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

AX6-149
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)
Møller and
Kristensen (1992)
Europe-Denmark-
Copenhagen
County-Glostrup
Population Studies
1976-1990
A cohort born in 1936 was followed at
age 40 (women n = 546, men n = 504),
age 45 (women n = 430, men n = 463) and
again at age 51 (men only n = 439).
Reported no difference in results if
subjects taking antihypertensive
medications were excluded. Reported
results included these subjects. Linear
multiple regression models of systolic and
diastolic blood pressure of follow up,
stratified by sex and by yr, used a
sequence of forced entry of covariates:
natural log blood Pb was tested alone
(unadjusted), then adjusted for tobacco,
cholesterol, physical activity, and sex
(Model 1), then adjusted for the above
covariates plus systolic blood pressure
(Model 2), and then adjusted for the above
covariates plus alcohol (Model 3).
Another group of linear multiple
regression models of change of systolic
and diastolic blood pressure from age 40
to 51 yrs in men only, following the same
covariate entry scheme as above, but used
change in covariates instead of the
original covariates. All subjects were
followed until 54 yrs of age (from 1976 to
1990) to assess Pb association with total
mortality and with coronary heart disease
(CHD; ICD-8 410-414) and
cardiovascular disease (CVD; ICD-8 430-
435) combined morbidity and mortality
using Cox proportional hazards models
(n = 1050). Cox models were adjusted as
above.
Arithmetic mean (SD,
range) blood Pb by age
and sex:
Women 40 yrs:
9.6 µg/dL (3.8, 4-39)
Women 45 yrs:
6.8 µg/dL (3.5, 2-41)
Men 40 yrs: 13.6 µg/dL
(5.7, 5-60)
Men 45 yrs: 9.6 µg/dL
(4.3, 3-39)
Men 51 yrs: 8.3 µg/dL
(4.1, 2-62)
In women, each one unit increase in natural log blood Pb was associated with a
significant increase in systolic blood pressure of 4.93 mm Hg (p = 0.002; neither SE nor
CI stated) at age 40 and an increase of 2.64 mm Hg (p = 0.06; neither SE nor CI stated)
at age 45, in models adjusted for tobacco, BMI, and physical activity (Model 1). When
alcohol (Model 2) or alcohol plus hemoglobin (Model 3) were added to the models Pbblood
pressure relationships were not significant at either age. With each one unit
change in natural log blood Pb, diastolic pressure increased 4.26 mm Hg (p = 0.002;
neither SE nor CI stated) at 40 yrs and 3.26 mm Hg (p = 0.002; neither SE nor CI
stated) at 45 yrs in Model 1. In Model 2, the increase in diastolic blood pressure was
3.21 mm Hg (p = 0.02; neither SE nor CI stated) at 40 yrs and 2.86 mm Hg (p = 0.01;
neither SE nor CI stated) at 45 yrs. In Model 3, the increase in diastolic blood pressure
was 2.65 mm Hg (p = 0.07; neither SE nor CI stated) at 40 yrs and 2.78 mm Hg
(p = 0.01; neither SE nor CI stated) at 45 yrs.
In men, the only significant association between natural log blood Pb and blood
pressure was at 45 yrs. For every increase of one unit of natural log blood Pb the
increase in systolic blood pressure was 2.73 mm Hg (p = 0.05; neither SE nor CI
stated).
The change in blood Pb between 40 and 51 yrs was not significantly associated with
change in systolic or diastolic blood over the same period in any of the models.
None of the relative hazard ratios for CHD and DVD combined morbidity and mortality
between 40 and 54 yrs were significantly related to blood Pb concentration. Total
mortality, however, was significantly increased with increased blood Pb. In Model 1,
every increase of one natural log unit of blood Pb was associated with an increased
relative hazard of mortality of 1.96 (p = 0.009; neither SE nor CI stated). For Model 2,
every increase of one natural log unit of blood Pb was associated with an increased
relative hazard of mortality of 1.82 (p = 0.03; neither SE nor CI stated). There were 40
cases of CHD recorded, of which 13 were fatal. There were 54 cases of CVD recorded,
of which 19 were fatal. Of the total of 46 subjects who died during the period, 32
(70%) died of cardiovascular problems. It was not clear if blood Pb at a particular age
or a mean blood Pb across ages was used in the Cox proportional hazards models.