CARDIOVASCULAR

DISEASES
117- Diet in Metabolic Disorders
Semester I
 DEFINITIONS
• Apolipoproteins- Proteins that carry lipids in the blood and control the metabolism of lipoprotein
molecules.
• Lipoproteins - Particles that, by containing varying amounts of triglyceride, cholesterol, phospholipids,
and protein, solubilize lipids for transport in the bloodstream.
• High-density lipoproteins (HDLs) - A group of plasma lipoproteins containing mostly protein and less
cholesterol and triglycerides, high levels of which are associated with a decreased risk of coronary heart
disease.
• Low-density lipoproteins (LDLs) - Class of lipoproteins that are the predominant cholesterol carriers in
the blood and considered atherogenic; main target for interventions be cause high levels are associated
with increased risk of cardiovascular disease.
• Intermediate-density lipoproteins (IDLs) - products of very low-density lipoprotein catabolism that are
the precursors of low-density lipoproteins and considered atherogenic; not routinely measured.
• Very low-density lipoproteins (VLDLs) - primary triglyceride carrying lipoproteins that transport
endogenous lipid from the liver to the peripheral circulation.
• Chylomicron- the lipoprotein particle that transports dietary fat from the intestines into the circulation.
• Dyslipidemia- An abnormality in any one of the lipoprotein fractions.
• Atheroma - any of the lesions of atherosclerosis; synonym for plaque.
• Plaque- Early lesions seen in atherosclerosis; composed of cholesterol, calcium, and fibrin.
• Atherosclerosis- Disease characterized by thickening and narrowing of the arterial walls caused by
inflammation and the accumulation of oxidized cholesterol, smooth muscle cells, and fibroblasts
below the intima, or innermost layer of the artery.
• Atherothrombosis- Atherosclerosis and thrombus caused complications; major cause of angina,
heart attack, and sudden death.
• Ischemia- Insufficient blood flow in a tissue resulting from functional constriction or actual
obstruction of a blood vessel.
• Myocardial infarction (MI)- Ischemia in one or more of the coronary arteries resulting in necrosis,
tissue damage, and sometimes sudden death.
• Stroke - Occlusion or hemorrhage of a cerebral artery resulting in impaired function, tissue
damage, or death.
CARDIOVASCULAR DISEASES
• Coronary Artery Disease (CAD) also called as Coronary heart disease or Cardiovascular disease
(CVD), is often a preventable disease.
• It causes dangerous thickening and narrowing of the coronary arteries.
• Overtime, the heart has to work more and the damaged arteries may become completely blocked, or
become prone to clotting.
• This disrupts the flow of oxygen and nutrients to the heart, causing serious problems such as
angina, myocardial infarction, arrhythmias and possible heart failure.
• The symptoms depends on the stage of illness. The commonly noticed first indication is shortness
of breath or chest pain on exertion.
• CVD develops slowly, usually over decades, with great opportunity for prevention through healthy
eating habits and good lifestyle patterns.
 ATHEROSCLEROSIS
• Cholesterol and triglycerides are the main form of fat carried into the blood stream.
• These fats or lipids come partly from food, and partly from the body’s own production in the liver.
• Fats are not water soluble and hence cannot travel through the blood easily.
• With the help of lipoprotein, digested fat from the liver is carried to various parts of the body by the blood
vessels. The cholesterol returns to liver and repeats its job.
• The liver places cholesterol into packages called lipoproteins, made from lipids and protein. (chylomicrons,
VLDL, LDL and HDL).
• Chylomicrons carry triglycerides, contains 10-12 carbon atoms, monoglycerides, glycerol and small amounts of
cholesterol and phospholipids.
• VLDL transports endogenous triglycerides formed in the liver and travels through blood to unload fat
throughout body. The empty VLDL becomes LDL.
• LDL is the main carrier of cholesterol, LDL pieces get stuck to blood vessel walls narrowing the same. High
LDL decreases Endothelium Derived Relaxing Factor and blood vessels become narrow and cannot dilate. It is
termed as ‘bad’ cholesterol because it causes atherosclerosis.
• HDL plays a role in reverse transport of cholesterol from tissues throughout the body back to the liver for
conversion to bile acids or excretion as biliary cholesterol. It is termed as ‘good’ cholesterol.
• If too much fat is consumed, the liver makes extra VLDL to carry the fat. More LDL pieces get
stuck if there is not enough HDL to rescue them all. The blood vessels may become blocked. If this
happens to a blood vessel in the heart, a heart attack may result.
 Diet

High Saturated/ High trans fatty acids/ High cholesterol

P.Cholesterol LDL Lipid HDL-C EDRF Arrhythmia Factor Prostacyclin

P.Triglycerides receptors oxidation VII

LDL Injury to Constriction Thrombosis

cholesterol coronary of blood
arteries vessels

Atherosclerosis
Risk factors:
Diagnosis

Cholesterol Desirable Normal risk High risk

Total Cholesterol mg/d <160 200-240 >240
HDL cholesterol mg/d >55 35-55 <35
Triglycerides mg/d <50-150 200-400 >400
LDL cholesterol mg/d <130 130-160 >160
Clinical Findings:
• The principal clinical results of atherosclerotic lesions are due to partial or total occlusion of the
arterial lumen.
• The cracks and fissures developed in the lesions leads to thrombosis which is the principal cause of
angina pectoris(pain in chest provoked by exercise), myocardial infarction (death of heart muscle
tissue) and sudden ischemic death (deficient blood supply).
• Plaques usually develop slowly and insidiously over many years beginning from childhood. They
may lead from a fatty streak to a fibrous plaque and the to a complicated plaque that is likely to lead
to clinical effects.
• Impairment of the heart is manifested by: dyspnoea on exertion, weakness and pain in the chest.
• In severe failure there is marked dilation of heart.
• The circulation to the tissues through the kidney is so impaired that sodium and water are held in
tissue spaces.
• Edema fluid collects first in the extremities and with increasing failure in the abdominal and chest
cavities, is referred to as congestive heart failure.
Dietary Management:
Diet therapy remains the first line of treatment for patients with high cholesterol levels. Low calorie, low
fat (particularly low saturated fat, low trans fat, low cholesterol, high in PUFA with ꞷ-6 to ꞷ-3, low
carbohydrate and normal protein, minerals and vitamins are suggested. High fiber diet with increases
amount of antioxidants is also recommended.
• Total Energy- Those patients whose weight as a desirable level are permitted a maintenance level of
calories during convalescence and their return to activity. Lost of weight by the obese leads to
considerable reduction in the work of the heart because the basal metabolism is at a lower level.
• Fat- Restrict fat to not more than 20% of total energy intake. It is not desirable to restrict all form of fat.
PUFA and MUFA sources are beneficial to increase HDL cholesterol. Blended oils rich in ꞷ-6 and ꞷ-3 in
correct proportions help prevent atherosclerosis.
• Carbohydrates- Only complex carbohydrates should be included in the diet. Carbohydrate intake should
be limited to 60% of total energy in patients with metabolic syndrome. Food rich in soluble fibers reduce
LDL cholesterol
• Protein- Normal allowances are recommended. Animal proteins are not suggested for atherosclerotic
patients.
• Vitamins- Vit A deficiency may occur, hence supplementation is necessary. Niacin increases HDL. Vit C
regulates cholesterol metabolism and might prevent tissue damage that leads to CHD.
• Minerals- Sodium is restricted in hypertension. Intake of salt, 3g/day is safe. Sodium restriction should be
ordered individually as the condition of the patient requires. Potassium helps to maintain cell fluid balance
and plays a key role in muscle contraction. Low levels of potassium have been associated with High BP.
• Water- Restriction of fluid is not required as long as sodium is not restricted.

Functional foods:
• Vitamin E- Vegetable oils, DGLV’s, nuts and whole grain cereals.
• Carotenoids- Green leafy vegetables, yellow and orange coloured vegetables.
• Vitamin C- Fruits: Guava, pomegranate, pineapple, lemon, GLV’s and cruciferous vegetables.
• Fruits and vegetables
• Soy protein
• Garlic
• Nuts
• High Fibre- Guava, Apple, Oats, Fenugreek seeds, whole fruits, brown rice, cluster beans
• Curry leaves and turmeric
Dietary Guidelines:
• Patient should maintain body weight slightly lower than standard weight. For obese, weight reduction is a
key to prevent and treat CVD.
• The patient should eat variety of foods low in fat, saturated fat and cholesterol. Trans fat should be avoided.
• Vegetable oils rich in PUFA’s like sunflower, safflower oil should be included. Solid fats should be
avoided.
• Small quantities of almonds and walnuts can help bring down the cholesterol levels. High amounts of nuts
and oilseeds increase the calorie and fat content.
• Coconut should be avoided as it contains high amount of SFA’s and it is a concentrated source of energy.
• Egg yolk contains cholesterol. Hence limit intake of whole eggs, or suggest egg whites.
• Avoid meat and pork as they contain high amounts of SFA’s. All sea foods are rich in sodium, hence should
be consumed in moderation.
• Patient should take low-fat milk or skim milk.
• Boiling steaming, grilling or baking without fat are preferable methods of cooking.
• Concentrated foods, foods giving empty calories, outside foods must be avoided.
• 5 servings of fruits and vegetables should be consumed daily. Choose high fiber foods.
• Avoid heavy meals. Small and frequent meals are preferred.
Drugs:
• Drugs lower blood LDL and total cholesterol.
• Statins are inhibitors of hydroxymethylglutaryl-CoA reductase enzyme and lower total cholesterol, low-
density lipoprotein (LDL), and triglyceride concentrations.
• Statins reduce the amount of lipid deposited in artery walls, reduce heart attacks, unstable angina and
stroke. May also reduce the fat content of plaque.
• The FDA-approved statins include atorvastatin, rosuvastatin, simvastatin, pravastatin, fluvastatin,
lovastatin, and pitavastatin.
• Along with dietary and lifestyle modifications, exercise and proper medications reduce the risk of
atherosclerosis.
• The patient should stop smoking and reduce stress as part of treatment of CVD.
 HYPERTENSION
• Hypertension or High Blood Pressure is the modifiable risk factor of CVD and stroke.
• Every individual has blood pressure which is necessary to move blood through arteries and to provide
oxygen to the tissues of the body. Hypertension is elevated blood pressure.
• Hypertension is defined as a persistently high arterial blood pressure, the force exerted per unit area on
the walls of arteries. When the systolic blood pressure (SBP), the blood pressure during the contraction
phase of the cardiac cycle, has to be 140 mm Hg or higher; or the diastolic blood pressure (DBP), the
pressure during the relaxation phase of the cardiac cycle, has to be 90 mm Hg or higher, and they are
reported as 140/90 mm Hg.
• It is often called a "silent killer" be cause people with hypertension can be asymptomatic for years and
then have a fatal stroke or heart attack. Although no cure is available, hypertension is easily detected and
usually controllable.
• Types of Hypertension:
1. Essential or Primary Hypertension: (95% incidence) Is of unknown origin, can be caused due to a
combination of environmental and genetic factors.
2. Secondary Hypertension: (5% incidence) Can be caused by illness or medication.
Risk factors:
• Renal, endocrine or neurological disorders
• Heredity
• Stress
• Obesity
• Smoking
• High viscosity of blood due to too many red blood cells in the circulating blood
• Narrowing of the blood vessels due to hormone secretions especially cortisone, aldosterone, adrenaline
and noradrenaline.
• Aging
• Alcohol consumption
• Salt sensitivity and a person’s dietary choices may influence hypertension risks.
• Diabetes mellitus
Pathogenesis:
• Blood pressure is a function of cardiac output multiplied by
peripheral resistance (the resistance in the blood vessels to the
flow of blood).
• The diameter of the blood vessel markedly affects blood flow.
When the diameter is decreased (atherosclerosis) , resistance
increases and blood pressure increases. Conversely, when the
diameter is increased (vasodilator drug therapy), resistance
decreases and blood pressure is lowered.
• Many systems maintain homeostatic control of blood pressure.
The major regulators are the sympathetic nervous system (for
short-term control) and the kidney (for long term control).
• In response to a fall in blood pressure, the sympathetic nervous
system secretes norepinephrine, a vasoconstrictor, which acts on
small arteries and arterioles to increase peripheral resistance and
raise blood pressure.
• The kidney regulates blood pressure by controlling the
extracellular fluid volume and secreting renin, which activates
the renin-angiotensin system. When the regulatory mechanisms
falter, hypertension develops.
Diagnosis:
• Diagnosis of hypertension is made from at least two elevated blood pressure readings on two or more
occasions.

Cut off values in mm Hg

Category
Systolic Diastolic
Normal <120 <80
Elevated 120-129 <80
Stage I Hypertension 130-139 80-89
Stage II Hypertension 140 and above 90 and above
Symptoms:
• Usually asymptomatic
• Headache
• Dizziness
• Impaired vision
• Failing memory
• Shortness of breath
• Pain over the heart
• Gastrointestinal disturbance
• Unexplained tiredness

Too much blood pressure can weaken blood pressure wall. It causes bulges and ruptures as well as damage
delicate organs like heart, eyes, or the kidney that receive blood flow. It can force the heart to work harder
contributing to eventual heart failure.
Medical Management:
• The goal of hypertension management is to reduce morbidity and mortality from stroke, hypertension-
associated heart disease, and renal disease.
• If blood pressure remains elevated after 6 to 12 months of lifestyle changes, antihypertensive medications
are started.
• The standard treatment for hypertension includes diuretics and β-blockers, and other drugs (β-angiotensin
converting enzyme inhibitors, α-receptor blockers, and calcium antagonists)
Dietary Management:
• The ‘Dietary Approaches to Stop Hypertension’ (DASH)
diet is used for prevention and controlling hypertension. It
is a flexible and balanced eating plan that helps create a
heart-healthy eating style for life.
• It emphasizes increased amount of fruits and vegetables,
inclusion of fish, inclusion of low fat milk, reducing the
fat intake and reducing sodium.

Food Groups Daily servings

Grains 7-8
Vegetables 4-5
Fruits 4-5
Milk (low fat) 2-3
Meat (lean) 2 or less
• Sodium intake should be restricted to 1500-2000mg in adults with hypertension. The use of non-food
items containing sodium such as antacids, chewing tobacco and drugs should be restricted. The patient
should be provided with a list of high sodium foods and advised on minimizing sodium intake.
• Use of salt substitutes should be ascertained, especially in the presence of renal disease when it would be
contraindicated.
• Adequate potassium consumption is needed for blood pressure control.
• Adequate dietary calcium should be encouraged for blood pressure control.
• Magnesium intake may be assessed and supplements should be considered.
• Moderate alcohol intake has no effect on BP but heavy drinkers need to be advised abstinence.
• Regular physical activity should be encouraged, as permitted by the physician. Aerobic exercised for
40mins/day are effective.
• Smoking cessation is advised.