IGF1 and osteoporosis: Secondly, the increase of ET-1 can increase the risk of bone loss by activating oxidative stress, leading to disorder of calcium and phosphorus metabolism balance.21 Some researchers have discussed the changes of serum biological factor spectrum in elderly patients with osteoporosis and found that there were significant fluctuations in IGF-1 and other factors and IGF-1 decreased significantly with the progress of the disease and had obvious linear trend difference.22