Could You Have Been Misdiagnosed With Type 2 Diabetes?

You're doing everything right and your type 2 diabetes treatment still isn’t working. If you don't actually have the condition, you could face serious complications.

by Mary Shomon Patient Advocate

Along with a diabetes diagnosis, which more than 30 million Americans have received, comes symptoms to manage, diet changes to make, and exercise to fit into your schedule. You may also need medications to lower your blood sugar or increase insulin sensitivity. But sometimes you can do everything you're supposed to do and still not improve. What then? Maybe you don't have what they think you have.

In fact, two recent studies show that being diagnosed with the wrong type of diabetes is not so uncommon. In fact, researchers have found that a significant percentage of the millions of Americans diagnosed with type 2—the most common type—have been misdiagnosed. If you’re one of them, it could mean that you have received the wrong treatments and may face an increased risk of serious complications. If you’re not responding to type 2 diabetes treatment, or if you have unexplained symptoms, it’s time for a second opinion and a new plan.

The Different Types of Diabetes

The American Diabetes Association (ADA) classifies four subgroups of diabetes:

Type 1 diabetes, is due to autoimmune b-cell destruction, usually leading to absolute
insulin deficiency. In children, it’s called “juvenile diabetes.” When diagnosed in adults, it’s called latent autoimmune diabetes in adults (LADA), or sometimes type 1.5 or maturity onset diabetes of the young (MODY).

Type 2 diabetes, the most common type, is a progressive loss of b-cell insulin secretion frequently on the background of insulin resistance.

Gestational diabetes mellitus diabetes (GDM), is diagnosed in the second or third trimester of pregnancy that was not clearly overt diabetes prior to gestation.

All “other specific types” of diabetes due to other causes such as monogenic diabetes syndromes (neonatal diabetes and maturity-onset diabetes of the young (MODY), diseases of the exocrine pancreas (cystic fibrosis and pancreatitis), and drug- or chemical-induced diabetes (glucocorticoid use, in the treatment of HIV/AIDS, or after organ transplantation).

The types of diabetes that are increasingly misdiagnosed as type 2 diabetes are LADA and diabetes of the exocrine pancreas.

The 411 on Latent Autoimmune Diabetes of Adults (LADA)

Latent autoimmune diabetes of adults (LADA) has characteristics of both type 1 and type 2 diabetes, which is why it is sometimes called “type 1.5” diabetes.

Like juvenile diabetes, LADA patients have antibodies that destroy pancreatic beta cells. Unlike type 1, LADA typically develops slowly and is diagnosed in adults.

Like type 2 diabetes, LADA can involve insulin resistance—an impaired ability to respond to your body’s insulin. But unlike type 2, LADA usually requires insulin treatment after several years.

About 10% to 15% of adults with LADA are misdiagnosed with type 2 diabetes, researchers report. This number grows to 25 percent when you include those under the age of 35 who are diagnosed with type 2 diabetes. And some experts believe that as many as half of those who are underweight or at a healthy weight when diagnosed with type 2 may actually have LADA.

Specifically, misdiagnosis of LADA is high because the condition is far less common than type 2 diabetes, and both the adult-onset and the increasing rates of obesity in general make it harder to distinguish between the two.

One prominent example was former British Prime Minister Theresa May. She was first diagnosed and treated for type 2 diabetes in her 50s, when she was overweight. Several years later, after a period of rapid weight loss, she learned that she had LADA and needed insulin treatment. Said May, “My very first reaction was that it’s impossible because at my age you don’t get [juvenile diabetes]."

Could You Have LADA?

There are four key signs that you may have LADA and not type 2 diabetes:

  • You are underweight or normal weight.

  • You are unable to manage your blood-sugar levels effectively with type 2 diabetes medications along with lifestyle, diet, and exercise interventions.

  • You progressed quickly to insulin treatment for your type 2 diabetes. One study found that 47 percent of LADA patients required insulin within three years of their initial type 2 misdiagnosis, compared to fewer than 5 percent with type 2 diabetes.)

  • You already have a personal or family history of autoimmune disease.

Sofia Carlsson, Ph.D. is a professor of medicine at Karolinska Institute in Sweden, and a renowned researcher on LADA. According to Dr. Carlsson, diagnosis of LADA requires a fasting C-peptide test. This can show whether you are secreting enough insulin. In addition, the glutamic acid decarboxylase antibodies (GADA) test is important. Says Dr. Carlsson: “This antibody is far more common in patients with adult-onset autoimmune diabetes.”

Treating LADA

The current guidelines recommend treating LADA with type 2 diabetes drugs and dietary recommendations for the first six months after diagnosis. The only type 2 diabetes drugs that are not generally recommended in LADA patients are sulfonylureas, which can damage beta cells and worsen glucose control in LADA patients. Chlorpropamide (Diabinese), glimepiride (Amaryl), glyburide (Glynase), glipizide (Glucotrol), glyburide (DiaBeta), glipizide (GlipiZIDE), and tolazamide (Tolinase) are sulfonylurea drugs.

Even with drug treatment, the destruction of pancreatic beta cells impairs the ability to produce insulin, and most LADA patients require insulin therapy within five years of their initial diagnosis.

According to Silvia Pieralice, M.D., and Paolo Pozzilli, M.D., of the Department of Endocrinology and Diabetes at the University Campus Bio-Medico, in Rome, “Due to misdiagnosis, [LADA] patients are often treated with therapies commonly used in type 2 diabetes.” He explains, “That might further worsen the autoimmune process and accelerate beta cell loss, which can lead to a faster progression toward insulin dependency.” It’s recommended that insulin therapy be considered as early as possible in LADA patients.

The 411 on Diabetes of the Exocrine Pancreas

Diabetes of the exocrine pancreas is not autoimmune. Instead, it develops after disease or surgery has damaged pancreatic function. The most common cause of pancreatic damage is chronic or acute pancreatitis. Other causes include pancreatic cancer, pancreatic surgery, and two diseases that can impair your pancreas: hemochromatosis and cystic fibrosis.

According to recent research, diabetes of the exocrine pancreas is more common than type 1 diabetes and makes up from five to 10 percent of all cases of diabetes. The challenge is that most patients with the condition have been misdiagnosed. According to a study recently published in the American Diabetes Association’s journal, Diabetes Care, “It’s estimated that diabetes of the exocrine pancreas is misdiagnosed as type 2 in almost 88 percent of patients. Less than 3 percent of patients get a correct first diagnosis. ”Another study found that 40 percent of a study group of patients hospitalized for diabetes of the exocrine pancreas were originally misdiagnosed with type 2 diabetes.

Why is there such a high rate of misdiagnosis? Simon de Lusignan, M.D., one of the authors of the Diabetes Care study, and a professor at Oxford University, says, “In the early clinical phases, the conditions can be indistinguishable. After a period of time, however, the insulin production failure will become more evident.” According to Dr. de Lusignan, there have also been advances in diagnostic and radiologic tests to help pinpoint the causes of diabetes, and better diagnose pancreatic conditions.

Diabetes of the exocrine pancreas differs from other types of diabetes in several clinical ways:

  • The diabetes diagnosis comes after pancreatic disease or pancreatic surgery.

  • Patients have a high degree of insulin resistance.

  • Patients experience more frequent, severe, and erratic swings between high blood sugar (hyperglycemia) and low blood sugar (hypoglycemia).

  • Up to 46 percent of patients require insulin within 5 years, compared to less than 5 percent with type 2 diabetes.

Could You Have Diabetes of the Exocrine Pancreas?

If you have diabetes of the exocrine pancreas, the common signs and symptoms include:

  • Diet, exercise, and drugs are ineffective at lowering and managing your blood sugar.

  • Your doctor has accused you of being “non-compliant” because treatment isn’t working.

  • You have frequent, erratic, or severe episodes of high and/or low blood sugar.

  • You experience diarrhea, gas, bloating, or steatorrhea—greasy stools that are bulky, oily, and may be foul-smelling.

According to Dr. de Lusignan, diagnosis requires a detailed and relevant medical and medication history and examination, including discussion of any pancreatic conditions or surgeries. Tests for pancreatic function–including fecal elastase and amylase—are also helpful. And, says Dr. de Lusignan: “Measurement of C-peptide and autoimmune antibodies can help distinguish Type 1 diabetes from Type 3c diabetes.”

In their journal article, Dr. de Lusignan and his co-authors also made a critical point: Clinicians must ask every patient diagnosed with type 2 diabetes about their history of pancreatic disease, ideally when first diagnosed.

Treating Diabetes of the Exocrine Pancreas

Treatment of diabetes should ideally be personalized to each patient’s situation, says Dr. de Lusignan. For example, mild diabetes of the exocrine pancreas is typically treated like type 2 diabetes, with lifestyle changes and the drug metformin to improve insulin sensitivity.

Other type 2 diabetes drugs—including dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors), glucagon-like peptide 1 receptor agonists, thiazolidinediones (TZD drugs), and sulfonylureas — are less frequently recommended, because they pose various risks, including pancreatic cancer, low blood sugar, and weight loss.

Most patients need supplemental pancreatic enzymes to address deficiencies. Vitamin supplements are also needed, and researchers estimate that 90 percent of patients need extra vitamin D.

Dr. de Lusignan notes that because conditions like pancreatitis and cystic fibrosis can be involved, a personalized approach is best. Says Dr. de Lusignan: “Some cases may not progress, while others do require insulin earlier in treatment.”

Your Next Steps

Careful management of blood sugar and treatment of diabetes help reduce symptoms and lower your risk of serious diabetic complications, including heart disease, damage to your eyesight, neuropathy, and amputations. That means it’s crucial that you are not misdiagnosed.

In general, if you have a diagnosis of type 2 diabetes and your treatments aren’t working, or you develop new symptoms such as weight loss, excessive thirst, or digestive problems, it’s time to talk to your doctor to rule out the possibility that you may have LADA or diabetes of the exocrine pancreas.

If you have any history of pancreatic disease or surgery—but have not been diagnosed with diabetes—ensure that your doctor periodically checks you for diabetes. Also, make your doctor aware if you experience any of the common and lesser-known signs and symptoms of diabetes.

Make sure that the doctor treating your type 2 diabetes is fully aware of any pancreatic disease or pancreatic surgery in your medical history. It’s also worth ensuring that your doctor has evaluated you for—and ruled out—the possibility that you have diabetes of the exocrine pancreas.

Finally, if you are being newly diagnosed with type 2 diabetes and you’re not overweight, and/or you have a history of autoimmune disease, your doctor should rule out the possibility of LADA. Interestingly, while it’s controversial, some experts recommend that everyone with type 2 diabetes has antibody screening to detect LADA from the start.

Mary Shomon
Meet Our Writer
Mary Shomon

Mary Shomon is a patient advocate and New York Times bestselling author who empowers readers with information on thyroid and autoimmune disease, diabetes, weight loss and hormonal health from an integrative perspective. Mary has been a leading force advocating for more effective, patient-centered hormonal healthcare. Mary also co-stars in PBS’ Healthy Hormones TV series. Mary also serves on HealthCentral’s Health Advocates Advisory Board.