3c. Pancreas (Diabetes Mellitus)

Question 1

what is/occurs in type 1 diabetes mellitus

Answer 1

INSULIN DEPENDENT

autoimmune destruction of the pancreatic beta-cells

destroys the ability to produce insulin and seriously compromises the patients ability to absorb glucose from the plasma

Question 2

diabetes is similar to starvation in the lack of nutrients - what happens in the body when nutrients are scare

Answer 2

body relies on stores for energy - adipose tissue broken down and fatty acids are released

Question 3

How are FFAs used by the body in type 1

Answer 3

used by most tissues to produce energy - liver converts excess into ketone bodies which provide additional energy source for muscles and the BRAIN

Question 4

what is ketoacidosis

Answer 4

the build up of acidic ketone bodies in the plasma - create life threatening acidosis with plasma pH <7.1

dead can occur in hours if untreated

Question 5

how does ketoacidosis come about in type 1

Answer 5

poorly controlled insulin-dependent type 1 diabetes causes a lack of insulin - this depresses ketone body uptake so they build up in the plasma

Question 6

how can ketoacidosis be detected

Answer 6

detectable in urine and produce distinctive acetone smell on the breath

Question 7

what is/occurs in type 2 diabetes mellitus

Answer 7

NON-INSULIN DEPENEDENT

peripheral tissues become insensitive to insulin = INSULIN RESISTANCE

muscle and fat no longer respond to normal levels of insulin

Question 8

what are the two causes of insulin resistance in type 2

Answer 8

1. abnormal response of insulin receptors in tissues

2. reduction in number of insulin receptors in tissues

Question 9

are beta cells affected in type 2

Answer 9

beta cells are NOT affected - remain intact and appear normal - there may even be hyperinsulinaemia

Question 10

what percentage of patients have type 1 and 2 diabetes mellitus

Answer 10

10% type 1

90% type 2

Question 11

what is the first line treatment for type 2

Answer 11

trying to restore insulin sensitivity of tissues with exercise and dietary chang

Question 12

what is the second line treatment for type 2

Answer 12

oral hypoglycaemic drugs -

1. Metformin is the first line treatment
2. then Sulphonylureas

Question 13

how does metformin work

Answer 13

inhibits hepatic gluconeogenesis and antagonises action of glucagon

Question 14

how do sulphonylureas

Answer 14

act to close the KATP in  cells and therefore stimulate Ca2+ entry and insulin secretion.

(obviously requires functioning beta cells so can’t be used in type 1)

Question 15

why do many type 2 patients end up taking insulin

Answer 15

to prevent hyperglycaemia

Question 16

how does a glucose tolerance test indicate diabetes

Answer 16

Patient ingests glucose load after fasting [BG] measured

[BG] will normally return to fasting levels within an hour

elevation after 2 hours is indicative of diabetes

*Does not distinguish Type 1 from 2

Question 17

what 4 complications can arise from diabetic hyperglycaemia

Answer 17

retinopathy, neuropathy, nephropathy, CV disease