What are the indications for referral to a nephrologist in patients with diabetic nephropathy?

Referral to a nephrologist for patients with diabetic nephropathy is indicated in several situations:

• Albumin:creatinine ratio (ACR): A specialist nephrology opinion is needed if there is a urine ACR greater than 30 mg/mmol ¹,³. Referral is also indicated for an ACR of 70 mg/mmol or more, unless it is known to be caused by diabetes and is already appropriately treated ⁶. Additionally, an ACR of more than 30 mg/mmol (ACR category A3) together with persistent haematuria warrants referral ²,⁴,⁶.
• eGFR Changes: Refer if there is a sustained decrease in eGFR of 25% or more and a change in eGFR category within 12 months ⁶. Referral is also indicated for a sustained decrease in eGFR of 15 ml/min/1.73 m² or more per year ⁶.
• Hypertension: Referral is needed if hypertension remains poorly controlled (above the person's individual target) despite the use of at least four antihypertensive medicines at therapeutic doses ²,⁴,⁶.
• Suspected Other Renal Disease or Causes: Consider referral if there are known or suspected rare or genetic causes of chronic kidney disease (CKD), such as polycystic kidney disease ²,⁴,⁶. A specialist opinion is also needed if non-diabetic causes of renal disease are suspected ¹,³. Suspect other renal disease if progressive retinopathy is absent, blood pressure is particularly high, proteinuria develops suddenly, significant haematuria is present, or the person is systemically unwell ⁵.
• Suspected Renal Artery Stenosis: This should be suspected and referred if there is a reduction in eGFR of 30% or more within 3 months of starting (or increasing the dose of) a renin-angiotensin system antagonist ²,⁴,⁶.
• Complications of CKD: Refer if there are suspected complications such as a decline in nutritional status or malnutrition, persistent hyperkalaemia, end-stage renal disease (ESRD), renal anaemia, renal mineral and bone disorder, or persistent metabolic acidosis ²,⁴.
• Risk of Renal Replacement Therapy (RRT): Refer adults with CKD if they have a 5-year risk of needing RRT of greater than 5% (measured using the 4-variable Kidney Failure Risk Equation) ⁶.
• Diagnostic Uncertainty: Referral is appropriate if there is diagnostic uncertainty ²,⁴.

It is also advisable to consider discussing management with a specialist by letter, email, telephone, or virtual meeting if there are concerns, even if the person with CKD does not immediately need to see a specialist ²,⁴,⁶.