January 26, 2001
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Abstract of the scientific publication is below.
Lead Linked to Kidney Disease Progression, Taiwan Researchers Report
Even low levels of lead in the blood may impair kidney
function--especially in patients with kidney disease, researchers in
Though advances have been made in controlling environmental lead, the
heavy metal is still considered to be an important pollutant. And while
the toxic effects of heavy lead exposure on the kidney are well
documented, ``few studies have attempted to evaluate the (kidney)
effects of low-level lead exposure,'' according to Dr. Ja-Liang Lin of
the Lin-Kou Medical Center in Taipei, Taiwan, and colleagues.
In a new study, Lin's group followed 110 chronic kidney disease patients
for 3 years. The patients were split into two groups--those with
high-to-normal blood lead levels and those with low levels of blood
lead. Their findings are published in the January 22nd issue of the
Archives of Internal Medicine.
The patients with higher blood lead levels were shown to have 1.5 times
more creatinine in their urine. Creatinine, a compound found mostly in
muscle tissue, is used as an indicator of kidney function.
During the second year of evaluation, it was found that people with the
higher blood lead levels showed worsening kidney function than did those
with lower blood lead levels, the report indicates.
After the primary evaluation was completed, the patients with the higher
blood lead levels underwent therapy to remove lead from the blood. A
``significant improvement'' of kidney function was noted and the
improvement lasted more than 12 months, the researchers report.
SOURCE: Archives of Internal Medicine 2001;161:264-271. Vol. 161 No. 2,
January 22, 2001
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Environmental Lead Exposure and Progressive Renal Insufficiency
Ja-Liang Lin, MD; Dan-Tzu Tan, RN; Kuan-Huang Hsu, PhD; Chun-Chen Yu, MD
Several recent studies show that serum creatinine level or creatinine
clearance is inversely associated with blood lead levels. However, the
studies did not allow direct inferences about causality.
To evaluate the relation between body lead burden (BLB) and progressive
renal insufficiency in patients without previous heavy lead exposure.
A prospective, longitudinal study with a controlled clinical trial.
One hundred ten patients with chronic renal insufficiency (serum
creatinine level, 133-354 µmol/L [1.5-4.0 mg/dL]) and normal BLB (EDTA
mobilization tests, <600 µg per 72-hour urine collection) and without a
history of previous heavy lead exposure were divided into 2 groups
according to BLB: the high-normal BLB group (BLB 80 µg and <600 µg) and
the low BLB group (BLB <80 µg). Patients were prospectively followed up
for 2 years.
Main Outcome Measures
The primary outcome was a 1.5 times increase in the initial creatinine
level. The secondary outcome was a change over time in the value of
creatinine clearance. At the end of follow-up, a 3-month clinical trial
with chelation therapy for patients with high-normal BLB was performed
to clarify the role of environmental lead exposure in progressive renal
Fifteen patients (14 in the high-normal BLB group and 1 in the low BLB
group) reached the primary outcome within 24 months. Renal outcome was
significantly better in the low BLB group (P<.001). From month 12 to
month 24, renal function of high-normal BLB patients had a greater rate
of progressive renal insufficiency than that of low BLB patients. In the
Cox multivariate regression analysis, BLB was the most important risk
factor for determining the progression of renal insufficiency. After
chelation therapy, significant improvement in renal function was noted.
In addition, the effect of improving renal function lasted for more than
12 months in these patients.
Long-term low-level environmental lead exposure may subtly affect
progressive renal insufficiency in the general population. Progressive
renal insufficiency may be improved for at least 1 year after lead
chelating therapy. Further investigations are needed to clarify this
Arch Intern Med. 2001;161:264-271
>From the Poison Center and the Division of Nephrology, Chang Gung
Memorial Hospital, Lin-Kou Medical Center, Medical College (Drs Lin and
Yu and Ms Tan), and the School of Public Health and Epidemiology (Dr
Hsu), Chang Gung University, Taipei, Taiwan, Republic of China.
Corresponding author and reprints: Ja-Liang Lin, MD, Poison Center and
Division of Nephrology, Chang Gung Memorial Hospital, 199, Tung Hwa
North Road, Taipei, Taiwan, Republic of China (e-mail:
jllin99 at hotmail.com).
Accepted for publication July 20, 2000.
This study was supported in part by grant NSC89-2314-B-182A-022 from the
National Science Council Foundation, Taipei, Taiwan, Republic of China.
Gary N. Greenberg, MD MPH Sysop / Moderator Occ-Env-Med-L MailList
gary.greenberg at duke.edu Duke Occupat, Environ, Int & Fam Medicine
OEM-L Maillist Website: http://occhealthnews.com