Blood lead and chronic kidney disease in the general United States population: results from NHANES III.
BACKGROUND
High lead exposure is associated with hypertension and renal dysfunction but the effect of low-level environmental exposure is not as well studied.


METHODS
We examined the association between blood lead and renal function among a representative sample of the civilian noninstitutionalized United States population with and without hypertension, age 20 years old or older, participating in the Third National Health and Nutrition Examination Survey (NHANES III) (N=15211). Elevated serum creatinine was defined as >or=99th percentile of each race-sex specific distribution for healthy young adults and chronic kidney disease (CKD) as a glomerular filtration rate (GFR) <60 mL/min estimated using the Modification of Diet in Renal Disease (MDRD) formula.


RESULTS
Among persons with and without hypertension, mean blood lead was 4.21 and 3.30 ug/dL, respectively, the prevalence of elevated serum creatinine was 11.5% and 1.8%, respectively, and CKD was 10.0% and 1.1%, respectively. Among persons with hypertension, a graded association was present between higher quartile of blood lead and a higher odds ratio of both an elevated serum creatinine and CKD. Comparing the highest to lowest quartile of blood lead, the multivariate adjusted odds ratio (95% CI) of an elevated serum creatinine and CKD were 2.41 (1.46, 3.97) and 2.60 (1.52, 4.45), respectively. The analogous adjusted odds ratios (95% CI) among normotensives were 1.09 (0.53, 2.22) and 1.09 (0.41, 2.89), respectively. Associations were consistent when modeling lead as a continuous variable and in all subgroups except smokers.


CONCLUSIONS
In the United States population with hypertension, exposure to lead, even at low levels, is associated with CKD. Reduction of lead exposure may reduce the burden of CKD in the community.
Muntner
Paul
P
Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana 70112, USA. pmuntner@tulane.edu
He
Jiang
J
Vupputuri
Suma
S
Coresh
Josef
J
Batuman
Vecihi
V
D000328:Adult; D000368:Aged; D002908:Chronic Disease; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D006977:Hypertension, Renal / Q000097:blood* / Q000453:epidemiology*; D007854:Lead / Q000097:blood*; D007855:Lead Poisoning / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D015995:Prevalence; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
D007854:Lead; D003404:Creatinine