Here we bring to you a popular article and video from our archives by Dr. V Mohan on 'Precision Diabetes'.

We all know the adage “One size doesn’t fit all” and the practical implications for this. Same is true for the treatment and management of the very common chronic condition- diabetes.

The diagnosis and treatment of diabetes has evolved rapidly in recent times. Till the 1980’s, it was considered that there were only two types of diabetes: insulin dependent (now called type 1) , or non-insulin dependent (now called type 2), diabetes. With refinements in technology and advances in genomics and other fields, we now know that there are at least 20 types of diabetes. The diagnosis of each one of these types is based on certain tests which will help the diabetologist to clinch the diagnosis. The advantage of knowing which type of diabetes one has, is that the treatment can be tailored accordingly. For eg., in patients with type 1 diabetes, if insulin injections are withdrawn, the patient may die or at the very least, become very severely ill.

On the other hand, the ‘common garden’ variety of type 2 diabetes is a condition where the body usually produces insulin but the main defect is insulin ‘resistance’ i.e. the insulin fails to act properly. Thus in many cases of type 2 diabetes, the tablets may work even better than insulin! However, in addition to these two well known types, there are other forms of diabetes. One instance in point, is the ‘monogenic’ form of diabetes where there is a single gene defect. The commonest of this variety of diabetes, is called as Maturity Onset Diabetes of Youth (MODY). The main defect in MODY, is ‘insulin secretion’ and not insulin resistance. It is now known that there are at least 14 different types of MODY itself. Several types of MODY like MODY 3, MODY 1, MODY 11 and MODY 12 respond much better to ‘sulphonylurea’ tablets which correct the defect in insulin secretion. In contrast, metformin is the drug of choice for ‘type 2 diabetes’ as it corrects insulin resistance. All this underscores the importance of making an accurate diagnosis of the type of diabetes one has.

Dr. V Mohan speaks

"There are many instances where patients are unfortunately wrongly diagnosed to have type1 diabetes. "

"I recall a 16 year old girl who was lean and had severe diabetes and was therefore diagnosed by her physician to have type 1 diabetes and was told that she has to take four injections of insulin all her life. Devasted, the family came for a second opinion. When I reviewed her history I saw that she had a strong family history of diabetes going through four generations. She also had good pancreatic beta cell function. On further investigations, it was found that the markers for type 1 diabetes like GAD antibody test were negative. Encouraged by this,  genetic testing for MODY was carried out and it revealed that she had MODY 3, a form of diabetes which responds to the common sulphonylurea tablets. The insulin injections were therefore stopped and she ws put on Glibenclamide, one of the cheapest anti-diabetic drugs and she responded beautifully. It was later found that her younger sister also had MODY 3, as did her mother and several other members in her family and they could all be switched over to the sulphonylurea tablets. If the genetic testing had not been done for this patient, she would probably have been continued on life long insulin therapy."

"This is one example of ‘Precision Diabetes’. There are several such miracles which have happened in treating diabetes, thanks to the introduction of Precision Diabetes."

Fibrocalculous Pancreatic Diabetes (FCPD) is yet another type of diabetes where calculi (stones) develop in the pancreas. This type of diabetes apart from requiring insulin, also require pancreatic enzyme replacement as therapy because these patients develop indigestion, malabsorption and diarrhoea because the ‘exocrine’ part of the pancreas which is involved in digestion, is also affected along with the endocrine part of the pancreas (which is responsible for diabetes). There are many other types of diabetes such as genetic syndromes associated with diabetes, endocrine diabetes, and others.Over the last several years, Dr. Mohan and his team have developed algorithms by which a precise diagnosis of diabetes can be made. These are examples of “Precision Diabetes”. They will now be undertaking a major research collaboration with the of Dundee at Scotland with Prof. Colin Palmer, and his team to delve deep into the field of ‘pharmacogenomics’ of diabetes’.

Dr. V Mohan explains,

"What this means is that by studying genes, we can hopefully, predict which patient will respond to a particular anti-diabetic drug and who is likely (or unlikely) to develop a side effect with a particular drug. Applying the principles of ‘Precision Diabetes’, it will be possible in the near future to very accurately classify a patient and determine the type of diabetes he or she has and then decide the type of treatment that this patient is likely to respond to."

These are indeed exciting times in the field of diabetology!

Wish to know more about 'Precision Diabetes'? Watch Dr. V Mohan speak on the topic in the video below. 

The article was originally published on 25 March, 2018.