Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

AX6-151
Table AX6-5.1 (cont’d). Effects of Lead on Blood Pressure and Hypertension
Reference, Study
Location, and
Period Study Description Pb Measurement Findings, Interpretation
Europe (cont’d)
Staessen et al.
(1996a)
Europe-Belgium-
PheeCad study.
1985-1995
359 men and 369 women
participated at baseline (between
1985 and 1989) and again about 5
yrs later (median 5.2 yrs) at
follow up (between 1991 and
1995), mean age (range) at
baseline 46 yrs (20-82), about
half of whom were recruited from
towns surrounding a non-ferrous
smelter (targeted to produce high
cadmium exposure) and half from
towns without heavy metal
production. Over half the men
had occupational exposure
(59.0% from the near smelter
towns, 17.4% from the other
towns).
Four different outcomes were
explored: time-integrated
conventional blood pressure (avg
of 10 baseline and 5 follow up
blood pressure measurements),
24-h ambulatory blood pressure
only during the follow up period
(avg of readings every 20 minutes
from 8 AM to 10 PM and every
45 minutes from 10 PM to 8 AM,
weighted by interval between
measurements), difference in
conventional blood pressure over
the five yr follow up period, and
incidence of developing
hypertension during follow up.
Geometric mean (5th-
95th percentile) by sex
and time period:
Baseline women:
6.6 µg/dL (3.3-14.5)
Follow up women:
4.8 µg/dL (1.7-11.8)
Baseline men:
11.4 µg/dL
(5.6-28.8)
Follow up men:
7.7 µg/dL
(3.7-20.1)
The study was one of the few prospective longitudinal studies reported and was innovative in its
use of 24-h ambulatory blood pressure as one of its outcome variables.
Time-integrated conventional blood pressure models:
In 187 peri- and post-menopausal women, after adjusting for age, BMI, gammaglutamyltransferase
activity, and hematocrit, each increase of one unit of natural log blood Pb
was associated with an increase in diastolic blood pressure of 7.49 mm Hg (95% CI: 1.48,
13.50). No other time-integrated conventional blood pressure measurements were significantly
associated with time-integrated natural log blood Pb in either men or women, nor in stratified
groups within sex.
Ambulatory 24-h blood pressure models:
In all 345 women, after adjusting for age, hematocrit, gamma-glutamyltransferase activity, and
oral contraceptive use, each one unit increase in natural log blood Pb was associated with an
increase of diastolic blood pressure of 3.49 mm Hg (95% CI: 0.02, 6.96). When the group was
limited to the 174 premenopausal women each unit increase in natural log blood Pb was
associated with an increase of diastolic blood pressure of 5.48 mm Hg (95% CI: 0.56, 10.40).
Difference in blood pressure between baseline and follow up:
After adjustment for change in BMI, beginning use of antihypertensive medication and
contraceptive medication during the follow up period, and starting smoking there was no
significant relationship between difference in either systolic or diastolic blood pressure and blood
Pb in women. After adjustment for change in BMI, change in exposure at work, change in
smoking, beginning use of antihypertensive medication in men there was no significant
relationship between difference in either systolic or diastolic blood pressure and blood Pb in
men.
Incidence of hypertension:
At baseline 107 (14.7%) and 120 (16.5%) subjects had borderline and definite hypertension,
respectively. At follow up 98 (13.5%) and 186 (25.5%) had borderline and definite
hypertension, respectively. 51 of 501 initially normotensive subjects became borderline
hypertensive and 47 of the 501 became border line hypertensive during the follow up period.
After adjusting for sex, age, and BMI, natural log baseline blood Pb was not related to significant
risk ratios of becoming hypertensive (not stated, but presumably combined definite and
borderline hypertension) or becoming a definite hypertensive.