DO YOU HAVE AUTOIMMUNE DIABETES?

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WHY DO YOU NEED TO KNOW IF YOU HAVE DIABETES AUTOIMMUNITY?

Sonia Kumar (not her real name) a 38 year old mother of two young girls, spent seven frustrating months trying to get her blood sugar under control.She was recommended escalating doses of oral anti-diabetes medications. She was even accused of cheating on her diet!But none of this helped her! It took an astute physician (not me!) to test her for diabetes autoantibodies to find out that she actually had Type 1 Diabetes!

The diagnosis was missed because people often think that Type 1 Diabetes does not develop in adults.

WHAT IS DIABETES?

Diabetes is a group of metabolic diseases with high blood sugar (hyperglycaemia) as the common feature. The high blood sugar results from defects in insulin secretion, defects in insulin action or both. About 20 years ago diabetes was classified into Insulin Dependent (IDDM) or Juvenile and Non-Insulin Dependent (NIDDM) or Adult Onset Diabetes. However, in the last several years it has become apparent that the use of insulin or age at onset could not adequately explain the disease conditions and specify the best treatment plan. Therefore, there is an opinion amongst diabetes researchers that the time has come for a new classification of the disease.

Diabetes develops because of an interaction between genes and the environment. Our genes have not changed in thousands of years,but our environment has.To a great extent this explains the dramatic increase in diabetes over recent years. Some of the influences have originated in the intrauterine environment before a person is born!

Exposure to environmental toxins like BPA have also contributed to the recent epidemic of diabetes.

Developments in the field of precision medicine, ethnicity-specific data and big data along with patient-participatory research will change the management of diabetes for the better.

TYPES OF DIABETES:

(For a medically appropriate classification please check the American Diabetes Association website for “Etiologic classification of diabetes mellitus”).

  • Type 1 Diabetes
  • Type 2 Diabetes (Commonest)
  • Gestational Diabetes (GDM/Pregnancy Diabetes)
  • Maturity Onset Diabetes of the Young (MODY)♣
  • Latent Autoimmune Diabetes of the Adult(LADA)♣
  • Drug Induced Diabetes.♣
TYPE 1 DIABETES

High blood sugar resulting from an absolute deficiency of insulin secretion. Type 1 Diabetes may be

  • Autoimmune or
  • Idiopathic.

Autoimmune Diabetes occurs when the Insulin producing cells in the pancreas are destroyed by an autoimmune process. Autoimmune markers for Type 1 Diabetes, also called Diabetes-Associated Autoantibodies (DAA) are usually present in most of these patients.

Idiopathic—In a small percentage of patients there is Insulin deficiency but no autoimmunity.

Though absolute insulin deficiency is a hallmark of Type 1 Diabetes, about 30 % of people with this condition have insulin resistance as well.

DIABETESASSOCIATED AUTOANTIBODIES (DAA):

  • Glutamic Acid Decarboxylase Autoantibodies (GAD65 or Anti-GAD)
  • Insulin Autoantibodies (IAA)
  • Insulinoma-Associated-2 Autoantibodies (IA-2A)
  • Islet Cell Cytoplasmic Autoantibodies (ICA)
  • Zinc Transporter 8 (ZnT8Ab) Autoantibodies
GESTATIONAL DIABETES (GDM or PREGNANCY DIABETES)

GDM is defined as any degree of glucose intolerance that was first recognized during pregnancy. This definition would include women who had previously undiagnosed Type 2 Diabetes and also those women who developed diabetes for the first time during pregnancy.Asian Indian women are at a very high risk for pregnancy diabetes. Therefore it is very important for them to be screened at the beginning , during mid-trimester as well as in the last trimester.

GDM raises the risk of several complications in both the mother as well the baby. Increased birth defects, increased birth weight, early (preterm) delivery are some of the risks in the babies born of mothers with GDM. The mother is at increased risk of pregnancy high blood pressure and pre-eclampsia and is at a higher risk for developing diabetes later in life. In addition, she is at increased risk for heart disease even if she does not develop diabetes later on in life!

TYPE 2 DIABETES

This is the commonest type of diabetes.Type 2 diabetes includes individuals who have insulin resistance and usually relative insulin deficiency. These individuals may not need insulin treatment to survive. However, use of insulin does not decide the type of the disease. Diabetes Associated Autoantibodies are absent in people with Type 2 Diabetes.

HOW DOES THIS AFFECT YOU?

It is important to keep in mind that adults can develop autoimmune diabetes too! British Prime Minister Theresa May, who was diagnosed with Type 1 Diabetes at age 56 and Sonia Kumar mentioned above were both initially diagnosed as Type 2 Diabetics. However both of them needed insulin therapy to control their blood sugar levels,when they were found to have Diabetes Antibodies.

Sulfonylurea (SU) drugs like chlorpropamide,glyburide,glipizide which work by stimulating the pancreas to release more insulin, are not the right drugs for these people.Use of these drugs in patients with diabetes autoimmunity have shown poor metabolic control and earlier loss of insulin producing beta cells in the pancreas.

A study in apparent long-standing type 2 diabetes found that those with Diabetes Associated Autoantibodies or with low C-peptide did not respond well to glucagon-like peptide 1 (GLP-1) agonist drugs like Liraglutide,Exenatide etc.

People with one autoimmune condition are at a higher risk for other autoimmune conditions as well. Diabetes Autoimmunity has often been associated with thyroid autoimmunity.

NUMBERS TO KNOW

If you have diabetes you obviously know your blood sugar and glycated haemoglobin (HbA1C) levels. In addition the following tests are important for the right treatment:

  • Diabetes Associated Autoantibodies (DAA)
  • C-Peptide ♣ :This  test can indicate how much insulin your body is producing.

(♣ Separate blog posts on these topics later.)

As Dr. Elliott P. Joslin, (who was the first doctor in the United States to specialize in diabetes and the founder of Joslin Diabetes Center) wrote “ . . . unless the physician takes care, he will fall into schematic ways and forget that it is the patient who comes for treatment and not the diabetes. Each is a case unto itself.” 

 

REFERENCES

Mohan V, Usha S, Uma R. Screening for gestational diabetes in India: Where do we stand? Journal of Postgraduate Medicine. 2015;61(3):151-154. doi:10.4103/0022-3859.159302.
Goueslard, Karine, et al. "Early cardiovascular events in women with a history of gestational diabetes mellitus." Cardiovascular diabetology 15.1 (2016): 15.
Leslie, R. David, et al. "Diabetes at the crossroads: relevance of disease classification to pathophysiology and treatment." Diabetologia 59.1 (2016): 13-20.
Brophy S, Davies H, Mannan S, Brunt H, Williams R. Interventions for latent autoimmune diabetes (LADA) in adults. Cochrane Database of Systematic Reviews 2011, Issue 9. Art. No.: CD006165. DOI: 10.1002/14651858.CD006165.pub3.