Insulin is a peptide hormone produced by the body and belongs to the prohibited doping substances. It is produced in the pancreas by specialised cell aggregates called islets of Langerhans. Insulin lowers the blood sugar level and also affects the metabolism of fats and amino acids. Insulin is the only hormone that can lower the blood sugar level by promoting the uptake of glucose (simple sugar) into the cells and the synthesis of glycogen. Glycogen is a multiple sugar composed of glucose units. It is the storage form of glucose which serves as the body's energy supply.
Effect of insulin
Insulin promotes the uptake of glucose into the cells (especially in the liver and the muscles) and the synthesis of glycogen. The end result is a reduction in the blood sugar level. Insulin is the only hormone that can lower the blood sugar level. It inhibits the metabolisation of fat and increases the uptake of amino acids that regulate metabolic processes and tissue growth in the body and protects against diseases and toxins. In addition, it stimulates cell division and cell growth.
The body produces its own insulin in the pancreas.
It is released into the bloodstream, distributed throughout the body via the circulation, and binds to insulin receptors. Insulin receptors are produced by nearly all body cells. Additionally administered insulin also binds to these receptors.
By this mechanism, administration of insulin lowers the blood sugar level, increases the uptake of glucose and amino acids and inhibits fat reduction of the cells.
⬇ Blood sugar level
⬆ Glucose and amino acid uptake
⬇ Fat reduction of the cells
Diabetes mellitus is a metabolic disorder characterised by insulin resistance or insulin deficiency and chronically increased blood sugar levels.
Diabetes mellitus type 1
Type 1 diabetes is an autoimmune disorder. It is caused by a destruction of the beta cells in the pancreas, whose function is to produce insulin in order to regulate the body's blood sugar level. In type 1 diabetes, the hormone insulin is missing and needs to be substituted artificially in the form of synthetic insulin products. The disorder is more prevalent among children and young adults but can occur at any age of life. People with type 1 diabetes depend on life-long insulin injections. A cure has not yet been found.
Diabetes mellitus type 2
In people with type 2 diabetes, the pancreas continues to produce insulin, but the quantities are inadequate or the body is unable to use it to convert blood sugar into energy (insulin resistance). The development of type 2 diabetes is promoted by hereditary factors, a high-fat diet, excess body weight and lack of exercise. Usually, a combination of these risk factors triggers the disorder. In most cases, type 2 diabetes occurs in people over forty years of age. An alarming fact is, however, that nowadays young adults between 20 and 35 and even children have increasingly been affected by the disorder. By maintaining a healthy lifestyle and avoiding excess body weight, much can be done to reduce the risk of type 2 diabetes.
Side effects and consequences of insulin abuse
Synthetic insulin inhibits the release of the body's own insulin. This effect is called "negative feedback".
Insulin doping can be dangerous to life! Overdoses of synthetic insulin cause heart palpitations, restlessness and trembling. If the blood sugar level drops so deeply that the nervous system is no longer adequately supplied with energy, severe brain damage may follow. In the worst case, this can lead to death. Another danger involved in the abuse of insulin is the risk of diabetes.
Insulin abuse is especially found in the domain of strength sports, often in conjunction with anabolic steroids and growth hormones. While anabolics and growth hormones both promote muscle growth, insulin inhibits muscle reduction. Moreover, the growth hormone somatotropin reduces the uptake of glucose in muscle cells, which can be compensated with insulin.
Abuse of synthetic insulin is also widespread among endurance athletes. Synthetic insulin expands the glycogen stores of the muscles, thus enhancing strength endurance and aerobic endurance. During a raid at the 2001 Giro d’Italia, police investigators found an insulin syringe in the hotel room of the Italian professional cyclist Marco Pantani, who has since died. Thereupon, Pantani was banned for eight months.