What Is Hyperinsulinemia?

Hyperinsulinemia is an condition that indicates that there are alterations in our body related to blood sugar control. These alterations are potentially dangerous for our health.

Written and verified by the doctor Leonardo Biolatto.

Last update: 12 July, 2023

Insulin is a very important hormone in our body, since it regulates the amount of sugar in the blood and in the tissues so that they can perform their different functions. However, when we find high insulin in the blood, we may be dealing with hyperinsulinemia.

Normally, the effect of the lack of insulin in our body, or hypoinsulinemia, is well known since it occurs in people with type 1 diabetes. However, there’s a common lack of recognition of hyperinsulinemia as a condition, which makes it difficult to diagnose. Therefore, in this article, we’ll explain what hyperinsulinemia is and what causes it.

What is insulin?

Before explaining what hyperinsulinemia is, we’ll first take a look at the function of insulin. Insulin is a hormone synthesized and stored by the beta cells of the pancreas.

After eating, our food is broken down into minute substances capable of passing through the intestine into the blood. One of these substances is glucose, which is the fundamental sugar used by our body to produce energy and carry out its functions.

When glucose reaches the blood, it passes through the pancreas, activating the beta cells that release the stored insulin. This insulin passes into the blood and directs the glucose to the tissues so that it can be used. In other words, insulin is responsible for maintaining correct blood glucose levels.

Blood glucose levels, or glycemia

Normal fasting blood glucose levels are between 70-110 mg/dl. If blood glucose is too high or too low, it can cause serious health problems. Abnormal glucose levels are known as:

• Hyperglycemia: Abnormally high blood glucose values
• Hypoglycemia: Abnormally low blood glucose values

What is hyperinsulinemia?

In reality, there’s no concrete definition of hyperinsulinemia. It’s usually described as more insulin than normal in the blood. The causes are diverse, and we’ll explain the most common ones below:

Insulin resistance

Insulin resistance is a condition that has gained momentum in recent years, given the increase in people suffering from type 2 diabetes.

When there’s no good sugar control in the body for years, insulin increases to carry this excess sugar to the tissues and maintain stable blood levels. However, when this happens, our bodies become accustomed to using higher amounts of insulin. Therefore, they won’t respond to smaller amounts, which will create resistance.

To compensate for the resistance, the body will generate more insulin that will be circulating in the blood. We will then have hyperinsulinemia with hyperglycemia.

Insulin-producing tumors

A less frequent cause of hyperinsulinemia is insulin-producing tumors, also called insulinomas. Insulinomas are difficult to diagnose because they’re very small and difficult to see on imaging tests. Approximately 10% of insulinomas are malignant.

These are tumors derived from the beta cells of the pancreas that produce and release a lot of insulin into the blood. This hyperinsulinemia causes all the glucose to be carried to the tissues, and there’s no glucose left in the blood, which is when hypoglycemia occurs.

Hypoglycemia is a serious situation. It can give many symptoms, such as the following (among others):

• Nervousness
• Tremors
• Palpitations
• Sweating
• Irritability
• Hunger
• Pallor

If the hypoglycemia is very marked, it can even affect the brain, which is the consumer par excellence of glucose, and it can cause alterations such as:

• Headaches
• Blurred vision
• Paresthesias (a type of tingling that’s usually in the extremities)
• Behavioral alterations
• Confusion
• Convulsions
• A loss of memory
• Coma and, in the worst case, death

Therefore, if it’s a tumor, it must be removed to avoid these symptoms. In addition, insulin is also a growth factor that can cause a person to gain weight.

The location of the insulinoma is usually the pancreas, but some people may have pieces of the pancreas that aren’t in their usual position, which is called an ectopic pancreas; this makes the diagnosis more difficult. Fortunately, insulinomas are rare in the general population.

External insulin

Another cause of hyperinsulinemia can be because insulin has been injected externally. This can happen in two cases:

• A person with diabetes who, by mistake, injects more insulin than is needed. This causes hypoglycemia, which, as explained above, is a very serious condition.
• Factitious hypoglycemia: In this case, the person self-injects insulin without having diabetes. This occurs in the case of the well-known Munchausen’s syndrome, in which the person self-medicates or injures him/herself in order to appear ill.

In both cases, we would find low blood glucose levels with high insulin levels, but this insulin is not the one produced by the body and is instead external.

Important clues to detect hyperinsulinemia

If you have hyperinsulinemia, this is most often due to a case of insulin resistance, which implies that you likely have a lot of sugar in your blood. This type of hyperglycemia is dangerous because it will cause diabetes and damage to your cardiovascular system. In addition, as we’ve said before, insulin is a growth factor and favors the growth of tumors.

Therefore, you must control your blood sugar and lead a healthy life. If there’s no good sugar control in your diet, your doctor will recommend certain treatments to control it. On the other hand, if you have symptoms of hypoglycemia, you should also see a doctor because of its seriousness.