More than 500 million people suffer from type 2 diabetes – slightly more than 6% of the world’s population. Type 2 diabetes, in short, results in the body becoming less receptive to the insulin hormone along with the body’s own insulin production being reduced.  

This results in chronically high blood sugar levels as the body cannot regulate the blood sugar. A high blood sugar can result in various forms of physical discomfort; tiredness, thirst, frequent urination, headaches and overall general discomfort – just to name a few examples. But besides these various discomforts, untreated high blood sugar can lead to serious complications.

Type 2 diabetes: A hereditary lifestyle disease 

Type 2 diabetes is a lifestyle disease which can be caused by an unhealthy lifestyle. People with an unhealthy diet and who eat more calories than they burn raise the body’s blood sugar levels. This is normally when the insulin comes into play to lower the blood sugar levels. But if a person has led this lifestyle for several years, the body will not be able to keep up – it simply cannot produce enough insulin, and the body becomes resistant to the insulin hormone.  

The disease has a high heritability, estimated at 40 – 70%, which means that various genetic factors play a key role in the risk of developing the disease. People whose parents suffer from the disease can lower the risk of they themselves developing the disease with a healthy lifestyle – but due to the high heritability it can never be guaranteed that a person will not develop the disease.  

Type 2 diabetes is a complex disease that can result in several grievous complications, among others: cardiovascular diseases, diabetic retinopathy and chronic kidney disease. It is therefore imperative to receive appropriate treatment for the disease to prevent these complications.

Study shows several drugs as candidates 

A study performed by researchers at Aarhus University and Aalborg University has explored the possibilities of repurposing drugs to see if it is possible to find alternative treatments to the disease. 

Repurposing of drugs means that the researchers have examined if drugs meant to treat other diseases could prove to be effective at treating type 2 diabetes.

The researchers have not analyzed genetic data from individuals with type 2 diabetes. Instead, they used the results from very large genetic population studies – the so-called genome-wide association studies (GWAS) - which shows exactly which genetic variants are coupled with the increased risk of type 2 diabetes.  

From these genetic correlations the researchers could identify the specific genes that play a crucial role in the disease. Afterwards they examined which known drugs that affect these specific genes and the biological processes that the genes are included in.  

In short, the genetic ”fingerprints” that have been produced from the big population studies have been used to couple type 2 diabetes with existing drugs – without testing the drugs on actual patients. This makes it possible to identify drugs already approved for the treatment of other diseases that might also influence the biological processes behind type 2 diabetes.  

The researchers did not just find single genes, but entire groups of genes affected by specific drugs, which together account for a large part of the genetic risk for type 2 diabetes. This means that the biological processes, which these drugs affect, seem to play a crucial role in the development of the disease. 

One of the promising drugs that the study found was a drug normally used for the treatment of increased cholesterol. The results indicate that this drug affects genetic processes also involved in type 2 diabetes. This potentially enables new possibilities for using existing drugs for new treatment purposes in the future – in this case: the treatment of type 2 diabetes.  

“The study doesn’t suggest that we can put new drugs to use tomorrow, but it demonstrates how genetic studies can be used in prioritizing the most promising candidates way earlier in the research process. In the future this can enable faster and cheaper research for treatments” says associate professor Palle Duun Rohde, who is one of the driving forces behind this study as well as the leader of research at Genomic Medicine at Aalborg University.

A hypothetical study 

The study’s focus has been on drugs where a genetic correlation with type 2 diabetes could be proved, and the study can therefore not assess the effects of treatments that do not leave a clear genetic signal – for example synthetic insulin. This means that there are potentially several drugs that affect type 2 diabetes which this study has not detected.  

Besides this study is based purely on genetic analyses and not clinical trials, which means that the study primarily shows promising candidates and not documented treatments. Therefore, the study does not take into consideration that all patients are different and require different treatments. This means that further clinical testing is required to examine if these alternative drugs work in practice. 

Even though this study has not resulted in new alternative drugs being immediately put to use – which was never likely – it has improved and nuanced the prioritization of drugs for future studies. It is a step closer to finding alternative – and potentially cheaper – drugs for the treatment of type 2 diabetes. Perhaps even drugs that could treat both the disease and its potential complications simultaneously. 

In short, the study shows that a series of existing drugs have the potential to be used in the treatment of type 2 diabetes, which can save both time and money compared to developing entirely new medicinal treatments.