Creatinine (Urine) - DUTCH

In this section of the DUTCH test, you’ll see your creatinine values from all four urine samples collected throughout the day.
Creatinine is measured for one important reason: to correct hormone results for urine dilution.

Why Creatinine Matters in Urine Hormone Testing

The concentration of hormones in urine can vary depending on how diluted your sample is.

• If you are well-hydrated, your urine is more diluted, and hormone concentrations appear lower.

• If you are dehydrated, your urine is more concentrated, and hormone levels may appear higher.

Creatinine correction adjusts for these differences. Because creatinine is excreted at a relatively steady, predictable rate in healthy individuals, it serves as a reliable reference point to “normalize” your results, regardless of hydration.

Creatinine Correction and Accuracy

The DUTCH test uses creatinine correction to make its spot urine samples comparable to the gold standard: a 24-hour urine collection.
A 24-hour urine test captures hormone excretion over an entire day but can be difficult for patients to complete correctly.

Research shows that when a 24-hour urine collection is done properly, creatinine-corrected DUTCH values match closely with 24-hour urine hormone results. This correlation supports the accuracy and validity of creatinine correction in the DUTCH method.

Important Considerations

• Abnormal kidney function (such as impaired creatinine clearance or low glomerular filtration rate – GFR) can affect creatinine levels and, therefore, the accuracy of correction.

• Any urine hormone test (DUTCH or 24-hour) should not be used to assess free cortisol in patients with significantly reduced kidney function, as results may appear artificially low.

• Proper hydration and following collection instructions closely help ensure more accurate results.

Key Takeaways

• Creatinine correction accounts for urine dilution, making hormone measurements more reliable.

• It allows spot urine samples from the DUTCH test to be compared to 24-hour urine results.

• Kidney health plays a role in creatinine accuracy—results may be skewed if creatinine clearance or GFR is abnormal.