Diabetes Mellitus Flashcards
Stress Hyperglycemia
- usual presentation in cats
- timing
- species differences
- urinary system
- 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
3 main things we look for to make a diabetes mellitus diagnosis
- consistent clinical signs
- fasting hyperglycemia
- glucosuria
Diagnostic Goals in Diabetic Suspects
- Make a diagnosis of DM
- Assess overall health
- Identify:
a. Complications of DM
b. Concurrent diseases associated with DM / risk factors for DM
c. Conditions that cause insulin resistance
complications of DM we look for when making our diagnosis, and what species they are found in
- Cataracts (dogs)
- Neuropathy (cats)
- UTI (dogs > > cats, overall not common)
co-morbitities / risk factors of DM we look for when making our diagnosis
- Diabetogenic medications
- Obesity
- Pancreatitis
causes of insulin resistance we investigate when attempting to diagnose DM
- Diestrus in intact female
- Renal disease
- Hyperthyroidism (cat)
- Hyperadrenocorticism, hypothyroidism (dog)
most important tests in our DM diagnostic approach
MOST IMPORTANT:
* Complete history & PE
* Serum biochemical profile (+ additional lipase testing)
* TT4 in cats >9 years of age
* Urinalysis
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ALSO GOOD IF WE HAVE THE MONEY:
* Complete blood count
* Blood pressure measurement
* Other testing (endocrine, etc) if warranted, often once DM stabilized
diabetes treatment modality options
- insulin
- diet
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Can also try non-insulin therapies
goals of DM treatment
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
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* Avoid hypoglycemia (< 4.5 mmol/L)
* Possible diabetic remission in cats
* Form treatment plan acceptable to client
type of insulins recommended for feline diabetics vs canine
§ Feline diabetics respond best to longer-acting insulins compared to dogs
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Commonly used in cats:
- glargine
- protamine zinc
- porcine lente
- determir
dietary goals for diabetic dogs and cats
Promote ideal body weight
* Weight loss if obese
* Correction of weight loss if thin body condition score
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Have predictable caloric intake
* Feed with insulin timing in mind
* Minimize post-prandial “swings” in BG
ideal diet for diabetic cats
- goals
- nutrient profile
- Goals: Promote ideal body condition & regulate glucose
- Recommend low carbohydrate / high protein diets if cat is of ideal body weight
How to Feed a Diabetic Cat
- timing / strategy
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
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Strategy:
* Offer main meals at insulin times (canned ideal)
* Allow access to some kibble throughout day
where to inject insulin
Ideal sites subcutaneous tissue where good blood supply (e.g., flank
area versus “scruff”)
a controlled diabetic means:
absence of clinical signs and hypoglycemia
diabetes mellitus monitoring options, their uses
§”Spot” or single glucose measurement
> Not ideal
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§ 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
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§ Fructosamine
> Average BG levels over the past week(s)
> Used in cats – trend data needed to be accurate
When to Perform a Glucose Curve
§ 7-14 days after any dose changes
§ ~ every 3 months in well-regulated DM pets
§ Recurrence of clinical signs / other concerns
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Some will recommend abbreviated curve after first dose of insulin
§ To detect hypoglycemia
> Generally not common when starting at low end of dose
how to perform a glucose curve
- at home vs in hospital
- technique
- timing
- what to do if hypoglycemia
At home:
§ Perform BG prior to meal / insulin injection
§ Measure BG every 2 hours until next insulin injection § Note times of injections, meals, snacks
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In clinic:
§ If picky eater in hospital - meal/insulin at home
§ Then start curve at clinic ASAP
§ May be more prone to stress hyperglycemia
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BG every 2 hours in between insulin doses
§ Could stretch to every 3-4 hours if giving glargine
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If hypoglycemia identified, measure BG every 1 hour until this resolves
§ And feed the pet
Glucose Curve Interpretation
- what do we look at?
- how to adjust insulin dose based on results?
- duration?
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
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Then: Look at insulin duration (assess BG throughout day)
§ Ideal to be <14 mmol/L in dogs, <17 mmol/L in cats
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§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%
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§ 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
glucose curves pros and cons
Advantages
§ Assess response to insulin, duration
§ Only tool to identify non-clinical hypoglycemia before progression to clinical signs
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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
what is fructosamine? what do levels tell us? pros and cons? follow up?
§ Glycosylated protein
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§ 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.
