Does leaving morning urine for 3 hours affect the detection of urinary protein?

Generally, leaving the first morning urine sample for 3 hours may affect the accuracy of the urine protein test results. The specific analysis is as follows:

If the room temperature is relatively high, the proteins in the first morning urine sample might degrade after being left for 3 hours, or bacteria in the urine may multiply. These changes could lead to inaccuracies in the urine protein test results, such as false negatives or false positives. Therefore, to ensure the accuracy of the urine protein test, it is recommended to send the first morning urine sample for testing as soon as possible, ideally within 2 hours after collection. If timely submission is not possible due to special circumstances, make every effort to avoid contamination of the urine sample and inform the doctor about the storage time and conditions before submitting the sample.

In addition, prior to collecting the first morning urine sample, it is advisable to maintain healthy lifestyle habits, avoid alcohol consumption and excessive smoking, and reduce the intake of spicy, stimulating, and greasy foods.