Activity, body composition and bone health in children

Area of Science:

• Pediatric Endocrinology
• Sports Medicine
• Biomedical Engineering

Background:

• Children born with low birth weights (<20th centile) may face long-term health challenges.
• Understanding the impact of physical activity on body composition and bone health is crucial for this population.

Purpose of the Study:

• To investigate the association between daily physical activity levels and body composition and bone outcomes.
• To explore these relationships in children born at term with birth weights below the 20th centile.

Main Methods:

• Activity levels were measured using accelerometers in 36 children.
• Body composition and bone outcomes were assessed using dual-energy X-ray absorptiometry.
• Data were analyzed using correlation to examine relationships between activity, body composition, and bone health z-scores.

Main Results:

• Moderate activity positively correlated with lean mass index (r=0.40, p=0.02).
• Sedentary activity negatively correlated with lean mass index (r=-0.50, p=0.002), whole body bone mineral density z-score (r=-0.44, p=0.01), and hip bone mineral content (r=-0.38, p=0.03).

Conclusions:

• Moderate and vigorous activity are linked to greater lean and bone mass in children with low birth weight.
• Conventional adiposity measures like BMI z-scores may not reflect the positive effects of physical activity on bone and lean mass.
• Regular physical activity is important for optimizing musculoskeletal development in at-risk children.