UNIVERSITY OF MAURITIUS

Bachelor of Pharmacy – Year 2

BIOLOGY OF DISEASE 1 

TITLE:

Discuss the causal association between cigarette smoking and Non- Communicable Diseases.

Presented by:

NARAINO MAJIE Nabiilah - 1216824

Date of Submission: 24th September 2013

Table of Contents

1. Introduction

2. How Cigarette smoking induces cardiovascular diseases?

3. How Cigarette smoking induces cancer?

4. How Cigarette smoking contributes in chronic lung disease?

5. How Cigarette smoking is involved in Diabetes?

6. Conclusion

7. References

References

1. Hyeon Chang Kim and Sun Min Oh, 2013, Noncommunicable Diseases: Current

Status of Major Modifiable Risk Factors in Korea, J Prev Med Public Health. Vol:

46(4): 165–172.

Available online: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3740221/

Accessed on: 20th Sept 2013

2. Kimberly C. Bowman, Gilbert L. Ross, M.D., Karen L. Schneider & Elizabeth

M. Whelan, Sc.D., M.P.H., 2005, Cigarettes: What the Warning Label Doesn’t Tell

You.

Available online: http://wwwstatic.kern.org/gems/schcom/CigarettesWarningLabelbook.pdf

Accessed on: 20th Sept 2013

3. Scottish Intercollegiate Guidelines Network (SIGN), 2006, Diagnosis and

management of peripheral arterial disease. A national clinical guideline. Edinburgh

(Scotland): Scottish Intercollegiate Guidelines Network (SIGN); (SIGN publication;

no. 89).

Available online: http://www.guideline.gov/content.aspx?id=9924

Accessed on: 20th Sept 2013

4. Anon, 2013, Smoking and cancer, Cancer Research UK

Available online:

http://www.cancerresearchuk.org/cancer-info/healthyliving/smokingandtobacco/smoking-

and-cancer

Accessed on: 22nd Sept 2013

5. Rajshri ., 2008, Mechanism Behind How Tobacco Carcinogens Cause Lung Cancer,

Cancer News

Available online: http://www.medindia.net/news/Mechanism-Behind-How-Tobacco-

Carcinogens-Cause-Lung-Cancer-37348-1.htm

Accessed on: 22nd Sept 2013

6. Penning., 2008, Mechanism Behind How Tobacco Carcinogens Cause Lung Cancer,

Proceedings of the National Academy of Sciences

Available online: Mechanism Behind How Tobacco Carcinogens Cause Lung Cancer

| Medindia http://www.medindia.net/news/Mechanism-Behind-How-Tobacco-

Carcinogens-Cause-Lung-Cancer-37348-1.htm#ixzz2fdD8huwL

Accessed on: 22nd Sept 2013

7. Sir Richard Doll, 2001, Lung cancer and tobacco consumption, International

Journal of Epidemiology, Volume 30 , Issue 1, Pp. 30-31.

Available online: http://ije.oxfordjournals.org/content/30/1/30.full

Accessed on: 22nd Sept 2013

8. D. P. Lane, 1992, p53, guardian of the genome, Nature 358, 15 – 16

Available online:

http://www.nature.com/nature/journal/v358/n6381/pdf/358015a0.pdf

Accessed on: 22nd Sept 2013

9. Anon, 2006, Smoking & lung disease, Quit [Information sheet]

Available online:

http://www.oxygen.org.au/downloads/sadownloads/infosheet_lung_disease.pdf

Accessed on: 22nd Sept 2013

10. Alice Park, 2011, Why Smoking Is Especially Bad If You Have Diabetes?, Health &

Family; TIME (Online Medical Newspaper).

Available online: http://healthland.time.com/2011/03/27/why-smoking-is-a-bad-idea-

for-diabetics/

Accessed on: 22nd Sept 2013

Introduction

A non-communicable disease (NCD) is a medical condition or disease that is by definition

non-infectious and non-transmissible among people. Currently, NCDs are the leading causes

of death and disease burden worldwide. The four main types of NCDs, including

cardiovascular disease, cancer, chronic lung disease, and diabetes, result in more than 30

million deaths annually. To reduce the burden of NCDs on global health, current public

health actions stress the importance of preventing, detecting, and correcting modifiable risk

factors; controlling major modifiable risk factors has been shown to effectively reduce NCD

mortality. The World Health Organization's World Health Report 2002 identified tobacco

use, alcohol consumption, overweight, physical inactivity, high blood pressure, and high

cholesterol as the most important risk factors for NCDs. Accordingly, the present report set

out to review the prevalence and trends of these modifiable risk factors in the Korean

population. Over the past few decades, we observed significant risk factor modifications of

improved blood pressure control and decreased smoking rate. However, hypertension and

cigarette smoking remained the most contributable factors of NCDs. Moreover, other major

modifiable risk factors show no improvement or even worsened. The current status and trends

in major modifiable risk factors reinforce the importance of prevention, detection, and

treatment of risk factors in reducing the burden of NCDs on individuals and society. (Hyeon

Chang Kim and Sun Min Oh, 2013)

Dr. Margaret Chan, Director-General of the World Health Organization explained that:

"The rise of chronic non-communicable diseases presents public health with an enormous

challenge. For some countries, it is no exaggeration to describe the situation as an

impending disaster. I mean a disaster for health, for society, and most of all for national

economies ..... Implement the WHO Framework Convention on Tobacco Control ... There is

no other 'best buy' for the money on offer."

We can clearly understand that Tobacco use is the only risk factor shared by all four main

categories of NCDs. Tobacco accounts for nearly one in six deaths from NCDs and kills

nearly six million people worldwide each year.

One of the astonishing things about tobacco is the number and variety of fatal and disabling

diseases and conditions it causes.

Tobacco causes at least 16 different types of cancer. It is most closely associated with

lung cancer, the world’s leading cause of cancer deaths, accounting for nearly one in

five cancer deaths. Tobacco use is known to cause several cancers of the throat and

oral cavity, as well as cancer in diverse sites, such as the bladder, kidney, stomach and

uterine cervix. Smokeless tobacco causes oral and other cancers, hypertension and

heart disease.

Cardiovascular disease is the leading cause of death in the world. Smoking increases

the risk of heart disease and stroke by two to four times.

Smoking causes chronic lung diseases that can be severely disabling or fatal,

increasing the risk of death 12 times.

Smoking is an independent risk factor for diabetes, and it has been estimated that 12%

of diabetes incidence in the United States is attributable to smoking. Diabetics who

smoke have an increased risk of death, and of complications associated with diabetes,

such as amputations and problems with vision.

How Cigarette smoking induces cardiovascular diseases?

Cardiovascular disease (CVD) incorporates the disorders of the heart and circulatory system,

including coronary heart disease (angina and heart attacks), peripheral arterial disease,

aneurysms and stroke.

Smoking is a leading cause of cardiovascular disease, causing around 25,000 deaths a year

from heart and circulatory disease. Around one in five premature deaths from heart and

circulatory disease are linked to smoking.

Inhaling tobacco smoke causes several immediate responses within the heart and its blood

vessels.

Within one minute of starting to smoke, the heart rate begins to rise: it may increase by as

much as 30 percent during the first 10 minutes of smoking. Nicotine stimulates the body to

produce adrenaline which makes the heart beat faster and raises blood pressure, therefore

causing the heart to work harder. The carbon monoxide in tobacco smoke exerts a negative

effect on the heart by reducing the blood’s ability to carry oxygen. Smoking can increase

blood cholesterol levels. Furthermore, the ratio of high-density lipoprotein cholesterol; the

“good” cholesterol, to low-density lipoprotein cholesterol; the “bad” cholesterol, tends to be

lower in smokers compared to non-smokers. Smoking also raises the levels of fibrinogen; a

protein which causes blood to clot, and increases platelet aggregation which makes the blood

stickier. Carbon monoxide attaches itself to haemoglobin which is the oxygen-carrying

pigment in red blood cells much more easily than oxygen does, which reduces the amount of

oxygen available to the tissues. All these factors make smokers more at risk of developing

various forms of atherosclerotic disease, which is when coronary arteries become narrowed

by a gradual build up of fatty material within their walls. As the atherosclerotic process

progresses, blood flows less easily through rigid and narrowed arteries and the blood is more

likely to form a thrombosis (clot). This sudden blockage of an artery may lead to a fatal heart

attack, a stroke or gangrene of the leg. (Kimberly C. Bowman et al., 2005)

Coronary Heart Disease (CHD)

The heart needs a steady supply of oxygen-rich blood to function effectively. Coronary heart

disease (also known as coronary artery disease or ischemic heart disease) is a general term

that describes conditions caused by an interrupted or diminished blood flow through the

coronary arteries to the heart muscle. The most common way that this flow of oxygen-rich

blood becomes reduced is by the build up of fatty deposits (atherosclerosis) or the formation

of a blood clot (thrombosis) in the arteries.

When the blood supply to the heart is interrupted, it sometimes causes the chest pain known

as angina. When the blood supply is cut off completely, a myocardial infarction or heart

attack occurs, which may cause permanent damage to the heart muscle.

Peripheral Arterial Disease (PAD)

Peripheral Arterial Disease (also called Peripheral Vascular Disease) is a disease that affects

the arteries. Most forms of PAD are caused by a gradual build-up of fatty material in the

walls of the artery, a condition called “atherosclerosis”. Over time, one or more of the

principal arteries may become so narrow that they are unable to deliver oxygen-rich blood to

the limbs. In severe cases, the blockage can cause gangrene requiring amputation. (SIGN,

2006)

Aneurysm

An aneurysm is a bulge in a blood vessel that is caused by a weakness in the vessel wall. As

the blood passes through the weakened part of the vessel, the blood pressure causes it to

bulge outwards like a balloon. There is a danger that the aneurysm will cause the artery to

burst (rupture) causing organ damage or internal bleeding, both of which can be fatal.

Aneurysms occur most commonly in the aorta (the main artery in the heart that pumps blood

out into the body) or in the brain (referred to as an intracranial aneurysm) but can occur in

any artery in the body.

Stroke

A stroke (also known as cerebral thrombosis or cerebro-vascular disease) occurs when blood

flow to the brain is interrupted causing brain cells to become damaged or die.

It can affect the way your body or mind functions. It is currently the second most common

cause of death world-wide after heart disease. The World Health Organization has predicted

that this will still be the case in 2030, with stroke expected to account for 12.1% of all deaths.

Smokers are more likely to have a stroke than non-smokers and the risk increases with the

number of cigarettes smoked.

How Cigarette smoking induces cancer?

Smoking causes more than four in five cases of lung cancer. Lung cancer has one of the

lowest survival rates of all cancers, and is the most common cause of cancer death

worldwide. The good news is that most of these deaths are preventable, by giving up smoking

in time. (Cancer Research UK, 2013)

Smoking also increases the risk of over a dozen other cancers including cancers of the mouth,

larynx (voice box), pharynx (upper throat), nose and sinuses, oesophagus (food pipe), liver,

pancreas, stomach, kidney, bladder, cervix and bowel, as well as one type of ovarian cancer

and some types of leukaemia. There is also some evidence that smoking could increase the

risk of breast cancer.

Tobacco smoke contains more than 70 different cancer-causing substances. When you inhale

smoke, these chemicals enter your lungs and spread around the rest of your body.

Scientists have shown that these chemicals can damage DNA and change important genes.

This causes cancer by making your cells grow and multiply out of control. There are two

types of cancer-causing agents in cigarettes; a nicotine-derived chemical and polycyclic

aromatic hydrocarbons (PAHs).

Earlier studies have shown how PAHs damage DNA, with the emphasis on how PAHs bind

directly to DNA itself, leading to the mutations in critical genes that cause disease. (Rajshri,

2008)

Now, researchers have shown that PAHs, via oxidative stress, can also lead to mutations in

critical genes important in lung cancer.

Oxidative stress is the accumulation of destructive molecules called free radicals that can lead

to cell death. Free radicals damage cell membranes, proteins, or genetic material by

'oxidizing' them, the same way oxygen causes iron to rust. It was shown from studies that

enzymes called AKRs are responsible for the oxidative stress from PAHs in the human lung

cells. The AKR enzymes transform PAHs to produce oxygen free radicals. These oxygen

radicals bind to DNA, and if this damage is not repaired it leads to mutations that are carried

through to the next generation of cells. (Penning., 2008)

How Cigarette smoking contributes in chronic lung disease?

Many smokers can tell that smoking is causing damage to their lungs. They sometimes feel

short of breath and puff more easily than they used to.

These things happen because every time a cigarette is smoked, the following occurs:

The minute hairs in the upper airways (cilia) are paralysed or damaged by the

chemicals in cigarette smoke.

The lungs are irritated so the airways narrow, which encourages phlegm and makes it

harder to breathe.

Carbon monoxide, a poison, is forced into the blood and restricts the oxygen carrying

capacity of the blood.

Smoking has been linked to a number of respiratory diseases:

Chronic Obstructive Pulmonary Disease (COPD) - a group of diseases including

chronic bronchitis and emphysema

Lung cancer and other cancers of the airways, including the oesophagus and larynx

Asthma.

Chronic Obstructive Pulmonary Disease (COPD)

Chronic obstructive pulmonary disease (COPD) is a long-term lung disease that causes

shortness of breath, which initially occurs with exertion and becomes progressively worse

over time.

Limitation of the airways due to COPD is irreversible.

Initially, shortness of breath may happen only when walking up hills or stairs. But with

serious disease, even walking and normal activities will become difficult. People with these

diseases often live for many years in varying degrees of discomfort and disability.

The following three things occur due to cigarette smoking:

• Inflammation of the bronchi, causing excessive amounts of mucus to be produced.

This leads to coughing and phlegm production, and breathlessness. It may be associated with

low-grade infection in the airways; this disease is named chronic bronchitis.

• The alveoli (air sacs) are gradually destroyed, so it becomes difficult to get enough oxygen;

this disease is called Emphysema.

• Bronchi become narrow and floppy, making it difficult to breathe out.

Lung cancer

The other major respiratory disease that smoking causes is lung cancer - the first major

disease to be causally linked with smoking.

New evidence has identified an important gene - p53, found in the nucleus of every cell. P53

is described as the 'guardian of the genome' and one of its main roles is to clean up any errors

or changes that occur within copied cells. This means that any cell with damaged p53 is

highly susceptible to cancer. In 1996, scientists made a direct link between

Smoking and lung cancer when they proved that benzopyrene, a carcinogen found in high

concentrations in cigarette smoke, directly damages p53, and leaves a distinctive signature.

(D. P. Lane, 1992)

The risk of developing lung cancer is related to both how long and how much a person has

smoked. For instance, a person who takes up smoking in their teens is five times more likely

to die of lung cancer than someone who starts after their mid twenties. Smokers' risk of dying

from lung cancer is more than 10 times that of a non-smoker, and heavy smokers are between

15 and 25 times more at risk. (Quit [Information sheet], 2006)

Asthma

Asthma is a very common condition affecting the airways in the lungs. These become

inflamed and irritable. When these irritable airways are exposed to certain 'triggers' the

airways narrow, leading to difficulty in breathing.

The result is a reduction of the flow of air in and out of the lungs. The most common

symptoms of asthma are difficulty in breathing or shortness of breath, a feeling of tightness in

the chest, wheezing and coughing (particularly at night). Asthma attacks can occur without

warning, but are often related to poor control.

Tobacco smoke is a powerful trigger for people with asthma, and one that all children should

avoid. Smoking should be avoided anywhere around infants and children - like family rooms,

kitchens, cars etc. Young people and adults with asthma should not smoke, as these further

damages lungs. Where possible, they should try and avoid places where other people smoke

too. Exposure to cigarette smoke during pregnancy and early childhood significantly

increases the risk of children developing asthma, and has also been shown to make asthma

attacks more severe. (Quit [Information sheet], 2006)

Other cancers of the respiratory system

Smoking is a major cause of cancers of the oral cavity, oesophagus and larynx. The use of

alcohol in combination with smoking greatly increases smokers' risk for these cancers.

How Cigarette smoking is involved in Diabetes?

Cigarettes contain more than 4000 chemical compounds and at least 400 toxic substances.

Everyone risks damaging their health through smoking a cigarette, pipe or cigar, but for

people with diabetes the risk may be even greater. Cigarette smoking increases the risk for

type 2 diabetes incidence. Nicotine, acknowledged as the major pharmacologically active

chemical in tobacco, is responsible for the association between cigarette smoking and

development of diabetes. Someone having diabetes has an increased chance of developing

cardiovascular disease, such as a heart attack, stroke or circulatory problems in the legs.

Combine this with smoking (which can also double the risk of complications); the chances of

developing these diseases even higher.

Researchers have long known that diabetes patients who smoke have higher blood sugar

levels, making their disease more difficult to control and putting them at greater danger of

developing complications such as blindness, nerve damage, kidney failure and heart

problems. (Alice Park, 2011)

It was reported by Xiao-Chuan Liu, a professor of chemistry at the California State

Polytechnic University that nicotine, when added to human blood samples, raised the levels

of haemoglobin A1c (HbA1c) by as much as 34% and a similar result was expected for

diabetic people. (Alice Park, 2011)

Haemoglobin A1c is a combination of haemoglobin and glucose which is a standard indicator

of blood sugar content in the body.

According to a research performed by Prof. Liu, it was confirmed that nicotine is responsible

for developing diabetes in a smoker who is non-diabetic. The higher A1c levels rise in the

blood, he says, the more likely it is that other protein complexes, which build up in various

tissues of the body, from the eyes, heart and blood vessels, can form, leading to blockages in

circulation and other complications. But perhaps more importantly, the results also suggest

that nicotine replacement products such as patches and nicotine-containing electronic

cigarettes are not a safe option for diabetes patients either. Because they still contain nicotine,

these products are just as likely to boost A1c levels as cigarettes are.

It is also observed that patients with type 2 diabetes mellitus (DM2) are at risk for micro and

macro vascular complications, which could be observed in heavy smokers.

Conclusion

We all know that cigarette smoking is injurious to health and with all these details on

different diseases linked to smoking, it implies that smoking is even more dangerous as it

seems to be. We have seen how smoking is correlated to NCDs including cardiovascular

diseases, cancer, lung diseases and eventually diabetes and through statistics, smoking is

estimated to cause about 71% of all lung cancer deaths, 42% of chronic respiratory disease

and nearly 10% of cardiovascular disease worldwide. (WHO Publication, 2011)

As health science representatives, it is our duty to make the public aware of the risk factors

associated with smoking. The best way to avoid or minimize such diseases is to quit smoking.

The good points in quitting smoking is a healthier life style, reduced risk of developing

diseases mentioned above, prolonged life and save money.