Interpretation of Creatinine Level 0.54 mg/dL
A creatinine level of 0.54 mg/dL is within the normal range for kidney function and does not indicate kidney disease. 1
Understanding Creatinine Levels and Kidney Function
Creatinine is a waste product produced by normal muscle metabolism and is filtered by the kidneys. Serum creatinine levels are used as a marker of kidney function, with higher levels typically indicating decreased kidney function.
Normal Creatinine Range:
- According to NHANES III data, the mean serum creatinine value is 0.96 mg/dL for women and 1.16 mg/dL for men in the United States 2
- Normal ranges vary by:
- Sex (lower in women)
- Age (increases with age)
- Ethnicity (highest in non-Hispanic blacks, lowest in Mexican-Americans)
- Muscle mass
Interpreting Your Result:
A creatinine level of 0.54 mg/dL is:
- Below the average values for both men and women
- Within normal physiological range
- Not indicative of kidney dysfunction
Clinical Significance
Low-Normal Creatinine:
Low-normal creatinine levels like 0.54 mg/dL can be seen in:
- Individuals with lower muscle mass
- Women (who typically have lower muscle mass than men)
- Elderly individuals with decreased muscle mass
- Malnourished states
- Pregnancy (due to increased GFR)
When to Be Concerned:
- Creatinine levels are concerning when they rise above the normal range, not when they are low-normal
- According to the National Kidney Foundation guidelines, chronic kidney disease is defined by either kidney damage or GFR <60 mL/min/1.73m² for ≥3 months 1
- AKI is defined as an increase in creatinine by 0.3 mg/dL within 48 hours or an increase to 1.5 times baseline 1
Assessment of Kidney Function
For a more accurate assessment of kidney function:
- GFR estimation using prediction equations is preferred over serum creatinine alone 1
- The MDRD Study equation or Cockcroft-Gault equation can be used to estimate GFR 1
- Serum creatinine alone may not accurately reflect kidney function, especially at extremes of muscle mass 3
Monitoring Recommendations
- If you have risk factors for kidney disease (diabetes, hypertension, family history of kidney disease):
- Annual screening for microalbuminuria is recommended 1
- Regular monitoring of kidney function
- If you don't have risk factors and your creatinine is normal:
- Routine monitoring as part of regular health examinations
Important Caveats
- Serum creatinine is less influenced by extra-renal factors than BUN and is generally a more accurate test of kidney function 4
- Trend in creatinine is often more important than absolute value, especially in those with altered muscle mass 3
- Very low creatinine levels can sometimes reflect decreased muscle mass rather than enhanced kidney function
In summary, a creatinine level of 0.54 mg/dL is within normal physiological range and does not indicate kidney dysfunction. It is at the lower end of the normal range, which could reflect lower muscle mass, but is not a cause for concern from a kidney function perspective.