Jothydev Kesavadev, MD
Jothydev’s Diabetes & Research Centre
jothydev@gmail.com
www.research.jothydev.com
www.jothydev.net

Diabetes is an ancient disease which has gained more and more public health importance over the centuries because of its tendency to result in functional and structural damage to vital organs.

For the good majority of doctors and other health care providers, insulin pump therapy(IPT) is still a mystery. In reality IPT dates back to more than 35 years with new generation revolutionary pumps in the market for more than 5 years.

What is insulin pump therapy?
Insulin was originally discovered in 1922 which won Nobel Prize to Frederick Banting and  John Macleod. Usually insulin is injected with a syringe or with a pen. Insulin pump is a device which can administer insulin in the most physiological way described as Continuous Subcutaneous Insulin Infusion (CSII). Insulin pump is a pager-sized device that can be connected to the body through an infusion set so as to deliver insulin continuously. It consists of a disposable reservoir for insulin and a disposable infusion set, including a cannula for subcutaneous insertion and a tubing system that connects the insulin reservoir to the cannula.

Advantages of the insulin pump
The main advantage of the insulin pump is that you can use rapid acting analogue insulin like Aspart which closely mimics the insulin which is secreted by the human pancreatic islets. Similar to the insulin secretion by the beta cells, rapid acting insulin will be released continuously which takes care of both the basal and also the bolus requirements. The basal insulin whether it is the NPH insulin or the newer Insulins like glargine or detemir will have statistically significant variability whereas with pumps variability is minimum. Insulin pumps support a delivery where 48 different basal profiles can be pre-programmed to create an environment where glycemic variability tends to be the least.

Functioning of the pump 
It’s a common myth that insulin pump deployment requires a surgery. No. 
Insulin pump approved by the FDA and used by type 1 and type 2 patients all over the world are the external insulin pumps which requires only a couple of seconds for deployment. With the help of an automatic inserter the needle is inserted subcutaneously usually over the abdomen. The metallic part of the needle is removed similar to the IV cannula. The part of the teflon needle which lies beneath the skin is extremely tiny which enables the patient to move around, exercise, sleep and to indulge in other activities without any discomfort. Since insulin pump is probably half the size of the usual cellphone, it functions as a mini computer and an intelligent educated techno patient can manipulate and exploit it for hundreds of purposes.

 A few examples
1. During the time of exercise or when the food is delayed, the insulin infusion rate can be automatically programmed either to reduce or stop it. 
2. The bolus insulin can again be programmed as an easy bolus before a meal, square wave bolus or an extended bolus based on the content of the food or duration of food like in a buffet where there is every chance for persistent elevation of sugars for some time.  Bolus wizard helps the patient make mathematical calculation of carbohydrate content of the diet; calculate the dose of insulin to maintain the sugar at normal levels etc.  The software program also takes in to consideration the active insulin which is insulin that is left in the system from a previously delivered bolus.

Merits of insulin pump
1. Regarded as the latest and the best device for any patient on insulin therapy.
2. Enables near physiological delivery of insulin.
3. Enables complete flexibility in life style. 
4. In children and in pregnant women(1) it is proven to be highly beneficial not only in treating hyperglycemia but also in maintaining normoglycemia without the risk of low sugars.
5. In brittle diabetes where sugars are mostly crazy.
6. In patients with autonomic neuropathy and hypoglycemia unawareness(2).
7. In the presence of co-morbid conditions like Coronary Artery Disease, Chronic Kidney disease etc (Indian Insulin Pump guidelines vividly describes all indications and contraindications)(2). 
8. Insulin pumps provide profound benefit in treating numbness and pain of peripheral neuropathy. This finding is established in all clinical status(3).
9. Insulin pumps results in dramatic improvement in sexual dysfunction of diabetes patients which is independent of glycemic control(3).
10. Most beneficial in active men and women involved in work and travel.
11. Insulin pumps are useful in neonates or those above the age of 80 years.
It is proven in the elderly provided they are not demented but still active. 

The above mentioned advantages and clinical benefits of insulin pump therapy like in sexual dysfunction, in neuropathic pain etc may be attributed to its action on Mean Amplitude of Glycemic Excursions (MAGE) which is not possible with the conventional insulin therapy.

Demerits of pump
1. Prohibitively expensive and also patient needs to pay for monthly disposable consumables.
2. It is a success only in highly motivated and educated subjects supported by a care giver at home or office. Not recommended in patients with dementia, acute illnesses or in bedridden patients.
3. Insulin pumps are found to be a failure in rich people who may probably have the resources to support a pump but are not motivated to take care of the diabetes and do not have a responsible and loving  care giver at home or office.

Conclusion
Considering the multitude of benefits of insulin pump therapy, this technology must definitely be promoted but never forced since it is a stress for those subjects who cannot afford and those who do not have an educated loving care giver staying with her. But for those eligible for an insulin pump therapy the possibilities should always be discussed in detail by the pump educator/ nurse educator/pump technician in the diabetes team so that they are not denied the profound benefits of this technological innovation(4).

REFERENCES:
1. Kesavadev J, Kumar A, Shankar A, Gopalakrishnan G, Permutt MA, Wasson J, Jothydev S. An Asian Indian woman with Wolfram syndrome on insulin pump: successful pregnancy and beyond. Diabetes Technol. Ther. 2011 Jul;13(7):781–785.[cited 2012 Aug 5 ]
2. Kesavadev J, Das AK, Unnikrishnan R 1st, Joshi SR, Ramachandran A, Shamsudeen J, Krishnan G, Jothydev S, Mohan V. Use of insulin pumps in India: suggested guidelines based on experience and cultural differences. Diabetes Technol. Ther. 2010 Oct;12(10):823–831.[cited 2012 Aug 5 ]
3. Kesavadev J, Balakrishnan S, Ahammed S, Jothydev S. Reduction of glycosylated hemoglobin following 6 months of continuous subcutaneous insulin infusion in an Indian population with type 2 diabetes. Diabetes Technol. Ther. 2009 Aug;11(8):517–521.[cited 2012 Aug 5 ]
4. Kesavadev J. Continuous insulin infusion systems in type 2 diabetes. J Assoc Physicians India 2011 Apr;59 Suppl:41–43.[cited 2012 Aug 5 ]