Effect Of Home-based Strength Training Program On Igf-i, Igfbp-1 And Igfbp-3 In Obese Latino Boys Participating In A 16 Week Randomized Controlled Trial.

Abstract

BACKGROUND: Accumulating evidence indicates circulating concentrations of insulin-like growth factor 1 (IGF-1), or IGF-1 relative to IGF binding proteins (IGFBP’s) is associated with increased risk for the development of several forms of cancers. Similarly, exercise has been linked with reduced cancer risk. PURPOSE: To assess the effects of a 16-week (2xweek) home-based strength training (HBST) program on serum IGF-1, IGFBP-1, IGFBP3, and their ratio we randomized 32 obese Latino adolescent males (aged 14-18 years) into a twice-weekly Home Based Strength Training group (HBST;n=16) or a Control group (C;n=16) for 16 weeks. METHODS: Home-based strength training for 16 weeks, composed of two one-hour sessions per week. Outcome Measures were assessed pre- and post intervention/control condition and included IGF-1, IGFBP-1 and IGFBP-3, fasting glucose, two-hour glucose, Body Mass Index (BMI), dual energy X-ray absorptiometry (DEXA) scan, dietary intake and physical activity using the Actigraph GT1X. GLM was used to assess differences in changes in outcome measures, between the C and the HBST groups. RESULTS: Over the 16 weeks of the intervention there was a trend for a significant within-subject’s differences for IGF 1 (p=0.078), but no significant within-subject’s differences for IGFBP-1 (p=0.187), IGFBP-3 (p=0.490), fasting glucose (p=0.87), and 2-hr glucose (p=0.38). There were also no between subject differences noted in fasting glucose (p=0.36), 2-hr glucose (p=0.84), SI (p=0.34), AIR (p=0.27), and DI (p=0.73). There was a trend for a between subject differences in IGF1 (p = 0.081). There were also no between subject differences noted in IGFBP-1 (p=0.194), IGFBP-3 (p = 0.202), fasting glucose (p=0.36), and 2-hr glucose (p=0.84). CONCLUSIONS: These preliminary results suggest that a twice per week 16-week home based strength training program does not affect concentrations of IGF-1, IGFBP-1, and IGFBP-3, in obese Latino boys.