L30: Feline Diabetes Mellitus (Brooks)

Question 1

Short-acting insulins

Answer 1

• Only have 2-6 hours of effect
• not suitable for long-term management!
• best for cats with DKA that aren’t eating
• Ex: humulin R, Novalin R
• given with U-100 syringes

Question 2

Intermediate-acting insulins

Answer 2

NPH, Lente, PZI

-max effect 2-14 hrs in cats

Question 3

Long-acting insulins

Answer 3

Glargine (Lantus)
Detemir

Max effect 8-16 hours

Question 4

See white board chart :)

Answer 4

:)

Question 5

Dosing and frequency of insulin

Answer 5

-starting dose and freq. same no matter which insulin you pick:
-BID dosing
4 kg: 1.5-2 U/cat

-if BG at dx is

Question 6

Dietary management

Answer 6

• consistent diet, portions, treats, schedule
• low carb, high protein food best to minimize postprandial hyperglycemia
• weight loss management important as obesity decreases insulin sensitivity

Question 7

Weight loss guidelines

Answer 7

• should lose 1-2% of BW per week
• calculate requirements based on ideal weight
• reduce kcals by 10-20% every 2-4 wks
• establish diabetic management before tackling weight loss

Question 8

Stomatitis, UTI, and oral glucocorticoids can –> insulin resistance

Answer 8

:)

-glucocorticoids should be stopped or switched to inhaled/topical form

Question 9

How can diabetes promote UTI formation?

Answer 9

glucose in urine, and diluted urine promotes bacterial growth

Question 10

Signs of hypoglycemia

Answer 10

Weakness
Collapse
Tremors
Seizures

Question 11

When to perform reevaluations in diabetic cat

Answer 11

1 week, then q2-3 wks PRN until glycemic control
*often takes 1-3 months to achieve adequate glycemic control

-q4-6 mos. once control is established

Question 12

What to do at 1 week recheck

Answer 12

• Hx, PE, BW
• blood glucose curve
• fructosamine (shouldn’t be used as only monitor)
• adjust dose as needed

Question 13

If remission occurs, when does it normally occur?

Answer 13

In the first 3 months (relapses common)

Question 14

Advantages and disadvantages of blood glucose curves

Answer 14

(Measure glucose q2hrs)
Adv:
-gives info on nadir, peak time and duration of effect
-can evaluate for Somogyi effect (rebound hyperglycemia)

Disadv:

• stress hyperglycemia
• laborious
• costly
• can miss Somogyi effect!

Question 15

Ideal nadir

Answer 15

80-140 mg/dL

Question 16

Ideal glucose range

Answer 16

80-270 mg/dL

Question 17

Somogyi Effect**

Answer 17

• rebound hyperglycemia that can last 24-72 hours despite subsequent insulin injections
• triggered by hypoglycemia OR rapid BG decrease
• caused by counter-regulatory hormones (ie. Epi and glucagon)
• causes good glycemic control followed by poor control
• should always be considered if BGC shows persistent hyperglycemia
• can easily miss if only perform spot BGs on animal** (causes cycle of incorrectly raising insulin dose because spot BG is high, but it might actually be high because you are overdosing on insulin and they are having rebound hyperglycemia)

Question 18

Fructosamine

Answer 18

• a glycosylated serum protein
• an indicator of BG of preceding 1-2 weeks
• higher in hyperglycemic animals
• gives good general idea of how patient was maintained in first couple weeks of tx
• can be low due to hypoproteinemia, hyperthyroid, lean cats, newly diagnosed or mild diabetes

Question 19

Insulin adjustments

Answer 19

• made based on CS and BG results
• make gradual changes of 0.5 U/injection (or more gradual if suspect Somogyi effect)
• reduce by 25-50% if evidence of hypoglycemia

Question 20

What to do at recheck 2-3 weeks after diagnosis

Answer 20

• repeat Hx, PE, BW, blood glucose curve, fructosamine

- discuss home monitoring or BGC and urine glucose weekly until insulin stable, then q3-4 weeks

Question 21

Urine glucose renal threshold

Answer 21

300 mg/dL

Question 22

Persistent negative glucose indicates:

Answer 22

Insulin overdose, or cat in remission

Question 23

Persistent urine glucose indicates:

Answer 23

Somogyi effect or need more insulin

Question 24

6-8 week recheck: what should you do if glycemic control still inadequate at this time and dose is at least 1 U/kg BID?

Answer 24

Look for evidence of insulin resistance:

• routine bloodwork
• oral exam
• urine culture
• hyperadrenocorticism
• acromegaly

Question 25

Goals of therapy

Answer 25

Control of CS*
Prevent complications
Blood glucose:
-nadir 80-140 mg/dL
-range 80-270 mg/dL
-fructosamine 350-450 

Diabetic remission?

Question 26

Causes of hypoglycemia in diabetic patient

Answer 26

Diabetic remission
Increased insulin sensitivity
Insulin overdose
CRF (kidneys help clear insulin normally; CRF –> decreased clearance)

Question 27

Complications of diabetes

Answer 27

Diabetic cataracts
Diabetic neuropathy
Diabetic ketoacidosis

Question 28

Which commonly used insulin often has a duration that is too short?

Answer 28

NPH (may need to switch to PZI or glargine)

Question 29

Consequence of prolonged duration of insulin (>12 hours)

Answer 29

Overlap insulin action can lead to Somogyi effect or to an overt hypoglycemia

-if nadir occurs at 10+ hours, suggests duration is too long and need to switch to shorter acting insulin or once a day dosing

Question 30

Diabetic cataracts

Answer 30

• more severe in dogs than cats
• generally doesn’t cause blindness in cats
• caused by decreased aldose reductase activity with age
• cats have less sorbitol in the lens as they get older and are less likely to get severe cataracts, but may be severe in diabetic kittens

Question 31

Diabetic Neuropathy

Answer 31

• one of most common chronic complications in diabetic cats, but only 10% develop CS
• pathophys not fully understood (combo of obesity, hyperlipidemia, hypertension)
• causes hindlimb weakness, ataxia, m. Atrophy, plantigrade posture, etc. usually in hindlimbs
• may improve with glycemic control but is rarely reversible**
• no effective tx

Question 32

Diabetic ketoacidosis

Answer 32

• caused by lack of insulin or insulin resistance

- if cat not eating, owners should give half dose

Question 33

Goals of therapy

Answer 33

Eliminate CS** (PU/PD, polyphagia, wt. loss, hypoglycemia, DKA, neuropathies)
Prevent complications
Quality of life
Remission (achieved in 25-50%)