From the Research
A creatinine level of 3600 micromol per kilogram per day in urine is within the normal range. Normal urinary creatinine excretion typically ranges from 3000 to 5000 micromol per kilogram per day (or approximately 124-230 mg/kg/day) in healthy adults 1. Creatinine is a waste product from muscle metabolism that is filtered by the kidneys and excreted in urine at a relatively constant rate. This measurement is often used as a reference point when measuring other substances in urine, as it helps account for variations in urine concentration. The value can vary somewhat based on muscle mass, with men generally having higher values than women, and athletes or those with greater muscle mass having higher values than those with less muscle mass.
Some key points to consider when interpreting creatinine levels include:
- The relationship between serum creatinine and glomerular filtration rate is hyperbolic, which can impact the precision of creatinine-based equations, especially in low or normal-low creatinine levels (or high or normal-high glomerular filtration rate range) 2.
- Serum creatinine is the most widely used functional biomarker of the kidney, but its use is associated with substantial shortcomings, including tubular secretion and the influence of muscular mass or protein intake on its concentration 3.
- Estimating static kidney function accurately and detecting changes in kidney function in a timely fashion are challenging but critically important tasks, and creatinine levels should always be interpreted within the full clinical context 4.
If you're concerned about this value in the context of other abnormal test results or symptoms, it would be appropriate to discuss this with your healthcare provider.