Diabetic Nephropathy

Question 1

What is the commonest cause of end-stage renal disease (ESRD) in the western world?

Answer 1

Diabetic nephropathy

Question 2

What percentage of patients with type 1 diabetes mellitus have diabetic nephropathy by the age of 40?

Answer 2

33%

Question 3

What percentage of patients with type 1 diabetes mellitus develop ESRD?

Answer 3

Approximately 5-10%

Question 4

What is thought to be key in the pathophysiology of diabetic nephropathy?

Answer 4

Changes to the haemodynamics of the glomerulus leading to increased glomerular capillary pressure

Question 5

What role does non-enzymatic glycosylation of the basement membrane play in diabetic nephropathy?

Answer 5

It is thought to play a key role in the disease process.

Question 6

What are the histological changes seen in diabetic nephropathy?

Answer 6

Basement membrane thickening, capillary obliteration, mesangial widening, and Kimmelstiel-Wilson nodules.

Question 7

What are Kimmelstiel-Wilson nodules?

Answer 7

Nodulular hyaline areas that develop in the glomuli.

Question 8

What are some modifiable risk factors for developing diabetic nephropathy?

Answer 8

Hypertension, hyperlipidaemia, smoking, poor glycaemic control, and raised dietary protein.

Question 9

What are some non-modifiable risk factors for developing diabetic nephropathy?

Answer 9

Male sex, duration of diabetes, and genetic predisposition (e.g. ACE gene polymorphisms).

Question 10

What is the recommended screening frequency for diabetic nephropathy?

Answer 10

All patients should be screened annually using urinary albumin:creatinine ratio (ACR).

Question 11

What type of specimen should be used for ACR screening?

Answer 11

Should be an early morning specimen.

Question 12

What ACR value indicates microalbuminuria?

Answer 12

ACR > 2.5.

Question 13

What dietary management is recommended for diabetic nephropathy?

Answer 13

Dietary protein restriction.

Question 14

What is the target for tight glycaemic control in diabetic nephropathy management?

Answer 14

Tight glycaemic control.

Question 15

What is the target blood pressure for diabetic nephropathy management?

Answer 15

Aim for < 130/80 mmHg.

Question 16

When should ACE inhibitors or angiotensin-II receptor antagonists be started?

Answer 16

Should be started if urinary ACR of 3 mg/mmol or more.

Question 17

Should dual therapy with ACE inhibitors and angiotensin-II receptor antagonists be initiated?

Answer 17

Dual therapy should not be started.

Question 18

How should dyslipidaemia be controlled in diabetic nephropathy management?

Answer 18

Control dyslipidaemia e.g. Statins.

Question 19

What are the five stages of diabetic nephropathy?

Answer 19

Diabetic nephropathy may be classified as occurring in five stages.

Question 20

What characterizes Stage 1 of diabetic nephropathy?

Answer 20

Stage 1 involves hyperfiltration and an increase in GFR, which may be reversible.

Question 21

What occurs during Stage 2 of diabetic nephropathy?

Answer 21

Stage 2 is the silent or latent phase where most patients do not develop microalbuminuria for 10 years, and GFR remains elevated.

Question 22

What defines Stage 3 of diabetic nephropathy?

Answer 22

Stage 3 is known as incipient nephropathy, characterized by microalbuminuria (albumin excretion of 30 - 300 mg/day, dipstick negative).

Question 23

What are the key features of Stage 4 diabetic nephropathy?

Answer 23

Stage 4 is overt nephropathy with persistent proteinuria (albumin excretion > 300 mg/day, dipstick positive), hypertension in most patients, and histology showing diffuse and focal glomerulosclerosis (Kimmelstiel-Wilson nodules).

Question 24

What occurs in Stage 5 of diabetic nephropathy?

Answer 24

Stage 5 is end-stage renal disease, with GFR typically < 10ml/min, requiring renal replacement therapy.

Question 25

How does the progression of diabetic nephropathy differ between type 1 and type 2 diabetes?

Answer 25

The timeline for type 1 diabetics is different from type 2 diabetes mellitus (T2DM), where some T2DM patients may progress quickly to the later stages.