Creatinine produced in the body, is formed from the breakdown of creatine. Off the total creatine (amino acid) generated in the body, almost 90% is found in the muscle tissue.
The breakdown of creatine (muscle metabolism) not only releases energy but also other products like creatinine, which are found in minimal amounts in the blood. This is because most of the creatinine in the blood is separated by the kidneys during filtration and then eliminated through the urine.
Urine Creatinine Normal Range
Generally, the patient is asked to collect urine passed in a period of 24 hours. A 24-hour urine sample will have normal creatinine levels in between 500-2000 mg/day. However, this normal urine creatinine range may differ as each laboratory has a slightly different reference range for creatinine levels.
Factors that Influence Urine Creatinine Levels
Sex: Urine creatinine levels depend upon the gender of the person. Men have higher muscle mass as compared to women. That is why creatinine levels in the blood and urine are always higher in men than in women.
Age: With age, creatinine levels in the blood decrease. This in turn shows a drop in urine creatinine levels. It is observed that muscle mass decreases with increasing age. Thus, one can say that age is inversely proportional to muscle mass.
Creatine being an integral constituent of the human muscle, a reduction in muscle mass will definitely decrease creatine levels. No wonder, old age will certainly bring down urine creatinine levels.
Decreased Creatinine Levels in Urine
In case, the blood test indicates that creatinine in the blood is in the normal range, it really doesn't matter whether urine creatinine concentration is high or low.
When are Low Urine Creatinine Levels Harmful?
Keep in mind that low urine creatinine levels is worrisome when blood creatinine concentration is abnormally high. This is definitely related to malfunctioning of the kidneys and cannot be ignored. The result proves the kidneys' inefficiency in removing adequate creatinine from the blood.
Usually, urine creatinine levels come into consideration, when blood tests indicate an alarming rise in blood creatinine concentration. In other words, creatinine concentration in the urine is not given much importance if the sample of blood is containing creatinine in normal amounts.
Disclaimer: The information provided here is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.