Effect of a change in the place of urine collection on urine composition

Completeness of urine collection and food intake can influence urinary biochemical composition (UC). These variables depend in part upon whether patients are ambulatory or in-patients. This study was conducted to see whether the change in the place of urine collection from village to hospital would affect UC. Six consecutive 24-hour urinary measurements for creatinine (cr), urea nitrogen (urea-N), calcium (Ca) and sodium (Na) were made in 8 normal male volunteers. The first three 24-hour urine specimens (UV) were collected at home and the last three when they were in the hospital. Food consumed while subjects were in their village was recorded and prepared in the same manner for the same subjects when they were at the hospital. Comparing the values between at the village and at the hospital, the urinary cr, urea-N, Ca and Na increased disproportionately with the average hospital/village ratio of 1.17, 1.20, 1.50 and 1.09 respectively. The median of relative rate of increase of urinary urea-N, Na and Ca compared to that of cr, being expressed as (hospital/village UV urea-N)/(hospital/village UV cr), (hospital/village UV Na)/(hospital/village UV cr) and (hospital/village UV Ca)/(hospital/village UV cr) respectively, were 1.00, 0.97 and 1.30 respectively. The data indicated that the change in urinary urea-N and Na when the subjects were at the hospital was mainly due to completeness of urine collection. In contrast, marked increment in UV Ca at the hospital was accounted for factor(s) by other than completeness of urine collection per se. The difference in dietary Ca intake between village and hospital might have been responsible in part for the changes.(ABSTRACT TRUNCATED AT 250 WORDS)