Results of Feline Insulin Dose Survey
August 4, 2002



The Survey

An informal survey was taken on the Feline Diabetes Message Board on June 17, 2002 and again on July 26, 2002.

On the first date, the question was simply "How much insulin is your regulated cat getting?" and members quickly proposed adding weight and diet questions.

The second survey was more specific, asking: for the amount, frequency (twice a day assumed), type of insulin, weight of cat, and composition of diet (low carbohydrate, dry, mixed were suggested as categories, but many people gave detailed responses).

Regulation was not formally defined, but is largely understood by members of the board to mean that the cat's blood glucose generally ranges between 100 and 300 mg/dl over the course of a day, and typically has a nadir in the low 100's.  It is likely that some respondents did not understand that, and two responses were eliminated when it became clear that the cat rarely dropped below 300 mg/dl.



The Results

Number of observations: 69 observations on 64 cats (there were duplicates for a small number of cats who were regulated separately on high- and low-carb diets).

Types of insulin: PZI (of various varieties, mostly animal-based) and Humulin Lente were the most popular types of insulin, with Humulin Ultralente coming in third.  Together, these three types covered 72% of the respondents.

    Insulin Type        Frequency
    -----------------------------
    PZI                       19
    Lente                     18
    Ultralente                12
    N                          9
    Caninsulin                 4
    Lente/Ultralente comb.     3
    UK Lente                   2
    Lente Iletin               1

Summary of doses:  SID doses (5 cats) were divided by 2 for comparison purposes.  Of the cats who were getting insulin (5 zero-dose cats not analyzed here), the mean dose was 3.0 units BID, and the median was 2.5 units BID.  Values ranged from .125 units BID to 11 units BID.   16% of the cats needed 1 unit BID or less, and 36% were getting 2 units BID or less.

Relationship between dose and weight:  There was a positive relationship between dose and weight, although this disappeared after controlling for diet and insulin type.  Further examination indicated that the cats receiving a combination of Lente and Ultralente tended to be the heaviest, and also tended to have the highest overall doses.

Relationship between dose and insulin type:  Generally, there was no relationship between dose and insulin type, with the exception of the Lente + Ultralente cats.  The source of PZI (BR, BCP, UK, Humulin) was also not related to dose.

Relationship between dose and diet:  There was a very strong relationship between insulin dose and general dietary type (p<0.001, Kruskal-Wallis test).

Relationship between dose, diet, and weight:
Standard deviation of error term = 1.75 units.
Interpretation of results:  Vets need to be very cautious with the initial dose of insulin, especially if the cat is on a low-carbohydrate diet. Even 2 units twice a day is too high for a starting dose, since almost half of our regulated cats on low-carb diets are below that dose.  There may be some leeway for larger cats, but there's not enough information on variability to ensure that this is the case.

Redacted raw data

 Dose   Freq  Insulin Type  PZI 
 type 
 Weight
(lbs) 
Diet
4.75 2 Ultralente -- 14  High-carb 
4 2 Lente --    
2.25 2 Lente --    
2.5 2 Ultralente -- 16 Low-carb
2.5 2 Ultralente -- 10 Low-carb
5.5 2 PZI --    
1.75 2 UK Lente -- 12 Low-carb
0.75 2 PZI BCP 12 Low-carb
2.5 2 PZI BCP 14 Mixed
1.5 2 Lente -- 15 High-carb
0 2 Lente -- 15 Low-carb
3 2 Ultralente -- 19 High-carb
5 2 Lente -- 15 High-carb
11 2 Caninsulin -- 19 High-carb
1.25 2   -- 11.5  
7 2 Caninsulin -- 12 High-carb
0 2 Caninsulin -- 12 Low-carb
3 2 Ultralente -- 13.5  
4.5 2 Lente -- 11  
2 2 N -- 9 Mixed
4.5 2 Lente -- 14  
2.5 2 Lente -- 12  
1.25 2 N -- 16  
12 1 N -- 14  
2.5 2 Ultralente -- 12 Low-carb
2.25 2 Lente --   Low-carb
3 2 Lente -- 13.5 Low-carb
3 2 Lente -- 12.5  
1.75 2 Ultralente -- 14 Mixed
0 2 Ultralente -- 14 Low-carb
2.5 2 Lente Iletin -- 15  
2.5 2 PZI BR    
0.5 2 Ultralente -- 11 Low-carb
2 2 PZI BCP 12 Low-carb
1.4 2 PZI BCP 12 Low-carb
5.5 2 Lente -- 14 Mixed
3 2 Lente -- 19 Low-carb
1 2 Ultralente -- 15 Low-carb
3 2 PZI BR 11.5 High-carb
1 2 Lente -- 13 Low-carb
1.25 2 N -- 17 Low-carb
4 2 N -- 14 High-carb
1.5 2 Ultralente -- 10.25 Low-carb
1 2 Caninsulin -- 12 Low-carb
5 2 Lente -- 15 Mixed
3.5 2 PZI BCP 14 Mixed
3 2 PZI BCP 11 Mixed
0.25 1 PZI UK 13.5 Low-carb
7.5 2 Lente/Ultralente -- 17 Low-carb
1 2 UK Lente -- 12 Low-carb
6 2 N -- 14.5 High-carb
3 2 N -- 14.5 Low-carb
5 2 PZI BCP 12 Low-carb
5 2 Lente/Ultralente -- 20 Mixed
4 2 Lente/Ultralente -- 20 Low-carb
2.5 2 PZI BCP 13 Mixed
2 2 Lente -- 16 Low-carb
1 1 PZI UK 16 Mixed
1.25 1 PZI Hum 8.5 Low-carb
2 2 N -- 10 High-carb
3.4 2 PZI BR 12.5 Mixed
4.9 2 PZI BR 17 Mixed
2.8 2 PZI BR 17 High-carb
3 2 Lente -- 19.7 Low-carb
0 2 Lente -- 18.5 Low-carb
5 1 N -- 17 Low-carb
0 2 Ultralente -- 12 Low-carb
0.5 2 PZI BR 11 Low-carb
1.6 2 PZI BR 13 Low-carb



Note to readers:   This document is copyright (C) 2002 by Janet M. Peerson.  You may freely copy and distribute the document, and you are especially invited to link your web page to it, but you may not charge money for it (not even handling costs), and you may not claim credit for the contents.   The original version was created August 4, 2002.

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