DIETARY ALTERATIONS IN PLASMA VERY-LOW-DENSITY LIPOPROTEIN LEVELS MODIFY RENAL EXCRETION OF URATES IN HYPERURICEMIC-HYPERTRIGLYCERIDEMIC PATIENTS

Hyperuricemic-hyperlipidemic patients exhibit decreased renal excretio n of urates relative to purely hyperuricemic patients; also, very low density lipoprotein (VLDL) levels are inversely proportional to the am ount of urate excreted. Based on this knowledge, the aim of this study was to alter VLDL levels by dietary manipulation and assess its effec t on uric acid levels and renal excretion of uric acid. Thirty-six men were studied in 2 groups consisting of 20 primary hyperuricemic (grou p I) and 16 primary hyperuricemic-hypertriglyceridemic patients (group II). The patients were analyzed for apoproteins and lipoproteins, ura te levels, and renal excretion of uric acid in a first, basal determin ation, after 3 weeks of a 1200-Cal diet, and after another 3 weeks of a 2500-Cal diet. After the 1200-Gal diet, patients in group I exhibite d significantly decreased levels of cholesterol (P < 0.05) and apoprot ein CIII (P < 0.05). There were significant differences in renal excre tion of uric acid (P < 0.05) between the basal and third determination s. Patients in group II exhibited significantly decreased levels of tr iglycerides (P < 0.01), VLDL cholesterol (P < 0.01), VLDL triglyceride s (P < 0.01), and VLDL apoprotein B (P < 0.05) after the 1200-Cal diet ; all of these parameters returned to values similar to the basal leve ls on completion of the 2500-Cal diet. With regard to purine parameter s, the low calorie diet led to significantly increased fractional excr etion of uric acid (P < 0.01) and uric acid clearance (P < 0.01), both of which decreased significantly to values near basal after the 2500- Cal diet. The results obtained in this study reveal that the decreased levels of triglyceride and VLDL components that arise from a low calo rie diet are accompanied by increased renal excretion of urates and th at the increase in the amount of this type of lipoprotein particle wit h an increase in dietary energy offsets the increase in renal excretio n of urate.