With this article we will try to give an answer to the many visitors who ask us why insulin, number one in the appearance of diabetes and obesity, is used by sportsmen as a doping drug.
A bit of physiology
Insulin is a hormone produced by the pancreas that plays a key role in body metabolism. Its secretion is stimulated by food and especially by carbohydrates and to a lesser extent by proteins and fats.
For all these reasons insulin is considered the quintessential anabolic hormone, even more powerful than anabolic steroids and growth hormone.
Doping and insulin
The doping properties of insulin are linked to its powerful anabolic action. Now let's see in detail which are the most interesting features of this hormone. Insulin:
increases the absorption of amino acids by stimulating protein synthesis, opposing muscle catabolism and improving recovery. For this reason it is often used together with steroids or other anabolic drugs (while on the one hand this class of doping substances stimulates the increase of the muscular masses on the other the insulin preserves them preventing their disintegration)
restores the hepatic and muscular reserves of glycogen allowing the athlete to recover the energy expended during a long training in a short time
Beyond the dangerous side effects that we will see in a few lines, from a strictly metabolic point of view, one of the disadvantages of this hormone is its ability to increase the uptake and storage of fatty acids. By reflex action, insulin also tends to increase appetite and because of these characteristics it opposes weight loss. If these peculiarities are a big problem for sedentary people, the same cannot be said for athletes who, through a balanced diet and the intense physical activity they undergo, manage to transform this apparent disadvantage into a precious resource.
The insulin administered to the athletes will therefore act mainly on muscle anabolism by increasing the deposit of proteins and carbohydrates inside the muscle. We must not forget that the increased entrance of fatty acids favors recovery in endurance athletes, restoring depleted fat stocks during endurance physical activity.
Because of all these characteristics, insulin is a doping drug particularly appreciated by both power athletes and endurance athletes.
Another very big advantage of this hormone is linked to the absolute impossibility of identifying the substance during doping controls. Recently (March 2007) German and Belgian scientists have developed a test that can prove the use of certain types of insulin (Lantus) through specific urine tests. The study also provided some interesting insights that could help them carry out a test in the future that can also unmask the use of other types of insulin (recombinant and Levimir). Currently this innovative test is waiting to receive validation and subsequent adoption by the international anti-doping commissions.
Doses and methods of employment
The insulin on the market is distinguished by origin (synthetic or biological) and duration of action (short, medium, long). However, it must be pointed out that the animal-derived insulin (bovine or porcine) has now been completely replaced by the human one, obtained through recombinant DNA technology. For therapeutic purposes, insulin doses and concentrations are expressed in Units, (the unit is the international measurement value equivalent to the amount of hormone required to reduce the plasma glucose concentration to 45 mg / dl in the fasted rabbit).
The production of insulin in a normal subject is generally between 18 and 40 Units / day equal to about 0.5-1 Units / Kg body weight. These values can increase significantly if the diet is rich in simple sugars.
Being a hormone of a proteinic nature, insulin cannot be ingested, otherwise the digestive enzymes would denature it, rendering it inactive. A particularly thin disposable needle is used for the injection which makes the operation comfortable and usually well tolerated. Insulin must be injected into the subcutaneous tissue, poor in blood capillaries, so that it can slowly spread into the circulatory stream. The recommended injection zones are, in rotation, the abdomen, at a distance of at least two to three centimeters from the navel; the arm, between the elbow and the shoulder, on the external side; the legs, halfway between knee and groin, in the front and the buttocks. Generally the absorption of insulin is the slower the greater the fat deposits and at least these areas are stressed during a possible physical activity.
Insulin doses vary from athlete to athlete and, together with the location and method of use, must be established by the doctor.
In the hours following the injection the athlete must consume a certain quantity of carbohydrates to avoid dangerous lowering of blood sugar. It is generally recommended to take 10 grams of sugar for each unit of insulin given within thirty minutes of the injection; if the dose used is low, it is advisable to take at least 100 grams of carbohydrates 20 or 30 minutes after the insulin has been injected. Along with carbohydrates, many athletes take free amino acids to stimulate protein synthesis to the maximum.
Let us once again remember that the methods of recruitment reported in this paragraph are of a general nature and must be established by the doctor in relation to the type of insulin used, the site of injection, nutrition and the type of physical activity performed during the day.
Side effects
Insulin is an exceptional drug that can save and improve the quality of life of many diabetics, however, if used incorrectly, it can be deadly or worse still turn a person into a "vegetable".
Its short-term side effects are related to the possible appearance of hypoglycemia. By favoring the passage of glucose from the blood to the tissues an excessive dose of insulin subtracts nourishment to the brain, a particularly sensitive organ whose functionality is directly linked to the presence of suitable quantities of glucose. Being an independent insulin organ and lacking in glucidic stocks, a brain deprived of glucose for 10-15 minutes undergoes a rapid degeneration due to the death of its cells.
Signs of cerebral distress appear at glucose levels below 60-70 mg / dl and include: sweating, hunger, peresthesia, palpitations, dizziness, blurred vision.
Although our body has effective biological mechanisms to counter hypoglycemia, an abrupt drop in plasma glucose levels can lead to convulsions and coma.
Other side effects attributable to improper use of insulin include: rupture of red blood cells (haemolytic anemia), impaired cardiac function, fluid retention (edema) and liver problems
For all these reasons before starting insulin therapy the athlete should become familiar with blood glucose meters. Frequent glycemic control is essential to avoid the unpleasant side effects of the drug. If the blood sugar drops too low, it is important to have sugar lumps on hand and the possibility of intervening with an intravenous infusion of glucose possibly assisted by glucagon (another hormone produced by the pancreas with an action opposite to that of insulin).
The widespread tendency to associate insulin with other doping drugs contributes to further aggravating the situation. In relation to the sport practiced, insulin is generally combined with anabolic steroids (testosterone derivatives), erythropoietin, IGF-1, GH, thyroid hormones, stimulants (caffeine, ephedrine, amphetamines), diuretics, supplements and more. forth. This hypothesis is confirmed by the admissions of some former professional athletes who during their careers even took more than 10 drugs a day.
