Why do teenagers with type 1 diabetes have higher growth hormone levels?
Levels of growth hormone are affected by insulin action at the liver. Insulin stimulates the production of insulin-like growth factor (IGF-1) and IGF binding protein (IGFBP-3), which help growth hormone to work normally. If levels of these substances are low, the brain responds by releasing more growth hormone. In teens who take insulin by injection, the liver does not produce as much IGF-1 and IGFBP-3 because it does not receive insulin directly. This means that more growth hormone is produced, which in turn means that insulin cannot work as effectively. The result is increased insulin resistance. The authors of this study had previously shown that injecting IGF-1 in teenagers and young adults with type 1 diabetes lowered both their need for insulin and their levels of hemoglobin A1C. Unfortunately, the treatment had many side effects, including fluid retention, jaw and joint pains, and worsening of early retinopathy (eye disease). These, obviously, could be serious with long-term use
