Which analyte should be reported as a ratio relative to creatinine concentration?

Reporting urinary microalbumin as a ratio relative to creatinine concentration is essential for assessing kidney function, particularly in the context of conditions like diabetes and hypertension. This practice helps to standardize the measurement, compensating for variations in urine concentration due to factors such as hydration status.

When an individual is more hydrated, urine becomes more dilute, potentially leading to lower concentrations of microalbumin in urine. Conversely, dehydration could cause an artificially high concentration. By normalizing urinary microalbumin to creatinine, which is produced at a fairly constant rate and is less influenced by hydration status, clinicians obtain a more accurate representation of microalbumin excretion. This ratio provides a reliable means of screening for early signs of nephropathy.

While urinary estriol, sodium, and urea may be valuable for different clinical assessments, they do not typically require normalization to creatinine in the same manner as microalbumin does. Using such a ratio for these other analytes would not enhance diagnostic accuracy to the same degree as with microalbumin.