The Causes of Diabetes

causes of diabetesThe main causes of diabetes all come down to one or more metabolic disorders coming together to manifest diabetes.

The end result is when a person has increased levels of blood glucose (or blood sugar) due to inadequate production of insulin, or the body is not able to use the insulin it produces effectively.

I like to describe this as a lock and a key.

Think of a lock on a door that doesn’t work so well or is broken. Imagine trying to get into a door with this defective key. This is what is going on in the body.

The locks are the cells of your body, and insulin is the key that gets those cells of your body to open their doors and let glucose (sugar) – our body’s energy source, into them.

This leads to high blood sugar levels, and diabetes.

High blood sugar levels lead to heart disease, kidney disease, stroke, blindness and damage to blood vessels and nerve cells. As you can see and imagine, diabetes also increases susceptibility towards a whole host of many other diseases.

There are three types of diabetes that I am going to discuss here. They are Type 1, Type 2 and Gestational diabetes.

All of these types of diabetes have various causes as I will describe below.

Causes of Type 1 Diabetes

causes of type 1 diabetesType 1 diabetes develops when there is a lack of production of a sufficient amount of insulin in the body.

Type 1 diabetes presents much more dramatically in its onset than type 2 and gestational diabetes.

Type 1 diabetes is more common among Caucasians and usually, but not always, develops during childhood. Only 5%-10% of diabetic cases are type 1.

Here are the main causes of type 1 diabetes:

Genetic susceptibility

Family history of type 1 diabetes plays an important role in passing the disease to a person from their biological parents.

Genes carry information about formation of cells in a baby and their functioning, creating a pathway for diseases to pass on from parents to their children.

Destruction of Beta Cells

Beta cells are those cells in our body (the pancreas) that store the insulin that is produced, and released when needed.

Destruction of these cells leads to a decrease in the insulin needed to counteract glucose.

Autoimmune destruction of beta cells

Studies have shown that the body’s immune system attacks and damages its own beta cells in type 1 diabetes. When this happens a person is completely unable to produce more insulin and daily insulin injections are needed to survive.

Viral or bacterial infection

Viral and bacterial infections may cause type 1 diabetes by destroying beta cells. They may cause inflammation of the pancreas, which decreases its insulin-producing ability.

Causes of Type 2 Diabetes

causes of type 2 diabetesThis is the most common form of diabetes.

This type accounts for 90%-95% of the cases and is mainly caused due to the body’s resistance to the effects of insulin.

Type 2 diabetes risk tends to increase with age. Just about 1 in every 4 people over 65 in the US has type 2 diabetes and it is equally distributed between men and women.

Although some people with type 2 diabetes will eventually need insulin injections as treatment, they don’t have the absolute deficiency of producing the hormone insulin, as with type 1.

Over time the pancreas in type 2 diabetes can’t keep up with the insulin demands and it begins to produce less and less insulin. But even after many years, people with type 2 diabetes continue to make SOME insulin, which is why type 2 can be more greatly affected by lifestyle than type 1.

Type 2 diabetes is much more gradual in its onset than type 1. In fact, of the hundreds of doctors that I have worked with over the years, many of them have said that they diagnose many of their patients through a routine physical exam.

The main causes of type 2 diabetes are:

Family History

Heredity CAN be a key factor in developing type 2, but isn’t the only factor. A large number of the people whose biological parents suffered with type 2 diabetes will develop it at some point of their life.

In my opinion, while there can be a genetic component to it, similar to type 1, it’s not as much the case with type 2.

I’m a firm believer that we learn from what we see and more often than not, we tend to have similar lifestyle habits as our parents. So the lifestyle that leads to a person’s parents developing type 2 diabetes often doesn’t skip their children.

NOTE: Type 2 diabetes occurs about twice as often in African Americans, Native Americans, and in Hispanic Americans than in Caucasians.


Obesity is another cause of type 2. People with excess belly fat and who live sedentary (low activity) lifestyles are more likely to develop type 2 diabetes.

Obesity is also one of the main reasons why you now have so many young adults and teenagers developing type 2 diabetes.

Insulin Resistance

With type 2 diabetes the most common cause is insulin resistance. This means a person with type 2 diabetes can’t use insulin effectively, which also leads to decreased insulin production.

In a person with type 2 diabetes muscle, liver, and fat tissues are insulin resistant.

Beta Cell Dysfunction

High blood sugar levels damage the beta cells resulting in them not functioning properly. Various studies have found that this is a leading factor in developing type 2 diabetes.

Causes of Gestational Diabetes

Gestational diabetes develops in women during pregnancy and generally goes away after delivery. But in some cases it may continue and lead to type 2 diabetes in future. Gestational diabetes looks a lot like type 2 rather than type 1 in how it develops.

The thing to watch out for with gestational diabetes though, is in women who have gestational diabetes, 50% of them will go on to develop type 2 diabetes in 5-10 years.

Every year about 4% of pregnant women develop gestational diabetes.

Women who have a history of pre-diabetes, have babies who are large for their gestational age, and women at high risk for type 2 diabetes are at a higher risk of developing gestational diabetes.

The causes of gestational diabetes are:

Insulin resistance

During pregnancy insulin resistance leads to elevated blood sugar levels and the development of gestational diabetes, which can be a sign of underlying diabetes all along. Obese women are at a higher risk.

PCOS (polycystic ovarian syndrome)

A large number of women suffering from PCOS have insulin resistance, which results in increased risk of gestational diabetes during pregnancy.

Physiologic stresses during pregnancy

Other Causes of Diabetes

The other causes of diabetes include:

  • Glucagonoma: an imbalance between insulin and glucagon production in body.
  • Pancreatitis: inflammation of the pancreas.
  • Cushing’s syndrome– abnormally high cortisol levels.

Consequences of Diabetes

consequences of diabetesHere are some diabetes statistics:

  • Diabetes is the 7th leading cause of death in the US.
  • Nearly 200,000 deaths in the US are attributed yearly to diabetes and diabetes complications according to the ADA.
  • Diabetes is the 6th leading cause of death by disease in the US according to the ADA.

If you have diabetes you already know that diagnosis can be alarming or catch you off guard.  But all it really means is now you must shift your priorities in your life.

Now you must focus on: food intake, carbohydrate intake, serving size, calories, time between meals, alcohol consumption, cholesterol intake, regular exercise, medication regimens, home blood sugar monitoring, foot care, high blood sugar, and low blood sugar.

You must also be cautious about long-term complications of diabetes such as:

  • Retinopathy (damage to your eyes)
  • Nephropathy (damage to the kidneys)
  • Neuropathy (damage to nerve cells)
  • Increased risk to heart attacks and strokes
  • Tough treatment regimens that require you to self-manage yourself
  • Commitment to educating yourself
  • Supplies
  • Frequent visits to your health care team

You must also be able to handle the daily challenges of possible debilitating or incurable, chronic illnesses without letting it dominate your life.

This isn’t easy…

People with diabetes may also lose their jobs due to discrimination or complications.

In fact, commercial airline pilots, truck drivers, police officers, and bus drivers may be denied employment or removed from their position if their diabetes isn’t well controlled or they are on insulin.

People with diabetes may also lose their independence. According to the ADA, people with diabetes report 4 times more lost work days and 3 times more restricted activity days than individuals without diabetes.

At the end of the day, treatment for diabetes and managing your blood sugar levels can be complicated and stressful, which can affect your overall well-being. But it doesn’t have to be this way.

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