Glucose - Ex 4

Question 1

Sources of Blood Glucose

Answer 1

1. Intestinal absorption
   - Simple-stomached animals
   - 2-4 hrs after meal
   - Ruminants absorb volatile FAs, not glucose
2. Hepatic production
   - Gluconeogenesis
   - Glycogenolysis

Question 2

What hormone decreases blood glucose?

Answer 2

Insulin

inc peripheral utilization, dec hepatic production

Question 3

What 4 things will increase blood glucose?

Answer 3

1. Glucocorticoids - MOST COMMON - stress
2. Catecholamines - Excitement
3. Glucagon
4. Growth Hormone

Question 4

Hypoglycemia - Differentials (7)

Answer 4

1. Increased Insuln levels
   * Insulinoma or iatrogenic (od)
2. Sepsis
   * early hyperglycemic phase
3. Hepatic failure
   * dec gluconeogenesis and glycogenolysis
4. Neonatal/Juvenile
   * lack adequate glycogen and protein stores
5. Xylitol toxicity
6. Ketosis/Pregnancy Toxemia
   * negative energy balance, dec glycogen
7. Starvation/Malabsorption
   * Rarely a cause!! Gluconeogenesis keeps up (cat missing 2 mo)

Question 5

Hypoglycemia (<60mg/dl) and increased serum insulin =

Answer 5

Insulinoma

Question 6

Serum insulin an hypoglycemia

Answer 6

When glucose drop <60mg/dL there should be a drop in serum insulin

Question 7

Serum insulin assay

Answer 7

Best to measure with blood glucose

Useful in both hypo- and hyperglycemic situations

Harvest from clotted blood w/in 30 mins and frozen

Question 8

Hyperglycemia Differentials (4)

Answer 8

1. Glucocorticoids - stress (ill animals) - most common
2. Post-prandial - test when fasted
3. Catecholamines - excitement (look at urine glucose)
4. Diabetes mellitus - lack of insulin or insulin effects

Question 9

Glucosuria

Answer 9

All glucose absorbed in proximal tubule (normal kidney)

If blood glucose passes RENAL THRESHOLD –> see glucose in the urine!

Fanconi syndrome - tubular defect = glucosuria P

Question 10

Hyperglycemia & negative urine glucose =

Answer 10

Stress response

*stress responses typically result in glucose (-) urine –> although can see positives w/ severe stress (cats)

Question 11

Hyperglycemia & glucosuria (positive urine glucose) =

Answer 11

Not stress, must be other problem

Question 12

Fructosamine concentration

Answer 12

Levels represent the BG concentrations during the previous 2-3 weeks

Question 13

Hyperglycemia & high fructosamine =

Answer 13

Chronically elevated glucose (e.g. diabetes)

Question 14

Equine Metabolic Syndrome - 3 components

Answer 14

1. Regional adiposity (fat neck)
2. Hyperinsulinemia
3. Insulin resistance

*Assoc’d with laminitis!

Question 15

Equine Metabolic Syndrome - Clin Path Findings (3)

Answer 15

1. normal to increased glucose
2. increased GGT/AST/SDH (fatty liver)
3. +/- increased triglycerides

*and assoc’d with laminitis

Question 16

Glucocorticoid Excess (hyperglycemic)

Answer 16

Prolonged glucocorticoids –> prolonged hyperglycemia –> prolonged insulin release:

• B cell exhaustion –> atrophy
• Hyperadrenocorticism & DM

Question 17

Proximal Duodenal Obstruction

Answer 17

Ruminants! Due to mechanical obstruction, inflammation/scarring, enteroliths –> thought to be combo of stress and decreased peripheral utilization

• Severe hyperglycemia = 600-1000 mg/dL