Diabetic Nephropathy Flashcards
What is diabetic nephropathy?
Diabetic kidney disease (DKD) is defined by albuminuria (increased urinary albumin excretion is defined as ≥3.4 mg/mmol [30 mg/g]) and progressive reduction in glomerular filtration rate (GFR) in the setting of a long duration of diabetes (>10 years’ duration of type 1 diabetes; may be present at diagnosis in type 2 diabetes), and is typically associated with retinopathy.
What are the risk factors for DKD?
- Sustained hyperglycaemia
- Hypertension
- Family history of hypertension and/or kidney disease
- Obesity
- Smoking
What are the signs of DKD?
- Hypertension
- Signs of retinopathy
- Oedema
What are the symptoms of DKD?
- Poor vision
- Numbness in lower extremities
- Pain in lower extremities
- Constitiutional symptoms e.g. fatigue and anorexia
- Foot changes
What investigations should be ordered for DKD?
- Urinanalysis
- Urinary albumin to creatinine ratio (ACR)
- Serum creatinine with GFR estimation
- Kidney ultrasound
Why investigate using urinalysis? And what may this show?
- Proteinuria indicates nephropathy is present
Why investigate using urinary albumin to creatinine ratio (ACR)? And what may this show?
- Performed on spot urine collection
- May be elevated
Why investigate using serum creatinine with GFR estimation? And what may this show?
- Glomerular filtration rate (GFR) may be raised in CKD stage 1, normal in CKD stage 2, and reduced in CKD stages 3-5
Why investigate using kidney ultrasound? And what may this show?
- Kidney size may initially be large if diabetes uncontrolled, but usually normal once DKD supervenes. Ultrasound is important to exclude other causes of renal impairment in diabetic patients, such as obstruction, infection, cysts, or mass. Pyelonephritis may show as swelling of the parenchyma.
- Normal-to-large kidneys with increased echogenicity.
What values of eGFR and proteinuria with urine ACR make a diagnois of CKD?
Make a diagnosis of chronic kidney disease (CKD) and manage appropriately if there is:
- A persistent reduction in kidney function, if the eGFR is less than 60 mL/min/1.73 m2 for 3 months or more, and/or
- Persistent proteinuria with urine ACR greater than 3 mg/mmol, for 3 months or more.
Briefly describe the 6 GFR categories
G1: GFR 90 (ml/min/1.73 m²) = normal or high
G2: GFR 60–89 (ml/min/1.73 m²)
G3a: GFR 45–59 (ml/min/1.73 m²)
G3b: GFR 30–44 (ml/min/1.73 m²)
G4: GFR 15–29 (ml/min/1.73 m²)
G5: GFR <15 (ml/min/1.73 m²) = kidney failure
Briefly describe the treatment of DKD
Intervention of hyperglycaemia, hypertension, dyslipidaemia, nutrition, and behaviour. Patient behaviour and self-management significantly improves diabetic outcomes and DKD outcomes.
How is glycaemic control maintained in DKD?
Treatments for hyperglycaemia include insulin, other injectable agents, and oral hypoglycaemic agents. Treatments and the combinations of drugs that are used need to be individualised for each patient.
Why is there an increased risk of hypoglycaemia in CKD patients?
In patients with chronic kidney disease (CKD), there is a risk for hypoglycaemia because of impaired kidney clearance of medications, such as insulin (two-thirds of insulin is degraded by the kidney) or sulfonylureas, and because of impaired kidney gluconeogenesis.
How is hypertension control maintained in DKD?
Treatment of hypertension reduces progression of DKD. Past recommendations were that blood pressure (BP) should be maintained at ≤130/80 mmHg. Intensive blood pressure lowering provides protection against kidney failure, particularly among those with proteinuria.
ACE-inhibitors (e.g. lisinopril, ramipril) or ARBs can be used (e.g. candesartan, losartan) are used to control BP.
