15.4 ±1.1 yrs) were randomized into one of two maintenance groups for 8 months: monthly newsletters (n=23) or group classes (n=30; monthly classes + individualized behavioral telephone sessions). The following outcomes were measured at months 4 (immediately following the intense intervention) and month 12: height, weight, blood pressure, body composition via BodPod™, lipids and glucose/insulin indices via frequently sampled intravenous glucose tolerance test (FSIVGTT).
There were no significant group by time interactions for any of the health outcomes. There were significant time effects in several outcomes for both groups from month 4 to 12: bench press and leg press decreased by 5% and 14% (p=0.004 & p=0.01), fasting insulin and acute insulin response decreased by 26% and 16% (p<0.001 & p=0.046); while HDL cholesterol and insulin sensitivity improved by 5% and 14% (p=0.042 and p=0.039).
Newsletters as opposed to group classes may suffice as follow-up maintenance programs to decrease type 2 diabetes and cardiovascular risk in overweight minority adolescents.
Maintenance; Obesity Intervention; Type 2 Diabetes; Cardiovascular risk factors; Latino and African American adolescents
The United States is currently in an age of obesity and inactivity despite increasing public awareness and scientific knowledge of detrimental long-term health effects of this lifestyle. Behavior-tracking diaries offer an effective strategy for physical activity adherence and weight management. Furthermore, Web-based physical activity diaries can engage meaningful partners in people’s social networks through fun online gaming interactions and generate motivational mechanisms for effective behavioral change and positive health outcomes.
Wellness Partners (WP) is a Web-based intervention in the form of a physical activity diary with social networking and game features. Two versions were designed and developed for the purpose of this study—“Diary” only and “Diary+Game”. The objectives of this study included pilot testing the research process of this intervention design, implementation, evaluation, and exploring the effectiveness of social gaming features on adult participants’ physical activity and anthropometric measures.
We conducted a field experiment with randomized crossover design. Assessments occurred at baseline, first follow-up (FU, 5-8 weeks after using one version of WP), and second FU (5-8 weeks of using the other version of WP). In the control condition, participants started with the “Diary” version of WP while in the experimental condition, participants started with the “Diary+Game” version of WP. A total of 54 adults (egos) ages 44-88, and their family and friends (alters) ages 17-69 participated in the study in ego-network groups. Both egos and their alters completed online surveys about their exercise habits. In addition, egos completed anthropometric measurements of BMI, fat percentage, and fat mass by bioimpedance.
From October 2009 to May 2010, flyers, emails, and Web advertisements yielded 335 volunteers who were screened. Rolling recruitment resulted in enrollment of 142 qualified participants in 54 ego-network groups, which were randomly assigned to a study condition. The final analytic sample included 87 individuals from 41 groups. Data were collected from December 2009 to August 2010, and data analysis was completed in 2011. Overall, the participants were given access to the intervention for 10-13 weeks. Statistical analysis suggested an increase in self-reported exercise frequency (mean days per week) from baseline (2.57, SD 1.92) to first FU (3.21, SD 1.74) in both conditions. Stronger effects were seen in the condition where Diary+Game was played first, especially in network groups with larger age variation between the alters and egos. Overall, the decrease in egos’ BMI was statistically significant from baseline to first FU, with greater decrease for those in the Diary+Game first condition (-0.26 vs -0.16 in the Diary first condition).
The Wellness Partners program increased physical activity among participants and resulted in health benefits among the egos. Web-based diary interventions designed with social gaming features hold potential to promote active lifestyles for middle-age adults and people in their social networks.
physical activity; social networking; diary; game; Web-based intervention; behavior change intervention
The aim of this study is to present the development of the Meanings of Eating Index (MEI) in a diverse sample of children. Exploratory factor analysis was performed on MEI items. Factors with eigenvalues above 1.0 were retained. Items that loaded on multiple factors or with item-total correlations below 0.50 were discarded. A 24-item, 5-factor scale comprised the final MEI. Personal Negative Emotions and Disturbed Eating were positively associated with frequency of high calorie snack food intake (r=0.21, p<0.05; r=0.33, p<0.01), Personal Well Being was positively associated with eating vegetables more frequently (r=0.20; p<0.05). Eating on Behalf of Others was negatively associated with frequency of vegetable intake (r=-.20; p<0.05). Pleasure Eating was not associated with dietary intake. The MEI shows promise as a tool for understanding the affective determinants of dietary intake in minority youth.
Eating behavior; Minority; Children; Latino
A brief motivational interviewing (MI) intervention may be a viable adjunct to school-based substance abuse prevention programs. This article describes the development and implementation of a brief MI intervention with 573 adolescents (mean age 16.8; 40.3% female, 68% Latino) enrolled in eight continuation high schools in Southern California. Study participants were assigned to the MI condition in a randomized controlled trial of Project Toward No Drug Abuse. Data are provided on dosage, topics discussed, and quality of MI determined with the Motivational Interviewing Skill Code (MISC). Results suggest that the protocol was feasible and implemented with adequate fidelity. The study’s limitations are noted.
adolescent; motivational interviewing; substance use; prevention; intervention; telephone; school-based; booster
This study aimed to test the effects of a circuit training (CT; aerobic + strength training) program, with and without motivational interviewing (MI) behavioral therapy, on reducing adiposity and type 2 diabetes risk factors in Latina teenagers.
Thirty-eight Latina adolescents (15.8 ± 1.1 yr) who are overweight/obese were randomly assigned to control (C; n = 12), CT (n = 14), or CT + MI (n = 12). The CT classes were held twice a week (60–90 min) for 16 wk. The CT + MI group also received individual or group MI sessions every other week. The following were measured before and after intervention: strength by one-repetition maximum; cardiorespiratory fitness (V̇O2max) by submaximal treadmill test; physical activity by accelerometry; dietary intake by records; height, weight, waist circumference; total body composition by dual-energy x-ray absorptiometry; visceral adipose tissue, subcutaneous adipose tissue, and hepatic fat fraction by magnetic resonance imaging; and glucose/insulin indices by fasting blood draw. Across-intervention group effects were tested using repeated-measures ANOVA with post hoc pairwise comparisons.
CT and CT + MI participants, compared with controls, significantly increased fitness (+16% and +15% vs −6%, P = 0.03) and leg press (+40% vs +20%, P = 0.007). Compared with controls, CT participants also decreased waist circumference (−3% vs +3%; P < 0.001), subcutaneous adipose tissue (−10% vs 8%, P = 0.04), visceral adipose tissue (−10% vs +6%, P = 0.05), fasting insulin (−24% vs +6%, P = 0.03), and insulin resistance (−21% vs −4%, P = 0.05).
CT may be an effective starter program to reduce fat depots and improve insulin resistance in Latino youth who are overweight/obese, whereas the additional MI therapy showed no additive effect on these health outcomes.
VISCERAL FAT; CIRCUIT TRAINING INTERVENTION; OVERWEIGHT LATINA ADOLESCENTS; FASTING INSULIN AND INSULIN RESISTANCE; MOTIVATIONAL INTERVIEWING
Minority girls are disproportionately affected by overweight and obesity. The independent effects of physical activity (PA), sedentary behavior (SB), and diet are not well understood.
This study examined the individual influences of PA, SB and diet on fat mass in Latina and African American (AA) girls, aged 8–11.
Baseline data from a longitudinal cohort study in minority girls is presented. Multiple linear regression analysis assessed the effects of PA, SB, and energy intake on fat mass, adjusting for lean mass, age, Tanner stage and ethnicity.
Participants were 53 Latina and AA girls (77% Latina; Mage=9.8 ± .9; MBMI%=80.8 ± 23.1). Moderate-to-vigorous physical activity (MVPA) by accelerometry (β= −.13, P<.01) and lean mass(β=.69, P<.001) were associated with fat mass (Model R2=.63; P<.0001). MVPA by 3-day-physical-activity-recall (β=−.04, P=.01) and lean mass (β=.75, P<.001) were associated with fat mass (Model R2=.61; P<.0001). SB and energy intake were not associated with fat mass in any model.
Using both objective and subjective measures of PA, MVPA, but not SB or diet, was associated with higher fat mass in Latina and AA girls, independent of lean mass, age, Tanner stage, and ethnicity. Prospective studies are needed to clarify the differential impact of diet and activity levels on adiposity in this population. (Ethn Dis. 2011;21(4):458–461)
Physical Activity; Overweight; Obesity; Latina; African American; Girls
To investigate the impact of worries on weight concerns and emotional eating and body mass index (BMI) percentile in an ethnically diverse sample of female youth.
This study uses baseline and follow-up data from a brief school-based physical activity intervention trial in minority female youth. Partial correlations adjusted for intervention status, age, and ethnicity were used to assess the relationship among emotional eating, weight concerns, and BMI percentile at follow-up. Multi-level modeling was used to analyze the relationships between baseline worries and follow-up emotional eating, weight concerns, and BMI percentile. Additional analysis assessed whether emotional eating mediated and/or moderated the relationship between baseline worries and follow-up BMI. Data were analyzed using SAS v9.1.
The sample consisted of 404 minority females (67.1% Latina; mean age 12.5±0.6; 60.6% normal weight). Weight concerns were positively correlated with emotional eating and BMI percentile (p< 0.001 for both). Baseline worries significantly predicted emotional eating (p= 0.027) and weight concerns (p< 0.001) but not BMI percentile (p= 0.183) at follow-up. Emotional eating did not mediate the relationship between baseline worries and follow-up BMI percentile; however it did moderate the relationship between baseline worries and follow-up BMI percentile (p= 0.003).
Worries were associated with psychosocial variables but not BMI percentile in this sample. Reducing worries in those with high emotional eating scores may influence future weight gain in Latina females.
psychosocial; minority; youth; BMI; weight concerns; emotional eating; mediation; moderation
The purpose of this study was to examine ethnic differences in the metabolic responses to a 16-week intervention designed to improve insulin sensitivity (SI), adiposity, and inflammation in obese African-American and Latino adolescents. A total of 100 participants (African Americans: n = 48, Latino: n = 52; age: 15.4 ± 1.1 years, BMI percentile: 97.3 ± 3.3) were randomly assigned to interventions: control (C; n = 30), nutrition (N; n = 39, 1×/week focused on decreasing sugar and increasing fiber intake), or nutrition + strength training (N+ST; n = 31, 2×/week). The following were measured at pre- and postintervention: strength, dietary intake, body composition (dual-energy X-ray absorptiometry/magnetic resonance imaging) and glucose/insulin indexes (oral glucose tolerance test (OGTT)/intravenous glucose tolerance test (IVGTT)) and inflammatory markers. Overall, N compared to C and N+ST reported significant improvements in SI (+16.5% vs. −32.3% vs. −6.9% respectively, P < 0.01) and disposition index (DI: +15.5% vs. −14.2% vs. −13.7% respectively, P < 0.01). N+ST compared to C and N reported significant reductions in hepatic fat fraction (HFF: −27.3% vs. −4.3% vs. 0% respectively, P < 0.01). Compared to N, N+ST reported reductions in plasminogen activator inhibitor-1 (PAI-1) (−38.3% vs. +1.0%, P < 0.01) and resistin (−18.7% vs. +11.3%, P = 0.02). There were no intervention effects for all other measures of adiposity or inflammation. Significant intervention by ethnicity interactions were found for African Americans in the N group who reported increases in total fat mass, 2-h glucose and glucose incremental areas under the curve (IAUC) compared to Latinos (P’s < 0.05). These interventions yielded differential effects with N reporting favorable improvements in SI and DI and N+ST reporting marked reductions in HFF and inflammation. Both ethnic groups had significant improvements in metabolic health; however some improvements were not seen in African Americans.
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.
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.
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.
Childhood obesity has become an epidemic on a worldwide scale. This article gives an overview of the progress made in childhood and adolescent obesity research in the last decade, with a particular emphasis on the transdisciplinary and complex nature of the problem. The following topics are addressed: 1) current definitions of childhood and adolescent overweight and obesity; 2) demography of childhood and adolescent obesity both in the US and globally; 3) current topics in the physiology of fat and obesity; 4) psychosocial correlates of childhood and adolescent overweight and obesity; 5) the three major obesity-related behaviors, i.e. dietary intake, physical activity and sleep; 6) genes components of childhood and adolescent obesity; 7) environment and childhood and adolescent obesity; and 8) progress in interventions to prevent and treat childhood obesity. The article concludes with recommendations for future research, including the need for large-scale, high dose and long-term interventions that take into account the complex nature of the problem.
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.