Diabetes Mellitus

Question 1

Stress Hyperglycemia
- usual presentation in cats
- timing
- species differences
- urinary system

Answer 1

• Usually mild to moderate hyperglycemia in cats
  > One study ranged from 8.1 to 32.9 mmol/L (median 10.7); ref interval ~3-8
  > Serum glucose increased ~10 min after stress
  > Remain elevated >3 hours
• Common in cats, rare in dogs
• Renal glucose threshold: Dogs > 10 mmol/L and Cats > 14 mmol/L
  > Glucosuria is possible however is transient

Question 2

3 main things we look for to make a diabetes mellitus diagnosis

Answer 2

1. consistent clinical signs
2. fasting hyperglycemia
3. glucosuria

Question 3

Diagnostic Goals in Diabetic Suspects

Answer 3

1. Make a diagnosis of DM
2. Assess overall health
3. Identify:
   a. Complications of DM
   b. Concurrent diseases associated with DM / risk factors for DM
   c. Conditions that cause insulin resistance

Question 4

complications of DM we look for when making our diagnosis, and what species they are found in

Answer 4

• Cataracts (dogs)
• Neuropathy (cats)
• UTI (dogs > > cats, overall not common)

Question 5

co-morbitities / risk factors of DM we look for when making our diagnosis

Answer 5

• Diabetogenic medications
• Obesity
• Pancreatitis

Question 6

causes of insulin resistance we investigate when attempting to diagnose DM

Answer 6

• Diestrus in intact female
• Renal disease
• Hyperthyroidism (cat)
• Hyperadrenocorticism, hypothyroidism (dog)

Question 7

most important tests in our DM diagnostic approach

Answer 7

MOST IMPORTANT:
* Complete history & PE
* Serum biochemical profile (+ additional lipase testing)
* TT4 in cats >9 years of age
* Urinalysis
<><>
ALSO GOOD IF WE HAVE THE MONEY:
* Complete blood count
* Blood pressure measurement
* Other testing (endocrine, etc) if warranted, often once DM stabilized

Question 8

diabetes treatment modality options

Answer 8

• insulin
• diet
  <><>
  Can also try non-insulin therapies

Question 9

goals of DM treatment

Answer 9

Minimize/eliminate clinical signs
* In an ideal world we would:
> Control BG below renal threshold for most of the 24-hour day yet avoid hypoglycemia > Below 10 mmol/L in dogs and 14 mmol/L in cats
<><><>
* Avoid hypoglycemia (< 4.5 mmol/L)
* Possible diabetic remission in cats
* Form treatment plan acceptable to client

Question 10

type of insulins recommended for feline diabetics vs canine

Answer 10

§ Feline diabetics respond best to longer-acting insulins compared to dogs
<><>
Commonly used in cats:
- glargine
- protamine zinc
- porcine lente
- determir

Question 11

dietary goals for diabetic dogs and cats

Answer 11

Promote ideal body weight
* Weight loss if obese
* Correction of weight loss if thin body condition score
<><><>
Have predictable caloric intake
* Feed with insulin timing in mind
* Minimize post-prandial “swings” in BG

Question 12

ideal diet for diabetic cats
- goals
- nutrient profile

Answer 12

• Goals: Promote ideal body condition & regulate glucose
• Recommend low carbohydrate / high protein diets if cat is of ideal body weight

Question 12

How to Feed a Diabetic Cat
- timing / strategy

Answer 12

Strict meal feeding might be less essential versus dogs
* Cats: longer gastric emptying times, slower carbohydrate absorption
* Also fits better with cat tendency to graze
<><><>
Strategy:
* Offer main meals at insulin times (canned ideal)
* Allow access to some kibble throughout day

Question 13

where to inject insulin

Answer 13

Ideal sites subcutaneous tissue where good blood supply (e.g., flank
area versus “scruff”)

Question 14

a controlled diabetic means:

Answer 14

absence of clinical signs and hypoglycemia

Question 15

diabetes mellitus monitoring options, their uses

Answer 15

§”Spot” or single glucose measurement
> Not ideal
<><>
§ Glucose “curve” or multiple measurements throughout day
> Gives idea of how BG fluctuates in response to insulin, food, and over time
> Usually performed for the time between one insulin dose to the next
<><>
§ Fructosamine
> Average BG levels over the past week(s)
> Used in cats – trend data needed to be accurate

Question 16

When to Perform a Glucose Curve

Answer 16

§ 7-14 days after any dose changes
§ ~ every 3 months in well-regulated DM pets
§ Recurrence of clinical signs / other concerns
<><>
Some will recommend abbreviated curve after first dose of insulin
§ To detect hypoglycemia
> Generally not common when starting at low end of dose

Question 17

how to perform a glucose curve
- at home vs in hospital
- technique
- timing
- what to do if hypoglycemia

Answer 17

At home:
§ Perform BG prior to meal / insulin injection
§ Measure BG every 2 hours until next insulin injection § Note times of injections, meals, snacks
<><>
In clinic:
§ If picky eater in hospital - meal/insulin at home
§ Then start curve at clinic ASAP
§ May be more prone to stress hyperglycemia
<><>
BG every 2 hours in between insulin doses
§ Could stretch to every 3-4 hours if giving glargine
<><>
If hypoglycemia identified, measure BG every 1 hour until this resolves
§ And feed the pet

Question 18

Glucose Curve Interpretation
- what do we look at?
- how to adjust insulin dose based on results?
- duration?

Answer 18

First: Look at the nadir - is it acceptable? §”Nadir” = lowest glucose level
§ Ideally 5-8 mmol/L
§ Adjust dose if too high or too low
> If too low must lower insulin dose
§ Need to optimize nadir before assessing duration of action
<><>
Then: Look at insulin duration (assess BG throughout day)
§ Ideal to be <14 mmol/L in dogs, <17 mmol/L in cats
<><><><>
§Nadir (Ideal 5-8 mmol/L) to evaluate insulin dose
If low:
§ Insulin overdosage? Reduce dose by 25-50%
If high:
§ Underdosage, stress, technical problems, Somogyi effect, insulin resistance
§ Underdosage: increase by 10-25%
<><><><>
§ Once nadir acceptable, evaluate duration of effect
§ How long is the BG below your target?
> If <8-10 hours, usually have clinical signs of DM
> Rule out insulin resistance, consider diet change, consider insulin type change.
§ Degree in BG fluctuation

Question 19

glucose curves pros and cons

Answer 19

Advantages
§ Assess response to insulin, duration
§ Only tool to identify non-clinical hypoglycemia before progression to clinical signs
<><><><>
Drawbacks
§ Intensive for some owners
> Some owners get intensive: We don’t regulate dogs/cats with DM as tightly as human DM patients – daily curves/adjusting insulin can make patient management difficult
§ Day to day variability can be high
§ Stress

Question 20

what is fructosamine? what do levels tell us? pros and cons? follow up?

Answer 20

§ Glycosylated protein
<><>
§ Glucose bound to serum proteins (mostly albumin)
> Reflect BG levels over past 1 (to 3) weeks
> Well-controlled diabetics can have elevated fructosamine. Conversely, uncontrolled diabetic pets can have normal levels
§ Can be normal in poorly controlled diabetics or high in adequately controlled diabetics
> Trends more useful than isolated values
§ Fructosamine is not affected by stress
> can help to differentiate stress hyperglycemia from diabetes
§ Fructosamine in lower 1⁄2 of ref interval – hypoglycemia? Do a BG curve.