The term diabetes mellitus covers various metabolic disorders. They all manifest themselves in chronically high blood sugar levels (hyperglycemia).
These diseases aretriggered by either insulin resistance or insulin deficiency. In some cases, both causes occur simultaneously.
The most common forms of the disease are type 1 and type 2 diabetes. The following types of diabetes are also known:
- Diseases of the pancreas (pancreatitis, iron storage disease, cystic fibrosis),
- genetic defects in insulin action,
- drug-chemically induced diabetes (by neuroleptics, glucocorticoids, pentamidine, alpha-interferon),
- rare forms of autoimmune-mediated diabetes,
- Diabetes due to infections and
- gestational diabetes.
The symptoms that accompany diabetes mellitus depend on how advanced the disease is. At the beginning, both type 1 and type 2 have no or only mild symptoms.
The typical signs of the disease include
- severe thirst,
- increased urination,
- tiredness and exhaustion,
- ravenous appetite,
- itching,
- visual disturbances and,
- susceptibility to infections.
Type 2 diabetes mellitus in particular is often initially completely symptom-free. It is therefore often only discovered by chance during routine examinations. Many sufferers have such minor symptoms that they do not even consult a doctor. As a result, this form of the disease is often only recognized when it has already caused late damage.
With type 1 diabetes mellitus, noticeable symptoms often only appear months later. During this time, insulin-producing islet cells are destroyed in the pancreas. Only when this process is about 80 percent complete is the body no longer able to compensate for the insulin deficiency. Only then do symptoms occur.
However, these are usually much more pronounced than with type 2 diabetes.
Sometimes a diabetic coma triggered by very high blood sugar levels can be the first sign of type 1 diabetes. Symptoms of this are unconsciousness and a typical acetone smell in the exhaled air.
Type 1 diabetes mellitus is caused by a lack of insulin. This results from the destruction of the cells in the pancreas responsible for insulin production. Most new cases occur in children between the ages of 11 and 13.
Type 2 diabetes mellitus is caused by a reduced response of the body to insulin. The cause is a functional impairment of the beta cells. Both factors alone would not cause diabetes. Together, however, they lead to a disruption of glucose homeostasis (blood sugar regulation).
Type 2 diabetes usually only becomes noticeable after the age of 40. In addition to a genetic predisposition, the triggering factors include
In most patients, the combination of these risk factors leads to the onset of the disease.
The video illustrates how insulin works in a healthy organism:
If diabetes mellitus is suspected, the doctor makes the diagnosis using blood glucose levels. Blood glucose levels are usually less than 90 milligrams per deciliter in whole blood or less than 100 milligrams per deciliter in blood plasma on an empty stomach. After eating, the values rise to a maximum of 140 milligrams per deciliter.
The presence of diabetes is indicated by
- an occasional blood glucose value of more than 200 milligrams per deciliter and classic diabetes symptoms or
- a fasting blood glucose value of more than 110 milligrams per deciliter in whole blood or 126 milligrams per deciliter in blood plasma or
- oGTT-2-h value of more than 200 milligrams per deciliter (oGTT = oral glucose tolerance test) or
- HbA1c value higher than 6.5 percent.
The sugar concentration in the urine can also indicate diabetes. If the blood sugar level is above 180 milligrams per deciliter, the kidney threshold for glucose is exceeded. The body then excretes the excess sugar in the urine. The excreted glucose can be detected in the urine using test strips.
During pregnancy, the renal threshold is somewhat lower, so that even healthy women can excrete small amounts of sugar. The doctor will therefore carry out further tests to rule out gestational diabetes.
If the body's cells lose the ability to utilize sugar due to a lack of insulin, they cover their energy requirements with the help of so-called ketone bodies. This is a fat metabolite produced by the liver.
An excess of ketone bodies is a sign that the diabetes is getting out of hand and the organism is over-acidifying (ketoacidosis). The doctor also uses a test strip to detect ketone bodies in the urine.
If initial tests do not produce clear blood glucose values, the oral glucose tolerance test (oGTT) is used. Here, the doctor takes blood from the patient to determine the blood glucose level.
The patient must eat sufficient carbohydrates in the three days prior to the test and remain fasting from ten hours before the blood sample is taken. This means: no food, no alcohol and no smoking.
On the day of the test, he drinks 75 grams of glucose dissolved in 250 to 300 ml of water within five minutes of the first blood sample being taken. After two hours, another blood sample is taken.
People with diabetes must measure their blood glucose levels regularly © Kwangmoo / Fotolia
The blood glucose values for non-diabetics in this test are
- less than 100 milligrams per deciliter on an empty stomach and
- below 140 milligrams per deciliter after two hours.
In contrast, fasting values of
- over 100 to 125 milligrams per deciliter indicate abnormal fasting glucose and
- a two-hour value of more than 140 to 199 milligrams per deciliter
indicates impaired glucose tolerance. Diabetes mellitus is present if the fasting blood glucose in the blood serum is
- at least 100 milligrams per deciliter or in the blood plasma at least 126 milligrams per deciliter and
- the value measured after two hours is more than 200 milligrams per deciliter
must be more than 200 milligrams per deciliter.
Sensible nutritional therapy plays a decisive role in diabetes. A diabetes-appropriate diet essentially corresponds to the mixed diet recommended by the German Nutrition Society (DGE).
Depending on the respective insulin therapy, patients sometimes have less and sometimes more freedom in designing their diet. Above all, it depends on
- the lack of insulin in type 1 or
- the reduced and delayed insulin effect in type 2
in such a way that the blood sugar levels after meals are within the normal range.
For diabetics who inject normal insulin, it is recommended that food is divided into three main meals and three snacks. People who use insulin analogs, on the other hand, should only eat three meals a day to avoid extreme fluctuations in blood sugar levels.
The chances of a cure depend on the particular form of the disease. Type 1 diabetes is not yet curable because lost insulin-producing cells cannot be easily replaced. However, experts from the German Diabetes Association (DDG) see a new combination therapy as a promising approach.
Type 2 diabetes can be significantly alleviated by making consistent lifestyle changes, at least in the early stages of the disease. Sometimes no further treatment with medication is necessary.
So far, only gestational diabetes can be completely cured. In this case, the woman's body returns to normal after the birth of the child.
The aim of diabetes therapy is to
- to minimize the risk of dangerous secondary diseases and
- enable those affected to enjoy a good quality of life.
The treatment of type 1 diabetes mellitus is aimed at replacing the missing insulin. Type 2 diabetes can be significantly improved through weight loss, a healthy diet and physical activity. If this is not enough, oral antidiabetic drugs in tablet form or insulin therapy are indicated.
In addition to elevated blood sugar levels, patients with type 2 diabetes often have other cardiovascular risks such as
are present. These risks are included in the therapy.
In many cases, a consistent change in diet helps to prevent gestational diabetes. If this is not sufficient, insulin therapy is also carried out.
