microvascular complications

Question 1

what are the sites of microvascular complications?

Answer 1

• retinal arteries
• glomerular arteries
• vasa nervorum (blood vessels that supply nerves)

Question 2

what can microvascular complications come about or be exacerbated by?

Answer 2

• severity of hyperglycaemia (worse hyperglycaemia, worse damage)
• hypertension
• genetic
• hyperglycaemic memory (poor diabetes control with give inc, risk)
• tissue damage through originally reversible and later irreversible alterations in proteins

Question 3

what are the mechanisms of glucose damage?

Answer 3

• polyol pathway
• AGEs
• protein kinase C
• hexosamine

Question 4

where is the macula and what is it involved in?

Answer 4

• colour vision and acuity

- located centrally

Question 5

what are the characteristics of background diabetic retinopathy?

Answer 5

• hard exudates
• microaneurysms (small blood vessels bulge)
• blot haemorrhages (blots of blood)

Question 6

what is pre-proliferative diabetic retinopathy?

Answer 6

cotton wool spots (soft exudates) - retinal ischaemia

Question 7

what is proliferative retinopathy?

Answer 7

visible new vessels on disc or elsewhere in retina

Question 8

what is maculopathy?

Answer 8

• same as background but near macula
• hard exudates nea near macula
• threaten direct vision

Question 9

how do you manage each type of retinopathy?

Answer 9

• background: improve blood glucose control, warn pt
• pre-proliferative: suggests general ischaemia. to stop progression to proliferative need pan-retinal photocoagulation
• proliferatuve: pan-retinal photocoagulation
• maculopathy: grid-retinal photocoagulation (just at macula)

Question 10

what are the features of diabetic nephropathy?

Answer 10

• hypertension
• progressive inc. proteinuria and deteriorating kidney fucntion
• classic histological features

Question 11

what are the glomerular histological features?

Answer 11

• mesangial expansion
• BM thickening
• glomerulosclerosis (hardening of capillaries)

Question 12

what happens if there is no retinopathy?

Answer 12

any CKD cannot be due to diabetes

they come together

Question 13

what is the epidemiology of diabetes patients with CKD

Answer 13

T1DM: 20-20% have CKD after 30-40 years
T2DM: same but difficult to determine

Question 14

what are the clinical features?

Answer 14

• progressive proteinuria (hallmark for CKD)
• inc. BP
• deranged renal function - GFR dec

Question 15

what are the interventions?

Answer 15

• diabetic control: lower HbA1C, lower microvascular complications
• BP control (will slow down deterioration of kidney function)
• inhibition of RAS (ACE inhibitors reduce rate of decline of creatinine and so kidney function)
• stop smoking

Question 16

what are the effects of angiotensin 2?

Answer 16

• vasoactive effects
• mediation of glomerular hyperfiltration
• inc. tubular uptake of proteins
• stimulation of glomerular and tubular growth
• induction of pro inflammatory cytokines
• stimulates fibroblast proliferation
• up regulation of lipoprotein receptors

Question 17

what causes neuropathy?

Answer 17

when small vessels supplying vasa nervorum get blocked

Question 18

what are the types of neuropathy?

Answer 18

• peripheral neuropathy

- mononeuropathy

Question 19

describe peripheral neuropathy

Answer 19

• affects peripheral nerves
• affects longest nerves that supply feet, results in loss of sensation
• more common in tall people and people w/ poor glucose control

Question 20

how is peripheral neuropathy investigated?

Answer 20

• monofilament examination

- tracks loss of sensation

Question 21

what are the characteristics of peripheral neuropathy?

Answer 21

• loss of ankle jerks
• loss of vibration sense
• multiple fractures on x-rays (Charcot’s joints)

Question 22

describe mononeuropathy

Answer 22

• only one nerve blocked
• usually sudden motor loss resulting in wrist and foot drop
• 3rd nerve palsy, get double vision

Question 23

what is mononeuritis multiplex?

Answer 23

• many nerves affected

- random combo of peripheral nerve lesions

Question 24

what is radiculopathy?

Answer 24

• dermatomes affected
• pain over spinal nerves
• usually dermatomes on abdoment or chest wall

Question 25

what is autonomic neuropathy?

Answer 25

• loss of SNS and PNS nerves to GIT, bladder and CVS

Question 26

what are the features of autonomic neuropathy?

Answer 26

• GIT: dysphagia, delayed gastric emptying, constipation, bladder dysfunction
• postural hypotension
• cardiac autonomic supply (can have sudden cardiac death)

Question 27

what clinical test procedure should you carry out in autonomic neuropathy?

Answer 27

• measure changes in HR in response to valsalva manoeuvre
• should have change in HR
• look at ECG and compare R-R interval

Question 28

what is diabetic amyotrophy?

Answer 28

inflammation and loss of pain

diabetic foot