Clinical trial NCT01041820: Critical Periods of Exercise
Official title: Critical Periods of Exercise
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Metabolism
Keywords: exercise
bone marrow adipose tissue
bone mineral density
Children in the intervention condition will complete a supervised physical activity program 3 days/wk for 10 weeks
Control treatment will be provided no intervention
All participants will be instructed not to change their current dietary habits during the study period.
Lead sponsor: University of Alabama at Birmingham
Sponsor class: OTHER
First posted: 2010-01-01
Enrollment: 20
Sex: ALL
Minimum age (years): 3
Maximum age (years): 7
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: Early childhood (\~3-7 years of age) is an important window for determining body composition trajectory and may be a critical period for the development of tissue partitioning patterns that influence obesity risk. As adiposity accelerates during this critical period, deposition/ preservation of fat stores may be sustained at the 'expense' of other tissues; i.e. energy homeostasis may be inherently biased toward fat gain. The type and amount of tissue mass accrued in early childhood has implications for metabolic profile, glucose/insulin homeostasis, hormone profile and resting energy expenditure.

The interplay between fat and bone deposition represents a physiologic trait enabling the body to choose between shuttling 'energy' towards accrual of a particular tissue. Plausibly the phenotype underlying obesity and diabetes risk may be determined by the differentiation of cell type (adipocyte, osteocyte, etc.) during this early stage of growth and development. In vitro studies demonstrate transdifferentiation under the influence of specific external stimuli, which can switch phenotypes toward other cell lineages. Further, rodent models have demonstrated that exposure to stimuli (exercise) early in life may prevent excess fat mass accrual in adulthood, even when the stimulus is later removed (animals are no longer exercising). Children's early experiences (engagement in physical activity vs. sedentary behavior) may 'environmentally induce' alterations in body composition and predispose individuals to obesity throughout life.

Aim 1. To examine the associations between body composition via DXA and objectively-measured physical activity/inactivity.

1. Hypothesis 1.1: There is a positive association between physical activity and bone mass.
2. Hypothesis 1.2: There is a positive association between sedentary behavior and total fat mass.

   Aim2. To examine the associations between adipose tissue distribution via MRI and objectively-measured physical activity/inactivity.
3. Hypothesis 2.1: There is an inverse association between physical activity and bone marrow adipose tissue.
4. Hypothesis 2.2: There is a positive association between sedentary behavior and bone marrow adipose tissue.


Eligibility criteria: Inclusion Criteria:

* children aged 3 to 7 years
* healthy, not under the care of a doctor
* not taking medications known to alter body composition or metabolism

Primary outcomes:
measure: Association between exercise and bone marrow adipose tissue in children 3-7 years
timeFrame: 10 weeks of exercise
Secondary outcomes:
Other outcomes:
Locations:
city: Birmingham
country: United States
facility: Family Care Center
state: Alabama
city: Birmingham
country: United States
facility: University of Alabama at Birmingham
state: Alabama
Study officials:
References: