Smoking the major risk factor for coronary heart disease

By

Dr. Sashi Acharya/Shivahospital, Nepal

shivahospital@hotmail.com

Smoking accounts for about more than a half million premature annual deaths world wide. Smoking is a leading and one of the most preventable risk factor for coronary heart disease (CHD).Smoking doubles the risk for CHD and sudden cardiac death. In Nepal there is evidence that among the patients with myocardial infarction and acute coronary syndrome more than 80% were smokers. The female smoking rate is highest in Nepal than any other part of the world accounting for 73% in the hilly region. WHO statistic’s reveals that the prevalence of smoking in Nepal among the age group varying from 15 to 30 is more than 70%.We have made one  randomized study among the patients attending the out patient clinic of our Shiva hospital. Age of the patients studied varied from 35 to 75 years, we did analyzed 200 people, 78 male (39%) and 122 female (61%).Our data shows the prevalence of smoking in female is 50 %( 61 out of122) and the prevalence of smoking in male is 46.15 %( 36 out of 78). The growing smoking rate in teens, the high smoking rate in females and males and the effect of passive smoking has definitely become a major problem in our country. Smoking in teens may accelerate the atherosclerotic process in adolescents thereby, making themselves more fertile to be hunted by CHD in their near adulthood.

 Smoking is bad for our health in many ways:

·        Inhaled tobacco smoke damages the endothelium of arteries and accelerates the atherosclerosis of blood vessel making higher chances for plaque formation within the walls of the arteries, making them more susceptible to coronary heart disease (CHD).

·        Smoking lowers HDL (good cholesterol) that protects heart.

·        Cigarette smokers also have raised level of fibrinogen a protein which causes blood to clot making favorable condition for plaque formation.

·        It raises blood pressure making heart work hard.

·        Oxygen free radicals are formed in our body during oxidation process. These are unstable molecules which can damage the cells i.e. endothelium or the inner lining of the arterial wall. Antioxidants neutralize those oxygen free radicals and protect from damaging arteries supplying heart. Smoking depletes antioxidants from our body making our heart more prone to CHD.

Smokers have less blood supply to their hearts, which is an indicator of future heart attacks or strokes as stated by Phillip A.Kaufmann,M.D.,and assistant professor at university Hospital in Zurich

Two main chemicals in the smoke that is responsible for negative effect on heart:

First of all it is to be noted that Smoking is not simply a habit but an addictive process. The addiction is due to the chemical nicotine. Nicotine and Carbon monoxide are the two main chemicals that affect our heart. Nicotine stimulates adrenal glands in our body secreting a hormone adrenaline. Adrenaline constricts the blood vessels thereby, raising blood pressure, heart beat and heart load. Extra working load of the heart can hurt the heart and its vessels. Nicotine injures the endothelium of the coronary arteries and all the other arteries. Carbon monoxide a poisonous gas is the next chemical in tobacco smoke that has a negative effect on the heart. Carbon monoxide combines with hemoglobin in the blood and forms carboxyhaemoglobin, thus, preventing oxygen to bind with hemoglobin and forming oxyhaemoglobin. As a result the blood oxygen content and the amount of oxygen to our heart and other vital organs are decreased, if oxygen supply is lower than the heart demands it may lead to angina and heart attacks as we know.

Smoking accelerates atherosclerosis and inflammatory process:

The recent data found the highest level of fibrinogen, C-reactive protein and homocystein among the current smokers as compared to former smokers and nonsmokers. It is now obvious that both fibrinogen and C-reactive protein are responsible for inflammation of the arteries progressing atherosclerosis.

Smoking a major risk factor for Coronary heart disease:

1.   A smoker has a 2 to four fold greater risk of sudden heart attacks and sudden cardiac death than a non smoker.

2.     If you have already heart attack but still you are smoking your chance of having next heart attack within one year is doubled.

3.     Smoking leads to frequent angina attacks in CHD patients, whereas, quit smoking reduces angina attacks.

4.     Men under 45 years of age who smoke 25 or more cigarettes a day are 15 times as likely to die from CHD as compared to non smokers of the same age

5.      Smoking- itself a great risk factor for heart attack. In women the incidence of heart attack and death is higher as compared to men among the smokers Women who smoke even 1-4 cigarettes a day had a 2, 5 fold increased risk of fatal CHD.

6.     Using of contraceptive pills and smoking at a time increases the risk for CHD in women 30 times higher as compared to the women using contraceptives alone.

7.                 Passive smoking is that when the nonsmokers inhale other people’ smoke. Heavy passive smoking is very harmful to our heart. Secondhand smoke could increase the risk of coronary heart disease, a major cause of heart attacks," said Dr Timo Kuusi of Helsinki University in Finland, reporting in the journal Circulation. Passive smoking has a serious and is a real killer.

The major, most preventable and modifiable risk factors of CHD are: Smoking, Hypertension, High Cholesterol level, obesity, physical inactivity, and diabetes mellitus. Active as well as passive or second hand smoking represent one of the most severe risks for atherosclerosis and coronary heart disease. But as soon as you stop smoking your risk of heart attacks drops sharply, after two years being smoke free your risk is nearly as low as a nonsmoker so it is never late to quit smoking. People suffering from heart disease ought to quit smoking right away before it is too late.

Bibliography:

1.    Smoking chokes the heart-Smoking chokes the heart. Cigarette smoking ... Association. Cigarette smoking is a major risk factor for coronary heart disease. The ... www.theacorn.com/News/2000/0928/Health_and_Wellness/62.html

2.    connected.telegraph.co.uk - Passive smoking 'may cause heart ...  - ... Passive smoking 'may cause heart disease' (Filed: 28/05/1998). HALF an hour in a smoke-filled space can deplete the body's stores ...
www.telegraph.co.uk/connected/main.jhtml?xml=/connected/1998/05/28/ecnsmok28.xml 

3.    Smoking And Your Heart  - Smoking And Your Heart. Understanding the effects of smoking on your heart and blood vessels is important. When you smoke, you inhale ...
www.alexian.org/progserv/heartcare/information/smoking.html

4.    Nutrition Research - New angle on smoking and the heart  - ... Nutrition update 4 February 2002. New angle on smoking and the heart. In studies of the effects of smoking on cardiovascular disease ...
www.everybody.co.nz/nutrition/nnfeb4_02smokeheart.html

5.    Smoking cessation decreases heart disease --- HealthandAge  - ... Smoking cessation decreases heart disease. [ Home > SMOKING CESSATION DECREASES HEART DISEASE ]. Smoking cessation decreases heart disease. Susan Aldridge, PhD. ...
healthandage.com/PHome/gm=20!gid1=1936 

6.    The Effect Of Cigarette Smoking On Coronary Heart Disease, Where ...  - Return to Document List The Effect Of Cigarette Smoking On Coronary Heart Disease, Where Do We Stand Now? Notes: Journal Article ...
www.library.ucsf.edu/tobacco/docs/html/2004.30/ 

7.    Fact sheet: Smoking, The Heart & Circulation  - FACT SHEET NO. 6. August 2002. SMOKING, THE HEART & CIRCULATION. Introduction. Each ... The role of smoking in Coronary Heart Disease. Inhaling ...
www.ash.org.uk/html/factsheets/html/fact06.html 

8.      The New England Journal of Medicine, volume347:1054-1055,October 3,2002,November 14

9.      http://www.bbc.co.uk/health/heart/prevention.shtml

10. http://www.heartcenteronline.com/myheartdr/community/showthread.cfm?doWhat=seeDiscussion&discussionTopic_id=87

11. http://www.gpnotebook.co.uk/simplepage.cfm?ID=1530200078&linkID=31138

12.  Nishtar S. preventing coronary disease in south Asia.heartfile.org/apend.htm

13.  Women and Coronary Heart Disease.http:/www.healthnet.org.uk/new/facts/facts 07.htm

14.  Even light smoking is harmful cutting down on cigarettes is just not good enough. http:// heartdisease.about.com/library/weekly/

15.  Women’s Health www.bbc.co.uk/health/heart

16.  Cigarette smoking and cardiovascular diseases http://www.americanheart.org/presenter.jhtml?identifier=4545

17.  Smoking ban reduces heart attackshttp://www.heartcenteronline.com/myheartdr/home/research-detail.cfm?reutersid=3506

18. attackshttp://www.heartcenteronline.com/myheartdr/home/research-detail.cfm?reutersid=3506

19. Smoking ban reduces heart 20.Parent’s smoke injures children’s blood vessels.http://www.heartcenteronline.com/myheart/home/research-detail.cfm?retersid=3164

20. Clot, inflammation factors-------- highep://www.heartcenteronline.com/myheartdr/home/research-detail.cfm?retersid=3613&pro=

21. Hong Kong Council on Smoking and health---Smoking can be, how many different types of diseases it---is also responsible for many other types of cancers---cancer of the mouth and throat; esophageal cancer---www.info.gov.hk/hkcosh/harm/en harm2html

22. Passive smoking’ harms heart’http://news.bbc.co.uk/1/hi/health/1454981.stm Tuesday,24 July,2001,23;14 GMT 00:14 UK

23. Europe ‘addicted’ to smokinghttp://news.bbc.co.uk/hi/health/1823049.stm

24. Mortality Risk Reduction Associated With Smoking Cessation in Patients With Coronary Heart Disease A systemic review Julia A. Critchley,MSc, DPhil;Simon Capewell,MD, FRCP JAMA.2003;290:86-97