Diabetes mellitus

1. Diabetes mellitus: what is it?

Diabetes mellitus is one of the most common widespread diseases in Europe and is characterized by a permanently high blood sugar level.
The name “diabetes mellitus” means “honey-sweet flow” and describes the excretion of excess sugar in the urine.
The body needs glucose (sugar) to produce energy. Sugar can be absorbed through food or produced by the body itself, and then it is transported through the bloodstream to the cells where it is needed. In order for the cells to be able to absorb sugar from the blood, they need help: the so-called insulin. Insulin is a messenger substance (hormone) that is produced in the pancreas and released into the bloodstream as soon as the blood sugar level rises. This ensures that the sugar can be transported into the body cells. In patients with diabetes mellitus, the transport of sugar into the cells is impaired, so that the sugar remains in the blood and can cause serious damage to the blood vessels there.
There are different forms of diabetes, which differ in the cause of the impaired absorption of the sugar into the cells. The best known and most common forms are type 1 diabetes and type 2 diabetes.

2. Type 1 diabetes — Causes and risk factors

Type 1 diabetes is an autoimmune disease in which the immune system attacks the body’s own cells. It is usually diagnosed in childhood or adolescence. In this form, the cells of the pancreas that are responsible for producing insulin are destroyed by autoimmune processes. At the beginning of the disease, when only a small part of the insulin-producing cells has been destroyed, the remaining cells can still produce enough insulin. In the course of the disease, however, the proportion of destroyed cells continues to increase until there is a shortage of insulin at some point. This is usually the moment when the symptoms of diabetes appear.
The causes for the development of type 1 diabetes mellitus have not yet been fully discovered. However, various relevant genes that increase the risk of disease have already been discovered. Heredity can therefore play a role, although it is not the disease itself, but only the predisposition to the disease that is inherited (but far less than, for example, in type 2 diabetes).

3. Type 2 diabetes — Causes and risk factors

Type 2 diabetes mellitus is also known as adult-onset diabetes, as most people affected are over 70 years old when diagnosed. However, especially in rich countries, significantly younger people are increasingly developing type 2 diabetes, as overweight (an increasing problem in wealthy societies) is considered to be the greatest risk factor for this form of diabetes. But heredity can also play a major role. The probability of developing type 2 diabetes if you have an affected parent is 50%. This high number may not only be due to the inherited predisposition to diabetes, but also to an often similar (unhealthy) lifestyle within a family.
In contrast to type 1, the problem with type 2 is not a lack of insulin, but a so-called insulin resistance. This means that the cells that need sugar from the blood do not react to insulin as a sugar transporter. As a result, the sugar cannot enter the cells, even though the pancreas produces enough insulin.

4. Symptoms

While type 2 diabetes often develops slowly and remains unnoticed over a long period of time, type 1 diabetes develops rather quickly and is more often associated with different, sometimes unspecific symptoms. These symptoms include general tiredness and exhaustion, but also increased urination and thirst, night cramps in the calves, blurred vision, itching, and skin infections.

5. Secondary illnesses

If diabetes mellitus remains untreated or not adequately treated for a long time, high blood sugar levels can cause damage to blood vessels, heart, eyes, nerves, kidneys and feet.
Elevated blood sugar levels lead to an increasing narrowing and stiffening (arteriosclerosis) of the vessels. Because of this vasoconstriction, among other things, patients with diabetes are twice as likely to suffer a heart attack or stroke as healthy people. Approximately more than half of diabetics die of a heart attack.
In the legs, the damage to the vessels leads to reduced blood flow. It is not uncommon that toes, feet or the entire lower leg are so poorly supplied with blood that amputation is necessary. Nerve damage leads to numbness and tingling, especially in the feet and legs. Decreased pain perception can have fatal consequences, because pain is usually a warning signal for the body that is supposed to protect against further damage. If this warning signal is missing, chest pain, for example, is not perceived as a sign of an acute or impending heart attack, which cannot therefore be treated in time. Another example are wounds, especially on the feet (diabetic foot), which are not noticed in time. This can lead to wounds which, due to their size and poor blood supply, can no longer heal completely or only heal through long therapy or surgical interventions.
In addition, vascular damage often causes diabetic eye diseases. Sometimes there are only slight visual problems, but complete blindness is not uncommon. About one third of all blindness in Germany is caused by diabetes.
The kidneys also deteriorate over time. For this reason, the kidney values of diabetics must be checked regularly in order to recognize kidney failure in time. And yet diabetes is the most common disease leading to dialysis (blood purification).
Many diabetics also suffer from sexual dysfunction. Women often have reduced desire for sex and pain during sexual intercourse, while men suffer from erectile dysfunction or ejaculation disorders.
The consequences of diabetes can therefore affect almost the entire body. However, not only the organs suffer from the disease, but also the psyche. The complex therapy, which requires constant attention, and the wide range of complaints and consequential damage that can occur, place a heavy burden on those affected. People with diabetes suffer from stress, anxiety, depression or dementia more often than the average. It is therefore particularly important that those affected, as well as their relatives and doctors, identify and treat symptoms in a timely manner.

6. Exams

The doctor diagnoses diabetes by measuring the amount of sugar in the blood. To determine the presence of diabetes mellitus, certain values have been established for the sugar level on an empty or full stomach. But there is also a gray area in which the blood sugar level is too high, but the threshold level for diabetes has not yet been reached. In this area in particular, type 2 diabetics can still prevent diabetes in many cases by radically changing their lifestyle.
Since diabetes in many cases remains unnoticed for a long time, but early treatment is essential to avoid consequential damage, (German) health insurance companies pay for a fasting blood sugar test for people over 45 years of age every 3 years. If there are risk factors such as high blood pressure or overweight, this screening is also carried out in younger people.
The fasting blood sugar should be below 100 mg/dl or below 5.6 mmol/l in healthy individuals. The diagnosis of diabetes mellitus is made from values of 126 mg/dl or 7.0 mmol/l or higher. In between, there is an area in which the values are already elevated. High values can indicate impending diabetes.
In the course of the disease, blood sugar must be checked regularly. For this purpose, the so-called HbA1c value (long-term blood sugar) is usually determined. It describes the proportion of the red blood pigment that is loaded with glucose (sugar). In contrast to the simple blood sugar value, which describes the proportion of free sugar in the blood, the HbA1c value is less subject to fluctuations and is therefore suitable for assessing the course of blood sugar over the last 6-8 weeks.
The HbA1c value, which is considered to be the “blood sugar memory”, should be lower than 5.7% in non-diabetics. Diabetes mellitus is present from 6.5%.
Type 1 diabetics in particular have to regularly measure their blood sugar independently in order to be able to flexibly determine the necessary insulin dose and prevent hypoglycemia. The patients can carry out this blood sugar test independently with a small prick on the finger or earlobe.
Preventive medical examinations also play a particularly important role in diabetics, in order to identify potential consequential damage from diabetes in time. They include regular checks of weight, blood pressure, blood lipids, blood vessels, kidneys, eyes, nerves, teeth and heart.

7. Treatment

In general, however, it is important for all diabetics to be aware of the possible consequences of their illness and to prevent them as long as possible. This includes, on the one hand, adherence to drug therapy in order to keep the blood sugar level under control as well as possible, and on the other hand, lifestyle changes, regular check-ups and good foot care. The treatment of comorbidities such as high blood pressure or disorders of lipid metabolism are also important components of diabetes therapy.
Since type 1 diabetics can no longer independently produce enough insulin for their metabolism, they have to supply it from outside in the form of insulin syringes or pumps. The therapy is extremely complex, because the amount of insulin required depends on many factors, such as the type and amount of food consumed, physical activity but also, for example, stress or other illnesses. Therefore, intensive training on insulin therapy, diet and physical activity is extremely important in order to provide those affected with the best possible support during therapy. Especially with type 1 diabetics, there is a risk not only of hyperglycemia, but also of possible hypoglycemia.
Type 2 diabetics in the early stage of the disease can often prevent the disease from progressing even without drug therapy. However, this usually requires a radical change in lifestyle. Many type 2 diabetics are overweight, have an unhealthy diet and do little or no sport. However, a healthy diet, weight loss, and regular exercise can have a positive effect on blood sugar levels. In some cases, this can make drug therapy unnecessary, at least for some time.
If a change in lifestyle is not possible or sufficient, type 2 diabetics start a therapy which aims to increase the sensitivity of the cells to insulin. For type 2 diabetics, the problem (at least for a long time) is not a lack of insulin, but that the insulin cannot affect the cells. There are several drugs available to improve the effectiveness of the existing insulin on the cells. The most common of these drugs is metformin. Metformin lowers blood sugar levels through various mechanisms and has been able to successfully prevent diabetes-related complications in various studies.