Case:Louis

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Louis is an 11 year old neutered male Siamese cat, diagnosed with diabetes 10/2006. Lantus has been the only insulin used at home. Difficult regulation over months probably due to glucose toxicity. Regulation was finally reached by gradually increasing dose and switching to a low-carb wet diet. Then he began healing and his dose was at first quickly, then gradually decreased, and he went off insulin shots in June 2007. In June 2008, an attack of pancreatitis threw him out of remission, he became ketoacidotic and was hospitalized 5 days. As of July 2008 he is again regulated on Lantus.

[edit] Background, symptoms and diagnosis

Louis had been healthy except for an episode in 2001 of urinary tract infection and urethral blockage caused by struvite crystals. To prevent more crystals he was on a diet of Hills CD dry kibble, and over several years, his weight had nearly doubled from 9 lbs (4 kg) to 16.9 lbs (nearly 8 kg). Diabetic symptoms became noticeable soon after a dental, but it is unknown whether this had had any bearing on the diabetes; his teeth had needed only cleaning and the vet reported no sign of infection. In ca. August 2006 I did not notice at first the gradual, insidious onset of polyuria, polydipsia and polyphagia with weight loss until they became more extreme. I did notice he was lethargic, spending most of his time lying on the cool wood floor in front of a fan, but I thought it was due to the hot weather. We also saw symptoms ofneuropathy (although did not at the time know what it was): avoiding high jumps, fell/nearly fell when he attempted a jump and didn't quite reach his goal; he also seemed less sure-footed on narrow places, stumbling a few times in a way he had never done. In addition to these typical symptoms, when his diabetes was out of control, Louis was having sneezing fits which had become very frequent just before dx, and until regulation the sneezing repeatedly coincided with increase in clinical signs of diabetes. Our vet could find no other cause for the sneezing. Louis was diagosed October 2006. blood glucose level was over 700 mg/dl at DX. Fructosamine was 450. Possibly stress raised BG somewhat extra at the clinic but clearly this was a cat with raging diabetes. Microalbuminuria high. (Very luckily)negative for ketones.

[edit] Treatment

After diabetes DX, before starting insulin, we first tried a diet change alone, adding Purina DM, (both dry and cans, but mostly dry) to his dry Hills C/D and gradually increasing the DM. After two weeks when this seemed to make no dent in his diabetes symptoms, he began Lantus /insulin glargine, initially at 2 units SID. 2 weeks later he went for a curve and BG still in 500s. Increased Lantus to 2 units BID, which again made little difference in clinical signs of hyperglycemia. We continued to "go slow" and increased dose gradually with at least two weeks between each dose change. By December 2006 had switched to a lower carb diet, and raised dose to 7 BID and there was some slight improvement but still in 400s in his curve at the vet.

[edit] low carb wet diet

Louis had been eating dry food for years--perhaps all his life--occasionally getting canned food as a "treat". From 1999-2001 I had fed him NutroMax or Science Diet. Since he had a urethral block and crystals were found in 2001, he was put on Hills C/D, which he ate until DM DX. At that time he began eating Purina DM --mostly dry but some cans. When I finally began to learn about feline nutritional needs, I started feeding more canned DM and less dry, but soon he grew to dislike the canned DM. I searched for a lower carb, grain-free food with better quantity and quality of protein from animal sources and in December 2006 I started feeding him Innova EVO--initially feeding both dry Evo and canned Evo, but as I read more I learned that NO dry food was good for him, and I gradually cut off the dry. To give him a change I sometimes fed Wellness grain-free varieties or Solid Gold Blended Tuna. As of April 2007 I cut down the percentage of EVO in his diet because of high phosphorus level, replacing with about 50% Wellness and Solid Gold.

[edit] Glucose toxicity

By late January 2007 we had increased the Lantus to 10 BID and suddenly the PU/PD greatly decreased like magic. From what I later read it seems very much that what we had experienced was breaking through the "glass ceiling" of insulin resistance caused by glucose toxicity. It is also possible, since the dose increases had been by 1 unit per dose (and so 2 per day), that we had missed the correct dose somewhere and he had since then been chronically overdosed and his high numbers and continued symptoms were from chronic rebound. But if that were the case, he finally adjusted to an even higher dose. If I had to guess I would go for glucose toxicity since increasing dose brought a sudden improvement.

Unfortunately, having been cautioned against it by 3 vets, I was not yet hometesting blood glucose, which would have given me a better understanding of what was happening. Even if I had been testing, chronic rebound with a high flat curve could have been difficult to distinguish from insulin resistance.

However it would have been much safer to be testing. I also did not know at that time that after breaking through the glucose toxicity "glass floor" the insulin needs may rapidly drop.

With his diabetes at last controlled, Louis was no longer so hungry and thirsty, seemed to feel much better. Over the coming weeks I began to notice an improvement in the neuropathy he had had. I had unwisely made the last three increases without tests, having misunderstood the vet- -when I asked about testing blood at home, he said that watching clinical signs was the best way for me to tell what was going on, along with testing for ketones. They had also directed me do some increases without a blood test.

He had been showing no clinical symptoms of either hyperglycemia or [[hypoglycemia] but at the cat clinic in March, his BG was only 33! The vet was shocked that it could be so low without him showing any neurological symptoms (or any symptoms) of hypoglycemia- -in fact, she couldn't believe he was not in a full-blown hypoglycemic crisis. Fructosamine was 276 on same date, so apparently he had been quite a bit higher recently. Dose was reduced to 3 units BID, and one week later BG was 126. BG and clinical signs showed a huge improvement from when he was on that same dose in 11/2006. Reduced to 2 units Lantus BID and on 2 units BID 20/3/07 - 26/4/07 he continued to do well. In the meantime I finally succeeded in testing his blood glucose at home.

[edit] Louis BG off insulin 26 April-4 May, 2007

Chart 1: Blood glucose test chart for Louis when off insulin 26 April - 4 May, 2007. In the first two days some of Lantus would still be affecting it. Note: Click for larger high res image.

[edit] A week off insulin

On 26 April, AMPS at 101; gave no shot. BG rose to 148 but went down to 69 after food, a very good sign. The first two days showed nearly all normal numbers; though some credit may be attributed to the long-acting Lantus, he was still under 100 at +48, when it would certainly have been past its peak. Louis's blood glucose during the insulin-free period is shown in Chart 1. Nearly each day he spent some of the time in normoglycemic range but also after the first two days he had higher numbers (up to 226) and pretty steep ups and downs.

[edit] Louis BG on Lantus SID with part time pancreas

Chart 2: Louis's blood glucose levels in early May 2007, showing pancreas working part time. For the first few days, the BG level is in a more expected diabetic-type relation with the SID insulin. Then we see more ups and downs in the middle of a shot cycle as Louis's pancreas now produces insulin to lower BG in response to food intake. Note: Lower line (dark blue) represents hours post shot. Green band shows normoglycemic level. Click for larger high res image.

Therefore we resumed Lantus but using a tighter form of regulation and shooting as needed, which was generally SID for a while. Continued monitoring of BG several times daily showed highs coming down a bit (aside from one shocking 300 that may have been a mistake or may have been insulin not catching up to food) and his pancreas appears to be lowering postprandial BG. Chart 2 above shows first week back on Lantus. It may change to smaller doses more often.

[edit] Working with Endogenous Insulin

In May, 2007, since his pancreas was healing and was now partially working, I began to divide Louis's food into multiple (about 6) small meals per day, to stimulate the pancreas without hitting it with too much glucose at once. Louis was getting definite post prandial drops in blood glucose so I could use food along with exogenous insulin as a tool to bring down blood glucose--in fact food became the primary tool with Lantus as the back-up. I would test, feed and re-test about 3 hours later; if BG had not gone down, I would then give exogenous insulin.

[edit] Remission June 2007-June 2008

This proved successful and throughout the rest of May and early June 2007 Louis continued to get better duration on Lantus and to show evidence of a partially working pancreas. He went off insulin June 10, 2007. Louis did have some higher BGs (mid to upper 100s) in late summer/ early autumn 2007 after getting into high carb food. I have also noticed that not sticking to the multiple small meals, or going many hours through the day with no food causes his BG to rise.

[edit] Pancreatitis and DKA

In June 2008 Louis had an attack of pancreatitis that sent him out of remission. He was at the time not being tested frequently. The combination of hyperglycemia and lowered appetite led to ketosis which quickly spiraled into diabetic ketoacidosis. In addition, he had a UTI. Louis was hospitalized five days on R insulin and then switched to Lantus again. Pancreatitis was diagnosed by ultrasound and by the fPLI test. The ultrasound also revealed diffuse hepatopathy.

[edit] Re-regulation on Lantus

In the first week or so after release from the hospital, Louis had erratic and often very high (400s to over 600) blood glucose levels, but this quickly resolved and Within a few weeks after hospitalization, Louis was regulated and most of the time between 60-200 mg/dL. We are using the German Tight Regulation protocol for Lantus & Levemir.

[edit] Other notes

Microalbuminuria still high (2.8) as of March 2007 but lower since dx and other kidney numbers as well as x-ray normal. Still negative for ketones. Has not had any more problems with Feline Lower Urinary Tract Disease since the episode in 2001. Crystals have not been observed in urinalysis since the switch from dry C/D to low carb canned food, and at last test pH was 6.5. From January-July 2007 there was no recurrence of the sneezing we had seen before regulation. When in July, at much lower BG, he began sneezing again, another vet suggested allergies.