Microvascular Complications of Diabetes

Question 1

What are the 3 major clinical consequences of diabetic neuropathy?

Answer 1

painful neuropathic symptoms, autonomic neuropathy and its manifestations and insensitivity that results in foot ulceration and amputation

Question 2

What is the most common complication of diabetes?

Answer 2

Diabetic peripheral neuropathy

Question 3

What happens in diabetic peripheral neuropathy?

Answer 3

• starts in the toes and gradually marches proximally in a stocking distribution
• typical ‘glove and stocking’ sensory loss
• significant motor deficit is not common

Question 4

What are risk factors for diabetic neuropathy?

Answer 4

• hypertension
• smoking
• BMI
• TG
• cholesterol

Question 5

How is painful diabetic neuropathy treated?

Answer 5

• Good glycaemic control
• Anticonvulsants (carbamazepine, Gabapentin)
• Opiods (Tramadol, oxycodone)

Question 6

What is the most common cause for hospital bed occupancy?

Answer 6

Diabetic Foot Ulceration (DFU)

Question 7

What are the 2 principal factors that contribute to high-risk diabetic foot?

Answer 7

1. Peripheral neuropathy – damage to the nerves that serve the lower limbs and hands
2. Peripheral vascular disease, which affects the larger vessels of the lower limbs

Question 8

What is the nature of diabetic foot disease?

Answer 8

• Painless
• A significant amount of damage can occur; people are completely oblivious to this until they notice blood or swelling

Question 9

What other things can occur in neuropathy?

Answer 9

• Sensory nerve damage
• Motor nerve damage
• Localized callus
• Autonomic nerve damage

Question 10

What does motor nerve damage lead to?

Answer 10

• This causes weakness in the intrinsic muscles of the feet, leading to contraction of the muscles and clawed toes
• As the toes claw back, the fat pads are pulled forward from under the metatarsal heads, increasing the pressure under these metatarsal heads and on the tips of the toes (common places for neuropathic ulceration)

Question 11

How do localised calluses form and what do they lead to?

Answer 11

• Build up of callus at the site of most pressure (as no sensation)
• Ultimately this hard, localized callus can cause the tissue underneath to breakdown forming ulceration

Question 12

What does autonomic nerve damage lead to?

Answer 12

• people lose the ability to perspire; the skin dries out and becomes cracked
• These cracks are a very common portals for infection

Question 13

What are screening tests for diabetic neuropathy?

Answer 13

• Test sensation
• Vibration perception
• Ankle reflexes

Question 14

What is peripheral vascular disease?

Answer 14

• Decreased perfusion due to macrovascular disease
• Sites: more distal
• 15-40 times more likely to have lower limb amputation

Question 15

What are symptoms of peripheral vascular disease?

Answer 15

• Intermittent claudication
  
  • pain in the calf that is brought on by walking, especially upstairs or up a hill, and is relieved by rest
• Rest pain
  
  • is experienced pain in the lower limbs, even at rest
• Surgical intervention is required to relieve the symptoms

Question 16

What are signs of vascular disease?

Answer 16

• Diminished or absent pedal pulses
• Coolness of the feet and toes
• Poor skin and nails
• Absence of hair on feet and legs

Question 17

What is the treatment for vascular disease?

Answer 17

• Quit smoking
• Walk through pain
• Surgical intervention

Question 18

What 3 things are in the pathogenesis of diabetic retinopathy?

Answer 18

• LEAKAGE
• OCCLUSION
• Ischaemia

Question 19

What leads to leakage in diabetic retinopathy?

Answer 19

• Basement membrane thickening
• Pericyte loss
• reduces junctional contact with endothelial cells
• LEAKAGE

Question 20

What leads to occlusion in diabetic retinopathy?

Answer 20

Glial cells grow down capillaries → OCCLUSION

Question 21

What leads to ischaemia in diabetic retinopathy?

Answer 21

Pericyte loss, endothelial cells respond by increasing turnover → thickening → ISCHAEMIA

Question 22

What does ischaemia and occlusion lead to?

Answer 22

Proliferation

Question 23

What is the only proven treatment for DR?

Answer 23

Laser Therapy
- Aim is to stabilise changes
- Treatment does not improve sight (prevents severe sight loss)

Question 24

What are the risks of laser therapy?

Answer 24

• Over half notice difficulty with night vision
• One in five lose peripheral vision
• 3% stop driving because of tunnel vision
• May notice temporary drop in acuity if intensive laser
• Vitreous haemorrhage

Question 25

What are features of diabetic nephropathy?

Answer 25

• Characterized by progressive kidney fibrosis resulting in loss of function
• Hallmark is development of proteinuria
• Followed by progressive decline in renal function
• Major risk factor for CVD
• Risk factors are poor BP and BG control
• Diabetes is main cause of end stage renal disease

Question 26

What is diabetic nephropathy defined as?

Answer 26

• generally defined as a rise in urinary albumin excretion (UAE) and reduced renal function
  
  • reflected by raised plasma creatinine concentration, reduced calculated creatinine clearance or decreased glomerular filtration rate (GFR)

Question 27

How do you treat diabetic nephropathy?

Answer 27

1. Blood pressure control
2. Glycemic control
3. RAS blockade: max tolerated ARB/ACEi
4. Add SGLT-2i, NS-MRAs and GLP-1 RA
5. Cholesterol control
6. Proteinuria control