What is diabetes?
Diabetes is actually a group of diseases that share the characteristic of high glucose (sugar) levels in the blood. This increase in glucose is due to a defect in the way insulin is secreted or acts, or to both mechanisms together. Insulin is a hormone that is secreted in the pancreas, specifically in cells known as pancreatic beta cells. The production mechanism of insulin is as follows: after eating the food, it is digested in the stomach and in the intestine. Carbohydrates, present mainly in pasta, bread, cereal, vegetables and fruit, are broken down into sugar molecules, with glucose being the most important one. Glucose is then absorbed by the intestine and moves into blood. This causes the blood glucose level to rise. The amount of glucose present in the blood, known as glycemia, stimulates the beta cells to produce insulin. Insulin causes the glucose to leave the blood and be absorbed into the cells, mainly muscle and liver. These cells will convert the glucose into energy the body needs to function. Excess glucose is turned into fat and accumulates in the body. We can think of glucose as the “fuel” of our body.
Types of diabetes
Diabetes type 1.
Formerly known as insulin-dependent diabetes mellitus and also as juvenile diabetes. It occurs in children and young adults.
Diabetes type 2.
Known as non insulin-dependent diabetes or adult diabetes. It occurs in adults.
Diabetes in pregnancy.
Also known as gestational diabetes. It occurs during pregnancy and disappears after childbirth.
Other types of diabetes.
These types of diabetes are due to specific genetic diseases or can be caused by surgery, malnutrition, drugs, infections, etc.
Diabetes type 1
In diabetes type 1, pancreatic beta cells, which produce insulin, are gradually destroyed and may disappear altogether. With an absence or complete lack of insulin, glucose cannot be absorbed by cells and therefore accumulates in the blood and leads to an increase in glucose levels known as hyperglycemia. Glucose in high concentrations in the blood is passed into the urine via the kidneys, a phenomenon known as glycosuria.
Symptoms of this type of diabetes include weakness (due to the inability to use or process glucose), weight loss (due to the same reason), increased appetite (the body reacts to the lack of glucose in its cells with hunger), an increase in the amount of urine eliminated known as polyuria (glucose in urine causes the body to excrete more water in the urine) and thirst (due to the body losing so much water with the polyuria). In summary, diabetes type 1 occurs in children or in young people, who begin to feel weak, hungry and eat a lot, yet lose weight. They also urinate excessively and feel very thirsty.
Likely causes. There are several recognized causes acknowledged of diabetes type 1.
- Autoimmune factor. Diabetes type 1, before manifesting itself clinically, is typically preceded by a period without any symptoms, known as insulitis, in which the body’s T-cells destroy its beta cells. Under normal conditions, T-cells attack germs and fight infections. But in the case of diabetes type 1 they attack the beta cells in the pancreas. It is not known why this occurs and is classified as an autoimmune condition because the body’s immunological mechanisms (T-cells) are directed against itself. There might be a genetic predisposition and, in addition, there might be external factors, such as viral infections. Approximately half the cases of insulitis do not evolve into clinical diabetes, and if they do, the process can take up to seven years. When the symptoms do appear, up to 80% of the beta cells are lost.
- Genetic factor. So far some 18 anomalies of genes related to diabetes type 1 are known. At the same time, the likelihood that a child of a parent who is a first-degree diabetic would become diabetic themselves is only 10%. A child is more likely to be diabetic if his father is diabetic, rather than if his mother is diabetic.
- Viral factor. A viral infection might trigger the reaction of T-cells that could then confuse pancreatic beta cells with the virus which they are attacking. The viruses that are most often implicated in this process are those that attack the intestine.
- “Cow’s milk” factor. There are studies that have found a relationship between feeding infants in the early stages of life with cow’s milk and diabetes type 1. Children fed with cow’s milk during the first eight months of life, rather than with breast milk, have twice the chance of developing diabetes type 1.
Complications. In time, type 1 diabetic patients can develop complications arising in mainly two areas of the body: the nervous system and the cardiovascular system.
- Cardiovascular complications. Diabetic patients suffer from myocardial infarction and acute stroke more often than the non-diabetic population.
Diabetic patients suffer more often from myocardial infarction and acute stroke than the non-diabetic population. There may also be circulation problems in the limbs and in other parts of the body.
- Diabetic neuropathy. Occurs in a large percentage of diabetics. It predominantly affects the nerve sensitivity of fingers and toes, and can extend to the arms and legs.
Diabetes type 2
Diabetes type 2 is the type of diabetes that occurs most frequently. Approximately 90% of diabetic patients belong to the type 2 variation. In patients with diabetes type 2 insulin secretion can be normal or even increased but the liver and muscle cells have become resistant to utilizing the insulin. Insulin reaches the whole body but it is not used. Consequently, glucose does not penetrate the liver or muscle cells. This phenomenon is known as insulin resistance. Diabetes type 2 is typically associated with obesity.
Genetic factors. Genetic factors play an essential role in the onset of diabetes type 2. Various genes related to this disease have been identified. Among these are genes linked to the metabolism of fatty acids, another one to the relationship between obesity and diabetes and still another one to the relationship between cardiac risk and diabetes.
Age at onset of the disease. Diabetes type 2 typically appears after 40, and its incidence increases with aging. In people 60 years old, between 3.8 and 5.9 % suffer from diabetes type 2. In people over 85, this percentage increases by 20%.
Diabetes and obesity. The association between diabetes and obesity is strong. Being even slightly overweight can be linked to a greater incidence in the onset of diabetes. Not only is being overweight a factor, but how the excess fat is distributed across the body is important also. Fat accumulated in the abdomen and in the upper half of the body (apple-shaped body) is associated with a resistance to insulin and diabetes, cardiac disease, high blood pressure, acute stroke and high levels of “bad” cholesterol.
Fat that accumulates in the lower part of the body, hips and sides of the body (pear-shaped) has a lower association with diabetes type 2.
Cigarette smoking. Smoking increases the risk of developing diabetes type 2.
Development of the disease. Diabetes type 2 is a disease whose onset is gradual. Symptoms may take years to appear. Symptoms include an increase in the need to urinate, increased thirst, fatigue, blurred vision and the loss of weight. It can also cause itching. In women, vaginal fungal infections are frequent, as well as in the under-breast crease and in the groin. Impotence may occur in men.
Complications. In time, patients suffering from diabetes type 2 may develop serious complications. These complications often occurring in the nervous and the cardiovascular systems.
- Cardiovascular complications. Patients suffering from diabetes have a greater incidence of myocardial infarction and acute stroke than the population that is not diabetic. Problems with circulation in the limbs may occur as well as in other parts of the body. Diabetes accelerates the development of atherosclerosis. At the same time, resistance to insulin is often associated with high blood pressure.
- Diabetic neuropathy. Occurs in a great majority of diabetic patients. It mostly affects sensitivity of fingers and toes and can extend to the arms and legs. This is complicated by bad circulation which makes diabetics very prone to simple infections in the feet that easily turn into serious infections and call for surgery. If the damaged nerves belong to the autonomic nervous system, the patient may experience erectile disorders. In some cases, diabetics may not feel the pain produced by myocardial infarction which can mean they are at serious risk.
- Ocular complications.
Diabetes in pregnancy
This type of diabetes begins during pregnancy and disappears after giving birth. In theory, all women can develop gestational diabetes during pregnancy. However, there are predisposing factors: obesity, cases of diabetes in the family, having had a high-weight baby, a dead fetus or a child with some kind of anomaly. A past pregnancy with a lot of amniotic liquid (polyhydramnios) also predisposes women to this type of diabetes. Women over 24 are more likely to develop gestational diabetes than younger ones.
What are the signs of gestational diabetes?
The placenta is the organ that allows nutrients needed by the fetus to reach him so that he can grow. It also takes away waste substances produced by the fetus. As a pregnancy moves ahead, the placenta continues to grow. The placenta produces hormones that restrict the effects of insulin. This can cause maternal glycemia. Most women produce more insulin in their pancreas but their glycemic levels remain steady at normal levels. However a small percentage of women find it impossible to offset the effect of the placenta on their insulin levels and they suffer from hyperglycemia.
What to do if you are pregnant and develop gestational diabetes?
The most important thing is to maintain normal glycemic levels. It is imperative to stick to the diet prescribed by your doctor. If you are not able to maintain normal glycemic levels your doctor may need to prescribe insulin for you.
What effects does gestational diabetes have on the fetus?
Fetuses of mothers suffering from gestational diabetes have a high body weight. Since the maternal blood often has high levels of glucose, this in turn is passed on to the fetus. The fetus’ pancreas produces all the insulin needed to convert this glucose into fat. The result is a very large baby. After delivery, the child may suffer from hypoglycemia, especially if the mother has had high steady glycemic levels. Neonatal hypoglycemia occurs because the child was producing a lot of insulin as a fetus in order to adapt to the high glucose levels in utero. However once the child is born his glucose level drops because his natural glucose production is normal while he is still producing excess insulin for a short time. Children have no increased risk of becoming diabetic due to the gestational diabetes suffered by their mother.
What will birth be like for a mother with gestational diabetes?
It depends on each specific case. Some women shall have normal labor, whereas others may require a C-Section due to the size of the baby or other complications.
Other specific types of diabetes
These are very rare types of diabetes. Treating them will be case by case under the care of your physician.