A study of circadian rhythmicity in urinary volume excretion.

This research investigated the presence of circadian rhythmicity in urinary volume excretion. A retrospective study medical record was completed to investigate the occurrence of rhythmic variation. Twenty-five subjects were utilized to gather urinary volume data, collected at either four- or six-hour intervals. All subjects had experienced spinal cord injury resulting in neurogenic bladder syndrome. Consequently, urinary catheterization protocol was necessary for bladder emptying. The population consisted of para- and quadriplegic subjects, ranging in ages from 18 to 55 years of age. Urinary “volume†and associated “time†of collection were the principal variables of this research. Secondary variables for this study were: blood pressure, pulse, temperature, level of activity, and amount of fluid intake. Result of (consignor) analysis indicated no (circadian) rhythmicity in the group “as a whole.†Four subject had “fair†(r[2] > .25) individual results with 24-hour periods (range: 23 to 25 hours). Significant correlation was seen between urinary volume and amount of fluid intake. Otherwise, secondary variable analysis revealed non-significance in regard to urinary volume excreted.