Kidney Function Assessment Using BUN/Creatinine Ratio

Interpretation and Clinical Significance

• A low BUN/creatinine ratio may indicate malnutrition or low protein intake 1
• Age-related changes in muscle mass can affect creatinine levels in older adults, potentially masking mild renal dysfunction despite normal-appearing laboratory values 1
• The National Kidney Foundation recommends estimated GFR using formulas like MDRD or CKD-EPI for more accurate assessment of kidney function than relying solely on BUN and creatinine values 1
• Verification of other renal function parameters, such as eGFR and urinalysis, is recommended for comprehensive assessment 1
• Assessment of hydration status and review of dietary protein intake should be considered when interpreting BUN/creatinine ratios 1
• More frequent monitoring of renal function may be warranted in patients with risk factors for kidney disease, such as diabetes, hypertension, or family history 1
• The MDRD formula may be the estimation of choice in elderly patients, whereas the Cockcroft-Gault formula is preferable in subjects younger than 65 years 2