by Dr. Leo Galland
Researchers at Johns Hopkins University have found an association between low level exposure to lead and reduced kidney function in healthy American teenagers. Although all of the teens had blood lead levels within a range generally accepted as safe, those with higher levels within that range had reduced kidney function when compared to those with lower lead levels.
The importance of these findings is that even small decreases in kidney function tend to become amplified with time and 26 million Americans currently suffer from chronic kidney disease.
The study’s authors speculate that reducing the body burden of lead may help to prevent development of chronic kidney disease or improve kidney function in those who already have impaired kidney function. They cite a study done in Taiwan which found that chelation to remove lead improved kidney function in adults with moderate kidney impairment who had evidence of low-level lead exposure.
Sources of lead exposure include drinking water, old paint, and construction materials, especially those used for plumbing. The soil around new homes is contaminated with lead.
Learn about ways to reduce lead exposure in my article “Twelve Simple Steps to A Healthy Home” at the Foundation for Integrated Medicine Website
Reference and Abstracts
Fadrowski et al, Blood lead level and kidney function in US adolescents. Arch Intern Med 170: 75-82 (2010). (abstract not yet available)
Nephrol Dial Transplant. 2007 Oct;22(10):2924-31. Long-term outcome of repeated lead chelation therapy in progressive non-diabetic chronic kidney diseases.Lin-Tan DT, Lin JL, Yen TH, Chen KH, Huang YL.Division of Nephrology and Poison Center, Chang Gung Memorial Hospital, 199 Tung Hwa North Rd., Taipei, Taiwan, ROC.
BACKGROUND: Previous research suggest that repeated lead-chelation therapy decelerates progression of renal insufficiency in non-diabetic (non-DM) patients with high-normal body lead burden (BLB). Study findings are limited by relatively short-term follow-up and small sample size.
METHODS: A total of 116 non-DM patients with chronic kidney diseases (serum creatinine level of 1.5-3.9 mg/dl), high-normal BLB (>60 microg and <600 microg) and no lead exposure history were randomly assigned to a chelation or control group in this 4-year clinical trial. For 3 months, the 58 chelation group patients received initial lead-chelation therapy with calcium disodium EDTA, and the 58 control group patients received placebos. During the ensuing 48 months, repeated chelation therapy was administered weekly to chelation group patients unless, on repeated testing, BLB was <60 microg; the control group patients received weekly placebo infusions for 5 weeks at 6-month intervals.
RESULTS: Mean change in the glomerular filtration rate (GFR) in the chelation group was -1.8 +/- 8.8 ml/min/1.73 m(2), as compared with -12.7 +/- 8.4 ml/min/1.73 m(2) in the control group (P <0.0001) at study end. Chelation group rates of decline in the GFR was lower than that in the control group, although they had similar decline rates before chelation. At study end, 18 patients, including 15 control group patients, had elevated serum creatinine levels to two times the baseline values. Both Cox and Kaplan-Meier analysis demonstrated repeated chelation therapy was the important determining factor of progression of renal insufficiency. CONCLUSIONS: Repeated chelation therapies can, over a four-year period, slow progression of renal insufficiency in non-DM patients with high-normal BLB
Kidney International (2003) 63, 1044–1050; Blood lead and chronic kidney disease in the general United States population: Results from NHANES III. Paul Muntner, Jiang He, Suma Vupputuri, Josef Coresh and Vecihi Batuman. Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine; Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana; Department of Epidemiology, Biostatistics, and Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland; and Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
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 = 15,211). Elevated serum creatinine was defined as ≥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. Conclusion: 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.
