Gabriel Q. Shaibi

Promoting Healthy Lifestyles in High School Adolescents: A Randomized Controlled Trial

BACKGROUND Although obesity and mental health disorders are two major public health problems in adolescents that affect academic performance, few rigorously designed experimental studies have been conducted in high schools. PURPOSE The goal of the study was to test the efficacy of the COPE (Creating Opportunities for Personal Empowerment) Healthy Lifestyles TEEN (Thinking, Emotions, Exercise, Nutrition) Program, versus an attention control program (Healthy Teens) on: healthy lifestyle behaviors, BMI, mental health, social skills, and academic performance of high school adolescents immediately after and at 6 months post-intervention. DESIGN A cluster RCT was conducted. Data were collected from January 2010 to May of 2012 and analyzed in 2012-2013. SETTING/PARTICIPANTS A total of 779 culturally diverse adolescents in the U.S. Southwest participated in the trial. INTERVENTION COPE was a cognitive-behavioral skills-building intervention with 20 minutes of physical activity integrated into a health course, taught by teachers once a week for 15 weeks. The attention control program was a 15-session, 15-week program that covered common health topics. MAIN OUTCOME MEASURES Primary outcomes assessed immediately after and 6 months post-intervention were healthy lifestyle behaviors and BMI. Secondary outcomes included mental health, alcohol and drug use, social skills, and academic performance. RESULTS Post-intervention, COPE teens had a greater number of steps per day (p=0.03) and a lower BMI (p=0.01) than did those in Healthy Teens, and higher average scores on all Social Skills Rating System subscales (p-values <0.05). Teens in the COPE group with extremely elevated depression scores at pre-intervention had significantly lower depression scores than the Healthy Teens group (p=0.02). Alcohol use was 12.96% in the COPE group and 19.94% in the Healthy Teens group (p=0.04). COPE teens had higher health course grades than did control teens. At 6 months post-intervention, COPE teens had a lower mean BMI than teens in Healthy Teens (COPE=24.72, Healthy Teens=25.05, adjusted M=-0.34, 95% CI=-0.56, -0.11). The proportion of those overweight was significantly different from pre-intervention to 6-month follow-up (chi-square=4.69, p=0.03), with COPE decreasing the proportion of overweight teens, versus an increase in overweight in control adolescents. There also was a trend for COPE Teens to report less alcohol use at 6 months (p=0.06). CONCLUSIONS COPE can improve short- and more long-term outcomes in high school teens. TRIAL REGISTRATION This study is registered at www.clinicaltrials.gov NCT01704768.

Examining Metabolic Syndrome Definitions in Overweight Hispanic Youth: A Focus on Insulin Resistance

OBJECTIVE To examine the prevalence of the metabolic syndrome in overweight Hispanic youth according to 3 published pediatric definitions. Furthermore, the relationship of each definition to directly measured insulin resistance was examined. STUDY DESIGN We conducted a secondary data analysis of 218 overweight Hispanic youth with a family history of type 2 diabetes mellitus. The metabolic syndrome was defined as >/=3 of these criteria: elevated triglyceride level, low high-density lipoprotein cholesterol level, elevated blood pressure, abdominal obesity, and hyperglycemia. The cutoff points were derived from updated definitions of Cook et al,(1) Cruz et al,(2) and Weiss et al.(3) Insulin sensitivity was determined with the insulin-modified frequently sampled intravenous glucose tolerance test. RESULTS Prevalence of the metabolic syndrome ranged from 25.7% to 39%, with moderate to substantial agreement between definitions (kappa = 0.52-0.70). Regardless of definition, an inverse relationship between metabolic risk and insulin sensitivity was noted such that children with the metabolic syndrome had 51% to 60% lower insulin sensitivity compared with children without any risk factors (P </=.001 for all definitions). CONCLUSION The metabolic syndrome is prevalent in overweight Hispanic youth and may provide pediatricians with additional clinical insight for identifying the most metabolically at-risk children. Working toward a uniform and practical definition of the metabolic syndrome may improve its clinical implementation.

Dietary Intake and the Metabolic Syndrome in Overweight Latino Children

Little is known about the relationship between diet and metabolic health in Latino children, a population at increased risk for diabetes. The present study evaluates diet composition and the metabolic syndrome in a cross-sectional sample of 109 overweight Latino children aged 10 to 17 years with a family history of type 2 diabetes. Dietary intake was assessed by two 24-hour recalls. Associations between nutrients and features of the metabolic syndrome were examined using multiple linear regression and analysis of covariance. Log cholesterol intake was positively associated with log systolic blood pressure (beta=0.034, P=0.017) and log soluble dietary fiber intake was inversely associated with log waist circumference (beta=-0.069, P=0.036). Log soluble fiber intake was significantly higher in participants with 0 features compared to those with 3+ features of the metabolic syndrome (P=0.046), which translates to 5.2 g vs 4.1 g soluble fiber daily. No other significant associations were found between dietary variables and either the individual features of the metabolic syndrome or the clustering of metabolic syndrome components. Increases in soluble fiber through the daily consumption of fruits, vegetables, and beans may improve metabolic health in Latino children.

Ecodevelopmental contexts for preventing type 2 diabetes in Latino and other racial/ethnic minority populations

Diabetes is the sixth leading cause of death in the United States and it is now cited along with obesity as a global epidemic. Significant racial/ethnic disparities exist in the prevalence of diabetes within the US, with racial and ethnic minorities disproportionately affected by type 2 diabetes and its complications. Racial/ethnic and socioeconomic factors influence the development and course of diabetes at multiple levels, including genetic, individual, familial, community and national. From an ecodevelopmental perspective, cultural variables assessed at one level (e.g., family level dietary practices) may interact with other types of variables examined at other levels (e.g., the availability of healthy foods within a low-income neighborhood), thus prompting the need for a clear analysis of these systemic relationships as they may increase risks for disease. Therefore, the need exists for models that aid in “mapping out” these relationships. A more explicit conceptualization of such multi-level relationships would aid in the design of culturally relevant interventions that aim to maximize effectiveness when applied with Latinos and other racial/ethnic minority groups. This paper presents an expanded ecodevelopmental model intended to serve as a tool to aid in the design of multi-level diabetes prevention interventions for application with racial/ethnic minority populations. This discussion focuses primarily on risk factors and prevention intervention in Latino populations, although with implications for other racial/ethnic minority populations that are also at high risk for type 2 diabetes.

Deterioration of insulin sensitivity and beta-cell function in overweight Hispanic children during pubertal transition: A longitudinal assessment

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

PARENTAL HISTORY AND RISK OF TYPE 2 DIABETES IN OVERWEIGHT LATINO ADOLESCENTS: A LONGITUDINAL ANALYSIS.

OBJECTIVE— The purpose of this article was to examine metabolic risk factors for type 2 diabetes in children and adolescents as a function of maternal versus paternal family history of type 2 diabetes and to examine whether differences in these risk factors emerge during adolescent growth. RESEARCH DESIGN AND METHODS— A total of 247 overweight Latino children (baseline age = 11.1 ± 1.7 years) with a parental history of type 2 diabetes were followed annually for 5 years (2.2 ± 1.2 observations/child) with measures of insulin sensitivity, acute insulin response to glucose, and disposition index. Longitudinal linear mixed-effects modeling was used to evaluate the influence of maternal versus paternal family history of type 2 diabetes on changes in diabetes risk factors over age. RESULTS— Insulin sensitivity and the disposition index decreased over age (β = −0.052 and β = −0.033, P < 0 0.01). Acute insulin response to glucose and fasting and 2-h glucose increased (β = 0.019, β = 0.002, and β = 0.003, P < 0.01). Declines in insulin sensitivity were significantly greater in participants whose maternal grandmothers had a history of type 2 diabetes (β = −0.03, P = 0.03). Declines in the disposition index (β = −0.02, P = 0.04) and increases in fasting glucose were significantly influenced by a maternal history of type 2 diabetes (β = 0.60, P < 0.05). CONCLUSIONS— Maternal but not paternal family history for diabetes may have a significant impact on insulin dynamics, becoming more pronounced during growth in overweight Latino adolescents. Further research is clearly warranted.

Effects of a Culturally Grounded Community-Based Diabetes Prevention Program for Obese Latino Adolescents

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

Glucose Response Curve and Type 2 Diabetes Risk in Latino Adolescents

OBJECTIVE In adults, the shape of the glucose response during an oral glucose tolerance test (OGTT) prospectively and independently predicts type 2 diabetes. However, no reports have described the utility of this indicator in younger populations. The purpose of this study was to compare type 2 diabetes risk factors in Latino adolescents characterized by either a monophasic or biphasic glucose response during an OGTT. RESEARCH DESIGN AND METHODS A total of 156 nondiabetic Latino adolescents completed a 2-h OGTT. Monophasic and biphasic groups were compared for the following type 2 diabetes risk factors: fasting and 2-h glucose, HbA1c, glucose area under the curve (AUC), insulin sensitivity (Matsuda index), insulin secretion (insulinogenic index), and β-cell function as measured by the disposition index (insulin sensitivity × insulin secretion). RESULTS Of the participants, 107 youth were categorized as monophasic and 49 were biphasic. Compared with the monophasic group, participants with a biphasic response exhibited lower HbA1c (5.4 ± 0.3 vs. 5.6 ± 0.3%, P < 0.01) and lower glucose AUC (14,205 ± 2,382 vs. 16,230 ± 2,537 mg ⋅ dL−1 ⋅ h−1, P < 0.001) with higher insulin sensitivity (5.4 ± 3.2 vs. 4.6 ± 3.4, P ≤ 0.05), higher insulin secretion (2.1 ± 1.3 vs. 1.8 ± 1.3, P = 0.05), and better β-cell function (10.3 ± 7.8 vs. 6.0 ± 3.6, P < 0.001). Differences persisted after adjusting for age, sex, and BMI. CONCLUSIONS These data suggest that the glycemic response to an OGTT may differentiate risk for type 2 diabetes in youth. This response may be an early marker of type 2 diabetes risk among high-risk youth.

Cardiorespiratory fitness predicts changes in adiposity in overweight Hispanic boys

We have previously shown that cardiorespiratory fitness predicts increasing fat mass during growth in white and African‐American youth, but limited data are available examining this issue in Hispanic youth. Study participants were 160 (53% boys) overweight (BMI ≥ 85th percentile for age and gender) Hispanic children (mean ± s.d. age at baseline = 11.2 ± 1.7 years). Cardiorespiratory fitness, assessed by VO2max, was measured through a maximal effort treadmill test at baseline. Body composition through dual‐energy X‐ray absorptiometry and Tanner stage through clinical exam were measured at baseline and annually thereafter for up to 4 years. Linear mixed models were used to examine the gender‐specific relationship between VO2max and increases in adiposity (change in fat mass independent of change in lean tissue mass) over 4 years. The analysis was adjusted for changes in Tanner stage, age, and lean tissue mass. In boys, higher VO2max at baseline was inversely associated with the rate of increase in adiposity (β = −0.001, P = 0.03); this effect translates to a 15% higher VO2max at baseline resulting in a 1.38 kg lower fat mass gain over 4 years. However, VO2max was not significantly associated with changes in fat mass in girls (β = 0.0002, P = 0.31). In overweight Hispanic boys, greater cardiorespiratory fitness at baseline was protective against increasing adiposity. In girls however initial cardiorespiratory fitness was not significantly associated with longitudinal changes in adiposity. These results suggest that cardiorespiratory fitness may be an important determinant of changes in adiposity in overweight Hispanic boys but not in girls.

Physical fitness, dietary intake, and metabolic control in adolescents with type 1 diabetes

Purpose:  We examined whether physical fitness and dietary intake predicted better glycemic control and lipid profile in adolescents with type 1 diabetes mellitus (T1DM).