Falsely low or negative results can result from any of the following: Ascorbic acid Ketones Aspirin Levodopa Tetracycline Very high urine pH Dilute urine Glucose can appear in the urine despite normal plasma glucose levels in Fanconi syndrome (proximal tubule defect), renal glucosuria, and with use of sodium-glucose co-transporter 2 (SGLT2) inhibitor.