Hypoglycemia is the medical term used when there is a reduction in levels of glucose (sugar) in the blood. As glucose is the main source of energy in the body, the occurrence of hypoglycemia produces typical signs and symptoms such as weakness, sweating, tremors, and the other, which only disappear if the blood glucose level is corrected.
While most cases of hypoglycemia occurs as side effect of diabetes treatment, it can also occur rarely in non-diabetic patients.
In healthy individuals, blood glucose, or glucose levels in the blood are kept more or less stable through the action of various hormones, and insulin and glucagon key. To understand how hypoglycemia arises, we will summarize very simply the physiological mechanisms of control of blood glucose.
When we feed a large glucose load is absorbed in the intestines. This absorbed glucose is released into the bloodstream, causing their concentrations in blood will rise, causing a transient hyperglycemia. At this time, the pancreas increases its release of insulin, the hormone necessary for glucose that can be used by body cells. Insulin decreases the blood glucose in two main ways: by allowing the glucose uptake by cells and stimulate the storage of glucose in the liver, as glycogen.
Conversely, when we long time without feeding us, glucose levels in the blood are reduced gradually as the cells will consume sugar to generate energy. To avoid hypoglycemia, the pancreas begins to release the glucagon, a hormone that has an antagonistic action to insulin. Glucagon acts by stimulating the release of glucose from liver, or by use of stored glycogen or by direct glucose production in the liver itself, a process called gluconeogenesis. Glucagon is also able to use our fat reserves and turn it into glucose (glycerol, present in lipids, is widely used in gluconeogenesis).
In normal people, hypoglycemia is a very rare event, because even when we were many hours fasting, the body is able to mobilize our reserves of glycogen and fat in order to provide sufficient quantities of sugar into the blood. An individual is able to stay several days without eating and still not develop hypoglycemia if you have enough reserves.
Therefore, summarizing, the Insulin is the hormone that acts normalizing blood glucose when it is high (hyperglycemia), whereas glucagon is the hormone that acts to normalize the blood sugar when it is low (hypoglycemia).
Normal glucose values in the blood when we are fasting usually get between 70 and 100 mg / dl. We consider hypoglycemic blood glucose levels below 60 mg / dl (some authors use 70 mg / dl as the limit).
When we feed, the rate of blood sugar can rise a little, until the insulin can bring it back to normal levels. Therefore, transient hyperglycemia are normal immediately after feeding. In people without diabetes, the value of blood glucose after a meal, called postprandial blood glucose, usually does not exceed 140 mg / dl.
Unlike hyperglycemia, which is an event that may occur transiently after meals, hypoglycemia, in healthy people, is not an ordinary event. This is because, usually, there are situations that cause rapid drop in the concentration of blood sugar, which enables the glucagon exert its anti-hypoglycaemic effect before the glucose to be lower than 70 or 60 mg / dl. In patients with diabetes, the story is quite different, as we will see later.
In most cases, hypoglycemia symptoms arise only when the value of blood glucose falls below 60 mg / dl. As glucose is the main fuel of the body, when your blood levels are low, we feel typical signs and symptoms, which arise not only cellular suffering, especially the neurons, lack of energy, but also the reaction of the nervous system the drop in glucose values in the blood. We will explain the two situations.
Adrenergic symptoms of hypoglycemia
When the blood sugar level becomes dangerously low, in addition to stimulating the production of glucagon, the brain under metabolic stress also causes an increase in epinephrine, which is a hormone that in addition to inhibiting insulin also encourages the release of reservations glucose from the liver. The presence of increased levels of adrenalin, glucagon and some other counterregulatory hormones in the blood are responsible for the adrenergic symptoms of hypoglycemia, also called neurogenic symptoms of hypoglycemia.
Neurogenic symptoms of hypoglycemia typically arises when blood glucose is below 60 mg / dl. Some of the more sensitive patients can have mild symptoms to blood glucose levels below 70 mg / dl.
Neuroglycopenic symptoms of hypoglycemia
The so-called neuroglycopenic symptoms of hypoglycemia are those that arise due to lack of glucose to the brain cells. Usually occur when the blood glucose is reduced to below 55 or 50 mg / dl. As the glucose the main source of energy of neurons when it becomes scarce, the brain cells begin to function improperly, may cause, among others, the following signs and symptoms:
The last three described clinical manifestations usually occur only in cases of severe hypoglycemia with blood glucose values below 40 mg / dl. hypoglycemic values below 30 mg / dl can lead to death if not recognized and corrected.
Hypoglycemia overnight
One of the biggest problems who take insulin at night is the risk of hypoglycemia during sleep time, being unconscious, the patient can not recognize the presence of early symptoms of low blood sugar.
The hypoglycemic episodes that arise during the morning manifest as nightmares, agitation during sleep and excessive sweating. Upon waking the patient may feel tired, angry or confused. The big risk is the patient into a coma while sleeping, a fact that obviously will not be readily recognized by the families.
In medical practice, virtually all cases of hypoglycemia occurring in diabetic patients, because adverse effect of treatment with insulin or oral hypoglycemic agents. Rarely, however, hypoglycemia can occur in nondiabetic patients. Some causes are:
Medicines. Gatifloxacin, quinine, indomethacin, lithium and pentamidine
Surgery to reduce stomach
Healthy people rarely hypoglycemia. The fact that you become tired, irritable, have a headache or without power after long periods of fasting does not necessarily mean that you are having hypoglycemia. This is a normal reaction to the hunger of the body, it is not necessarily low levels of blood sugar. To characterize hypoglycemia, the patient must have a blood glucose below 60 mg / dl.
Hypoglycemia reactive
Reactive hypoglycemia, also called postprandial hypoglycemia or postprandial hypoglycemia is the name given to a phenomenon characterized by episodes of symptomatic hypoglycemia occurring within 4 hours after meals. Reactive hypoglycemia is not a disease or diagnosis itself, it needs to be investigated so that their cause is clarified.
Reactive hypoglycemia usually occur when there is a rapid absorption of carbohydrates eaten in the meal, which stimulates the pancreas to secrete a lot of insulin in a short time. This type of reaction is one of the common complications of stomach reduction surgeries.
As we have said, hypoglycemia is an event that, except cases rare, occurs primarily in patients with diabetes mellitus in treatment, especially those that make insulin injections, which is common in patients with type 1 diabetes or type 2 diabetes at an advanced stage.
In people without diabetes, the pancreas can precisely control glucose levels in blood. Insulin is produced steadily with increases and decreases in its release throughout the day, according to blood glucose values.
Patients with type 1 diabetes do not produce insulin and need this hormone is artificially replaced several times a day. When insulin is administered artificially, the pace and the amount that reach the bloodstream are completely different from the way the pancreas does. If the insulin dose is too high for the amount of blood sugar, glucose will fall much, can lead to hypoglycaemia. Hypoglycemia can also occur if the patient becomes too long without food or suddenly change your diet, eating fewer carbohydrates.
The insulin prescription is usually fixed, the patient takes x units this time of day. If the patient usually takes 10 units of insulin at night, this amount may be excessive if it decides not to dinner, or poor, if he still dine and spend the night raiding the refrigerator. The healthy pancreas can easily handle such an hour diet changes to another, but the diabetic patient insulin dependent, no.
Even if the patient makes use of pump to infuse insulin or correct the doses according to blood glucose, there is still risk of hypoglycemia because these techniques are also much lower when compared to the natural form of the pancreas produce hormones. Unfortunately, we could not find a way of administering insulin that is at least similar to the natural secretion of insulin from the pancreas.
Patients taking insulin, unfortunately, need to have a regular and stable diet and need to maintain physical activity levels more or less similar throughout the day. Any change must be accompanied by correction of insulin dose, which in practice is difficult because there is not an exact calculation of the amount to be reduced. It's all through by trial and error.
Patients with type 2 diabetes usually produce insulin, but the body is resistant to the hormone. There insulin but it does not work well. For these cases there are drugs that increase the effectiveness of insulin and its production by the pancreas. They are the so-called oral hypoglycemic agents or oral antidiabetics. Some of these drugs such as glipizide, glyburide, glimepiride or repaglinide, can also cause hypoglycemia, particularly in elderly patients. Most oral antidiabetic agents, however, do not usually cause hypoglycemia, including metformin, acarbose, rosiglitazone or pioglitazone.
Patients with diabetes should be instructed to early recognize the signs and symptoms of hypoglycemia so they can promptly take action to correct the values of blood sugar. If the patient has the device to measure blood glucose at hand, the ideal is to measure the blood glucose to identify the degree of hypoglycemia. These values can be useful for a later correction of insulin doses if needed.
In conscious patients with mild symptoms, hypoglycemia can be easily reversed with the intake 15 to 20 grams of glucose. This amount can be obtained through a glass of juice or non-diet soft drink, 1 tablespoon of honey or sugar, a slice of toast, crackers 4, or a portion of any food rich in carbohydrates. There are special sale tablets for diabetes containing about 5 grams of glucose each. Diabetic patients using insulin are advised to take these tablets on hand in case of hypoglycemia that may arise during the day.
It is important to note that when hypoglycaemia arise, says do not eat excessively as this, and does not correct the glucose faster, can still lead to hyperglycemia frame. The right is to eat 15 to 20 grams of glucose and wait 15 minutes. If hypoglycemia persists, a new dose of glucose can be ingested. If after 3 doses hypoglycemia not give the patient should seek medical attention. The person with hypoglycemia should not, under any circumstances, drive vehicles. Someone needs to take him to the hospital.
In cases of more severe hypoglycemia, in which the patient is reduced level of consciousness, family members should take the patient immediately to a hospital so that it can be properly treated. While medical care is not enough, if the patient is not agitated or having seizures, you can rub small amounts of sugar in your gums. Do not try to offer food or fluids to people with reduced level of consciousness, as they may choke and pulmonary aspiration (aspirate the contents toward the lungs).
If the patient has a history of frequent bouts of severe hypoglycemia, some families can learn to administer subcutaneously or intramuscularly one glucagon injection. There are kits available in pharmacies.
At the hospital, the more severe hypoglycemia patients are treated with intravenous glucose. The correction of hypoglycemia in this way is almost immediate.
In most cases, episodes of hypoglycemia, even serious, do not usually leave sequelae. However, in children, many episodes of severe hypoglycemia frequently can disrupt their development.
