Week 5 - E(1) - Kidneys in systemic disease - Diabetes & renovascular disease (causes)

Question 1

What are macrovascular complications of diabetic nephropathy?

Answer 1

This would be Stroke Myocardial infarction Peripheral vascular disease

Question 2

What are examples of microvascular complications of diabetic disease?

Answer 2

Retinopathy Neuropathy Nephropathy

Question 3

What are the four types of diabetic neuropathy?

Answer 3

Peripheral neuropathy Autonomic neuropathy Proximal neuropathy Focal neuropathy

Question 4

What are the features of peripheral neuropathy?

Answer 4

Peripheral neuropathy is usually where there is damage to the peripheries and there is a loss of sensation and ulceration can form in the feet and hands

Question 5

What type of neuropathy would gastroparesis come under?

Answer 5

Would come under autonomic neuropathy - the autonomic nervous system is affected

Question 6

What happens to the kidneys in the first stage of diabetic nephropathy?

Answer 6

In the first stage the GFR increases by about 25-50% due to renal hypertrophy

Question 7

What does the plasma glucose stimulate in the kidneys to cause the increase in GFR at the beginning of diabetic nephropathy?

Answer 7

Plasma glucose stimulates the production of vasocative mediators eg IGF1 (insulin-like growth factor 1) This causevasodilation of the afferent arteriole and therefore an increase in filtration

Question 8

After the renal hypertrophy that occurs in diabetic nephropathy, what takes place?

Answer 8

Mesangial expansion with glomerular basement membrane thickening

Question 9

Nodule Formation and diffuse glomerulosclerosis follows the mesangial expansion What are the nodules known as on histology?

Answer 9

These nodules are known as Kimmelstiel Wilson nodyles

Question 10

What happens in the overt diabetic nephropathy stage?

Answer 10

In the overt stage, there is proteinuria due to GBM thickening and podocyte dysfunction also with tubulointerstitial fibrosis

Question 11

12 What is the first step in diabetic kidney disease? A – Inflammation B – Increased albuminuria C –Mesangial expansion D – Tubulo-interstitial fibrosis E – Increased eGFR F – Decreased eGFR G– Nodular diabetic sclerosis

Answer 11

E - Increased eGFR - also accompanied by renal hypertrophy in the pre nephropathy stage

Question 12

What occurs in the overt stage of diabetic nephropathy?

Answer 12

Proteinuria - due to glomerular basement thickening and podocyte dysfunction Mesangial nodules (kimmelstiel Wilson nodules) and tubulointersitisal fibrosis

Question 13

History of Diabetes Mellitus Albuminuria / Proteinuria Presence of other diabetic complications eg retinopathy What is a late finding in diabetic nephropathy?

Answer 13

Renal impairment

Question 14

If already suspecting a histoy of diabetic nephropathy, a renal biopsy may not be required When would you carry out a renal biopsy?

Answer 14

Haematuria or if you supect there may be something that would alter your treatment plan

Question 15

When measuring urine albumin excretion per day What is normal, what is microalbuminuria and what is overt nephropthy?

Answer 15

Normal is less than 30mg/day Microalbuminuria - 30-300mg/day Overt diabetic nephropathy - >300mg/day

Question 16

In treating diabetic nephropathy, what is important as the initial treatment? (BP, glucose, astherosclerosis - what are the values for HbA1c and BP)

Answer 16

Get patinet under tight glycaemic control - HbA1c less than 7 (53%) Control blood pressure using ACEinhibitors or ARBs Lipids by giving statins

Question 17

So for, diabetes - control is to give an ACEinhibtor, lipid control and tight glycaemic control What should you advise regarding diet?

Answer 17

Low salt diet and low fluid intake

Question 18

If there is declining GFR below 20, what shoudl you inform the patinet about?

Answer 18

Inform the patinet about the likeliness to need dialysis

Question 19

Is an older or younger type 1 diabetic likely to experience diabetic nephropathy?

Answer 19

A younger patient as they have more time for the kidney function to decline

Question 20

Renal Replacement Therapy for Diabetic Nephropathy What are the three options?

Answer 20

Simultaneous kidney and pancreas transplant (type 1 only) Renal transplant Dialysis (haemo or peritoneal dialysis)

Question 21

The survival on dialysis in a diabetic patinet is better in T1DM than T2DM What is the survival rates in T1DM? (at one, two and five years)

Answer 21

One year - 81% Two years - 62% Five years - 24%

Question 22

What is the most common cause of renal failure in the UK? What does the microalbuminaemia progress to?

Answer 22

Diabetes is the most common cause Microalbuminaemia progresses to proteinuria and this produces to frank nephropathy

Question 23

What drugs are used to treat proteinuria in diabetic nephropathy as this is very good for slowing down progression?

Answer 23

ACEinhibtors and ARBs

Question 24

How do diabetic patients tend to cope on dialysis?

Answer 24

Diabetic patients tend to do badly on dialysis and cope better on transplant

Question 25

Refers to the reduced GFR associated with reduced renal blood flow beyond the level of autoregulatory compensation What is this known as?

Answer 25

Ischaemic nephropathy

Question 26

What is ischaemic nephropathy part of as a greater overall association?

Answer 26

Part of renovascular disease

Question 27

What is the main cause of ischaemic neprhopathy?

Answer 27

This would be essential hypertension

Question 28

renovascular disease is an important cause of secondary hypertension, how does this process occur? What will the hyoperfusion lead to if it continues?

Answer 28

The progressive narrowing of the renal arteries (or veins) leads to renal hypoperfusion which will cause hormonal changes to increase the blood pressure If the hypoperfusion continues this will lead to ischaemic nephropathy

Question 29

Ischemic nephropathy is almost always caused by arteriosclerosis (i.e., accumulation of fatty masses within blood vessel walls) in the renal arteries. What is this known as?

Answer 29

Renal artery stenosis

Question 30

What are the usual risk factors of Atherosclerotic Renovascular disease (Renal Artery Stenosis) ?

Answer 30

Older pts \>50 M \> F Risk factors for generalised atherosclerosis Prevalence of 4-20% (autopsy) Usually unilateral Smoking

Question 31

If treating someone with an ACE inhibtor for the ischaemic neuropathy and they have an AKI What is suspected?

Answer 31

Renal artery stenosis

Question 32

How is renal artery stenosis diagnosed?

Answer 32

Diagnosed by ultrasound to detect the blood flow through the renal artery Also a CT angiogram

Question 33

Why is it that in renal artery stenosis, that the renal blood flow is not significantly reduced until an ACE inhibitor is given?

Answer 33

This is because the renal blood flow tries to remain the same by constircting the efferent arteriole, however when an ACE inhibtor is given, the efferent tone is lost and the glomerular capillary blood pressure is losses=d

Question 34

What is the medication given to treat the renovascular disease, if not have renal arery stenosis? (want to lower BP, lipids and prevent clotting)

Answer 34

Give ACE, statin and an anti-platelet (clopidogrel)

Question 35

What can be used to treat the renal artery stenosis?

Answer 35

Angioplasty +/- stenting

Question 36

is a condition that causes narrowing (stenosis) and enlargement (aneurysm) of the medium-sized arteries in your body. Reduced blood flow from narrowed arteries to the organs can affect the function of the organs. What is this?

Answer 36

This is fibromuscular dysplasia

Question 37

How does fibromuscular dysplasia present? What can both fibromuscular dysplasia and renovascular disease cause?

Answer 37

Presents with secondary hypertension They can both cause chronic kidney failure

Question 38

What differntiates fibromuscular dysplasia from essential hypertension?

Answer 38

It is not due to astherosclerosis Often affects young to middle aged woman

Question 39

How is fibromuscular dysplasia diagnosed and what is seen on diagnosis?

Answer 39

It is diagnosed via CT angiography and you can see the sting bead appaearnce of the arteries due to hyperplasia

Question 40

Fibromuscular dysplasia affects most arteries but in particular the renal arteries and which other arteries?

Answer 40

Can also involve carotid arteries which could lead to dissection