What Causes Secondary Diabetes?

Secondary diabetes refers to glucose intolerance. "Glucose intolerance" is a term for health disorders that cause high blood sugar. In some instances, this condition can be caused by other medical problems. Secondary diabetes differs in some ways from other types of diabetes, but it still requires you to control your blood sugar and make lifestyle changes.

This article discusses the various causes of secondary diabetes and how they are managed. 

Secondary Diabetes vs. Type 2 Diabetes

Secondary diabetes (type 3C) and type 2 diabetes may present with the same symptoms. However, the two are not the same. Type 2 diabetes is caused by a problem with how the body utilizes insulin, a hormone created by the pancreas. Insulin converts sugar to energy in the body.

Once cells become resistant to insulin, the pancreas cannot make enough insulin. These issues typically result from lifestyle factors such as obesity, a lack of exercise, or an unhealthy diet.

Secondary diabetes, on the other hand, doesn’t develop because of an issue with insulin but rather because of other disorders that affect the endocrine system. In addition, secondary diabetes can result from problems with medication use, hormonal disorders, and genetic syndromes.

Pancreatic Disorders

Since the pancreas is in charge of insulin production, disorders that affect how it works can cause issues with blood sugar and, thus, lead to secondary diabetes. The two most common pancreatic disorders associated with secondary diabetes are chronic pancreatitis, which is long-term inflammation of the pancreas, and pancreatic cancer.

Hormonal Disorders

Hormonal disorders, or endocrine disorders, can arise when the glands that produce or release hormones are compromised. Several types of hormone disorders can lead to secondary diabetes, including:

• Acromegaly: This disorder arises when the body produces growth hormone in excess.
• Cushing’s syndrome: Cushing’s syndrome develops when cortisol, the stress hormone, is produced in dangerously high amounts in the body.
• Pheochromocytoma: This is a type of tumor that releases its own hormones, disrupting the balance in the body. 
• Hyperthyroidism and hypothyroidism: Hyperthyroidism and hypothyroidism are conditions that arise when the thyroid glands produce too much (hyper) or too little (hypo) of thyroid hormones.
• Glucagonoma: These tumors develop in the cells of the pancreas that produce glucagon, which helps the liver break down glucose, or sugar. 
• Somatostatinoma: This type of tumor produces excessive amounts of the hormone somatostatin, which helps to regulate the entire endocrine system.

Medications

Otherwise known as drug-induced diabetes, secondary diabetes can occur after taking drugs from certain medication classes, including:

• Corticosteroids
• Thiazide diuretics
• Beta-blockers
• Antipsychotics
• Statins

Other Conditions

Some genetic syndromes may lead to secondary diabetes because they cause severe insulin resistance. Genetic syndromes are the result of mutations in specific genes. Genes are instruction manuals that provide the body with the information it needs to produce particular proteins.

The information encoded in genes determines characteristics, physical traits, and how each person's body functions. A person gets two copies of every gene, one from each of their parents.

Gene mutations change the information encoded in the DNA and, thus, can lead to changes in how the body functions. In some cases, it leads to illnesses.

Some genetic syndromes connected to secondary diabetes include:

• Cystic fibrosis (inherited condition causing extreme damage to the lungs and other organs)
• Rabson-Mendenhall syndrome (extremely rare genetic condition causing severe insulin resistance)
• Type A insulin-resistant syndrome (rare genetic condition causing severe insulin resistance)
• Congenital lipodystrophic diabetes (rare, severe genetic disorder causing early-onset diabetes)
• Wolfram syndrome (inherited disorder causing early-onset insulin-dependent diabetes)

The genes that play a role in the function of the pancreatic cells are associated with the onset of secondary diabetes, In these illnesses, they can lead to insulin resistance, insufficient production of insulin, or a defect in how insulin is converted from proinsulin, a building block for insulin.

Treatments

The treatments for secondary diabetes may vary depending on the cause. For drug-induced diabetes, stopping the drug may reverse if the medication is only used short-term.

In cases of permanent secondary diabetes, medications must be taken to help the body control glucose levels in the blood. One common drug used to treat diabetes is Glucophage (metformin). Metformin makes cells more sensitive to insulin, thus, allowing them to pick up the glucose in the blood more easily.

That said, insulin therapy is often the first treatment for people with secondary diabetes, especially those with endocrine disorders and cystic fibrosis. 

Lifestyle changes may also need to be made to help address high blood sugar caused by secondary diabetes, including

• Avoiding smoking and alcohol consumption
• Doing moderate exercise
• Eating a diet that is high in fiber, low in fat, and contains high levels of nutrients

Summary

A variety of health disorders cause secondary diabetes. Some of the most common causes of secondary diabetes are pancreatic disorders and other conditions that affect the endocrine system. In some cases, medications can induce diabetes. In others, genetic syndromes may play a role in developing secondary diabetes.

While the symptoms and effects of secondary diabetes are the same as other types of the disease, they are not the same because secondary diabetes is brought on by another disorder and doesn’t develop as a primary condition. Treatment for this condition varies depending on what caused it. In some cases, it can be permanent, and you must manage your symptoms and blood sugar levels for the rest of your life.

A Word From Verywell

Having to cope with one chronic disorder and then having another one develop isn't easy. That said, when secondary diabetes is managed effectively, it can be a lot easier to live with.

If you have been recently diagnosed with secondary diabetes, talk to your healthcare provider about all your options and what you can do to manage it in the best way possible. Doing so will ensure that your quality of life isn't compromised further, and you can continue to enjoy your life as you have been.