The World Health Organization estimates that 6% of the world’s population—more than 420 million people—is living with diabetes. That’s a figure that has quadrupled since 1980, and it’s expected to rise to more than half a billion by the end of the decade. In Australia, around 1.5 million people are thought to be living with the condition, with 120,000 new cases being diagnosed each year.
In this article, we’ll explore the risk factors of diabetes, with a particular emphasis on how genetic factors interact with other influences in the development of the condition.
Types of risk factors
The development of diabetes is linked to four types of risk factors. These are:
- Genetic risk factors—the influence of a person’s genes.
- Environmental risk factors—such as exposure to toxins, climate and access to healthcare.
- Lifestyle risk factors—behaviours influencing diet, physical activity, smoking, alcohol consumption and stress management.
- Biomedical risk factors—these are bodily states, such as blood pressure and blood glucose levels, that have an impact on a person’s risk of disease. They can be influenced by all of the above.
Importance of understanding genetics and disease
Genetics research studies how genes are involved in health and disease. Understanding genetic risk factors and genetic disorders is important in both the treatment and the prevention of disease.
Understanding this makes it possible to work out how susceptible a person is to developing certain diseases. For example some genetic changes have been associated with an increased risk of having a child with a birth defect or developmental disability, or developing conditions such as cancer or heart disease. A knowledge of genetics can also help direct the course of treatment. Knowing, for instance, that cystic fibrosis is caused by certain genetic mutations allows the use of medication designed to counteract the consequences of the mutations. Understanding genetics can be useful in the prediction of how a disease is likely to progress, which also helps to shape a treatment plan.
Understanding diabetes
Diabetes is the name of a group of conditions in which there is too much glucose in the blood. There are three main forms of diabetes, type 1, type 2 and gestational diabetes (which occurs during pregnancy).
There is also a condition called pre-diabetes, where blood glucose levels are high but not high enough for a type 2 diabetes diagnosis. People with pre-diabetes are at higher risk of developing type 2 diabetes, however, research shows that in many cases, type 2 diabetes can be prevented or delayed.
Diabetes risk factors
Type 1 diabetes
In type 1 diabetes, the body is unable to produce insulin. It is an autoimmune disorder (where the immune system destroys healthy tissue) that is believed to arise mainly through genetic risk factors. Some of the ‘responsible’ genes are part of the human leukocyte antigen (HLA) group, which regulates the immune system. Although we don’t yet know how those genes trigger type 1 diabetes, they are thought to do so in combination with environmental factors such as infections and high levels of stress.
There are no modifiable risk factors for type 1 diabetes, but maintaining a healthy lifestyle is important for managing its symptoms and complications. Type 1 diabetes is not preventable, and currently there is no cure.
Type 2 diabetes
Type 2 diabetes occurs when not enough insulin is made by the body, or when the insulin is not working properly. 85–90% of people with diabetes have type 2. In 58% of cases, the onset of type 2 diabetes can be prevented or delayed.
The part played by biomedical and lifestyle factors in the development of type 2 is thought to be far greater than it is in type 1—but genetics is still significant. Mutations (changes) in genes, especially those involved in producing or controlling glucose and the production and regulation of insulin, have been linked to an increased risk. Gender and ethnicity also play a part.
Biomedical risk factors for type 2 diabetes include:
- pre-diabetes
- high blood pressure
- excessive levels of lipids (fats) in the blood
- excess body fat
- excess weight around the abdomen.
Lifestyle risk factors for type 2 diabetes include:
- unhealthy diet
- not being physically active
- smoking.
Risk factors for gestational diabetes include:
- excess body fat
- not being physically active
- having pre-diabetes
- having pre-eclampsia
- having had gestational diabetes during a previous pregnancy
- having polycystic ovary syndrome.
Genetic testing for diabetes
Genetic testing for diabetes involves examining your family history and analysing your DNA (a molecule that contains all the genetic instructions for your development) to identify genetic risk factors. Testing can be done through a simple blood or saliva test.
Genetic testing has the advantages of identifying potential cases early and enabling treatment to be far more tailored to the individual. However, while it can provide some useful information about a person’s risk of developing diabetes, it does not give the whole picture.
Steps to address type 2 diabetes modifiable risk factors
Sometimes it is possible to prevent or delay the onset of type 2 diabetes by:
- Reaching or maintaining a healthy weight—excess body fat increases your risk of developing type 2 diabetes.
- Eating a healthy diet.
- Doing regular physical activity.
Other ways to reduce type 2 diabetes risk are quitting smoking, drinking no alcohol (or moderate amounts), managing stress and making sure that you get proper sleep.
Treatment options for genetic diseases
New therapy options for treating genetic diseases are becoming available as a result of improvements in our understanding of genetics. These options include gene therapy and personalised medicine.
Gene therapy seeks to compensate for or correct genetic defects that cause disease. This may involve neutralising a damaging gene, replacing a defective gene with a healthy one or adding a new gene to fight the illness. Although it is in its early stages, gene therapy shows promise in treating illnesses like spinal muscular atrophy and some types of blindness.
Personalised medicine is where a person’s genetic information is used to create individualised medicinal treatment. Cancer treatment is increasingly using personalised medicine, where genetic analysis of tumours can direct the use of certain medicines.
Conclusion
The development of type 1 and type 2 diabetes are affected by genetic, environmental and lifestyle factors, but the level of influence of each of these differs for both types.
The Life! program can help you to tackle the modifiable factors that increase the risk of developing type 2 diabetes, as well as heart disease and stroke.
Life! is a free healthy lifestyle program that helps you improve your eating habits, increase your physical activity and manage stress. The program is for people who are at risk of developing type 2 diabetes, heart disease and stroke. If you are already living with diabetes, you are not eligible for the program, however there are other programs that can help you.
Life! is run by experienced health professionals, including dietitians and exercise physiologists, who guide and support you to make healthy lifestyle changes.
The program includes 7 sessions delivered over a 12-month period. You can choose from a group course or our telephone health coaching service. Learn more about the Life! program.
You can check your eligibility for the Life! program by taking a short online test here.
Sources
Diabetes: Australian Facts, Summary – Australian Institute of Health and Welfare, 2023
Diabetes Risk Factors – Centers for Disease Control and Prevention
Pre-eclampsia – Health Direct
Monogenic Diabetes: Symptoms, Diagnosis, Treatment – healthline
Earlier identification of people with type 2 diabetes (our position) – Diabetes UK
Genetic/genomic testing: defining the parameters for ethical, legal and social implications (ELSI) – BMC Medical Ethics
Genetics of Type 1 Diabetes – PubMed
Genetics of Type 2 Diabetes – PubMed
Health and Economic Benefits of Diabetes Interventions – Power of Prevention
