The World Health Organization estimates that around 422 million people live with some form of diabetes. According to a new study, many of those might be misdiagnosed with Type 2 diabetes when in fact they have a different form of the disease that researchers are now calling Type 3c.

You've probably heard of Type 1 and Type 2 diabetes. Type 1 is usually diagnosed in childhood and early adulthood. It occurs when the body does not produce its own insulin. In Type 2 diabetes, the pancreas either doesn't produce enough insulin to meet the body's needs or the body doesn't use that insulin effectively. Type 2 is typically diagnosed in adults and is often associated with obesity.

Health experts are now adding a new term to the group, Type 3 diabetes, recognizing a possible link between the condition and Alzheimer's disease. And to make matters more confusing, some have identified another type of diabetes — this one dubbed Type 3c — that may arise when damage or inflammation of the pancreas hinders the body's ability to produce insulin.

In a new study, published in Diabetes Journals, researchers found that only 3 percent of the 2 million diabetes patients sampled were correctly diagnosed with Type 3c, a misdiagnosis that may have led to incorrect treatment and a reduced likelihood of recovery for many.

When patients have Type 2 diabetes that can't be controlled by diet, doctors typically prescribe insulin to supplement the insulin produced by the pancreas. But with Type 3c diabetes, it's damage to the pancreas that has caused the reduction in supply. This means patients with this condition need insulin but also need supplements of the digestive enzymes and hormones that the pancreas produces that help the body digest and absorb nutrients from food.

More common than many expect

For the study, the research team sifted through the health records of the Royal College of General Practitioners Research and Surveillance Database, a system that contains health data for people of all ages from a sample of medical practices throughout England. Researchers looked for cases of diabetes that were diagnosed after a patient had been diagnosed with some level of pancreatic damage from pancreatitis, pancreatic cancer and tumors, or pancreatic surgery. While not all patients who have sustained pancreatic damage go on to develop diabetes, those that do typically have Type 3c diabetes and not Type 2.

According to this new data, researchers found that Type 3c is probably much more common than health experts realize — and in fact it may even be more widespread than Type 1 diabetes in adults. They also found that people with Type 3c were twice as likely to have problems controlling their diabetes than those with Type 2, further proof that treatment for Type 2 is not an effective way to control the Type 3c version of the condition.

Researchers hope that, armed with this new information, doctors will be more likely to recognize the signs that indicate a patient has Type 3c diabetes and thus do a better job of prescribing treatment options that will help these patients control their condition.