Week 13 - Diabetes Mellitus

Question 1

carbohydrate digestion

Answer 1

polysaccharides > (pancreatic and salivary amylase) > hydrolysis > disaccharides > (brush-border enzymes - sucrase, lactase, maltase) > hydrolysis > monosaccharides

Question 2

negative feedback loop of glucose digestion

Answer 2

intestines absorb glucose
increasing blood glucose level
pancreas responds - secretes insulin
insulin stimulates glucose uptake by liver, skeletal muscles and other tissues
homeostasis restored

Question 3

what process turns glucose to pyruvate

Answer 3

glycolysis

Question 4

what process turns glucose to glycogen

Answer 4

glycogenesis

Question 5

what process turns glycogen to glucose

Answer 5

glycogenolysis

Question 6

what is produced by pyruvate through an anaerobic pathway

Answer 6

lactate

Question 7

what does lactate produce

Answer 7

pyruvate or glucose

Question 8

what does pyruvate produce though an aerobic pathway

Answer 8

acetyl-CoA and co2

Question 9

risk factors for type 2 diabetes mellitus

Answer 9

overweight/obesity
age
abdominal/central obesity
low socioeconomic status
sedentary lifestyle
unhealthy diet choices
cigarette smoking
genetic ancestry
family history
psychosocial stress and depression

Question 10

diabetes mellitus presentation

Answer 10

asymptomatic and symptomatic hyperglycaemia

Question 11

symptoms of hyperglycaemia

Answer 11

polyuria, polydipsia. thirst
fatigue
recurrent infection
weight loss (type 1)

Question 12

diabetes diagnosis

Answer 12

random plasma glucose or 2hrs after 75g glucose load - > 11.1mmol/L
fasting plasma glucose - > 7mmol/L
haemoglobin A1c - > 48mmol/mol

asymptomatic patients - need 2 investigations separated in time

Question 13

pre-diabetes impaired glucose tolerance diagnosis

Answer 13

fasting plasma glucose < 7mmol/L and 2hr glucose after 75g glucose load 7.8-11.1mmol/L

Question 14

pre-diabetes impaired fasting glucose

Answer 14

fasting glucose > 6.1 and < 7mmol/L

Question 15

process of creation of haemoglobin A1c

Answer 15

glucose enters blood stream and RBC
glucose naturally binds to Hb
binding creates glycated haemoglobin (HbA1c)

Question 16

what is HbA1c often used for

Answer 16

monitoring response to treatment
reference range 20-42mmol/mol

Question 17

treatment of type 1 DM

Answer 17

destruction of pancreatic beta cells - insulin deficient
requires insulin therapy - common to have a basal long acting insulin combined with meal insulin boluses of short acting insulin
continuous subcutaneous insulin pumps

Question 18

pathogenesis of type 2 DM

Answer 18

pancreas - altered/reduced insulin secretion
adipose tissue - increased lipolysis, increased FFA release, decreased glucose uptake, inappropriate release of adipokines
muscle - decreased glucose uptake
liver - increased glucose production

Question 19

what factors lead to hyperglycaemia

Answer 19

decreased incretin effect
increased lipolysis - adipose
increased glucose resorption - kidneys
decreased glucose uptake - tissues
inflammation
neurotransmitter dysfunction
vascular insulin resistance
increased hepatic glucose production
decreased insulin secretion - pancreatic β-cells
increased glucagon secretion - pancreatic ⍺-cells

Question 20

treatment of type 2 DM - lifestyle advice

Answer 20

nutritional
weight loss
exercise
stop smoking
reduce alcohol

Question 21

treatment of type 2 DM - clinical

Answer 21

initially with metformin - sensitises insulin action, opposes action of glucagon, reduces hepatic gluconeogenesis, increases muscular glucose uptake, causes weight loss
most common side effect - GI upset
monitor HbA1c - aim for 48mmol/mol - ref range 20-42

Question 22

type 2 DM drug treatments

Answer 22

sulphonylureas
thiazolidinedione (TZD)
DPP4 inhibitor (gliptins)
SGLT2 inhibitor (flozins) - most likely second line drug)
GLP1 receptor agonist
insulin

Question 23

complications of DM

Answer 23

hypertension
kidney disease
retinopathy
CVD
neuropathy - autonomic or peripheral
infections