Diabetes mellitus

Question 1

diabetes mellitus - define

Answer 1

Clinically significant glucose intolerance

Question 2

clinical signs

Answer 2

weight loss with incr appetite
PD + PU
generally bright - hyperglycemia does NOT make you feel
unwell
if a patient develops diabetic ketoacidosis then they can develop vomiting & inappetance

Question 3

pathophysiology - dog

Answer 3

Normal insulin sensitivity + severe loss of islets
>90% of cases - absolute insulin deficiency
irreversible

Question 4

most common ages

Answer 4

7-12

Question 5

pathophysiology - cats

Answer 5

inslin resistance + Islet hyperactivity

islets become exhausted from over activity

Question 6

what causes insulin resistance

Answer 6

Obesity, oestrus, pregnancy
Anxiety
Altered ‘metabolites’ – hyperglycaemia, elevated plasma fatty acid levels
Hypercortisolaemia due to – any significant illness, stress
Endocrinopathies

Question 7

most common form of diabetes in cats

Answer 7

variably reversible insulin deficiency

Question 8

cats - endocrinopathies that can cause diabetes

Answer 8

hyperadrenocorticism

acromegaly

Question 9

acromegaly in cats

Answer 9

excess growth hormone - in the liver GH + insulin forms insulin-like growth factor (IGF1)

Question 10

physical exam - dog

Answer 10

reduced body mass, muscle wasting
hepatomegaly
bilateral cataracts - homgeneous lenticular opacities

Question 11

physical exam - cat

Answer 11

Variable body mass – lean and obese animals
hepatomegaly ?
no cataracts

Question 12

clinical pathology

Answer 12

fasting hyperglycaemia
fasting hyperlipaemia and ketonaemia
glucosuria and ketonuria
elevated fructosamine and glycosylated haemoglobin
elevated ALP and to a lesser extent ALT
altered total body potassium and phosphate
metabolic acidosis

Question 13

hyperglycaemia in cats

Answer 13

can often be because of other illnesses

Question 14

fructosamine

Answer 14

compound created when glucose binds irreversibly to albumin
binding occurs non-enzymatically + at a rate dependent on the overall concentration of glucose and albumin
when albumin is stable it reflects the average blood glucose
can be used to monitor disease

Question 15

“stress” hyperglycaemia

Answer 15

perhaps better thought of as anxiety-induced hyperglycemia
usually associated with accelerated muscle catabolism
lasts for short period - not reflected by the fructosamine
consequently fructosamine can help differentiate short-term elevations in blood glucose from a more protracted elevation

Question 16

management

Answer 16

correct underlying causes and/or factors that interfere with insulin’s actions
oral hypoglycaemic agents
which insulin preparation to use
daily dose & dose frequency
amount and type of food
importance of the timing of the insulin and the meal times

Question 17

duration of action of insulins available

Answer 17

8-14h

shorter in cats than dogs

Question 18

which insulin best for dogs

Answer 18

lente insulin twice daily for dogs

Question 19

which insulins best for cats

Answer 19

lente insulin twice daily for cats
protamine zinc insulin twice daily for cats
insulin glargine or determir twice daily for certain diabetic cats (peakless effect)

Question 20

principles of insulin therapy

Answer 20

insulin will lower the blood glucose
each meal will raise the blood glucose – more dramatic effect if meals are given at 12 hour intervals
match the opposing effects of the insulin and the meal
minimise malutilisation + achieve relatively stable blood glucose levels over the twelve hour period

Question 21

feeding

Answer 21

caloric content needs to be standardised – intake regulated to body weight
composition should be standardised – carbohydrate content, fat + fibre content ?
significant difference between species - cat carnivore (less tolerance of carbs), dog omnivore

Question 22

home glucose monitoring

Answer 22

suitable process for majority of animals & owners
75% of cases appear suitable
complimentary to fructosamine
various home-glucose monitoring devices available using <25µl of blood

Question 23

“optimal” monitoring

Answer 23

essential we see improved clincial signs
fructosamine performed 1-3 monthly
home glucose monitoring for cats (when possible)
glucose curves more valuable if you are looking for the unusual
glucose curves - use the overall data rather than the sequence of one/two curves

Question 24

remission rates in cats

Answer 24

15-68%
mixed insulins studies – 68% remission
lente insulin 12 hourly – 43% - 65% remission
glargine insulin 12 hourly – 40% - 84% remission
higher rate in diabetes present for <6 months
higher rate if on low carb diet
highest with intense management + home monitoring