Microvascular complications

Question 1

main sites of microvascular complications

Answer 1

Retinal arteries

Glomerular arterioles (kidney)

Vasa nervorum (tiny blood vessels that supply nerves)

Question 2

what factors contribute to the level/extent of microvascular complications

Answer 2

Severity of hyperglycaemia
Hypertension
Genetic
Hyperglycaemic memory

Tissue damage through originally reversible and later irreversible alterations in proteins

Question 3

mechanism of glucose damage

Answer 3

Polyol pathway
AGEs
Protein kinase C
Hexosamine

hyperglycemia and hyperlipidemia leads to oxidative stress, leading to inflammatory signalling cascades and local activation of pro-inflammatory cytokines leading to inflammation which can result in neuropathy etc

Question 4

what is diabetic retinopathy?

Answer 4

Diabetic retinopathy is the main cause of visual loss in people with diabetes and the main cause of blindness in people of working age

Question 5

signs of background diabetic retinopathy

Answer 5

Hard exudates (cheese colour, lipid)
Microaneurysms (“dots”)
Blot haemorrhages

Question 6

types of diabetic retinopathy

Answer 6

background
pre-proliferative
proliferative
Maculopathy

Question 7

signs of pre-proliferative diabetic retinopathy

Answer 7

Cotton wool spots also called soft exudates

Represent retinal ischaemia

Question 8

signs of Proliferative retinopathy

Answer 8

Visible new vessels

On disk or elsewhere in retina

Question 9

signs of Maculopathy

Answer 9

Hard exudates near the macula
Same disease as background, but happens to be near macula
This can threaten direct vision

Question 10

management of background diabetic retinopathy

Answer 10

Background:

• improve control of blood glucose
• warn patient that warning signs are present

Question 11

management of pre-proliferative and pro-liferative diabetic retinopathy

Answer 11

Pan retinal photocoagulation

Question 12

what do the cotton wool spots indicate?

Answer 12

Suggests general ischaemia

Question 13

management of maculopathy

Answer 13

Maculopathy

Only have problem around macula
Needs only a GRID of photocoagulation
NOT pan retinal photocoagulation

Question 14

problems with diabetic nephropathy

Answer 14

Hypertension
Progressively increasing proteinuria
Progressively deteriorating kidney function

Question 15

what histological features occur?

Glomerular changes

Answer 15

GLOMERULAR CHANGES
Mesangial expansion
Basement membrane thickening
Glomerulosclerosis

Question 16

epidemiology of nephropathy in T”DM?

Answer 16

Age at development of disease
Racial Factors
Age at presentation
Loss due to cardiovascular morbidity

Question 17

clinical features of diabetic nephropathy

Answer 17

Progressive proteinuria

Increased BP

Deranged renal function

Question 18

normal range for proteins in urine

Answer 18

<30mg/24hrs

Question 19

strategies for intervention for T2D?

Answer 19

Diabetic control
Blood pressure control
Inhibition of the activity of RAS system
stop smoking

Question 20

give some roles of angiotensin 2

Answer 20

Vasoactive effects
Mediation of glomerular hyperfiltration
Increased tubular uptake of proteins
Induction of pro fibrotic cytokines
Stimulation of glomerular and tubular growth
Podocyte effects
Induction of pro inflammatory cytokines
Generation of ROS & NF-kB
Stimulates fibroblast proliferation
Up regulation of adhesion molecules on endothelial cells
Up regulation of lipoprotein receptors

Question 21

what is diabetic neuropathy?

Answer 21

Diabetes is the most common cause of neuropathy and therefore lower limb amputation

Small vessels supplying nerves are called vasa nervorum

Neuropathy results when these get blocked

Question 22

what are the different types of diabetic neuropathy?

Answer 22

Peripheral polyneuropathy
Mononeuropathy
Mononeuritis multiplex
Radiculopathy
Autonomic neuropathy
Diabetic amyotrophy

Question 23

what is peripheral neuropathy?

Answer 23

Longest nerves supply feet
Loss of sensation
More common in tall people and those with poor glucose control

Question 24

what is the danger with peripheral neuropathy?

Answer 24

Danger is that patients will not sense an injury to the foot (eg. Stepping on a nail)

Question 25

what can you use to test for diabetic neuropathy?

Answer 25

monofilament examination

Question 26

signs of peripheral neuropathy

Answer 26

Loss of ankle jerks
loss of vibration sense (using tuning fork)
multiple fractures on foot X-ray (Charcot’s joint)

Question 27

what is mononeuropathy?

Answer 27

Usually sudden motor loss
wrist drop, foot drop
Cranial nerve palsy: double vision due to 3rd nerve palsy

Question 28

what’s the different between a diabetic third nerve palsy and an aneurysm causing third nerve palsy?

Answer 28

diabetic: Pupil DOES respond to light.parasympathetic fibres on outside.
Thus they do not easily lose blood supply in diabetes

In an aneurysm: Will press on parasympathetic fibres first causing fixed dilated pupil

Question 29

what is mononeuritis multiplex?

Answer 29

A random combination of peripheral nerve lesions

Question 30

what is radiculopathy?

Answer 30

Pain over spinal nerves, usually affecting a dermatome on the abdomen or chest wall.

Question 31

what is autonomic neuropathy?

Answer 31

Loss of sympathetic and parasympathetic nerves to GI tract, bladder, cardiovascular system.

Question 32

what problems can autonomic neuropathy cause in the GI tract?

Answer 32

GI tract:
difficulty swallowing
delayed gastric emptying
constipation / nocturnal diarrhoea
Bladder dysfunction

Question 33

what can autonomic neuropathy also lead to?

Answer 33

Postural hypotension
can be disabling: collapsing on standing.

Cardiac autonomic supply
case reports of sudden cardiac death

Question 34

how can you check for CVS changes in autonomic neuropathy?

Answer 34

Measure changes in heart rate in response to Valsalva manoevre
Normally there is a change in heart rate
Look at ECG and compare R-R intervals