Lifestyle, Adiposity, and Cardiovascular Health in Youth

Study Overview
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Brief Summary
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Adiposity is a key link between lifestyle factors (like diet and exercise) and cardiovascular (CV) disease. However, little is known about the link during the juvenile years, when the processes leading to CV disease are at an early stage of development. The specific aims are as follow: (1) to determine the relations of free-living diet and exercise to total body percent fat ( percentBF), visceral adipose tissue and CV fitness in black and white boys and girls of varying socioeconomic status. (2) to determine the relations of fatness and fitness to different CV disease risk factors. Design and methods: (1) Recruit 800 14 to 18 year olds, 200 in each ethnicity and gender subgroup. (2) Assess diet with seven 24-hour recalls, and exercise with two seven-day recalls and heart rate monitoring. (3) Measure percent body fat with dual-energy x-ray absorptiometry, visceral adipose tissue with magnetic resonance imaging and CV fitness with a multi-stage treadmill test. (4) Measure major fatness- and fitness-related CV disease risk factors (e.g., total cholesterol:HDL cholesterol ratio, insulin, systolic blood pressure, left ventricular mass indexed to height, fibrinogen). (5) Conduct multivariate and univariate analyses to determine relationships.

Detailed Description
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Adult studies have shown that adiposity, especially visceral adipose tissue, and cardiovascular (CV) fitness are key links between lifestyle factors like diet and exercise on one hand, and CV disease on the other. However, very little is known about these links during the juvenile years, when the processes leading to CV disease are at an early stage of development. The specific aims are as follow: (1) to determine the relations of free-living diet and exercise to total body percent fat ( percent BF), visceral adipose tissue and CV fitness in black and white boys and girls of varying socioeconomic status. (2) to determine the relations of fatness and fitness to different CV risk factors. Design and methods: (1) Recruit 800 14 to 18 year olds, 200 in each ethnicity and gender subgroup. (2) Assess diet with seven 24-hour recalls, and exercise with two seven-day recalls and Actigraph monitors. (3) Measure percent body fat with dual-energy x-ray absorptiometry, visceral adipose tissue with magnetic resonance imaging and CV fitness with a multi-stage treadmill test. (4) Measure major fatness- and fitness-related CV disease risk factors (e.g., total cholesterol:HDL cholesterol ratio, insulin, systolic blood pressure, left ventricular mass indexed to height, fibrinogen). (5) Conduct multivariate and univariate analyses to determine relationships. Health relatedness: The provided by this project will assist in the formulation of effective lifestyle interventions targeted to specific demographic groups for primary prevention of CV disease, starting early in life when the foundations for adult disease are being laid.

Official Title
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Lifestyle, Adiposity, and Cardiovascular Health in Youth Study

Conditions
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Lifestyle, Adiposity, Cardiovascular Diseases, Adolescent

Intervention / Treatment
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* Other: No intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: European or African American and age 14-18 years Exclusion Criteria: Taking medications or had any chronic medical conditions that might affect growth, maturation, physical activity, nutritional status, or metabolism.

Ages Eligible for Study
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Minimum Age: 14 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: No intervention|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fatness | Percentage of body fat (%) | Through study completion, an average of 4 years | 
| Fitness | Maximal oxygen consumption (VO2, mL/kg/min) | Through study completion, an average of 4 years | 
| Insulin resistance | Fasting insulin (pmol/L) | Through study completion, an average of 4 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fat distribution | Visceral adipose tissue volume (cm^3) | Through study completion, an average of 4 years | 
| Cardiovascular risk factor | Triglyceride (TG, mmol/L) and high density lipoprotein cholesterol (HDLC, mmol/L) will be combined to report TG/HDLC ratio | Through study completion, an average of 4 years |