2010 Annual Report
1a.Objectives (from AD-416)
Objective 1: Investigate the effectiveness of community-based intervention strategies to prevent childhood obesity and its associated health risks in 8- to 12-y-old Hispanic children with BMI >/= 85th percentile.
Sub-objective 1.A. Test the effectiveness of diet behavior modification, structured aerobic exercise, or diet behavior modification plus structured aerobic exercise for obesity prevention and improvement in fitness, health risks, and psychological state in at-risk Hispanic children, ages 8-12 y, assigned to one of three treatment groups or control in a 12-month family-based RCT.
Sub-objective 1.B. Evaluate the role of genetic variation in response to strategies aimed at diet and PA.
Sub-objective 1.C. Model energy balance in growing children to predict the obligatory changes in energy intake and/or energy expenditure and PAL required for obesity prevention.
Objective 2: Develop and evaluate family-centered intervention strategies for the pediatric primary care setting to prevent childhood obesity.
Sub-objective 2.A. Develop a conceptual model and perform formative work to evaluate the model for a pediatric obesity prevention program for primary care clinics.
Sub-objective 2.B. Develop and pilot test a parent-targeted obesity prevention program for pediatric primary care clinics.
Sub-objective 2.C. Evaluate the parent-targeted prevention program for effectiveness in pediatric primary care clinics.
1b.Approach (from AD-416)
The long-term objective of this project is to increase our understanding of how to prevent childhood obesity through targeted community interventions. A multifactorial theoretical approach based on Social Cognitive Theory (SCT) and parenting theory will be taken to address the built environment as well as family dynamics and child behavior at the community and primary care level. A 12-month family-based randomized controlled trial (RCT) will be conducted to test the effectiveness of diet behavior modification, structured aerobic exercise, or diet behavior modification plus structured aerobic exercise for obesity prevention and improvement in fitness, health risks, and psychological state in at-risk Hispanic children (Objective 1). The role of genetic variation in response to strategies aimed at diet and physical activity (PA) will be evaluated and a model developed to predict the obligatory changes in energy intake and physical activity level (PAL) required for obesity prevention. Family-centered intervention strategies will be developed and evaluated for the pediatric primary care setting to prevent childhood obesity (Objective 2). A conceptual model will be developed and formative work performed to evaluate the model for obesity prevention program for primary care clinics. A parent-targeted obesity prevention program will be developed and a pilot study conducted in pediatric primary care clinics. A RCT will be conducted to evaluate the parent-targeted prevention program for effectiveness in pediatric primary care clinics. Together, these strategies form a new paradigm that integrates community resources and pediatric primary care in support of the child and the family in the prevention and management of childhood obesity.
A family-based intervention, VIVA LA SALUD INFANTIL, was conducted to test the effectiveness of diet behavior modification with and without exercise for weight loss and improvement in fitness, psychological state, and co-morbidity risk. Weight loss was associated with improvements in several obesity-related risk factors. A 1-year community-based child obesity intervention called MEND (Mind Exercise Nutrition Do It) is underway at the YMCA. The MEND program involves twice-weekly sessions with parents and children in attendance. For the second hour of the two-hour program, the children participate in physical fitness activities while the parents receive information and counseling from trained health educators. To date, 23 Hispanic families have been enrolled into this 1-year program.
To explore the effect of genetic variation on behaviors related to diet and physical activity, we genotyped 1.1 million single nucleotide polymorphisms (SNPs) in 815 Hispanic children. Genetic association analysis will be performed on body size and composition, fasting metabolic and endocrine biochemistries, and physiological measures of energy expenditure, physical activity, and diet. Data collection is on-going in the above-mentioned community interventions to model changes in weight and body composition and energy expenditure in growing children.
We obtained IRB approval and interviewed an additional 11 parents of overweight 5- to 8-year olds for a needs assessment for obesity treatment in primary care. We are analyzing the data. We developed the Helping HAND program as a modular 6-month program that targets obesity-related child behaviors and corresponding effective parenting practices to support the child toward behavior change. The program can be delivered by ancillary staff in primary care clinics. A training manual was developed and used to train 5 Health Promotion Specialists from Texas Children's Health Plan to deliver Helping HAND in community clinics. We obtained IRB approval to pilot test Helping HAND with a randomized controlled trial. We recruited 4 clinics and 40 parent-child pairs of 5- to 8-year-old children. Twenty pairs were randomized to immediately start the program, and 20 were wait-listed to start the program after time 2 data collection. We collected baseline data on 40 parent-child pairs, including: family demographics; children's height and weight, dietary intake (3 24-hour dietary recalls), physical activity (5 days of wearing an activity monitor), and TV viewing; parent's height and weight, and parenting practices regarding children's physical activity, fruit and vegetable intake, and TV viewing with validated self-reported measures. Time 2 data were collected on 34 parent-child pairs (85%). We analyzed the time 2 data and are preparing manuscripts. We have conducted 29 exit interviews with participants from the study and are coding and analyzing the results.
The ADODR monitors activities for the project by routine site visits, and review of major purchases of supplies/equipment, use of SCA funds for foreign travel, and submission of grant applications by investigators funded through the SCA.
MC4R's role in energy expenditure and appetite regulation in Hispanic children. Melanocortin 4 receptor (MC4R) is a protein that binds to a hormone called alpha-melanocyte stimulating hormone (a-MSH) which is involved in eating behavior. Mutations in MC4R constitute the most common form of obesity caused by a single genetic mutation; however, the role that MC4R plays in childhood obesity is unclear. Researchers from the Children's Nutrition Research Center in Houston, Texas, performed studies to identify all possible genetic mutations in MC4R in Hispanic children. Several mutations of MC4R were shown to be associated with physical activity, total energy expenditure and sleeping energy expenditure, and the appetite hormone ghrelin. These novel findings provide strong evidence that this gene likely plays a role in the regulation of weight, not only through food intake but also physical activity. This research contributes to our understanding of the most commonly known genetic defect predisposing children to obesity.