Insulin-like growth factor
What is insulin-like growth factor?
Insulin-like growth factor is the most predominant somatomedin or growth factor hormone, with a very similar structure to insulin although it is released by the liver. It plays an important role in growth and development in children and is thought to have anabolic effects in adults.
Medical uses of insulin-like growth factor
Uses of insulin-like growth factor in medical instances are rare, although it can be beneficial in the treatment of:
• dwarfism and other growth problems in children; • diabetes mellitus type 2; • kidney disease; • osteoporosis (condition resulting in reduced bone mineral density, also known as brittle bones); • atherosclerosis (inflammation of the walls of the arteries); • osteoarthritis; • myotonic muscular dystrophy.
Effects on performance
Due to perceived anabolic effects, athletes use insulin-like growth factor to increase muscle mass and strength, although clinical studies have not shown any increases. It is thought that it is actually the insulin-like growth factor binding protein-3 which is responsible for growth rather than the growth factor itself. Insulin-like growth factor does, however, inhibit cell death and so may have a role in reducing recovery times.
Side-effects of insulin-like growth factor
The side-effects of insulin-like growth factor are:
• acromegaly in adult athletes (a condition where the pituitary gland produces too much human growth hormone, resulting in the growth and swelling of body parts, typically hands, feet, nose but can progress to brow and jaw protrusion and swelling of internal organs);
• organomegaly (the abnormal enlargement of organs);
• hypoglycemia (lower than normal levels of glucose in the blood);
• cancer (prostate, lung and colorectal cancers have all been reported).
S2. Peptide hormones, growth factors and related substances
S4. Hormone and metabolic modulators
S5. Diuretics and other masking agents
M1. Manipulation of blood and blood components
M2. Chemical and physical manipulation
Substances and methods prohibited at all times
