Uric acid kinetic studies in the immediate post-myocardial-infarction period

The etiology of hyperuricemia following myocardial infarction was investigated by uric acid kinetic studies carried out on seven male patients following myocardial infarction and on two control subjects. The patients selected had uncomplicated myocardial infarction and were maintained on a low-purine diet. Measurements of uric acid pool size and turnover rates using 2-C¹⁴ uric acid were made, commencing on days 2-5 following myocardial infarction. Initial concentration of serum uric acid ranged from 2.9 to 9.8 mg 100 ml. Uric acid pool size was elevated in six of seven patients. Five had a pool size of from 36.9 to 79.6 mg/kg, while the single gouty subject demonstrated 104 mg/kg compared with 12.6 and 16.8 mg/kg for the control subjects. Turnover rates were also increased, ranging from 1036 to 2772 mg/day (controls, 612 and 872 mg/day). Twenty-four-hour urine uric acid excretions ranged from 358 to 623 mg 24 hr. Serum lactic acid concentration was normal (1.03 ± 0.17 μM/ml), and endogenous creatinine clearance in all cases was 77.9 ml/min or greater. These data suggest that following myocardial infarction there is an expansion of the uric acid pool with an increased uric acid turnover rate. Only the patient with a previous history of gout had uric acid excretion outside the normal range.