Pump users / Glucose Control over duration of the vial volume

I am currently starting an MSc in Biomedical Science Project. I have had type 1 for nearly 30 years and started pump therapy in summer 2015. I have found that my BG control is excellent over the first 3 days but thereafter BG levels begin to rise until a new vial of insulin is filled when doing a set change. I am examining the effect that the temperature of the insulin within the pump may have on the efficiency of the insulin. There is some detail in the litterateur about storage and room temperature and the insulin producers say that insulin should be kept below 30 degrees. I would be delighted to receive any feedback from other pump users to see if they find loss in control towards the end of the pump vial - say after day 3? Thanks in advance. Andy

Hi Andy, I live in Brisbane, Australia and our day temperatures are regularly over 30 degrees, especially currently(10:00am and it is already 31 degrees!). Been a diabetic for 40+ years and on pump therapy for over 8 years. This is my second pump. My first pump had a cartridge with only 200 units and I would regularly run out half way through the third day. My problem was at the change over...after I had changed the infusion set I would have 8-12 hours where the new set was embedding (often needing top ups with an injection)! It would then run smoothly. The second pump has a 300u cartridge and lasts me 3+ days on average. I find the point of insertion tends to break down at 4 days and I change it at 3.5 days rather than continue. I can get lucky but I think it is a product of 30 years of injections and damage to the underlying fat layer (scarring?). I have not noticed any deterioration of the insulin over waves of 30+ days. We recently had a run of over 35 degrees and I found I drank more water and my insulin demand went up slightly (always does in the heat) but the insulin seemed fine.
All the best with your research. Helen

Hi Andy, what a fantastic inquiry into the basic premises of insulin and the veracity of the manufacturer. Over many years using various insulins I believe that there is a need for a healthy suspicion of products and the claims put forward by multinational pharmaceuticals. Helen mentioned living in Queensland poses a dilemma for users where to store the insulin over its lifetime. In Sydney NSW the temperature is also often over 30c. Do I keep the insulin in the fridge after opening as I sometimes routinely follow in the summer or follow the manufacturer instructions to the letter? My support for your study stems from being what I call the guinea pig many years ago for human insulin that was pushed onto the market to replace bovine and porcine insulins. How there has never been an inquiry or Royal Commission into the deaths of unassuming users believing their doctors and the manufacturers beggers belief. On this insulin I couldn’t walk down the street, had massive hypos at.night and was continually vomiting due to the intense lows until admitted to hospital. In fact, due to the problems deriving from this insulin a British organisation called IDDT was established to maintain animal insulin on the market due to the onslaught of the cheaper to manufacturer synthetic products and of course the bovine dilemma. After being hospitalised and telling the disbelieving specialists it was due to this new insulin I even rang the manufacturer who put their doctors on the phone to deny my accusations. “Dead in the Bed” is a well known phrase from this time but also users crashing cars from lows started to be talked about in conversations.
I commend you for your study and even though I have never used a pump would support you in your quest to determine the efficacy of the insulins we have on the market.

After three days yes, it does start to become less effective, however this is down to the body starting to heal up round the cannula is it not.....

We were told to change your cannula after three days because of this whether you have insulin in the vial or not.....