Second specimen testing in diabetes mellitus

Since hospitals practices vary in respect to the time for obtaining urine specimens to be tested for glycosuria, this study was done to determine if results differ in relation to voiding times. Based on the assumption that glucose spilled above the renal threshold collects and mixes in the bladder over a period of time causing a change in readings of glucose and acetone, the times for urine testing were set up to include routine collection times with a second specimen tested 30 minutes later (7:00 a.m., 11:00 a.m., 11:30 a.m., 5:00 p.m., 5:30 p.m., 9:00 p.m., and 9:30 p.m.). The sample consisted of 72 patients all receiving insulin injections at 7:30 a.m. each day with no food intake from 10:00 p.m. the preceding night until insulin injections were given the next morning. The five drop Clinitest method was used by six trained examiners to determine the glucose and acetone content of each voided specimen. Urinary volume was measured with each testing as an indirect index to voiding frequency. The results of an analysis of variance indicated significant differences between voiding times of both acetone and glucose concentrations. A Duncan Multiple Range of Means Test indicated the first voiding of the day to be significantly different than subsequent voiding in sugar and acetone. These results tended to support the theory of cumulation of spilled glucose and acetone in the bladder requiring emptying prior to urine collection for glycosuria and acetonuria.