There seems to be a connection between the two common diseases of diabetes and cancer. This is indicated by studies of various scientists. This mainly affects type 2 diabetes. The data situation for type 1 diabetes is less clear.
The exact causes are not yet known. However, scientists are working hard to unravel the mechanisms in order to develop suitable treatment methods.
It is important for people with diabetes – as it is for people with a healthy metabolism – to have regular check-ups and to lead a healthy lifestyle.
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Diabetes and cancer – how are they related?
The interaction between diabetes and cancer is very complex and difficult to decipher. Both chronic disease conditions are influenced by many factors and can show very different manifestations. However, it seems to be clear that diabetes can promote the pathological growth of some body cells. This is the result of population studies in which researchers combine data from numerous patients to uncover larger correlations.
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Numerous studies suggest a link between type 2 diabetes and various cancers. But the exact mechanisms are still not understood.
The majority of studies reporting a link between diabetes and cancer do not distinguish between the different types of diabetes. Since type 2 diabetes is much more common than type 1 diabetes, it can be assumed that the results apply predominantly to type 2 diabetes. According to the researchers, further studies are needed to make more accurate conclusions about possible links between type 1 diabetes and cancer.
A 16-year study with more than 1 million participants showed that various types of cancer are more common in people with diabetes than in metabolically healthy people. Diabetes type or age at diagnosis was not asked in this study either.
At women with diabetes mellitus the following types of cancer occur more frequently than in women without diabetes:
- Colorectal cancer
- Breast Cancer
- Pancreatic Cancer
At Men with diabetes mellitus the following types of cancer occur more frequently than in men without diabetes:
- Colorectal cancer
- Pancreatic cancer
- Liver Cancer
- Bladder Cancer
Tumors in the urinary tract and female reproductive organs continue to be under discussion, as other papers report. According to the German Diabetes Association (DDG), people with diabetes also have an increased risk of developing tumors of the kidney, thyroid and esophagus compared to the general population. In addition, certain diabetes medications are suspected of triggering tumors, while others are thought to have a protective mechanism.
However, the connections are by no means a one-way street: cancer (of the pancreas, for example) can also trigger diabetes, and certain cancer drugs can also lead to disturbed sugar metabolism.
Together with type 2 diabetes, obesity often occurs. It is now known that fatty tissue secretes hormones that promote cancer growth. Obesity is a chronic inflammatory condition. The numerous inflammatory cells in the adipose tissue release pro-inflammatory messenger substances that can promote the development of cancer.
Dia-be-tes and cancer: what happens in the body-per-cells?
Exactly how diabetes can contribute to the formation of tumors is not yet clear. Several factors are under observation here. One guess is that elevated insulin levels are responsible. The body initially forms these in type 2 diabetes in order to compensate for the weakening effect of the hormone (insulin resistance of the body cells).
However, insulin not only regulates sugar levels in the body, but also controls cell growth and cell division. Long-term elevated insulin levels can thus stimulate existing tumor cells to increase growth. In addition to insulin, insulin-like growth factor 1 (IGF-1) is also involved in sugar and fat metabolism. It further stimulates cell division.
In addition to insulin, other messenger substances from the fatty tissue, so-called "adipokines," are increasingly released when a person is overweight. These messenger substances, including the well-known leptin, not only regulate appetite and metabolism, but can also intervene directly in the control of cell division and growth. In addition, chronic inflammatory reactions, which are frequently associated with diabetes, as well as oxidative stress and hormonal changes are also mentioned. In particular, inflammatory reactions, such as those that occur in obesity, can contribute increasingly to tumor growth and cell division.
Studies on whether diabetes medications can be a cause of cancer are comparatively new. The analog insulin glargine, sulfonylureas and insulin itself are suspected of causing cancer. However, experts consider these studies questionable in part because the development of most types of cancer usually takes longer than these drugs have been on the market and used in diabetes therapy to date. If such a risk were actually present, the effects would therefore only be detectable at a later stage.
Metformin therapy, on the other hand, appears to actually reduce the rate of new cases and mortality from cancer. However, further studies are necessary to prove these correlations even more precisely.
The results of a study published in 2013 are similar: In this study, a research team linked the DPP-4 inhibitor sitagliptin and the GLP-1 analog exenatide to an increased incidence of pancreatic cancer in people with type 2 diabetes, among other things. In the opinion of the German Diabetes Society (DDG), further long-term studies are essential in this area.
Preventing cancer: What should people with diabetes consider??
A healthy lifestyle is important for all people – whether they have diabetes or not: poor diet, lack of exercise and obesity are not only detrimental to diabetes treatment, but also increase the risk of other diseases such as cancer or cardiovascular complications. A healthy lifestyle with regular exercise and a healthy diet, on the other hand, has a preventive effect and also improves the metabolism.
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People with diabetes should have regular check-ups and maintain a healthy lifestyle.
People with diabetes should be screened for cancer regularly, just like metabolically healthy people. This is because the earlier a tumor is detected, the better the chances of treatment. For example, all insured persons in Germany from the age of 50 are entitled to regular examinations for the early detection of colorectal cancer. The examination should be repeated every 5 years.
Corresponding studies also exist for other forms of cancer, such as breast or cervical cancer Screening programs. Whether an earlier check-up is advisable in the case of diabetes should be discussed with the doctor treating the patient. The German Federal Ministry of Health offers a Overview of the legally recognized early detection program.
Since therapy with very high amounts of insulin is also suspected of promoting cancer, the German Diabetes Society (DDG) advises: as much insulin as necessary, but as little as possible. Therapy with the blood sugar-lowering drug metformin, on the other hand, has been shown in various studies to have a protective effect on some types of cancer. For this reason, physicians should consider combining diabetes medication with metformin or other blood sugar-lowering drugs to save insulin, especially for overweight people with type 2 diabetes who inject high doses of insulin.
Dia-be-tes and cancer: Which for-schungs-an-sat-ze are there??
The decisive factor in the coming years will be to further decipher the possible links between cancer and diabetes or to disprove them. Does one condition the other, or are the diseases both simply based on the same risk factors?? Only when it is clearly understood which mechanisms act in one direction or the other can researchers begin to develop appropriate treatments.
The long-term effects of diabetes drugs are also under observation: If it were confirmed that certain drugs increase the risk of cancer, this would have consequences in the therapy.
Therapeutic options are also being explored: for example, researchers are investigating whether bariatric surgery used for obesity (for example, stomach reduction) also has an inhibitory effect on tumor growth.
A relatively new approach is interval fasting, which shows extremely positive effects on metabolism. According to initial findings, it can also have a protective effect against tumor growth and also improve the effectiveness of chemotherapeutic agents.
The relatively new field of epigenetics also offers new approaches to researching the links between diabetes and cancer. In contrast to genetics, the term epigenetics refers to the inheritance of traits that are not fixed in the genes. Chemical changes (methylations) of the genetic material, i.e. the DNA strand or its "packaging", the histones, indirectly influence the genetic information by controlling when which genes are read off. Environmental factors, nutrition and living conditions are possible triggers of these epigenetic changes.
Thus different studies deal with it whether as molecular markers or even cause the so-called microRNAs come into question. These are small molecules that can influence the activity of certain genes. If there are any correlations, you could try to intervene in them.