Low-intensity aerobic exercise for 6 weeks in healthy men decreased circulating IGF-I by 9% and increased IGFBP-1 by 16%, alongside a 20% improvement in insulin sensitivity.
Does low-intensity aerobic exercise reduce IGF-I and increase IGFBP-1 levels in healthy sedentary men?
Low-intensity aerobic exercise effectively downregulates IGF-I and upregulates IGFBP-1 levels while improving insulin sensitivity in healthy sedentary men, which may be relevant for cancer risk reduction.
Increased concentrations of circulating insulin-like growth factor-I (IGF-I) or IGF-I relative to IGF-binding proteins (IGFBPs) are associated with increased risk of developing several forms of cancer. Conversely, exercise is linked with reduced risk. This study aims to investigate the effect of a low-intensity exercise program on circulating levels of IGF-I, IGFBP-1, and IGFBP-3, in previously sedentary males. Fourteen healthy men participated in cycle ergometer training at lactate threshold intensity for 60 min/day, 5 days/week for 6 weeks. After aerobic training, insulin sensitivity improved by 20%, while fasting insulin levels decreased by 13%. Simultaneously, low-intensity aerobic training decreased the circulating levels of IGF-I by 9%, while IGFBP-1 levels increased by 16%. An interesting finding was that higher pretraining level of IGF-I was associated with greater decline in IGF-I with training. Insulin-sensitizing low-intensity aerobic exercise is thus considered to be an effective method for downregulating IGF-I and upregulating IGFBP-1 levels.
Nishida et al. (Fri,) conducted a other in Healthy, previously sedentary males (n=14). Low-intensity aerobic exercise (cycle ergometer training) was evaluated on Circulating levels of IGF-I, IGFBP-1, and IGFBP-3. Low-intensity aerobic exercise for 6 weeks in healthy men decreased circulating IGF-I by 9% and increased IGFBP-1 by 16%, alongside a 20% improvement in insulin sensitivity.