|
The most prevalent form of tobacco
addiction is cigarette smoking and intuitively, the lungs would have
to put up with the brunt of harmful effects of the cigarette smoke
that is inhaled.
Among the many lung diseases in smokers, 2 major respiratory
diseases are most significant, because these illnesses are almost
always caused by or associated with smoking, and these diseases have
major impact on the sufferer in terms of quality of life and
longevity.
The 2 common and serious lung diseases in
smokers are: (1) Chronic Obstructive Pulmonary Disease, and (2) Lung
Cancer. While Lung Cancer is garnering a certain amount of and
public awareness and media attention (Newsweek August 22,
2005 - cover story), chances are, you do not know much about the
other smoking-related “lung problem” - Chronic Obstructive Pulmonary
Disease (COPD).
This is unfortunate, as from a general perspective, more smokers
suffer from COPD than lung cancer and COPD is a deadlier disease
than lung cancer (i.e. causing more deaths annually).
Chronic Obstructive Pulmonary Disease
A major public health burden
COPD is a common disease afflicting millions
of people worldwide and exacting a very heavy global disease burden.
Surprisingly, public awareness of this disease is lacking and many
people have not even heard of it.
In America and many developed countries, COPD
is the 4th leading cause of death and, among the top 5
leading cause/s of death in the US, COPD is the only one that is
increasing in incidence - a disparity all the more striking amid the
dramatic decline in deaths from heart disease and stroke.
If the present trend continues, COPD will be
the 3rd leading cause of death in the US in about a
decade. In 1990, a study by the World Bank and World Health
Organization (WHO) ranked COPD 12th as a burden of disease; by 2020,
it is estimated that COPD will be ranked 5th.
What is COPD?
COPD is an umbrella term that
encompasses 2 main disorders--- emphysema and
chronic bronchitis--diseases that are characterized
by obstruction to air flow in and out of the lungs. Emphysema and
chronic bronchitis frequently coexist. Thus physicians prefer the
term COPD. Smoking is the major cause of this condition. Air
pollution, exposure to industrial smoke or dust and long term
inhalation of smoke from wood fires in developing countries are
other minor causes.
Smoking progressively and gradually destroys
the lungs and causes a decline in lung function (the capacity of our
lungs to ventilate i.e. bring fresh air in from the environment and
expired gases out from the body).
This capacity of the lungs to ventilate can be
measured by undergoing a simple lung function test known as
spirometry. One of the measurements during spirometry is the FEV1
(Forced Expiratory Volume in One Second), the volume of air exhaled
in the first second after a deep inhalation. For COPD patients, FEV1
is used to determine the severity of obstruction in the air passages
of the lungs.
In normal people who do not smoke, a loss of
lung function (FEV1) is expected as one grows older (see
Figure 1). In smokers, the rate of decline of lung function (FEV1)
is about double that of smokers. In smokers who have COPD, the rate
of decline can be 4-6 times that of non-smokers, i.e., the patient
has greater obstruction in the air passages and less lung function
as the patient gets older.
The problem is that the loss of lung function
in COPD patients is so gradual that most patients with COPD do not
realize that they have the illness till it is severe. By the time
most patients are diagnosed to have COPD, they may have lost at
least 50% of their pulmonary function. This is exactly why the
Chronic Obstructive Pulmonary Disease Association (Singapore) (www.copdas.com)
in cooperation with other international agencies such as the Global
Initiative for Chronic Obstructive Lung Disease (www.goldcopd.com)
strongly encourages smokers, especially those with symptoms such as
persistent cough and/or breathlessness to undergo spirometry
testing.
Who is likely to have COPD?
The symptoms of COPD can range from
chronic cough and sputum ('phlegm')
production to severe disabling shortness of breath.
In some individuals, chronic cough and sputum production are the
first signs that they are at risk for developing the airflow
obstruction and shortness of breath characteristic of COPD. In
others, shortness of breath may be the first indication of the
disease. Individuals with COPD increasingly lose their ability to
breathe.
Acute infections or certain weather conditions
may temporarily worsen symptoms (exacerbations), occasionally where
hospitalization may be required. Bear in mind that the progression
of the disease and the loss of lung function can be so gradual that,
presently, many patients don't realize they have COPD till late.
Hence if you are smoker or ex-smoker who is (A) Above
40 years old, with (B) Breathlessness and/or (C)
Chronic cough, please consult your doctor, and preferably
undergo spirometry testing to assess if you are have COPD.
Double-barrel smoking gun
Smokers with COPD are at least 2 times more
likely to develop lung cancer than smokers who do not have COPD.
Thus, COPD may be an additional risk factor for smokers developing
lung cancer! So the message is - do not smoke and if you are a
smoker, do quit for it may not be just a gun you are smoking but a
double-barrel one at that.
Written by:
Dr Ong Kian Chung
Consultant Respiratory Physician
Mount Elizabeth Medical Centre
[Dr Ong is the President of the Chronic
Obstructive Pulmonary Disease Association (Singapore)].
|
