Blood lead level and kidney function in US adolescents: The Third National Health and Nutrition Examination Survey.
BACKGROUND
Chronic, high-level lead exposure is a known risk factor for kidney disease. The effect of current low-level environmental lead exposure is less well known, particularly among children, a population generally free from kidney disease risk factors such as hypertension and diabetes mellitus. Therefore, in this study, we investigated the association between lead exposure and kidney function in a representative sample of US adolescents.


METHODS
Participants included 769 adolescents aged 12 to 20 years for whom whole blood lead and serum cystatin C were measured in the Third National Health and Nutrition Examination Survey, conducted from 1988-1994. The association between blood lead level and level of kidney function (glomerular filtration rate [GFR]), determined by cystatin C-based and creatinine-based estimating equations, was examined.


RESULTS
Median whole blood lead level was 1.5 microg/dL (to convert to micromoles per liter, multiply by 0.0483), and median cystatin C-estimated GFR was 112.9 mL/min/1.73 m(2). Participants with lead levels in the highest quartile (> or =3.0 microg/dL) had 6.6 mL/min/1.73 m(2)-lower estimated GFR (95% confidence interval, -0.7 to -12.6 mL/min/1.73 m(2)) compared with those in the first quartile (<1 microg/dL). A doubling of blood lead level was associated with a 2.9 mL/min/1.73 m(2)-lower estimated GFR (95% confidence interval, -0.7 to -5.0 mL/min/1.73 m(2)). Lead levels were also associated with lower creatinine-based estimated GFR levels, but the association was weaker than with cystatin C-based GFR and not statistically significant.


CONCLUSIONS
Higher blood lead levels in a range below the current Centers for Disease Control and Prevention-designated level of concern (10 microg/dL) were associated with lower estimated GFRs in a representative sample of US adolescents. This finding contributes to the increasing epidemiologic evidence indicating an adverse effect of low-level environmental lead exposure.
Fadrowski
Jeffrey J
JJ
Welch Center for Prevention, Epidemiology and Clinical Research, Baltimore, MD, USA. jfadrow1@jhmi.edu
Navas-Acien
Ana
A
Tellez-Plaza
Maria
M
Guallar
Eliseo
E
Weaver
Virginia M
VM
Furth
Susan L
SL
D000293:Adolescent; D002648:Child; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007677:Kidney Function Tests; D007854:Lead / Q000097:blood*; D007855:Lead Poisoning / Q000097:blood / Q000453:epidemiology; D016014:Linear Models; D008297:Male; D009749:Nutrition Surveys; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
D055316:Cystatin C; D007854:Lead; D003404:Creatinine