DOES LEAD PLAY A ROLE IN THE DEVELOPMENT OF RENAL-INSUFFICIENCY IN SOME PATIENTS WITH ESSENTIAL-HYPERTENSION

The association of excessive lead burden and essential hypertension ha s been a subject of much dispute. In particular, the potential detrime ntal effect of low level environmental exposure on BP has caused consi derable concern. We studied the urinary excretion of lead following th e infusion of EDTA (1 g of calcium disodium edetate) in 12 healthy con trols (group I), 10 subjects with essential hypertension alone (Group II) and in 36 subjects with chronic renal insufficiency. Those subject s with renal insufficiency were further divided into three groups: gro up III, 12 patients with a history of 7-19 years of essential hyperten sion who subsequently developed into renal failure; group IV, patients with chronic renal failure alone; and group II), patients with chroni c renal failure due to causes other than hypertensive nephropathy and associated with secondary hypertension. In comparison with other group s, subjects with hypertensive nephropathy (group III) had significantl y elevated lead body burden. In addition, we found that five of the 12 subjects with hypertensive nephropathy had histories of acute gouty a ttacks after the development of renal function impairment. In conclusi on, our observation of a higher EDTA postinfusional urinary lead excre tion among some patients with essential hypertension with renal functi on impairment indicates that lead may play a crucial role in a subgrou p of patients with hypertensive nephropathy.