What diseases can cause chronic kidney disease (CKD) with normal sized kidneys?

Diseases That Cause Chronic Kidney Disease with Normal Sized Kidneys

Several diseases can cause chronic kidney disease while maintaining normal kidney size, including diabetic nephropathy, minimal change disease, primary focal segmental glomerulosclerosis, and certain tubulointerstitial diseases. 1

Primary Causes with Normal Kidney Size

• Diabetic Kidney Disease (DKD): In early stages, diabetic nephropathy typically presents with normal-sized kidneys despite progressive kidney damage. This is particularly common in type 2 diabetes where kidney size is initially preserved despite declining function 1

• Minimal Change Disease: This glomerular disorder can cause significant proteinuria and kidney dysfunction while maintaining normal kidney morphology on imaging 1

• Primary Focal Segmental Glomerulosclerosis (FSGS): Can cause progressive CKD with normal-sized kidneys, especially in early stages 1

• Polycystic Kidney Disease: While eventually causing enlarged kidneys, in early stages kidney function may decline with relatively normal-appearing kidneys 1

Other Causes with Normal Kidney Size

• Tubulointerstitial Diseases: Autosomal dominant tubulointerstitial kidney diseases can lead to progressive fibrosis and CKD while maintaining normal kidney size 2

• Glomerulonephritis: Various forms of glomerulonephritis can cause CKD with normal-sized kidneys, particularly in early stages 2

• Infiltrative Disorders: Conditions that cause infiltration of kidney tissue can maintain kidney size while reducing function 1

• Polyneuropathy-Associated CKD: Certain conditions causing both polyneuropathy and kidney disease may present with normal kidney size 3

Diagnostic Considerations

• Ultrasound Findings: While CKD typically presents with small kidneys and cortical thinning, normal-sized kidneys do not exclude CKD, particularly in diabetic nephropathy and infiltrative disorders 1

• Kidney Biopsy: May be necessary to definitively diagnose the cause of CKD when kidneys appear normal on imaging, as up to 30% of patients with diabetic kidney disease may have other causes of CKD on kidney biopsy 1

• Laboratory Evaluation:

  • Persistent albuminuria (UACR >30 mg/g) for at least 3 months is a key marker for CKD even with normal kidney size 1
  • eGFR <60 mL/min/1.73 m² for at least 3 months confirms CKD regardless of kidney size 1

Clinical Implications

• Higher Risk of Misdiagnosis: Normal-sized kidneys in a patient with declining kidney function may lead clinicians to incorrectly attribute symptoms to acute rather than chronic kidney disease 4

• Monitoring Requirements: Patients with normal-sized kidneys but risk factors for CKD require regular monitoring of kidney function, including urinalysis for proteinuria and measurement of serum creatinine 4

• Disease Progression: Despite normal kidney size, these conditions can progress to end-stage kidney disease if not properly managed 2

Management Considerations

• Early Intervention: For diabetic kidney disease with normal-sized kidneys, early use of SGLT2 inhibitors can preserve kidney function and reduce cardiovascular events 2

• Blood Pressure Control: Optimal blood pressure management is crucial in all forms of CKD, regardless of kidney size 1

• Nephrology Referral: Consider referral when GFR <30 mL/min/1.73 m², confirmed significant proteinuria, or rapid decline in eGFR despite normal kidney size 1, 4

• Avoidance of Nephrotoxins: Patients with CKD and normal-sized kidneys should still avoid potential nephrotoxins such as NSAIDs 5

Remember that normal-sized kidneys on imaging do not exclude CKD, particularly in diabetic nephropathy, and a comprehensive diagnostic approach including laboratory testing and possibly kidney biopsy may be necessary to establish the underlying cause.