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 has been a subject of much dispute. In particular, the potential detrimental effect of low level environmental exposure on BP has caused considerable concern. We studied the urinary excretion of lead following the infusion of EDTA (1 g of calcium disodium edetate) in 12 healthy controls (group I), 10 subjects with essential hypertension alone (Group II) and in 36 subjects with chronic renal insufficiency. Those subjects with renal insufficiency were further divided into three groups: group III, 12 patients with a history of 7-19 years of essential hypertension who subsequently developed into renal failure; group IV, patients with chronic renal failure alone; and group II), patients with chronic renal failure due to causes other than hypertensive nephropathy and associated with secondary hypertension. In comparison with other groups, subjects with hypertensive nephropathy (group III) had significantly elevated lead body burden. In addition, we found that five of the 12 subjects with hypertensive nephropathy had histories of acute gouty attacks after the development of renal function impairment. In conclusion, our observation of a higher EDTA postinfusional urinary lead excretion among some patients with essential hypertension with renal function impairment indicates that lead may play a crucial role in a subgroup of patients with hypertensive nephropathy.