Evaluation of biochemical parameters in calcium oxalate renal stone formers

Abstract

Background: Calcium oxalate renal stones are the most predominant cases of renal stones, their formation is more complex and no specific cause for the stone can be identified so called 'idiopathic'. This study was designed to analyze the metabolic and biochemical alterations in serum, urine and their relation to pathophysiology of calcium oxalate stone formation Patients and Methods : In this study, individuals have been classified into three groups: Group (A) included (29) apparently healthy persons of non calcium oxalate stone formers aged (20-35 years), group (B) included (16) patients with calcium oxalate renal stone aged (20-35 years) and group(C) included (15) patients with calcium oxalate renal stone aged (40-70 years). Fasting serum, random urine and 24-hours urine samples were collected from all individuals to determine urine volume, creatinine clearance, serum and urine levels of calcium, phosphate ,uric acid ,zinc, copper and serum levels of total cholesterol, high density lipoproprotien-cholesterol and urea .Results: Calcium oxalate stone formers group (B) exhibited significantly decreased serum levels of uric acid (P=0.015),zinc (P=0.031) with increased serum level of total cholesterol(P=0.034) when compared to similar age group of healthy control ,group (A). Urinary parameters in calcium oxalate stone formers also showed significantly increased levels of 24-hour urine calcium(P=0.05) and urine calcium: creatinine ratio (P=0.05)when compared to healthy control. While, older age calcium oxalate stone formers, group (C) showed significantly decreased urine volume (P=0.015)with increased kidney stone size(P=0.03) when compared to younger age calcium oxalate stone formers, group (B). Conclusions: Level of urinary calcium and urine volume are the most important urinary factors in enhancing calcium oxalate stone formation. While the observed changes in biochemical measurements of serum in calcium oxalate stone formers may indicate a probable metabolic relation in pathogenesis of this disease.