Home testing and the glucose curve

An invaluable tool for the monitoring of feline diabetes is the glucometer. This is a device designed so that human diabetics can test their own blood. It is very useful for cats as well. Many people question the use of them as they are designed for human blood, but in reality, the devices cannot read DNA and tell that it is a cats blood :). Glucose is glucose.

The technique involves pricking the cats ear and getting a blood droplet. This goes onto a test strip that gets drawn into a glucometer. There are many types of glucometers on the market. We are using the Accucheck Advantage. If you are considering a glucometer, I would recommend one that has sipping strips (although I don't know if you can even get the other type anymore).

The ability to home test your cat's blood means that you will be able to do glucose curves at home. A glucose curve is when you give your cat his insulin and then check every 2-3 hours to see what the insulin is doing. The lowest number readings are the "nadir" and this is when the insulin is considered to "peak". Below is a glucose curve that we have done on Kitty (note the preshot is at the end of the previous 12 hour cycle)

Time after shot	mmoL/dl
Preshot	23
3.5	11
6	7.5
8	8.2
12	15.6

In this instance, we are getting some overlap where the beginning of the next cycle is lower than the previous. Overlap can be very good where you get some time before the next insulin shot kicks in and the old one wears off. It can also be very bad, if it is too much and you can't schedule shots due to their unpredictability.

The glucose is important because it can also tell you how low your cat is going. Most veterinarians consider a cat regulated if their numbers range from 18-8 or so. Therefore, if your cat drops very low very quickly, you will need to take some action. Conversely, if your cat doesn't drop at all, you may need to consider whether they need more insulin or are perhaps experiencing somogyi.

One of the best benefits of doing curves at home is that your cat will not be subject to "vet stress" which can increase glucose levels artificially.

I believe we have Somogyi

The last post described the phenomenom known as somogyi or rebound.
I believe we just experienced this with Kitty last night.

His evening preshot was 26.1 mmol/dl, quite high. I gave him his full dose. Note that when I report a result, I report it as the amount of time after his shot. Therefore, preshot is before he gets his shot. +5 is 5 hours after his shot, etc. At +5 he was at 3.2, which is a HUGE drop from his preshot. At +6, he was at 4.2, so I felt he wasn't going to go any lower and I went to bed.

This morning, his preshot was 21.6, which isn't too bad considering the huge drop he had last night. However, it all went down hill from there, until +7 where I actually got a reading of HI on the glucometer, meaning he was over 33.3 mmol/dl.

This is crazy because it happens inconsistently. I suspect I will need to reduce his dose slightly and start again. I am seriously considering switching insulins at this point as well, to the all beef PZI. I dono't want to waste any more time, it has been five months already and we have seen little improvement.
Not a good day. Hopefully tomorrow will be better.

Somogyi Rebound in Feline Diabetes

Contrary to what common sense would tell us, there are times when the best solution to high blood glucose numbers is to give LESS insulin. This instinctively seems wrong. However, there is very interesting physiology to explain this phenomenon.

In a non-diabetic, there are two hormones that maintain blood glucose levels. These are insulin, and glucogen, both produced by the pancreas. Insulin allows the body to use sugar in the blood or to store it for later use. Glucagon is basically offering a moderating effect to insulin by causing cells to release glucose. Therefore, in a non diabetic, if the blood sugare goes too low, the glucagon will utilize some of the stored glucose. These hormones work together to moderate blood sugar levels.

In a diabetic cat, if the blood sugar drops too low or drops too quickly, the glucagon causes the liver to indiscrimintely dump glucose into the bloodstream. This causes the cat to become hyperglycemic (high blood sugar). It is the body's self defense mechanism to stop hypoglycemia(low boood sugar). This is a simplistic description of the phenomenon as there are other hormones and biochemical processes involved, however this is essentially the mechanism.

This sharp drop followed by unusually high blood glucose levels is known as Somogyi rebound.

Because of all the hormones involved in this process, this rebound may last several cycles,
punctuated by higher blood glucose levels. The blood glucose curves will possibly be flat and high, which normally indicates that more insulin is required. However, this is not the case and the treatment for somogyi is a REDUCTION in insulin, to stave off the precipitious drops that start the whole cycle.

Somygi is difficult to detect but if you are having trouble regulating your cat despite increasing insulin levels, please discuss with your veterinarian the possibility of somogyi rebound.