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This talk is on the
pathology of Chronic
Obstructive Lung Disease.
My name is Jim Hogg,
and I'm from
Vancouver in Canada.
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This is from a famous study
conducted by Fletcher
and his associates
on London postmen,
where they followed a
group of people over the
course of six to seven
years and followed
the progression of their
forced expiratory volume
(FEV_1) in one second.
That refers to the
volume of air you
can blow out of your
lungs in one second,
you blow as hard and as
fast as you can and it's
a measurement of how well
you empty your lungs.
This indicates the GOLD
classification of the severity
of chronic obstructive
pulmonary disease (COPD).
It was named by a committee
that had the acronym,
GOLD for Global
Obstructive Lung Disease
and divided into four
categories of severity.
You can see from the top curves,
which are normal people
and non-smokers,
their FEV_1 declines with age.
That happens in everybody
and it is a function
of getting older.
The bottom one of
the three represents
what happens to most
people when they smoke,
and the middle curve represents
what happens to nonsmokers
if they've smoked for
a long period of time
and then stop for a
long period of time,
they go back towards
the normal decline.
Not absolutely the same,
but it's close to that.
Now, GOLD 1 is the mildest
form of the disease,
and at this level
of the disease,
that person doesn't really know
that there's anything wrong.
But you can see
this bottom curve,
which is the next step,
indicates that importantly,
many people don't get
to the very maximum
they should get to at age 25
when you're supposed to
be at your very best
because they've either
been born prematurely
or they've had a
childhood infection
that has done something
to their lungs.
Now, they become in
this group of what
we call the
susceptible minority,
who are usually smokers
but can be people
that have been exposed to
other things, other aerosols.
Most commonly of the others,
is in the developing world,
where people, mostly women,
are exposed to smoke
from cooking fires
and that is an enormous
factor in causing COPD.
There is this
susceptible minority
that have a rapid
decline in their FEV_1.
The real reason for
that is not known.
But the pathology is
such that we think that
they lose their airways at
a faster rate than normal
and that that causes this
rapid decline to occur.
