We conducted the present study using data
from six epidemiological studies that included
participants of different ages from the general
population living in Brussels and the southernage. This similarity holds even in quantitative
terms because the relative increases of U-Cd
for both men and women during that period
(3-fold for U-Cd per liter and 4-fold for U-Cd
per gram of creatinine) are in the same range as
that observed with K-Cd in the nonsmoking
general population (Benedetti et al. 1999).
However, it is necessary to exercise caution
before interpreting this similarity as evidence
that U-Cd reflects a concomitant increase of
K-Cd. Unexpectedly, the U-Cd increase with
age did not differ between former smokers and
never-smokers. In addition, the difference in
U-Cd between current smokers and neversmokers
remained fairly constant over the
lifetime, instead of increasing as described for
K-Cd (Hahn et al. 1987). These results are
in agreement with a previous study in which
Ikeda et al. (2005) observed no significant difference
in U-Cd between former smokers and
never-smokers. Our results suggest that the
higher U-Cd observed among current smokers
reflects the higher intake of Cd from tobacco
smoke rather than the increasing Cd renal burden
from chronic smoking.