Atherosclerosis is a disease of large and medium sized arteries. Atherosclerosis occurs when lipoproteins containing apo B enter the arterial wall, become oxidized and are engulfed by macrophages, creating foam cells. A maladaptive inflammatory response occurs, and over time, a complex and potentially vulnerable plaque develops (atheroma). This disease process may start as early as 10 years of age and the build-up gradually increases in size with time. This process is accelerated in presence of other risk factors. Clinical manifestations appear once atheroma increases in size sufficient to compromise the blood flow.
Clinical presentation/feature of the patient depends on extent and severity of the involvement of type of vascular system(s).
Vascular System Manifestation
Coronary artery disease chest pain (angina) on effort/myocardial infarction (heart attack) /sudden death /LV dysfunction /arrhythmias.
Cerebrovascular disease Stroke fatal or non fatal/ dementia.
Renal artery stenosis
Peripheral artery disease
Claudication / gangrene
Risk factors for atherosclerosis
- Tobacco chewing
- Sedentary life style
- Genetic predisposition
LDL is labeled as the â€˜Bad Cholesterol â€˜because it is the main lipoprotein responsible for initiating the process of atherosclerosis.. HDL is called the â€˜Good Cholesterolâ€™ as it transports the cholesterol deposited in arteries back to liver thereby decreasing the atheroma volume in blood vessels.
In well designed clinical trials employing hypolipidemic drug regimens that reduce LDL levels moderately (30-40%), fatal and non fatal coronary heart disease (CHD) events and strokes were reduced by 30-40%. Lipid modifying therapy is also recommended for patients with low HDL and normal LDL levels. In such patients drug therapy reduced the CHD events by 20-35%.
It is also well documented that early treatment and early reduction of modifiable risk factors can minimize the growth of atheroma.
Since the incidence of atherosclerosis and associated cardiovascular events are growing among the young population, it is recommended that the children should be screened for lipid profile between 9 and 11 years of age, followed by every five years as per guidelines endorsed by the American Academy of Pediatrics.
Ideal methods of blood sample collection
For lipoprotein analysis blood samples should be drawn after fasting for 9-12 hours (no food or drink, except water)..
It is recommended that prophylactically all the subjects who has completed 20 years of age should get their Lipid profile analysed and then be repeated every 5 yrs.â€“ 1% reduction in LDL-C results in 1% reduction in cardiovascular events. (Heart Attack, Stroke & Death)
â€“ 40 mg/dL reduction in LDL-C results in 25% reduction in Cardiovascular events
â€“ 40 mg/dL reduction in LDL-C in children results in 54% reduction in Cardiovascular events
â€“ 1% increase in HDL-C results in 2-3% reduction in Cardiovascular events
â€“ Recently released data from AHA shows that Fourteen percent of adults have total cholesterol of 240 mg/dL or higher.
Treatment of dyslipidemias:
Treatment of secondary causes viz diabetes mellitus, Cholestatic liver disease, Nephrotic syndrome ,Chronic renal failure, Hypothyroidism, Cigarette smoking,.Obesity.
Life style Changes
Healthy eating practices are mentioned below:
*if you are a diabetic then it is recommended to consult a dietician or a nutritionist.
â€¢ Avoid butter/ghee
â€¢ Type of oil: Preferred oils include canola oil, soybean oil, olive oil and sunflower oil. If possible, interchange.
â€¢ Avoid sweets and chocolates.
â€¢ Choice of milk should be double toned milk and its milk products such as pannier and curd.
â€¢ Avoid red meat.
â€¢ Consuming fish once or twice a week.
â€¢ Consuming chicken once or twice a month.
â€¢ Consuming fruits and fresh vegetables
â€¢ Consuming an egg without yolk every day
For further advice you should contact a cardiologist.
Weight loss reduces the risk of coronary artery disease:
â€¢ 1 Kg loss of weight increases HDL by .35mg/dl.
â€¢ Improves insulin resistance.
â€¢ Decreases Blood Pressure.
â€¢ 5-10% reduction in weight reduces triglyceride by 20%.
â€¢ Reduces LDL
(if there is a history of a positive stress test then consult cardiologist before planning an exercise regimen.)
â€¢ Avoid exercise if there is discomfort during exercise
â€¢ Walk with an empty stomach early morning or 4-5hrs after meal
â€¢ Avoid exposure to cold; wear warm clothes in extreme winter.
â€¢ Avoid walking in winter; if possible walk before lunch, when weather is a bit warm.
â€¢ Cover all possible body parts during winter including wearing a monkey cap.
â€¢ Jogging to be avoided
Exercise: Goal heart rate with exercise is a 50% rise above the base line and this should be maintained for at least 15 minutes, with a 10 min induction (warm up) and 10 min reduction (cooling down).
Exercise reduces the incidence of coronary artery disease by:
â€¢ Reducing weight: weight loss of one pound for every 3500 calories lost with exercise.
â€¢ Decreasing Blood Pressure.
â€¢ Improving cardiovascular stability.
â€¢ Improving HDL by 5-10%
â€¢ Decreasing TG by 10-15%
â€¢ Decreasing insulin resistance
Yoga is an alternative system of healing. It helps in reducing mental stress in addition to promoting relaxation, therefore helps in controlling blood pressure and diabetes.
Statins: Statin primarily reduces LDL-C and increases HDL.
Benefits of lowering LDL-C extend to LDL-C levels of 50-70 mg/dl, well below the previously recommended LDL-C target of < 100 mg/dl for high risk patients
Fibrate: Fibrates primarily reduces Triglycerides (TG).
Nicotinic acid: Niacin primarily increases HDL by 15% to 30%, decreases TG by 20% to 30% and LDL-C by 5% to 15%.
There is an inverse relationship between serum HDL-C and risk for future cardiovascular events. The higher your HDL-C, the more resistant you are to developing atherosclerotic disease. The lower the HDL-C, the higher the risk is for developing atherosclerotic disease and for sustaining cardiovascular events, such as myocardial infarction as well as cardiovascular mortality.
Omega fatty acid (OMA) : Omega fatty acid primarily reduces triglycerides and increases HDL.
- Hypertension (high blood pressure) is one of the most common diseases affecting more than one billion humans worldwide and is a major risk factor for heart attack (coronary artery disease), stroke and chronic kidney disease.
Recently released data from AHA (American Heart Association) shows hypertension is present in about 33% of adults with African-Americans having the highest prevalence worldwide (44%).
- Data from NHANES (National Health and Nutrition Examination Survey) 1999-2006 estimated that 30% of adults age 20 years and above have pre-hypertension defined as untreated systolic blood pressure (SBP) 120-139mm Hg or untreated diastolic blood pressure (DBP) of 80-89mm Hg.
- Hypertension is the leading cause of death worldwide with approximately 12% of deaths attributable to hypertension followed by smoking.
- Risk for cardiovascular disease (heart attacks, strokes etc.) begins to increase when BP exceeds 115/75 and doubles for each increment of 20mmg Hg of SBP and 10mm Hg for DBP.
- If untreated, 50% of patients with hypertension will die of coronary artery disease, 30% will die of stroke and 10-15% will die of renal failure.
- Recently released data from AHA shows that more than 8% of adults have diagnosed diabetes, 8.2% of adults have undiagnosed diabetes while 38.2% have prediabetes.
- Risk factors for development of diabetes include family history of diabetes, history diabetes during pregnancy, obesity and a sedentary lifestyle.
- Heart disease affects people with diabetes twice as often as people who do not have diabetes.
- People with diabetes tend to develop heart disease at a younger age than nondiabetics.
- Two out of every 3 people with diabetes die of heart disease or stroke.
- Decrease in HbA1C (Glycosylated hemoglobin, which is measure of diabetic control-target <7%) from 8% to 7% reduces the risk of diabetes and its complications including diabetic kidney disease, eye disease and nerve disease.
- Almost 20% of all deaths from heart disease are directly related to cigarette smoking, according to the British Heart Foundation. This is because smoking is a major cause of coronary artery disease.
- Passive smoking (involuntary inhalation by a nonsmoker of diluted sidestream smoke for example, cigarette smoke and smoke originating from chulhas) can cause chronic lung disease, cancer and heart disease. It is estimated that more that 10,000 die each year in the UK as result of passive smoking.
- If you smoke, your risk of developing heart disease and dying of it is increased by approximately 2-4 times that normal population.
- Your risk of death from heart disease is the same as that of a non-smoker only after 15 years of quitting smoking.
- 30% of men and 19% of women around the world smoke. One lakh children under the age of 15 years start smoking every day.
- With these statistics, it is hard to imagine why smoking continues to be so widespread. Recently release data from AHA shows that despite four decades of improvement, 21.3% of men, 16.7% of women and 18% of students in grades 9 to 12 report smoking.
Current concepts and guidelines for dyslipidemia management
- All individuals should be screened by age 20. If lipid profile is in satisfactory range, repeat every 5 yrs till 40 year of age and thereafter every 2 yrs provided there is no change in body weight (BMI) and/or change in life style.
- In very high risk patients use medicine or combination of medicines in addition to life style changes to achieve LDL-C targets to around 50 to 70 mg/dl, triglycerides <150mg/dl preferably less than 100mg/dl, HDL .>40mg in men and> 50mg/dl in women , non HDL of less than 100mg/dl and apo-B less than 90 mg /dl under medical supervision is strongly recommended. Treatment of other modifiable risk factors are equivalently important.
- Keep LDL-C below 100mg/dl with life style changes even in low and moderate risk group patients. Try to achieve level around 70 mg/dl. Using statins is debatable.
Lipid profile should be done at age 2 for children with family history of premature cardiovascular disease or elevated cholesterol as per National Lipid Association Consensus Statement.