Scientific support: Prof. Dr. Julia Szendrödi
Cardiovascular diseases are the most common complication resulting from diabetes. The cause is “calcification” of the arteries. This is when fats, cholesterol, calcium, and connective tissue deposits build up on the inner arterial walls. Medical professionals call these deposits plaques and the calcification arteriosclerosis.
Those affected often don’t notice the signs of the condition for a long time. Over time, the deposits increase in size and cause blood circulation problems. In the most severe case, the blood vessels are completely blocked which can result, for example, in a heart attack.
Depending on the organ affected, patients can suffer a variety of consequences: Circulatory disorders in the brain can cause dizziness or even stroke, and in the heart, they can cause sudden painful episodes, heart attacks, or cardiac insufficiency (heart failure). Circulatory disorders in the aorta, abdomen, or blood vessels of the legs can lead to intermittent claudication or “smoker’s leg”.
This is why regular blood vessel assessment is important for people with diabetes to enable targeted treatment to improve blood circulation. Alongside high blood sugar levels, high blood pressure and high cholesterol levels in particular, should be avoided. This can help prevent and avoid heart attacks, stroke, or the development of wounds on the feet.
People with type 1 diabetes should have their blood fat levels (lipids) checked within the first year of the initial diagnosis. They should also undergo regular blood pressure testing from 11 years old onwards. People with type 2 diabetes should visit a doctor at least every 1 to 2 years to assess their risk of potentially developing cardiovascular diseases.
There are a number of factors that increase the risk of cardiovascular disease associated with diabetes. Firstly, the high blood sugar levels caused by diabetes damage the blood vessels. But accompanying diseases, such as fat metabolism disorders, high blood pressure, or kidney disease increase the risk.
Some young patients with type 1 diabetes can be at low risk if their HbA1c level is below 7 percent (53 mmol/mol), they don't smoke, and they have no other accompanying diseases.
People with diabetes can do a lot to prevent the onset of cardiovascular disease:
- Well managed blood sugar levels from the time of diagnosis delays the onset of vascular complications.
- Try to maintain normal blood pressure levels.
- Ensure healthy cholesterol levels.
- Try to maintain a healthy weight.
- A healthy lifestyle is essential:
- Don’t smoke.
- Try to avoid alcohol as much as possible.
- Eat a balanced diet. Eat a lot of fruit, vegetables, and wholewheat products. Avoid animal fats.
- Exercise regularly.
- Get enough sleep.
People with a high cardiovascular risk should maintain lower cholesterol levels than healthy people.
A medical examination is necessary every 1 to 2 years to assess the risk of potentially developing cardiovascular disease.
Upon the first signs of circulatory disorders, the physician will prescribe general measures to help improve vascular health. The physician will also try to optimally manage blood sugar levels. This is to prevent blood sugar levels that are too high or too low. If a patient with diabetes also has high blood pressure or blood fat levels, then the physician will also initiate treatment of these accompanying diseases. A healthy lifestyle coupled with drug-based therapy is especially important in this context. For example, people with type 1 diabetes or type 2 diabetes who are also overweight may find metformin helpful.
Depending on the complications of vascular calcification that have already developed and the organ affected, the physician will then initiate further treatments. They can prescribe various drugs or surgery.
Please find below a detailed description of some cardiovascular diseases and their treatments.
Coronary heart disease and heart attack are the most significant complications affecting people with diabetes. Coronary heart disease is caused by calcification of the coronary arteries. These are the blood vessels that encircle the heart in the shape of a crown while supplying the heart with the oxygen-rich blood it needs. Calcification causes arterial narrowing and blockage.
A typical sign of the condition is the spontaneous onset of a dull pain in the chest (pectoral angina). Some people also have a feeling of tightness in their chest. When the cardiac muscle does not receive enough blood for a prolonged period, this is known as a heart attack.
A doctor carries out multiple tests to determine how well blood is circulating through the heart. For example, an ECG or an ultrasound examination is performed while the patient is active (stress ECG). They sometimes use contrast agents as part of a CT or MRI or during an invasive procedure, such as cardiac catheterization, to assess blood flow through the heart. Medical professional call this heart scintigraphy.
In the case of type 2 diabetes coupled with coronary heart disease, there are certain types of drugs that can help. People with diabetes and heart disease are more likely to require surgery than people without diabetes. A stent can be used to repair narrowing of a blood vessel. A stent is a vascular support made from metal. It is put in place during cardiac catheterization. In cases affecting long segments of the cardiac blood vessels, specialists will carry out bypass surgery.
Heart failure is one of the main problems affecting people with type 1 diabetes as they age. It normally manifests via dyspnea during physical exertion (climbing stairs). Patients with heart failure suffer from shortness of breath during the night and sleep better with their upper body in an elevated position. An irregular pulse is another typical symptom. They also often suffer from water retention (e.g., in the legs), which means that they have to go to the bathroom often during the night.
Heart failure usually develops as a consequence of other conditions, e.g., a heart attack. Heart failure is particularly common in people with diabetes. High blood sugar levels can disrupt certain metabolic processes that result in not enough energy being generated for the heart.
If heart failure is suspected, the doctor will first conduct an ECG. Subsequently, they will carry out a special ultrasound examination known as a tissue Doppler echocardiography. The examination is supplemented by the determination of various laboratory blood values.
Alongside changes to lifestyle and good blood sugar management, certain diabetes medications can help with heart failure, e.g., SGLT2 inhibitors, GLP receptor agonists, ACE inhibitors or diuretics. Metformin should no longer be used when suffering from heart failure.
PAD is a disorder affecting blood flow in the pelvis, arms, and legs. PAD frequently results in calcification of the blood vessels of the legs, causing them to become severely narrowed or blocked. The blood can no longer reach the feet. This means the feet no longer receive enough oxygen or nutrients.
Those affected suffer pain in the leg during exertion and are forced to take repeated breaks when walking. Poor blood circulation in the feet causes some of those affected to develop diabetic foot syndrome.
People with diabetes often do not notice the condition because their pain perception is reduced.
Only when 90 percent of the blood vessels in the legs are narrowed do those affected notice signs of the disease. This is the reason why PAD is often diagnosed at a very late stage by a physician. The diagnosis process begins with a consultation with a doctor to compile a medical history. Subsequently, the doctor will take a close look at the skin on the legs and feel for a pulse in the feet. In cases of PAD, the pulse is weak or barely detectable.
A walking test is an important part of the diagnostic process. This helps determine the distance the patient can walk without pain. Using a Doppler ultrasound, a physician can make blood flow and possible narrowing of the arteries visible on a screen. They then assess blood flow using a diagnostic imaging technique, such as MRI.
Lifestyle changes and good blood sugar management are an important basis for the treatment of PAD. Depending on the severity of the circulatory disorder in the legs, the doctor will order further treatment measures.
If patients feel movement-related pain in their legs, then they have to walk more. They should walk what for them is a pain-free distance several times each day. Blood-thinning medications, such as aspirin, can also help. In some cases, doctors will prescribe drugs that dilate the blood vessels. Surgery may also be necessary. For example doctors may implant stents to dilate the blood vessels. If a longer segment of a blood vessel is narrowed, then bypass surgery is necessary. In case of severe narrowing of the arteries and wounds associated with diabetic foot syndrome, amputation may be needed.
A stroke is the result of the brain not receiving enough oxygen. It can be caused by a blood clot and calcification or rupturing of blood vessels.
The first signs of a stroke can be a sudden weakness affecting the arms or legs, facial paralysis, speech disorders and difficulty speaking, visual impairment, nausea, vomiting, dizziness, or headaches. Typically, these symptoms appear suddenly.
Rapid professional medical assistance is essential.
In Germany and worldwide, stroke is the second most common cause of death and one of the most common causes of physical and/or mental impairment affecting adults. People over 60 years old with diabetes are at greater risk. The consequences are usually severe impairments in daily life, e.g., affecting mobility, managing personal hygiene, or the ability to feed oneself.
Many patients suffering from stroke, or their relatives, wait up to two days before seeking medical help. And this despite the fact that rapid medical attention is crucial. The latest medical procedures can be applied up to 3 hours after the first signs of stroke to prevent or reduce the most severe consequences.
This is why, if a stoke is suspected, call the emergency services immediately by dialing 112 to get the affected person to a hospital as quickly as possible. Ideally, the hospital will have a specialized stroke unit.
In the event of a stroke, it is important to keep an eye on the blood sugar levels. This applies both for people with and without diabetes. High blood sugar levels exceeding 200 mg/dl (11.1 mmol/l) should be counteracted immediately using insulin, because they can have a negative influence on the course and the consequences of the stroke. Low blood sugar levels (hypoglycemia) should be avoided and combated in conscious patients using dextrose or sweetened tea. If the affected person is unconscious, then a glucagon injection or infusion is a possible treatment option.
For people with diabetes, after a stroke, alongside good blood sugar level management, normal blood pressure levels are important. Depending on the existence of other cardiovascular risk factors, ideally, blood pressure levels for people with diabetes should be between 130/80 mmHg and 139/90 mmHg to reduce the risk of another stroke.
The target blood pressure level is determined during a consultation with a doctor. Depending on the existence of other cardiovascular risk factors, ideally, blood pressure levels for people with diabetes should be between 130/80 mmHg and 139/90 mmHg. It is crucial that these levels are coupled with a healthy lifestyle. This means a healthy diet, avoiding salt, regular physical activity, and avoiding smoking or drinking alcohol. Weight loss often leads to a dramatic drop in blood pressure. If blood pressure exceeds 140/90 mmHg, doctors will prescribe additional medication to reduce blood pressure, such as ACE inhibitors. If there are difficulties managing the blood sugar level, then the possibility of other underlying diseases, such as hormonal disorders, is investigated.
Blood pressure below 120/70 mmHg should also be avoided because it can increase the risk of complications.
Blood pressure is the pressure level within the vascular system that pumps blood around the body. A normal blood pressure level is around 120/80 mmHg. Medical professionals diagnose hypertension at levels exceeding 140/90 mmHg. In the long term, elevated blood pressure can damage numerous organs. High blood pressure is a primary risk factor for cardiovascular disease. High blood pressure can also damage the eyes and kidneys.
People with diabetes are more likely to develop high blood pressure than people without diabetes. Permanent high blood sugar levels can damage blood vessels and affect function of the nerves. The vessels and nerves are no longer able to correctly control the blood pressure. In the early stages of type 2 diabetes, the pancreas produces an especially high amount of insulin. Insulin can also cause an increase in blood pressure. As with all people, smoking, obesity, lack of physical activity, and poor diet are cardiovascular risk factor for people with diabetes.
At every check-up, a doctor will take a blood pressure measurement using an inflatable cuff and a stethoscope. There are also electronic blood pressure measurement devices that allow patients to monitor their blood pressure at home.
American Diabetes Association: Standards of Medical Care in Diabetes - 2019. In: Diabetes Care, 2019, 42: S1-S193
Bundesärztekammer et al.: Nationale Versorgungsleitlinie Chronische Herzinsuffizienz. Langfassung. 2. Auflage. Version 2. 2017
Bundesärztekammer et al.: Nationale Versorgungsleitlinie Chronische KHK. Langfassung. 5. Auflage. Version 1. 2019
Bundesärztekammer et al.: Nationale Versorgungsleitlinie Therapie des Typ-2-Diabetes. 1. Auflage. Version 4. 2014 (Gültigkeit abgelaufen, in Überarbeitung)
Busch, A. et al.: 12-Monats-Prävalenz von Schlaganfall oder chronischen Beschwerden infolge eines Schlaganfalls in Deutschland. In: Journal of Health Monitoring, 2017, 2: 70-76
De Boer, I. H. et al.: Diabetes and Hypertension: A Position Statement by the American Diabetes Association. In Diabetes Care, 2017, 40: 1273-1284
Deutsche Diabetes Gesellschaft et al.: Deutscher Gesundheitsbericht Diabetes 2019. Kirchheim Verlag, Mainz, 2019
Deutsche Gesellschaft für Allgemeinmedizin und Familienmedizin: S3 Leitlinie Hausärztliche Risikoberatung zur kardiovaskulären Prävention. 2017
Deutsche Gesellschaft für Allgemeinmedizin und Familienmedizin: Schlaganfall. Langfassung. 2012 (Gültigkeit abgelaufen, in Überarbeitung)
Deutsche Gesellschaft für Angiologie - Gesellschaft für Gefäßmedizin: S3-Leitlinie zur Diagnostik, Therapie und Nachsorge der peripheren arteriellen Verschlusskrankheit. 2015
Deutsche Gesellschaft für Neurologie: S1 Leitlinie Akuttherapie des ischämischen Schlaganfalls. 2012 (Gültigkeit abgelaufen, in Überarbeitung)
Schütt, K. et al.: Diabetes mellitus und Herz. In: Diabetologie, 2018, 13: S214-216
Williams, B. et al.: 2018 ESH/ESC Guidelines for the management of arterial hypertension. In: J Hypertens, 2018, 36: 1953-2041
As of: 24.04.2020