Urinary citrate level in urinary stone formers versus controls

ABSTRACT

To determine the urinary citrate [UC] level in stone formers [SF] versus controls. Case control study. Department of Pediatric Nephrology, National Institute of Child Health [NICH], Karachi from January- July 2008. Eighty six children of 1-13 years, 43 in each group, stone former [SF] and controls were studied. In both groups, 24-hours UC was measured by citrate lyase method. Hypocitraturia was defined as 24- hours UC-level < 5mg/kg for children under 9 years and <7mg/kg for 9 years and above. Data including age, sex, weight, 24-hours urine volume [UV] and UClevel were analyzed using descriptive statistics on SPSS version 15. Of the 86 children, 59 [68.6%] were males and 27 [31.4%] females. Overall mean age was 5.65 + 3.05 years, while that of SF and controls was 5.61+ 3.1 and 5.70 + 3.04 years respectively. Mean 24-hours UV and UC-level in total of 86 samples was 385.10+130 ml and 88.10 + 62.11mg respectively. Mean + SD 24-hours UC-level [mg] in SF and controls was 69.4 + 53.55 [95%CI 53.39-85.41] and 106.8 + 65 [95%CI 87.37-126.23] respectively. Overall hypocitraturia was found in 42[48.8%] children. Frequency of hypocitraturia was high in SF [n 30, 69.8%] compared to controls [n 12, 27.9%] with a significant difference between the two groups [p<0.001]. Overall hypocitraturia was found in 48.8% of cases. Though hypocitraturia was prevalent in both groups, but was significantly high [69.8%] in SF compared to controls [27.9%]. Hypocitraturia may be an important metabolic risk factor and urinary citrate level should be included in the metabolic evaluation in all stone formers