A study on evaluation of different urinary constituents and their ratios in patients with urolithiasis

Abstract

Background
The lifetime prevalence of kidney stone disease is estimated 1% to 15 % with the probability of varying according to age, gender, race and geographic location. Adult men are 3 times more affected than adult women. Calcium oxalate stones are common in south east. Uric acid stones are common in the east. In India prevalence is more than 11%.Stone disease peaks at 4th to 6th decade. Higher prevalence of stone disease is found in hot, arid or dry climates. Metabolic defects are less likely to occur in the first time stone formers than in patients with recurrent disease. Hypocitraturia and hyperoxaluria are common abnormalities found in stone formers. Stone formers have significantly higher calcium, oxalate and uric acid levels. Citrate/calcium ratios are found to be low in stone formers.Objectives:1.Estimation of urinary parameters such as calcium, magnesium, uric acid, creatinine, oxalate, phosphate and citrate in 24 hour urine. 2.Estimation of calcium/creatinine, citrate/creatinine, uric acid/creatinine, calcium/citrate ratios in 24 hour urine and specifically to screen a patient with renal stone and in turn it will help in the treatment and prevention of stone formation in recurrent stone formers.Materials &Methods:The study included 100 subjects comprising of 50 healthy controls and 50 urolithiasis cases. 24 hour urine was collected and toluene was added as preservative. Urine calcium was estimated by Arsezano’s method. Urine magnesium was estimated by Xylidyl blue method. Urine phosphorus was estimated by end point method. Urine uric acid was measured by uricase method. Urine creatinine was estimated by modified Jaffe’s method. Citrate and oxalate was estimated by enzymatic method.Results:The urinary calcium, phosphorus, uric acid, oxalate was increased in cases when compared to controls. Urine magnesium and citrate was reduced when compared to controls. Urine creatinine was normal or decreased in cases than controls.Conclusion:This study is being undertaken to estimate different ratios so as to get specific ratio as an index in stone formers whereas high calcium/creatinine ratio can be used as a screening procedure to detect increase calcium in urine.