Introduction and Need for the Study

Introduction and Need for the Study

INTRODUCTION AND NEED FOR THE STUDY

Cigarette smoking is the single most preventable cause of preventable diseases and premature deaths. It has been practiced by people all over the world from centuries. Only recently hazards due to smoking are being recognized and massive media propaganda of the possible health hazards of smoking has been taken globally. Cigarette smokers have a higher risk of coronary artery disease than non-smokers2. Several possible explanations have been offered for this association of which one is through its dyslipidemic effects.

Coronary artery disease (CAD) is the most common form of heart disease and single most important cause of death in the young. Ischemic heart disease is a result of either reduced blood supply to the heart or an increased myocardial demand. The reduced blood supply is the main cause and it occurs as a result of coronary atherosclerosis4. Among the many risk factors associated with the development of atherosclerosis, the principle cause is dyslipidemic3. Various studies have shown that Low Density Lipoprotein (LDL) and Very Low Density Lipoprotein (VLDL) are atherogenic and High Density lipoproteins (HDL) protective factor against it. HDL has got an ability to mobilize cholesterol from peripheral tissues to the liver, which excretes it. Several studies have shown the association of smoking with increased levels of LDL, triglycerides and decreased levels of HDL. Thus smoking which is a risk factor for atherosclerosis is a major cause of coronary artery disease, hence a study will be carried out to find out lipid profile in smokers and its association in ischemic heart disease.

AIMS AND OBJECTIVES

  1. Quantitative estimation of Total Cholesterol, Triglycerides, High-Density lipoproteins and low density lipoproteins in smokers and non- smokers.
  2. To study variable patterns of lipid profile in terms of duration and severity of smoking, to find out the association between lipid levels and smoking among patients admitted in ICCU with ECG changes suggestive of ischemia or infarction.
  3. To compare with similar studies done by others.

REVIEW OF LITERATURE

The relation between smoking and atherosclerosis was observed as early as 1908 by Berger, who noted severe distal ischemia among young male addicted smokers.

According to Albany and Framingham the incidence of myocardial infarction in heavy smokers is three times than in non smokers. The Framingham heart study was initiated in 1948 by United States Public Health Service to ·study a number of risk factors (e.g., serum cholesterol, blood pressure, weight and smoking) to subsequent development of cardiovascular disease.

In the Finnish Survey (Karen et al 1959) higher serum cholesterol values were found in heavy smokers of all groups.

SMOKING AND LIPID PROFILE

Smoking of tobacco by people started centuries ago but the health and environmental hazards, posed by it was recognized only in the 20th century. Atherogenesis, which is important risk factor for ischemic heart disease (IHD) and cerebrovascular accidents is thought to be accelerated by smoking1. The exact atherogenic mechanism of smoking is still unclear. It has been observed, by workers that smoking leads to dyslipidemia which is a major factor for atherosclerosis6.

Gofman J. W et al were the early pioneers of this study and had found that cigarette smoking and serum lipoproteins had a strong association between themselves as well as with coronary heart disease.

The Framingham heart study7was initiated in 1948 by the United States Public Health Service to study the relationship of a number of (risk) factors (e.g., serum cholesterol, blood pressure, weight smoking) to the subsequent development of cardiovascular disease. Wendy H Graing et al demonstrated significant)" higher serum levels ofTriglycerides (+11.8%), VLDL (+12.4%) and LDL (*4.1%) and lower level of HDL (8.5%) and TC (- 3~7%). His study was in age group 8-19 years old. These changes were comparable with the changes seen in adult smokers except for total cholesterol, which is usually high in adult smokers.

Misawa K9 and his colleagues ascertained the relationship among HDL cholesterol, other serum lipids with active and passive smoking. Obesity, alcohol, drinking and working status in healthy adults and in school children sampled at random who were medically healthy. They found that triglycerides where high and had a direct relation to smoking while high-density lipoprotein where low and had an inverse relationshipto the number of cigarettes.

George Steiner11 and his associates, who studied on the pathophysiology and natural history of atherosclerosis of coronary artery and its association with elevated level of intermediate density lipoproteins, found that cigarette smoking and triglycerides were high among the groups with increased rate, of cigarette smoking.

Tilwani R.K and his associates who studied total cholesterol, triglycerides, LDL, VLDL and HDL found that TG, LDL, VLDL and TC were significantly high, in smokers when compared to non-smokers. Increasing progressively from light to heavy smokers, showed a direct relationship and an inverse dose relationship was found in HDL in smokers..

Tiwari A.K10and his associates studied the effect of cigarette smoking on serum total cholesterol and HDL cholesterol in normal subjects and coronary heart patients.

Gofman J.W. et al pioneers in the study of relationship of smoking, serum lipoproteins and heart diseases found a strong relationship between themselves as well as with coronary artery disease.

MATERIALS AND METHODS

The present study will be carried on 200 patients, attending Sri Adichunchanagiri Hospital and Research Centre, B.G.Nagara between JANUARY 2008 to JUNE 2009.

1]40 non smokers

i) Criteria for inclusion

a) Those who never smoked

b) Non obese healthy

ii) Criteria for exclusion

a) Those on diet restriction

b) Those on any drugs known to alter lipid profile

e.g. Beta blockers, Thiazides, Statins etc.

c) Those with ischemic heart disease, hypertension or any systemic disease which may alter lipid metabolism.

e.g., Diabetes, Renal failure, Hypothyroidism etc.

d) Those who are below 30 years of age

e) Females will be excluded from the study.

2]60 smokers

i) Criteria for inclusion

a) Those who were non obese healthy

b) Those who smoke, divided depending upon Severity and Duration of smoking:

Mild smokers - Regularly between 1 - 10 cigarettes or beedies/day OR for a period of 1 -10 years

Moderate smokers- Regularly between 11 - 20 cigarettes or beedies/day OR for a period of 11 -20 years

Heavy smokers – Regularly>20 cigarettes or beedies/day OR for a period of >20 years

ii) Criteria for exclusion

a)Those on diet restriction

b) Those on any drugs known to alter lipid profile e.g., Beta blockers, Thiazides, Statins etc.

Those with ischemic heart disease, hypertension or any systemic disease which may alter lipid metabolism. e.g., Diabetes, Renal failure, Hypothyroidism etc.

c) Those who are below 30 years of age

d) Females will be excluded from the study.

Both cigarette smokers and Beedi smokers will be included in the study

3]100 patients admitted to the ICCU

i)Criteria for inclusion

a) Those with ischemic heart diseases evidenced by ECG.

b) Both smokers and non smokers.

ii) Criteria for exclusion

a)Those on diet restriction

b) Those on any drugs known to alter lipid profile e.g. Beta blockers, Thiazides, Statins etc

c) Those with hypertension or any systemic disease which may alter lipid metabolism e.g., Diabetes, Renal failure, Hypothyroidism etc.

d) Those who are below 30 years of age.

e) Females will be excluded from the study.

Smoking is less prevalent among females in India. So this study will be conducted in male patients.

REFERENCES

  1. Andrew P.Selwyn/Eugene Braunwald “Ischemic Heart Disease” in Harrison’s Principles Of Internal Medicine, 16th Edition.
  2. Valentin Fuster “ Atherosclerosis,Thrombosis,and Vascular Biology” in Cecil Text Book Of Medicine ,22nd Edition
  3. Cleeman Ji et al: Executive summary of Third Report of the National Cholesterol Education Programme (NCEP); Expert Panel on detection,Evaluation and Treatment of High Blood Cholesterol in Adults( Adult Treatment Panel iii).JAMA 285:2486,2001
  4. Morrow D et al: Chronic Ischemic Heart Disease,in Braunwald’s Heart Disease,7th Edition,D Zipes et al (eds)
  5. P. Bloomfield;A.Bradbury; N.R Grubb; D E Newby “Cardiovascular Disease” in Davidson’s Principles and Practice Of Medicine, 20th Edition.
  6. Wendy Y. Craig, Glenn. E. Palomaki,_ James E. Haddow. (1989): "Cigarette smoking and serum lipid concentrations. An analysis of published data". B.M.J, 298: 784-787.
  7. "Cigarette smoking and coronary heart disease. Combined experience of the Albany and Framingham studies". The New Eng. J Med, 266: 796.
  8. K. Park. "Park's Text book of Preventive and Social Medicine". 19th edition, Mis Banarsidas Bhanot Publishers, pg 303 – 308; 2007
  9. Misava K, Matsukih, Kasuga H (1989) “ An epidemiological study on the relationship among HDL- cholesterol, smoking and obesity. Nippon Eiscigaku Zasshi, 44(3): 725-32
  1. Tiwari AK, Gode J.D, Dubey G.P (1989): “Effect of cigarette smoking on serum total cholesterol and high density lipoprotein cholesterol in normal subjects and coronary heart patients”. Indian Heart Journal, 41(2):92-94
  1. George Steiner, Leonard S.(1987): “ the association of increased LDL with smoking and coronary artery disease”. Circulation,75(1):124-30

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