What causes Type 2 Diabetes?

What causes Type 2 Diabetes?

There are several causes behind getting type 2 diabetes.  The most common causes are lifestyle changes and heredity. Usually it takes both of these risk factors to develop insulin resistance, which is a state in which the cells of the body are resistant to the insulin normally produced by the pancreas.  When the cells become resistant, glucose isn’t taken up by the cells that must use other types of molecules for use as part of cellular metabolism.

Genetics and its Role in causing Type 2 Diabetes

Type 2 diabetes is partially caused by heredity.  If you have a first degree relative with type 2 diabetes, such as a parent, sibling, or child, you also have a higher risk for developing the disease.  The exact genes involved in the development of type 2 diabetes are unknown and there may be more than one gene that puts a person at risk for developing type 2 diabetes.  Research is ongoing as to which genes might be responsible for this disease.

Lifestyle Changes and their Role in causing Type 2 Diabetes

While genetics is believed to play a role in who gets diabetes and who doesn’t, a person’s lifestyle is also important in determining who gets the disease. It is possible to be genetically prone to getting type 2 diabetes and still not get the disease if you take care of your body.

If you eat a healthy diet, exercise regularly, have a low cholesterol level, maintain a normal weight, and eat foods low in sugar, you may never develop the disease.  If you eat unhealthy foods, fail to exercise, have certain conditions that predispose you to the disease, and become overweight, this may tip the scales toward having type 2 diabetes.

Things you need to avoid in order to prevent type 2 diabetes include the following:

  • Failing to exercise. There are many benefits to regular exercise.  It is recommended by the American Diabetic Association that you exercise at least 150 minutes per week in order to decrease the risk of having type 2 diabetes.
  • Eating processed and unhealthy foods. If you eat foods that come premade from the factory or foods that are high in sugar, fat, and calories, you will predispose yourself to developing type 2 diabetes.
  • Being obese or overweight. If you have a body mass index of greater than 25, you have an increased risk of developing type 2 diabetes. Your weight is directly impacted by the amount of calories you take in and the amount of exercise you get.

The Role of Insulin Resistance in Type 2 Diabetes

The mix of genetic factors and poor lifestyle choices may lead to insulin resistance, which is the real cause of type 2 diabetes.  In insulin resistance, the cells don’t use insulin well and the blood glucose cannot get into the cells for use as cellular fuel.  Instead, the glucose remains in the bloodstream and the blood glucose levels are higher.  This leads to the symptoms of type 2 diabetes and the need for treatment of the disease.

Insulin Resistance

When Insulin Resistance is Normal

It is possible to have normal insulin resistance and still have type 2 diabetes.  There is a type of type 2 diabetes that is the direct result of not making enough insulin to cover for the glucose needs.  Doctors don’t know why some people fail to make enough insulin other than the presence of pancreatic autoantibodies, which is seen in type 1 diabetes and an intermediate form of type 2 diabetes, known as diabetes type 1.5. More research needs to be done to determine why this occurs and how it causes type 2 diabetes.

Risk Factors for Type 2 Diabetes

There are many risk factors behind having type 2 diabetes.  The most common risk factors contributing to type 2 diabetes include the following:

  • Ethnicity. There are certain ethnic groups that seem to have a higher risk of having type 2 diabetes.  These include Hispanic Americans, Asian Americans, Native Americans, and African Americans.  The reasons behind this is not yet clear.
  • Family history. There may be hereditary reasons why a person can get type 2 diabetes.  If you have a first degree relative (parent, sibling, or child) with type 2 diabetes, your risk of developing the disease will be greater.  There are likely several genes that play into who gets diabetes and who doesn’t.
  • Age. As a person gets older, there is a greater chance of having type 2 diabetes. The risk for the disease increases after the age of 45 and really goes up after the age of 65.
  • Gestational diabetes. If you had gestational diabetes while you were pregnant, it puts you at a greater risk of developing type 2 diabetes later in life. The reasons behind this aren’t completely clear.
  • Polycystic ovarian syndrome (PCOS). Women who have polycystic ovarian syndrome also seem to have insulin resistance along with cysts on the ovaries.  This insulin resistance is the basis behind developing type 2 diabetes at some point in their lives.

It should be noted that when developing countries begin to take on a Western diet and have Western lifestyle choices, such as eating poor foods and exercising rarely, the risk of type 2 diabetes in these countries goes up.  For instance, in places like China, the risk of type 2 diabetes was once very low.  As their diet became more westernized and fewer people exercised, the rate of type 2 diabetes went up to levels approaching that in the Western world.  Industrialization seems to play a role in who gets diabetes and who doesn’t.

Typical American lifestyle choices seem to be the basic cause for developing type 2 diabetes.  These include eating too many calories, eating larger portions of food per meal, being overweight (having a BMR of more than 25), and failing to exercise regularly.  Regardless of ethnicity, if you follow this American lifestyle, you are at risk for developing type 2 diabetes, regardless of your ethnicity.

References:

  1. Type 2 diabetes causes. http://www.endocrineweb.com/conditions/type-2-diabetes/type-2-diabetes-causes. Accessed 5/16/16.
  2. Type 2 diabetes risk factors. http://www.endocrineweb.com/conditions/type-2-diabetes/type-2-diabetes-risk-factors. Accessed 5/16/16.