Association of dietary fatty acids with urinary oxalate excretion in calcium oxalate stone-formers in their fourth decade

OBJECTIVE: To examine the influence of the dietary intake of fatty acid on urinary oxalate excretion in calcium oxalate stone-formers in their fourth decade, as previous reports show that animal fat intake is associated with urinary oxalate excretion. PATIENTS AND METHODS: The dietary intake of 58 idiopathic stone-formers in their fourth decade was recorded using the dietary-record method. The patients collected 24-h urine samples at home and their urinary oxalate excretion was measured in a clinical biochemistry laboratory. The results were used to determine the relationship between the dietary intake of fatty acids and urinary oxalate excretion. Associations between urinary oxalate excretion and dietary contents of animal fat, animal protein and various fatty acids were assessed using Spearman's correlation coefficient and multiple regression. RESULTS: The dietary content of arachidonic acid was positively correlated with urinary oxalate excretion, as assessed by univariate and multivariate analysis. CONCLUSION: The association between arachidonic acid and oxalate excretion suggests that arachidonic acid increases the intestinal absorption of oxalate and increases the clearance of oxalate in the kidneys.