T1 DM chronic consequences

Question 1

Cellular mechanism of microvascular complications

Answer 1

High blood glucose= too much glucose into cells
- Some cell types are unable to control glucose entry when there is excess efflux

Leads to cell damage

• Peripheral nerve cells, Schwann cells
• Retinal cells [endothelial]
• Mesangial cells of glomerulus

Complications take many years to develop

Question 2

Microvascular complications for T1 DM

Answer 2

Rarely occur if DM has occurred in less than 5-10 years

- Due to steep decline of insulin

Question 3

Retinopathy

- Pathology

Answer 3

Neovascularisation

• Death of BV causes new, small ones to be created
• Small new vessels are more fragile and susceptible to rupture.
• Loss of pericytes
• Thickening of basement membrane
• Closure of capillary causes ischaemia
  Release VEGF,
  Leaky capillaries: proteins released [causes ‘white spots’ in retina]

Question 4

Retinopathy epidemiology

Answer 4

Diabetic cause is the 2nd most common cause of blindness.

Question 5

Treatment of diabetic retinopathy

Answer 5

Controlling blood sugar and BP.

Laser treatment

• Pan retinal [burn the peripheral retina]
• Focal

Anti VEGF ab
- injected into retina

Question 6

Peripheral neuropathy

Answer 6

Glove and stocking syndrome
- Loss of sensation in the feet that rises to hands.

Neuropathic foot ulcers that can present as callous

Charcot foot
- Deformed foot from inflammation, broken bones

Question 7

Mononeuropathy

Answer 7

Loss of function of a single nerve

Includes carpel tunnel [entrapment neuropathy]

Question 8

Autonomic neuropathy

Answer 8

Dysfunction of the ANS nerves

• CVD problems [postural hypotension]
• Gastroparesis
• Erectile dysfunction
• Diarhhoea
• Gustatory sweating

Question 9

Nephropathy in diabetes

- Epidemiology

Answer 9

Most common cause of end stage kidney disease in western world
- 21% of death in T1, 11% in T2.

Tends to present with other microvascular complications
- Retinopathy

Question 10

Nephropathy pathology

Answer 10

Thickening of BM

Loss of podocytes

Scaring- glomerular sclerosis

Mesangial expansion

Increases CVD risk

Question 11

Diabetic nephropathy treatment

Answer 11

Reducing BP
- ACEi and ARBs

Glucose control important but overt proteinuria

Question 12

Macrovascular disease treatment

Answer 12

Controlling risks

• BP
• Lipids
• Smoking

Glucose control not as important compared to microvascular

Question 13

UKPDS

Answer 13

Diabetes study
- Assessed the outcome of controlling glucose in diabetic patients

Risk reduction took 15 years for significant reduction in risk.

Whereas controlling BP saw greater reduced risk of microvascular event.
- Significance seen at 5 years

Question 14

DCCT

Answer 14

Diabetes control and complications trail

Glycosated haemoglobin does not show linear correlation with increased risk of microvascular events
- Therefore reducing glycated haemoglobin at one level does not have the same effect as at another level.

Question 15

Clinical stages of retinopathy

Answer 15

Non-proliferative

Proliferative
- Diabetic retinopathy mechanism

Macular oedema
- Sight or non sight threatening