What Is LADA (Latent Autoimmune Diabetes in Adults)?

You may not have heard of LADA (latent autoimmune diabetes in adults), but this slow, progressive form of diabetes is likely more common than the better-known type 1 diabetes. Because LADA symptoms and features overlap with both type 1 and type 2 diabetes, experts are still trying to determine if LADA is a distinct subtype of diabetes, or if it falls on a continuum between types 1 and 2. In fact, sometimes physicians refer to LADA as type 1.5 diabetes.

Types of Diabetes

In healthy people, beta cells in the pancreas produce the hormone insulin and release it into the blood stream. Insulin enables glucose (blood sugar), the body’s primary source of energy, to enter cells. If the beta cells don’t produce enough insulin (as with type 1 diabetes), or the body doesn’t respond well to the insulin (as with type 2 diabetes), then glucose gradually builds up in the blood stream. Eventually, diabetes may damage nerves and blood vessels.

With type 1 diabetes, the immune system mistakenly perceives beta cells to be a foreign or potentially harmful substance (an antigen), so it develops antibodies, proteins that attack and destroy beta cells. As Amber Taylor, MD, Director of The Diabetes Center at Mercy Medical Center in Baltimore says, "Type 1 diabetes is autoimmune," and by the time individuals with type 1 diabetes are diagnosed, the immune system has destroyed most of their beta cells and they immediately need insulin treatment.

Patients with type 2 diabetes do not have antibodies in their blood. Type 2 diabetes develops as a result of both genetic and lifestyle factors—many type 2 patients are overweight or obese, and tend to be middle-aged or older.

LADA symptoms overlap with those of type 1 (patients have antibodies in the blood) and type 2 (patients are older when symptoms appear) diabetes. LADA patients may be told they have type 2 diabetes; in fact, "as many as 10 percent of people diagnosed with type 2 diabetes have LADA," according to the National Diabetes Information Clearinghouse.

Diagnosing LADA

The general symptoms of all types of diabetes include frequent urination, extreme hunger or thirst, fatigue, and irritability. If you experience these symptoms, see your physician to rule out diabetes.

According to Taylor, physicians use certain "nudge factors" to distinguish LADA from other forms of diabetes.

Unlike people with type 1 diabetes, LADA patients:

  • Are usually 30 or older when diagnosed; type 1 patients tend to be younger.
  • May not need for insulin within six months of diagnosis.

Unlike patients with type 2 diabetes, LADA patients:

  • Have antibodies in the blood.
  • Have a more rapid decline in insulin levels than usual in patients with type 2. Taylor says if a patient with a diagnosis of type 2 diabetes is progressing more quickly than expected, it might prompt a physician to test for LADA.

Testing for antibodies is important; LADA patients who’ve been misdiagnosed with type 2 diabetes may begin treatment with ineffective oral medications, and their remaining beta cells quickly lose their ability to produce insulin.

Treating LADA

Like those with type 2 diabetes, people with LADA can often manage the disease with diet, exercise, and weight loss (if needed), at least initially. Eventually, they will need insulin.

There is no single optimal treatment for LADA. Early insulin treatment may help beta cells produce insulin longer, but Taylor says the jury is still out on this.

Amber Taylor, MD, reviewed this article.


Sources

Interview with Amber Taylor, MD, Mercy Medical Center, Baltimore.

Maria J. Redondo, "LADA: Time for a New Definition." Diabetes 62, (2013): 339-340, accessed July 8, 2014.  

M. Regina Castro, MD. "Diseases and Conditions: Type 1 Diabetes." Mayo Clinic. August 14, 2013, accessed July 8, 2014.

Erika Gebel, PhD. "The Other Diabetes: LADA, or Type 1.5." Diabetes Forecast. May 2010, accessed July 8, 2014. 

Christy L. Parkin, MSN, RN, CDE, "LADA, the Other Diabetes, Can Be Hard to Spot." Diabetes Forecast. February 2013, accessed July 8, 2014. 

Roma Lightsey, RN, BSN. "Diagnosis and Treatment of Latent Autoimmune Diabetes in Adults Still Evolving." Clinical Advisor. May 23, 2011, accessed July 8, 2014. 

"Causes of Diabetes." June 2014, accessed July 8, 2014. National Diabetes Information Clearinghouse. June 2014. 

"Type 1 Diabetes." MedlinePlus. Page updated May 14, 2014. 

Richelle J. Koopman, Arch G. Mainous, III, Vanessa A. Diaz, and Mark E. Geesey. "Changes in Age at Diagnosis of Type 2 Diabetes Mellitus in the United States, 1988 to 2000." Ann Fam Med. Jan 2005; 3(1): 60–63.