Urinary lead excretion in uremic patients.

Urinary excretion of lead (Pb) was measured in the basal state and following the infusion of EDTA (1g of calcium disodium edetate) in healthy German controls and in patients with chronic renal failure with and without gout. When evaluated with Zeeman-compensated atomic absorption spectroscopy using the L'vov platform and urine pretreated with nitric acid and Triton X-100, the control basal Pb excretion (median 28, range 11-19 nmol Pb/24h) and the postinfusion Pb increment (306, range 131-1,587 nmol/4 days/1.73 m2) were considerably lower than most values reported previously in the literature. Elevated Pb body burden was found in 7 of 8 patients who developed gout in the course of renal failure, but only in 2 of 8 patients who had gout prior to development of renal failure; this confirms that appearance of gout in patients with renal failure points to prior Pb exposure. In 7 of 19 nongouty patients with impaired renal function secondary to known renal diseases, urinary Pb excretion was above the 95th percentile of normal. All these patients had occupational Pb exposure. The high prevalence of elevated Pb body burden in patients with renal failure of known cause may not be coincidental and raises the possibility that Pb adversely affects the course of renal disease.