Several factors have to come together for a person to develop type 2 diabetes. Elements like nutrition and exercise are extremely important. However, type 2 diabetes also has a strong hereditary component.
If you have recently been diagnosed with type 2 diabetes, look around. There is a good chance that you’re not the first person with diabetes in your family. According to the American Diabetes Association, your risk of developing type 2 diabetes is:
- one in seven, if one of your parents was diagnosed before the age of 50
- one in 13, if one of your parents was diagnosed after the age of 50
- one in two, if both your parents have diabetes
However, not all of your type 2 diabetes risk is genetic. Major risk factors for type 2 diabetes also include obesity and a sedentary lifestyle.
That said, several gene mutations have been associated with type 2 diabetes risk. None of these genes cause diabetes on their own. Instead, they interact with environmental factors — for instance, toxins, viruses, and foods — and each other to increase your risk.
Type 2 diabetes is caused by both genetic and environmental factors. Understanding the role of genetics requires looking at other factors as well.
Scientists have linked several gene mutations to a higher diabetes risk. Not everyone who carries a mutation will get diabetes. However, many people with diabetes have one or more of these mutations.
Lifestyle and Family Inheritance
It can be difficult to separate lifestyle risk from genetic risk. Lifestyle choices tend to run in the family. Sedentary parents tend to have sedentary children. Parents with unhealthy eating habits are likely to pass them on to the next generation. On the other hand, genetics play a big part in determining weight. Sometimes behaviors can’t take all the blame.
Studies of twins have shown that type 2 diabetes might be influenced by genetics, according to the American Diabetes Association. However, these studies were complicated by the environmental influences that also affect type 2 diabetes risk.
Still, scientists have persevered. To date, numerous mutations have been shown to affect type 2 diabetes risk. The contribution of each gene is generally small. However, each additional mutation you have seems to increase your risk.
In general, mutations in any gene involved in glucose regulation can affect your risk of type 2 diabetes. These include genes that control:
- production of glucose
- production of insulin
- how glucose levels are sensed in the body
- regulation of insulin
Genes that have been associated with type 2 diabetes risk include:
- TCF7L2, which affects insulin secretion and glucose production
- the sulfonylurea urea receptor (ABCC8), which helps regulate insulin
- calpain 10, which is associated with type 2 diabetes risk in Mexican Americans
- glucose transporter 2 (GLUT2), which helps move glucose into the pancreas
- the glucagon receptor (GCGR), a glucagon hormone involved in glucose regulation
Tests are available for some of the gene mutations associated with type 2 diabetes. However, the risk increase for any given mutation is small. Other factors are far more accurate predictors of whether you’ll develop type 2 diabetes, including:
- body mass index (BMI)
- family history
- high blood pressure
- elevated triglycerides and cholesterol levels
- history of gestational diabetes
Focusing on Prevention
The interactions between genetics and the environment make it hard to get a handle on the true cause of type 2 diabetes. That doesn’t mean you can’t reduce your risk. Strong evidence supports the fact that behavioral changes can reduce your risk of developing type 2 diabetes.
The Diabetes Prevention Program study, a large study of people at high risk for diabetes, suggested that weight loss and increased physical activity can prevent or delay type 2 diabetes. Blood glucose levels return to normal levels in some cases. Similar results have been found in other international studies.