18 - Macrovascular complications of DM

Question 1

Describe the development of an atheroma

Answer 1

• Small accumulations of extracellular lipid lead to atheroma (and then fibroatheroma)
• Initially, this process begins with accumulation of lipid but progresses to involve smooth muscle
• This can lead to smooth muscle hypertrophy, fibrosis and calcification
• Can lead to a complicated lesion which can ulcerate (rupture of fibrous cap), exposing the fat underneath and this can either thrombose entirely or send emboli further down the circulation

Question 2

What factors are associated with damaged arteries?

Answer 2

• elevated glucose affects atheroma production
• low HDL
• Hypertension or high BP
• increased waist circumference
• insulin resistance
• inflammation
• adipocytokines
• urine microalbumin

Question 3

Describe the relationship between insulin levels and life expectancy

Answer 3

Hyperglycaemia is associated with significantly reduced life expectancy . If insulin levels are low (the patient is insulin sensitive), they are likely to live longer.
Subjects with insulin resistance have a significantly increased chance of heart attack

Question 4

Describe the relationship between the length of someone having diabetes and life expectancy

Answer 4

• Diabetics are expected to die earlier when age of diagnosis is earlier
• This is related to the length for which someone has had diabetes
  Diabetes is a progressive disorder – it gets worse with time.

Question 5

Describe the occurrence of microvascular disease in T2DM

i.e. the relationship between glucose levels and microvascular disease

Answer 5

most be hyperglycaemic
• In T2DM, microvascular disease doesn’t occur if the glucose is near normal
• As glucose enters a diabetic range, microvascular disease risk shoots up (relates to hyperglycaemia)

Question 6

Describe the relationship between glucose levels and macrovascular disease in T2DM

Answer 6

the higher the glucose, the higher the risk of myocardial infarction - proportional

Question 7

How does the occurrence of ischaemic heart disease differ between those with and without diabetes?

Answer 7

(ischaemic heart disease is the major cause of morbidity and mortality in diabetes)
The mechanisms are similar with and without diabetes (but in diabetes, it occurs earlier on)

Question 8

How does the occurrence of cerebrovascular disease differ between those with and without diabetes?

Answer 8

• Occurs earlier than without diabetes
• More widespread – has the risk factors of high blood pressure and cholesterol
• In a non-diabetic individuals, cerebrovascular disease occurs in elderly patients (younger in diabetes)

Question 9

How does the occurrence of peripheral vascular disease differ between those with and without diabetes?

Answer 9

• Contributes to diabetic foot problems with neuropathy

* Neuropathy alone can cause diabetic foot problems, but peripheral vascular disease worsens this

Question 10

How does treatment for diabetes that targets hyperglycaemia alone affect macrovascular disease?

Answer 10

Treatment targeted to hyperglycaemia alone has a minor effect on increased risk of cardiovascular disease.
(slightly reduce coronary artery disease risk)

Question 11

What are the modifiable factors that can be targeted in order to reduce macrovascular disease and death in diabetes.

Answer 11

dyslipidaemia, high blood pressure, smoking, diabetes

e. g. giving statins early on in diabetes massively reduces risk of heart attack or stroke
(e. g. antihypertensives)