Hi,
You have asked some very good questions:
First, let me mention that there are limitations with the dipstick test commonly used to assess proteins in urine, which make the test less sensitive when there is a small amount of protein in urine (trace). This makes the results of the test less meaningful.
1. On the day of the test, I drink very little water. I just got urine a little bit more than the tube the doctor provided, the color was dark yellow, does this affect the result?
Yes, the dipstick method is associated with false positives in
highly concentrated urine. This is overcome in the lab by doing another confirmatory test called sulfosalicylic acid test.
There are other causes of false positive results such as contamination with disinfectants, x-ray contrast media, massive doses of penicillin, cephalosporins as well as other drugs (including sulfa drugs). The dipstick method is also less sensitive to positively charged proteins as opposed to negatively charged proteins such as
albumin.
I think you can see why your doctor isn't willing to give too much importance to your results when there's only a trace of protein detected. As the test is very unreliable in this range.
There are also many benign causes of the so called transient proteinuria which can occur as a result of
fever, exercise or cold exposure.
Your doctor would have evaluated your result in perspective to your overall medical history as well as your other test results. If you have another risk for protein in urine (eg,
diabetes,
hypertension, pregnancy in females), he would want to make sure that this isn't something more serious.
To answer your other questions:
2. I am taking simvastatin 5 mg and other high blood pressure medicine. All my blood pressure and
cholesterol results are ok, I heard that some statin drug can break down the muscle, is there any possible of that to cause protein in my urine?
Yes,
statins can cause myopathy - I personally have seen only one such case. This is because it's extremely rare. However, if this does happen it won't be a trace of proteins in your urine and it would be accompanied with muscle related symptoms (commonly a proximal myopathy).
3. I have a small cyst on one of my kidney, will that cause it?
Highly unlikely given that all our other tests are normal and there are no complaints, and the questionable significance of a trace of protein in urine.
4. Should I go back to see a doctor sooner or as my doctor said come back at 3 months?
Only if new symptoms / complaints arise, otherwise I would wait for 3 months.
I hope this helps, please keep us updated.
Best regards,
Dr. Tamer Fouad, MD
MB, BCh, MSc Internal Medicine.
Consultant of Hematology - Oncology.
