Diabetes mellitus: causes, symptoms, treatment
Diabetes mellitus (diabetes) is a pathological disorder of the sugar metabolism. The blood sugar level of the affected person is permanently elevated. Over time, this damages the vessels and various organs. Therefore, diabetes should be detected and treated early. Read answers to all the important questions: What exactly is diabetes? What symptoms and late effects does it cause? How do you get diabetes? How is diabetes diagnosed and treated?
Diabetes: short overview
- Important forms: Diabetes type 1, diabetes type 2, gestational diabetes
- Common symptoms: severe thirst, frequent urination, itching, dry skin, weakness, tiredness, weakness of the immune system
- Complications: Hypoglycemia (low blood sugar), hyperglycemia (high blood sugar) with diabetic ketoacidosis or hyperosmolar hyperglycemic syndrome
- Secondary diseases: Retinal damage (diabetic retinopathy), kidney disease (diabetic nephropathy), diabetic foot, cardiovascular diseases etc.
- Important research: Measurement of blood glucose and HbA1c, oral glucose tolerance test (oGTT), test for autoantibodies (for diabetes type 1)
- Treatment options: Change of diet, regular physical activity, blood sugar-lowering tablets (oral antidiabetics), insulin therapy
Diabetes: symptoms and consequences
The pathologically elevated blood sugar levels trigger a wide variety of symptoms in diabetes mellitus. This applies to both the two main forms of diabetes (type 1 and type 2 diabetes) as well as to the rarer forms.
For example, acute symptoms of diabetes occur above all when the metabolism is derailed and the blood sugar level is extremely high. Then there are strong changes in the water and mineral balance. At the same time, a severe lack of energy in the body cells and the central nervous system occurs. The main acute symptoms of diabetes are:
If blood sugar levels are permanently elevated, increased sugar (glucose) is excreted in the urine via the kidneys (glucosuria). Since sugar physically binds water, affected persons excrete large quantities of urine (polyuria) at the same time – they very often have to go to the toilet. Especially at night, many diabetics have an annoying urge to urinate. The urine discharged is usually clear and only slightly yellow in colour.
Polyuria is a typical sign of diabetes mellitus, but can also have other causes. Thus, increased urination also occurs in various kidney diseases and during pregnancy.
By the way: The sugar in the urine of diabetics gives it a slightly sweetish taste. This is also where the technical term diabetes mellitus comes from: it means “honey-sweet flow”. However, the times when doctors still had to use their patients’ urine for diagnosis are long gone. Today, the sugar content can be detected with a diabetes rapid test with indicator sticks.
The strong urge to urinate triggers an agonizing feeling of thirst in diabetes patients: The body wants to compensate for the loss of fluid by drinking more. However, this is often not sufficiently successful. Even if those affected drink a lot, the thirst cannot really be quenched.
Weakness, fatigue and concentration problems
Poor performance is also a common sign of diabetes. This is because diabetics have a lot of high-energy glucose in their blood. However, this cannot enter the cells to be recycled. This causes a lack of energy within the cells. As a result, patients often feel powerless and are physically less capable.
Most of the glucose that the body needs during the day is intended for the brain. A glucose deficiency therefore affects normal brain function. It can cause lack of concentration and fatigue up to severe disturbances of consciousness and coma.
If diabetes mellitus is not or not sufficiently treated, the blood sugar level is not only greatly increased, but also fluctuates greatly. These strong fluctuations can cause the lens in the eye to swell. This changes their optical refractive power and thus their visual acuity – the patients suffer from visual disorders. These usually last for several hours and then subside again.
Itching (pruritus) and dry skin
Sometimes diabetes causes itching and very dry skin. One reason for this is the high loss of fluid due to increased urination (glucosuria). Other mechanisms are also suspected to be responsible for increased itching in diabetics. These could, for example, be stress hormones such as adrenaline and cortisol, which are released into the bloodstream by the adrenal gland when blood sugar levels are too high or too low. Perhaps changes in the blood vessel walls also contribute to the development of itching in diabetics.
Weakened immune system
Elevated blood sugar weakens the body’s defenses against infections in a way that has not yet been fully clarified. That is why many diabetics suffer more frequently and for longer than non-sugar patients, for example from bronchitis, pneumonia, skin inflammation or various fungal diseases. As protection, flu vaccination and pneumococcal vaccination are recommended for diabetic patients (pneumococcus causes pneumonia and meningitis).
Long-term diabetes symptoms
Late symptoms of diabetes mellitus occur mainly when blood sugar levels are not well adjusted and are often or latently too high. Then blood vessels and nerves are irreversibly damaged – with serious consequences for various organ systems and body functions.
Nerve damage (polyneuropathy)
High blood sugar levels damage the peripheral nervous system over time. Affected are both motor (controlling the muscles) and sensitive (feeling) and vegetative (controlling the organs) nerve paths. Diabetics therefore often have a disturbed pain sensation. For example, they do not perceive injuries to the skin or a heart attack as pain. Muscle coordination during movements can also suffer.
The function of internal organs (such as the digestive tract) can also be disturbed in diabetes: diarrhoea and other digestive problems can result. If high blood sugar levels damage the autonomic nervous system that supplies the digestive tract, this can lead to nerve paralysis of the stomach (gastroparesis) or intestine. Possible consequences are a feeling of fullness and vomiting, flatulence, diarrhoea or constipation.
Damage to the blood vessels (angiopathies)
High blood sugar levels usually first trigger changes in the inner wall layer of the small and smallest blood vessels (capillaries) (microangiopathy). Over time, the middle and large blood vessels can also be damaged (macroangiopathy). The vascular damage results in circulatory disorders up to complete occlusion. A wide variety of organs can be affected. Here are the most important examples:
- Heart: Due to constriction or occlusion of small blood vessels, the heart muscle is less well supplied with oxygen. Possible consequences are cardiac insufficiency, coronary heart disease (CHD) and heart attack.
- Brain: Circulatory disorders in the brain impair brain performance and can trigger chronic neurological deficits. In the worst case, a stroke occurs.
- Eyes: Damage to the blood vessels of the retina of the eye (diabetic retinopathy) causes symptoms such as “flashes of light“, blurred vision, impaired colour vision and finally loss of vision until blindness.
- Kidneys: Here, circulatory disorders cause changes and damage to the tissue. This diabetic nephropathy can eventually lead to impaired renal function (renal insufficiency). If the kidneys fail completely, the patients are dependent on dialysis in the long term.
- Skin: Due to damage to the small skin vessels, the skin is more susceptible to colonisation with germs (skin infections). In addition, poor wound healing is observed. Poorly healing chronic wounds and ulcers in the lower leg / foot area are called diabetic foot.
Diabetes and Depression
About a quarter of all diabetes patients suffer from depressive moods or depression. The trigger is usually the diabetes itself as well as possible late effects, which can be very stressful for the patient.
Conversely, people with depression also have an increased risk of developing type 2 diabetes. One reason for this could be that depressives pay less attention to a healthy lifestyle, for example by eating unhealthy food and taking little exercise. Such factors contribute to the development of type 2 diabetes. In addition, depressions might use different signalling pathways to alter the hormonal system and metabolism of the patient in such a way that diabetes is promoted.
Regardless of the exact link between diabetes and depression, both diseases should be treated professionally. Otherwise, the health of the person concerned may deteriorate. For example, many depressive patients neglect blood sugar-lowering therapy – they no longer take their blood sugar tablets or insulin injections seriously.
Diabetes and impotence
Many male diabetics complain of erectile dysfunction. The reason: the high blood sugar levels damage the blood vessels at the erectile tissue of the penis. This can affect the blood flow necessary for an erection. Damage to the autonomic nervous system, which is important for erection, and the sensitive nerve tracts can also play a role in the development of impotence in diabetes mellitus.
Diabetes: causes and risk factors
All forms of diabetes mellitus are based on a disturbed blood sugar regulation. More detailed information can only be understood if one knows the basics of blood sugar regulation:
After a meal, food components such as sugar (glucose) are absorbed into the blood via the small intestine, which causes the blood sugar level to rise. This stimulates certain cells of the pancreas – the so-called “Langerhans beta-island cells” (short: beta cells) – to release insulin. This hormone ensures that the glucose from the blood reaches the body cells, where it serves as an energy supplier for the metabolism. So insulin lowers the sugar level in the blood.
How insulin works: In healthy people, insulin binds to the insulin receptor on the surface of the cell. This causes the channel for the uptake of sugar (glucose) into the cell to be opened, allowing sugar from the blood to be absorbed into the cell.
With diabetes, this blood sugar regulation is disturbed in (at least) one important place.
Diabetes mellitus type 1
In diabetes mellitus type 1, the location of the disturbed blood sugar regulation is the pancreas: In patients, the insulin-producing beta cells are destroyed by the body’s own antibodies. These autoantibodies mistakenly consider the beta cells to be dangerous or foreign and attack them.
Diabetes type 1 is therefore an autoimmune disease. It is not yet known exactly why she appears. Experts assume a genetic predisposition and various risk factors (such as infections) which favour the development of this diabetes disease.
The destruction of the beta cells results in an absolute insulin deficiency. People with type 1 diabetes have to inject insulin throughout their lives to compensate.
You can read more about the development, treatment and prognosis of this form of diabetes in the article Diabetes type 1.
Diabetes mellitus type 2
In type 2 diabetes, the starting point of the disturbed blood sugar regulation lies in the body cells: The pancreas usually produces enough insulin in the beginning. However, the body cells are becoming increasingly insensitive to this. This insulin resistance triggers a relative insulin deficiency: Actually, there would be enough insulin, but it cannot develop its effect sufficiently. In response, the body causes the beta cells to produce more and more insulin. The pancreas cannot keep up with this overproduction forever: Over time, the beta cells become depleted so that insulin production decreases. Then an absolute insulin deficiency sets in.
Differences in type I and type II diabetes
While in diabetes type I the pancreas does not produce insulin, in diabetes type II insulin is produced, but the body cells are increasingly insensitive to insulin. In both cases the sugar can no longer be absorbed into the body cells and the sugar level in the blood rises.
It is not known exactly why some people develop these pathological developments and thus develop type 2 diabetes. But unfavourable lifestyle factors play a major role:
Most type 2 diabetics are overweight or even obese (obesity). Especially the fat cells in the abdominal area form inflammatory substances that can cause insulin resistance. An increased abdominal girth therefore increases the risk of type 2 diabetes mellitus, as do other factors such as smoking and lack of exercise. Diabetes mellitus type 2 is also attributed a genetic component.
You can read more about this most common form of diabetes in the article Diabetes type 2.
Some women become temporarily diabetic during pregnancy. Doctors then speak of gestational diabetes (or diabetes type 4). Various factors seem to be involved in its creation:
During pregnancy, increased amounts of hormones are released which are the antagonists of insulin (for example, cortisol, estrogens, progesterone, prolactin). In addition, affected women apparently have a chronically reduced insulin sensitivity: the body cells therefore respond to insulin in a reduced manner. This is even more so in the course of pregnancy.
In addition, there are several factors that increase the risk of gestational diabetes. These include, for example, obesity and diabetes in the family.
You can read more about the development, symptoms, risks and treatment of gestational diabetes in the article Gestational diabetes.
Diabetes mellitus type 3
There are some rare forms of diabetes, sometimes referred to as type 3 diabetes. They have causes other than type 1 and type 2 diabetes and gestational diabetes.
One example is MODY (maturity onset diabetes of the young), also called diabetes type 3a. It covers various forms of adult diabetes that occur in children and adolescents. They are caused by certain genetic defects in the beta cells of the pancreas.
In contrast, diabetes type 3b is based on genetic defects that impair the effect of insulin. If certain chemicals or drugs are the cause of diabetes, doctors speak of type 3e.
You can read more about this group of rare forms of diabetes in the article Diabetes type 3.
Diabetes in children
Most diabetic children suffer from type 1 diabetes. In the meantime, however, more and more offspring are also suffering from type 2 diabetes:
In the past, this was mainly a problem of older people – hence the earlier name “adult-onset diabetes” for type 2, but modern Western lifestyles have led to a situation where more and more children and adolescents have the main risk factors for the disease. These are overweight, lack of exercise and unhealthy nutrition. This is why type 2 diabetes is now also more common in young people.
You can read more about the causes, symptoms and treatment of childhood diabetes in the article Diabetes in children.
Diabetes: examinations and diagnosis
The right contact person in case of suspected diabetes is your family doctor or a specialist in internal medicine and endocrinology. However, the vast majority of all sugar diseases are caused by type 2 diabetes, which develops only slowly. Many symptoms (such as fatigue or visual disturbances) are not directly related to sugar metabolism by patients. Many people therefore ask themselves: “How do I recognize diabetes? At what signs should I think of possible diabetes?” The answer: If you can answer “yes” to one or more of the following questions, you should discuss it with your doctor:
- Have you been feeling an agonizing thirsty feeling lately without any unusual physical strain and are you drinking significantly more than usual?
- Do they have to urinate frequently and in large quantities, even at night?
- Do you often feel physically weak and tired?
- Is there a history of diabetes in your family?
Interview and physical examination
The doctor will first talk to you in detail to take your medical history (anamnesis). For example, he asks you about your symptoms. Describe to him also those complaints for which you actually suspect another cause (such as stress as a reason for concentration problems).
Also inform your doctor about any concomitant diseases such as high blood pressure or circulatory problems in the legs. They could already be the consequences of a longer lasting type 2 diabetes.
The interview is followed by a physical examination.
Measurement of blood sugar and HbA1c
In the case of diabetes mellitus, the measurement of blood sugar levels is understandably the most meaningful. Very important is the fasting blood sugar. It is measured in the morning after a minimum of eight hours of abstinence from food. However, a single measurement is not sufficient to make a diagnosis of diabetes. Only if repeated measurements of the fasting blood glucose (on different days) always show too high values, a diabetes disease is present.
In order to be able to assess the blood sugar levels of the last two to three months, the doctor determines the so-called HbA1c value in the blood. It is also called “long-term blood sugar”. However, the HbA1c value is more important than for the diagnosis of diabetes for the assessment of the course of an already known diabetes.
Oral glucose tolerance test (oGTT)
If diabetes is suspected, an oral glucose tolerance test (oGTT) is also performed. It is also called the sugar load test or glucose load test.
For the test the patient first drinks a defined sugar solution. The blood sugar value is then measured several times at certain intervals. In this way it can be found out whether the body can normally cope with the sudden sugar load.
Depending on the result, either impaired glucose tolerance (precursor of diabetes) or manifest diabetes mellitus can be diagnosed.
You can read more about the oral glucose tolerance test in the article oGTT.
Summary: Diabetes testing
The measurement of fasting blood glucose and HbA1c and the oral glucose tolerance test (oGTT) are often referred to as diabetes testing. This often includes urine tests, which are carried out if diabetes is suspected. This is because sugar can be detected in the urine of diabetics (glucosuria) – but not in healthy people.
Blood and urine tests to diagnose diabetes are performed by the doctor. There are also some self-tests available in stores that every layman can perform independently at home. However, they do not allow a diagnosis to be made – but if the test results are conspicuous, one should go to a doctor for a more detailed examination.
For detailed information on diabetes testing, see the text Diabetes Test.
Diabetes is present if the values for fasting blood glucose, HbA1c or the oral glucose tolerance test are too high. But what does “too high” mean? Which threshold values mark the transitions from “healthy” to “impaired glucose tolerance” and further to “diabetes”?
For example, the following applies to fasting blood sugar: If it is repeatedly 126 mg/dl or higher, the patient is diabetic. If repeated measurements give values between 100 and 125 mg/dl, there is an impaired glucose tolerance. It is considered a precursor of diabetes.
The different diabetes levels not only play a decisive role in the diagnosis of diabetes. They must also be checked regularly afterwards: This is the only way to assess the course of the disease and the effectiveness of diabetes treatment. Some of the control measurements are carried out by the patients themselves (such as blood glucose measurement).
You can read more about limit values and assessment of blood glucose, HbA1c and oGTT in the article Diabetes Values.
Antibody test for diabetes type 1
The detection of antibodies against beta cells (islet cell antibodies) or insulin (insulin antibodies) is also helpful in the diagnosis of the autoimmune disease type 1 diabetes. These autoantibodies can be detected in the blood of many patients long before the first symptoms appear.
An antibody test may also be indicated to differentiate type 1 and type 2 diabetes from each other – for example, if type 2 occurs unusually early in life.
Further examinations serve to determine possible consequences of the diabetes disease at an early stage. For example, the doctor will examine whether your sense of touch in the area of the hands and feet is normal. Because elevated blood sugar levels can damage the nerve tracts. Over time, this causes sensory disturbances.
Vascular damage can also affect the retina of the eyes. The doctor will therefore check whether your eyesight has deteriorated. A special eye examination is then usually performed by the ophthalmologist.
The therapy of diabetes mellitus aims to reduce the elevated blood sugar level and prevent harmful consequences of diabetes on blood vessels, nerves and organs. On the one hand, this is to be achieved by non-drug measures: Above all, the right diet and sufficient exercise can improve blood sugar levels. Regularly measuring your blood sugar level helps to keep track of the course of your disease (possibly with the help of a diabetes diary).
Secondly, diabetes treatment often requires additional diabetes medication (antidiabetics). Available are oral preparations (blood sugar-lowering tablets) and insulin, which must be injected. Which antidiabetics are used in each individual case depends on the type of diabetes and the severity of the disease.
In the following you will find more information about the different measures of diabetes therapy:
If diabetes is detected, patients should attend diabetes education. There, they learn everything important about their disease, the possible symptoms and consequences as well as the treatment options. In addition, diabetics learn in the training what can lead to sudden complications (such as hypoglycaemia) and what to do then.
After being diagnosed with “diabetes mellitus”, you must regularly measure your blood sugar levels. For a better overview you should keep a diary. All measured values are logged there. You can also enter other important parameters, such as the use and dosage of blood sugar tablets or insulin or blood pressure readings. Take the diary with you when you visit the doctor.
Such a diabetes diary is particularly advisable for type 1 diabetics with a so-called “Brittle Diabetes”. This is an outdated term for type 1 diabetics who suffer from strongly fluctuating blood sugar values (brittle = unstable). The metabolic disorders can make numerous hospital stays necessary.
A varied and balanced diet is important for everyone, but especially for diabetes patients. It is important to avoid massive blood sugar peaks after eating and sudden hypoglycaemia. Therefore, patients should receive individual nutritional advice immediately after diagnosis of diabetes. There they learn how to eat properly and healthily.
If patients consistently implement their individual nutritional recommendations, they can make a significant contribution to lowering their blood sugar levels and keeping them under control. Therefore, an appropriate diet is part of every diabetes therapy.
You can read more about the right diet for diabetes in the article Diabetes – Nutrition.
Carbohydrates play a special role in the correct nutrition of diabetes patients. They are mainly responsible for the increase in blood sugar levels after eating. Especially patients who inject insulin must therefore be able to estimate the amount of carbohydrate in a planned meal. This is the only way they can select the correct dose of insulin.
To facilitate the assessment of the carbohydrate content of a food, the bread units (BE) were introduced. The following applies: 1 BE corresponds to 12 grams of carbohydrates. For example, one slice of wholemeal bread (60 grams) has 2 bread units. One glass of carrot juice yields 1 BE.
More about the calculation of bread units and a BE-table with different foods can be found in the article bread units.
Diabetes and sport
Diabetics can benefit from sporting activity in several ways:
Firstly – regular physical activity supports the reduction of overweight, from which many type 2 diabetics in particular suffer. Obesity is often the main reason why the body cells respond to insulin in a reduced way.
Secondly – muscle work also directly increases the insulin sensitivity of the body cells. This improves the absorption of sugar from the blood into the cells. Anyone who is regularly active in sports can often reduce the dose of blood sugar-lowering medication (tablets or insulin) (only in consultation with a doctor! ).
Third – physical activity improves well-being and quality of life. This is particularly important for people with chronic diseases such as diabetes. Chronic suffering can be very stressful psychologically and contribute to depressive moods.
Diabetics should therefore take enough exercise to cope with everyday life and exercise regularly – naturally adapted to their age, physical fitness and general state of health. Diabetes patients should therefore seek advice from their doctor or a sports therapist about which and how much sport they can do and what they need to pay attention to during training. Because of the strong blood sugar-lowering effect of sports activity, type 1 diabetics in particular must control their blood sugar levels closely and practice the correct adjustment of their insulin and sugar intake.
Oral diabetes medication
The basis of any treatment for type 2 diabetes is a change in lifestyle. This includes above all a change in diet as well as regular exercise and sport. Sometimes these measures are sufficient to lower the blood sugar levels of type 2 diabetics to a healthier level. If not, the doctor will additionally prescribe oral antidiabetics.
There are different substance classes of these diabetes drugs in tablet form. They differ in the mechanism of action by which they lower elevated blood sugar levels. The most commonly prescribed drugs are metformin and so-called sulfonylureas (such as glibenclamide).
Initially, an attempt will be made to get the blood sugar levels of type 2 diabetics under control with only one such oral antidiabetic (monotherapy). If this is not successful, the doctor will prescribe other diabetes tablets or insulin (combination therapy). Rarely is the drug treatment of diabetes mellitus type 2 exclusively with insulin (see below).
By the way: Oral antidiabetics are not used for type 1 diabetes – they do not achieve sufficient success here. They are not approved for the treatment of gestational diabetes because harmful effects on the child cannot be ruled out for most active ingredients. Only in very rare and exceptional cases is metformin used, if absolutely necessary, to lower severely elevated blood sugar levels in pregnant women (as “off-label use”).
The treatment of type 1 diabetes aims to compensate for the absolute lack of insulin in patients. The only way to do that is with insulin syringes. This means that every type 1 diabetic must regularly administer insulin to himself. Rarely, type 2 diabetics and women with gestational diabetes also need insulin.
Insulin therapy can be administered in different ways:
Conventional insulin therapy: In conventional insulin therapy, insulin is injected according to a fixed schedule, usually in the morning and evening. Conventional insulin therapy is therefore easy to use. However, it restricts the patient: major deviations from the usual meal plan are not possible, and extensive physical activity can lead to problems. Conventional insulin therapy is therefore particularly suitable for patients who can adhere to a rather rigid daily and nutritional plan and for whom it would be too difficult to implement intensified insulin therapy.
Intensified insulin therapy (ICT diabetes): Intensified insulin therapy attempts to imitate the physiological insulin release as precisely as possible. The administration of insulin is accordingly more difficult than with conventional insulin therapy. This is done according to the basic bolus principle:
Patients inject a small amount of long-acting insulin once or twice a day to cover their basic insulin needs (basic insulin). In addition, a normal insulin or a short-acting insulin is injected before a meal. This bolus insulin is intended to “intercept” the expected rise in blood sugar (due to eating). Patients must calculate their dose by taking into account their current blood sugar level, the time of day and the planned meal.
Intensified insulin therapy requires good training and very good patient cooperation (compliance). Otherwise, incorrect calculations of the insulin dose can easily lead to dangerous diabetes hypoglycaemia.
The advantage of the basic bolus concept is that, when used correctly, it allows very good blood glucose control. In addition, patients can eat what they want and exercise as they please.
Insulin pump (“diabetes pump”): Diabetes treatment with an insulin pump is also called continuous subcutaneous insulin infusion therapy (CSII). The small device consists of a pump with an insulin reservoir which the diabetes patient always carries with him/her (for example on the waistband of his/her trousers). The pump is connected to a small needle via a thin tube, which permanently dwells in the subcutaneous fat tissue (usually on the abdomen).
The programmable insulin pump delivers small amounts of insulin to the tissue regularly and automatically to cover basal requirements. In this way the device imitates the function of the pancreas. Before a meal, the patient can take an additional amount of insulin (bolus) at the touch of a button, adapted to the meal, the time of day and the current blood sugar level.
The insulin pump saves type 1 diabetics from having to handle insulin syringes and allows for a flexible meal plan and spontaneous sporting activities. This is particularly beneficial for young patients. In addition, the blood sugar can be adjusted here to be even more stable than with insulin injections. Many patients report that their quality of life has improved significantly thanks to the “diabetes pump”.
The insulin pump should be set and adjusted at a specialized diabetes clinic or practice. Patients must be fully trained in the use of the pump. Dosage errors can quickly become life-threatening! In addition, the patient must immediately switch to insulin syringes if, for example, the insulin pump fails or is to be put down for a longer period of time.
By the way: A new development is a small glucose sensor that is inserted into the patient’s subcutaneous fatty tissue (for example, on the abdomen). It measures the glucose content in the tissue every one to five minutes (Continuous Glucose Monitoring, CGM). The measurement results can be transmitted by radio, for example to a small monitor to support intensified insulin therapy (Sensor Assisted Insulin Therapy, SAT). The measured values can also be transferred directly to an insulin pump (sensor-assisted insulin pump therapy, SuP). The CGM offers various alarm options that warn the patient if hyperglycaemia or hypoglycaemia is imminent.
However, it is important that patients still have to measure their blood sugar themselves, for example before a planned insulin administration. This is because there is a physiological difference between tissue sugar (as measured by CGM) and blood sugar.
As indicated above, various insulins are used in the treatment of diabetes mellitus. In most cases this is human insulin. It is produced artificially and has the same structure as the body’s own insulin.
In addition to human insulin, porcine insulin and insulin analogues are also available for diabetes treatment. Like human insulin, insulin analogues are produced artificially. However, their structure is slightly different from that of human insulin and thus human insulin.
The insulin preparations can be classified according to their onset of action and duration of action. For example, there are short-acting and long-acting insulins. For successful diabetes treatment, it is very important that the right insulins are administered at the right time and in the right dosage.
You can read more about the different insulin preparations and their use in the insulin article.
“DMP – Diabetes” (Disease Management Program)
Diabetes mellitus is one of the most common chronic diseases in western industrialized countries. This is why so-called disease management programs are becoming increasingly important. They originally come from the USA. This is a concept organized by the health insurance funds to make it easier for treating physicians to offer a standardized, close-meshed range of therapy and care for the chronically ill. In the case of diabetes, this includes information brochures, counselling sessions and training courses on diabetes.
Diabetes: course of disease and prognosis
The course of the disease and the prognosis vary greatly between the different types of diabetes. However, patients can have a positive influence on the course of the disease in all forms of diabetes if they conscientiously implement the therapy recommendations (compliance). This prevents complications and significantly reduces the risk of secondary diabetes diseases.
Regular check-ups by a doctor are also important for diabetics. For example, signs of secondary diseases of diabetes can be detected and treated early.
Whether diabetes is curable depends on the particular form of the disease. Thus, type 1 is currently usually an irreversible diagnosis. In type 2, at least at an early stage, a consistent adaptation of lifestyle can significantly alleviate the disease. Sometimes even no further therapy is necessary. A complete cure for diabetes is usually only possible with diabetes mellitus type 4 (gestational diabetes): In most cases, the woman’s body returns to its normal status after the hormonal emergency during pregnancy and the diabetes disappears.
In diabetes mellitus, life expectancy depends on whether blood glucose levels can be adjusted well in the long term and how consistently the patient adheres to the therapy (compliance). Possible concomitant and secondary diseases such as high blood pressure, elevated blood lipid levels or kidney weakness also have a major influence. If they are properly treated, this can have a positive effect on life expectancy.
Diabetes: complications and secondary diseases
Poorly controlled diabetes mellitus can lead to acute metabolic disorders – either because the blood sugar is much too low (hypoglycaemia) or much too high (hyperglycaemia). In the second case a hyperosmolar hyperglycemic syndrome or diabetic ketoacidosis may occur. Both can lead to a diabetic coma (Coma diabeticum).
By the way: The transitions between normal blood sugar levels, hypoglycaemia and hyperglycaemia are fluid.
In the long run, poorly adjusted blood sugar values can trigger secondary diseases. For example, the high blood sugar level damages the blood vessels (diabetic angiopathy), which results in circulatory disorders. This can result in “window dressing” (pAVK), kidney disease (diabetic nephropathy), eye disease (diabetic retinopathy), heart attack or stroke. The nerves are also damaged in diabetes patients (diabetic polyneuropathy). This leads to the diabetic foot syndrome, for example.
Read more about diabetes complications and secondary diseases below.
Hypoglycemia (low blood sugar)
Critically low blood sugar is the most common complication in patients with diabetes. It is caused by too much insulin in the blood for the current requirement. Diabetes patients who inject insulin or take tablets that stimulate insulin production (sulfonylureas or glinides) are particularly at risk for hypoglycaemia: if they accidentally overdose on their medication, the blood sugar level drops too much.
Skipping a meal or extensive exercise can also trigger hypoglycaemia if the drug therapy is not adjusted accordingly.
Hyperosmolar hyperglycemic syndrome (HHS)
This severe metabolic derailment occurs mainly in older type 2 diabetics. If they make mistakes when using insulin or oral antidiabetics, the result is a lack of insulin. This slowly develops into HHS over days to weeks:
The blood sugar rises to extremely high values (> 600 mg/dl). Due to physical laws (osmosis), the many sugars extract large amounts of fluid from the body cells. Since older patients generally tend to drink little, this can lead to extreme dehydration.
The signs of HHS develop slowly. In the beginning, mostly uncharacteristic symptoms such as fatigue and drowsiness appear. This is accompanied by other symptoms such as blurred vision, frequent urination, extreme thirst, calf cramps, weight loss and low blood pressure. Neurological symptoms such as speech disorders and hemiplegia are also possible. In extreme cases disturbances of consciousness up to unconsciousness (coma) occur. Then there is danger to life!
Hyperosmolar hyperglycemic syndrome must be treated immediately by a doctor! In case of disturbances of consciousness, the emergency doctor must be alerted immediately!
Diabetic ketoacidosis is also the result of hyperglycaemia. It occurs preferentially in type 1 diabetics:
Due to the absolute insulin deficiency of those affected, not enough “fuel” for energy production (blood sugar) can enter the cells. Then the liver tries to compensate for the lack of energy by producing new glucose (gluconeogenesis) and breaking down fat. But gluconeogenesis only exacerbates hyperglycaemia. And when fat is broken down, acidic metabolic products (ketone bodies) are formed. The body can only breathe out a part of it via the lungs in the form of carbon dioxide. The rest for causing an acidosis of the blood – called diabetic ketoacidosis.
The metabolic imbalance is usually triggered by an infection (such as a urinary tract infection or pneumonia): the body then needs more insulin than normal. If the insulin therapy is not adjusted accordingly, diabetic ketoacidosis is imminent. The same can happen if insulin syringes are forgotten or dosed too low or if the insulin pump is not working properly. Less frequent causes are, for example, heart attack and alcohol abuse.
Signs of diabetic ketoacidosis include increased thirst, frequent urination, nausea and vomiting, lack of appetite, abdominal pain and severe fatigue. Especially typical are a strikingly deep breathing (kissing mouth breathing) and an acetone smell in the exhaled air (smell of apple or even nail polish remover). If untreated, disturbances of consciousness can occur up to unconsciousness (coma). Then there is danger to life!
Diabetic ketoacidosis is a medical emergency! Those affected must be taken to hospital immediately and treated in the intensive care unit.
Poorly adjusted blood sugar levels in diabetes damage the small blood vessels of the retina in the eyes. This is how a retinal disease called diabetic retinopathy develops.
The patients affected suffer from visual disorders. Her vision’s getting worse. In extreme cases, blindness is a real threat. In industrialized countries, diabetic retinopathy is the skin cause of middle-age blindness.
If the retinal disease has not yet progressed too far, the course can be halted by laser therapy.
You can read more about the development and treatment of diabetes-related eye disease in the article Diabetic Retinopathy.
Diabetes-related kidney disease – like diabetic retinopathy – is based on damage to small blood vessels (microangiopathy) due to poorly adjusted blood sugar levels. The kidneys can then no longer adequately fulfil their functions. This includes filtering (detoxification) of the blood and regulation of the water balance.
Possible consequences of diabetic nephropathy are kidney-related high blood pressure, water retention in the tissue (edema), lipid metabolism disorders and anaemia. Kidney function can deteriorate continuously – up to chronic kidney failure.
Diabetes with permanently poorly adjusted blood sugar can lead to damage and disturbance of the nerves. This diabetic polyneuropathy first appears on the foot and lower leg – a diabetic foot develops (see below).
Diabetic neuropathy can also affect other nerves in the body. For example, nerve damage to the autonomic nervous system causes low blood pressure, bladder emptying disorders, and constipation or inability to control bowel movements. Gastric paralysis with nausea and vomiting (diabetic gastroparesis) can also occur. Some patients also suffer from palpitations or increased sweating. Erection problems are often observed in male patients.
The diabetic foot syndrome develops on the basis of diabetes-related nerve damage and diabetes-related vascular damage:
The nerve disorders cause sensations (such as “formication”) and sensitivity disorders in the foot and lower leg. The effect of the latter is that patients perceive heat, pressure and pain (e.g. from shoes that are too tight) only to a lesser extent. In addition, there are circulatory disorders (as a result of vascular damage). All this together leads to poor wound healing. This can lead to chronic wounds, which often become infected as well. Gangrene can also occur, in which case the tissue dies off. In the worst case an amputation is necessary.
You can read more about these diabetes complications in the article Diabetic foot.
Disabled person’s pass
Diabetes patients can take advantage of special facilities for severely disabled persons. A severe disability exists if the therapy effort is very large and the affected person is severely restricted by the disease in everyday life. In the meantime, many people affected apply for a disability card every year. Diabetes patients thus receive important compensation for disadvantages such as tax breaks, free public transport or reduced admission to cultural facilities.
Living with diabetes
Diabetes mellitus can affect the whole life of the affected person. This starts with small things (such as alcohol consumption at family gatherings) and extends to life issues such as family planning and the desire to have children.
Travel is also an important issue for many diabetics: What do I as a diabetic have to consider when travelling by air? What medications and medical utensils do I need to take with me? How should they be kept? What about vaccinations?
You can read the answers to these and other questions about everyday life with diabetes mellitus in the article Living with diabetes.
A new development is a small glucose sensor that is inserted into the patient’s subcutaneous fatty tissue (for example, on the abdomen). It measures the glucose content in the tissue every one to five minutes (Continuous Glucose Monitoring, CGM). The measurement results can be transmitted by radio, for example to a small monitor to support intensified insulin therapy (Sensor Assisted Insulin Therapy, SAT). The measured values can also be transferred directly to an insulin pump (sensor-assisted insulin pump therapy, SuP). The CGM offers various alarm options that warn the patient if hyperglycaemia or hypoglycaemia is imminent.
However, it is important that patients still have to measure their blood sugar themselves, for example before a planned insulin administration. This is because there is a physiological difference between tissue sugar (as measured by CGM) and blood sugar.