Type 2 diabetes, a cause of cancer

Type 2 diabetes, a cause of cancer

UPDATE DAY

According to a recent study, cancer is on track to become the leading cause of death for people with diabetes, surpassing even cardiovascular disease. 

It is estimated that nearly 500 million adults aged 20-79 were living with type 2 diabetes worldwide in 20,211.

This is a serious problem, as type 2 diabetes is associated with a higher risk of several vascular complications, including myocardial infarction, stroke and peripheral arterial disease, which increase significantly the risk of premature death. 

In recent years, new treatments have reduced the ravages of high blood sugar on blood vessels and substantially reduced its negative effects on cardiovascular health.  

On the other hand, this reduction in cardiovascular mortality means that diabetics are exposed longer to the imbalances caused by diabetes and are therefore more at risk of developing other types of complications, in particular cancer. 

< p>Increase in the risk of mortality

Two recent studies illustrate this phenomenon well.  

In the first, the authors identified 137,804 patients (mean age 64 years) who had been diagnosed with type 2 diabetes between 1998 and 2018 and compared the cancer mortality of this group with that of the general population, non-diabetic2. 

They observed that, overall, diabetics had an 18% increased risk of mortality linked to all cancers, and that this increase was particularly pronounced for colorectal (2.5 times higher), pancreatic (2 times), liver (2 times) and endometrial (uterus) (2 times) cancer.  

A 9% increase in breast cancer mortality has also been observed in women with diabetes, particularly those under 55, compared to the general population. 

Lung cancer

The other study looked at the association between diabetes and the risk of lung cancer in a population of 283,257  adults participating in the UK Biobank Study3.  

The researchers divided this cohort into three groups, based on their blood levels of glycated hemoglobin (A1c), a marker of chronic hyperglycemia: 

1. normoglycemics , with an A1c of less than 6%; 

2. prediabetics, with an intermediate A1c and 

3.< /strong> diabetics, with an A1c equal to or greater than 6.5%.  

The researchers noted that the risk of lung cancer was increased by 37% in prediabetics and by 33% in diabetics who were not taking any hypoglycemic medication.  

Antidiabetic medication allows however, to cancel out most of this increased risk of lung cancer in diabetics, which suggests that it is indeed uncontrolled hyperglycemia that contributes to the development of this cancer. 

This is especially problematic for people who are prediabetic. These people often have no symptoms and can therefore live for several years without suspecting the presence of chronic hyperglycemia. Not having been diagnosed with type 2 diabetes, they are therefore not treated with adequate medication so that the increase in their blood sugar remains untreated and is sufficient to promote the development of lung cancer. < /p>

In short, even if the mortality rate linked to cardiovascular accidents among diabetics has decreased in recent years, that due to various types of cancer is on the rise.  

It s This is another illustration of the serious dangers of type 2 diabetes which, let us remember, is in the majority of cases a disease linked to overweight and which can therefore be prevented by adopting better lifestyle habits to maintain a normal body weight.

1. International Diabetes Federation (2021) IDF diabetes atlas 2021. diabetesatlas.org/atlas/tenth-edition/
2. Ling S et al. Inequalities in cancer mortality trends in people with type 2 diabetes: 20 year population-based study in England.
Diabetologia, published January 24, 2023.
3. Hua J et al. Associations of glycosylated hemoglobin, pre-diabetes, and diabetes with incident lung cancer: a large prospective cohort study.
Lancet, published January 10, 2023.