Renal function 9 to 17 years after childhood lead poisoning

Renal function was studied in 74 subjects who, between 1966 and 1972 (ages 1 to 6 years) had had blood lead levels (PbB) ≥100 μg/dl (range 100 to 471 μg/dl, median 142 μg/dl) and in 21 sibling controls. PbB measured in 1983 in study subjects remained significantly higher than in sibling controls (mean ± 1 SD 14.5 ± 4.5 vs 11.6 ± 2.6 μg/dl, P<0.01). The two groups did not differ in development of hematuria or leukocyturia. The frequency of elevated serum creatinine concentration, depressed creatinine clearance, elevated protein excretion, low urinary osmolality, elevated serum β₂-microglobulin (β₂-M), and elevated fractional excretion β₂-M %×100 was similar in the two groups. Mean values for these tests were similar in study subjects compared with sibling controls. Mean systolic blood pressure was significantly higher in study subjects compared with that in sibling controls (117±12 vs 109±10 mm Hg), but the control group contained a preponderance of females and the study group had more overweight females; mean diastolic blood pressure was similar in the two groups. We conclude that in our adolescent subjects who had had lead poisoning 9 to 17 years earlier, there is little if any evidence of chronic nephropathy.