Low urine creatinine

Question
I am a registered nurse and, until recently, the director of nursing at a long-term care facility.  Recently, there was suspicion of drug diversion and the company completed drug screening on 27 employees out of 250 employees.  To provide a urine sample, the drop was closely observed.  I have a VERY shy bladder, therefore, I required 4 attempts and had to remain in the HR office until I could provide an adequate specimen.  I ended up drinking almost 4 liters of water and 32 ounces of coffee.  The Medical Review Officer deemed my urine to be "substituted" and not consistent with human urine based on the low level of creatinine.  During the three hour period, I emptied my bladder 4 times. Each time, the temperature of my urine was within normal temp (90-100 degrees). My creatinine was 1.0.  Due to this, the facility did not give me an additional opportunity to provide a drug screen of their choice, and I was terminated based on these findings.  As I stated before, I was closely observed each time I attempted to provide a specimen.  Is it possible, given these circumstances, for this urine to be "human urine" and not a substitute.  If so, is this something I should be concerned about related to my kidney function?


Answer
Hi Andrea,



I am sorry to hear that you had to pass through such an ordeal to provide a urine specimen.



Very dilute urine can cause abnormally low creatinine. It is entirely possible that the specimen you provided was "human urine" after all but was just very dilute. After all, what do you expect after drinking almost 5 liters of fluid?



Please ask for a re-test and don't drink too much this time.



Sincerely,



Dr. Shah