Diabetic nephropathy (E&M) Flashcards
Define diabetic nephropathy (AKA diabetic kidney disease).
Defined by albuminuria and progressive reduction in eGFR in the setting of long-standing diabetes (>10 years)
What is diabetic nephropathy the most common cause of?
CKD
How many patients develop diabetic nephropathy?
20-40% of patients with either T1DM/T2DM
What major histological changes do you see in diabetic nephropathy? (3)
- mesangial expansion
- glomerular basement membrane thickening
- glomerulosclerosis
What is diabetic nephropathy dependent on?
The extent and duration of hyperglycaemia and hypertension
What pattern is becoming more common in diabetic nephropathy?
Reduced eGFR without albuminuria
What are the clinical features of diabetic nephropathy? (7)
- hypertension
- oedema of extremities (in advancing disease)
- claudication
- polyuria
- lethargy / fatigue
- anorexia
- signs of retinopathy - blot haemorrhages, microaneurysms, neovascularisation
What are the signs of diabetic nephropathy? (4)
- hypertension
- oedema
- findings of associated microvascular complications - retinopathy, neuropathy
- signs of clinical uraemia
What are the features of clinical uraemia as seen in diabetic nephropathy? (7)
- anorexia
- encephalopathy
- N&V
- dysgeusia (foul taste in mouth)
- bleeding
- myoclonus
- pericarditis
What are the risk factors for diabetic nephropathy? (7)
- sustained hyperglycaemia
- hypertension
- Fx CKD
- obesity
- smoking
- physical inactivity
- dyslipidaemia
What are the first-line investigations for diabetic nephropathy? (4)
- urinalysis
- urinary ACR
- serum creatinine with GFR estimation
- kidney ultrasound
What is the characteristic lab finding (along with reduced eGFR) in diabetic nephropathy?
Proteinuria on urinalysis (1st-line)
What might urinary ACR show in diabetic nephropathy?
- moderately-increased albuminuria (microalbuminuria): 30-300mg/g
- severely-increased albuminuria (macroalbuminuria): >300mg/g
How often do patients need to be screened for urinary ACR in diabetes?
Annually
What might you see on serum creatinine with GFR in diabetic nephropathy?
GFR may be raised in CKD stage 1, normal in CKD stage 2, and reduced in CKD stages 3-5
I.e. GFR raised in early disease but reduced in late disease
What might you see on kidney USS in diabetic nephropathy?
- normal-to-large kidneys with increased echogenicity
- may show hydronephrosis if vesiculopathy and/or obstruction is superimposed
What is the gold-standard investigation for diabetic nephropathy? (1 + 4)
Renal biopsy:
- Kimmelstiel-Wilson nodules
- mesangial expansion
- GBM thickening
- glomerulosclerosis
What are some differential diagnoses for diabetic nephropathy? (5)
- non-diabetic kidney disease
- multiple myeloma (renal failure, proteinuria, bone pain, anaemia)
- renal tract obstruction
- glomerulonephritis (signs of systemic disease e.g. rashes/joint involvement, haematuria)
- renal artery stenosis (refractory hypertension/renal failure shortly after initiating ACEi/ARB)
What is the management plan for diabetic nephropathy? (6)
- glycaemic control
- hypertension - ACEi/ARB –> CCB/TLD+/-BB
- dietary modification - reduce protein and salt intake
- lipid control - statin (atorvastatin) +/- ezetimibe (recent ACS)
- in T2DM: non-steroidal mineralocorticoid receptor antagonist - finerenone
- consider pancreas-kidney transplantation
When do you consider pancreas-kidney transplantation in diabetic nephropathy? (3)
- if they do not have significant insulin resistance
- C-peptide>2 and BMI<30
- recipients must have a GFR<20mL/min/1.73m2 or be dialysis-dependent
What do you give a diabetes patient the second they present with microalbuminuria?
ACEi
What are some complications of diabetic nephropathy? (9)
- end-stage renal disease
- hyperkalaemia
- cardiovascular events
- blindness
- peripheral vascular disease
- anaemia
- refractory hypertension
- bone disease
- hypoglycaemia
Describe the prognosis of diabetic nephropathy.
Morbidity and mortality can be avoided/delayed with intensive treatment of hyperglycaemia, hypertension and dyslipidaemia and with careful attention to diet and avoidance of nephrotoxic agents
