Hypertension: Meaning, Treatment and Prevention

In this article we will discuss about the Hypertension:- 1. Meaning of Hypertension 2. Classification of Blood Pressure 3. Treatment 4. Prevention.

Meaning of Hypertension:

Hypertension is an important cause of several ma­jor disease and it is amenable to treatment. Hence, measurement of blood pressure is a part of all rou­tine clinical examinations of adults. Hypertension is a major risk factor for the development of cardio­vascular disease.

It is defined as systolic blood pres­sure of 140 mm of Hg or greater and/or diastolic blood pressure of 90 mm of Hg or greater or any level of blood pressure in patients taking antihy­pertensive medications.

The pathological changes accompanied by hypertension are a thickening of the arterioles with hyaline material and, later, hypertrophy of the myo­cardium of the left ventricle. If untreated, moderate hypertension eventually leads to cardiac failure, with dilatation of the left ventricle and congestion of the pulmonary or systemic veins. It also causes ischaemic changes in the kidney, nephrosclerosis.

The blood pressure if very high is said to be malignant hypertension. The heart, kidneys, retinal and other arteries are quickly affected and it shows immediate risk of a dangerous vascular accident. Therefore, vigorous treatment is most essential.

80 per cent of cases suffer from essential hy­pertension. Treatment has to be symptomatic. In the remaining cases the hypertension is usually secondary to renal disease, e.g., glomerulonephritis or pyelonephritis, and less commonly, to an endo­crine disorder, e.g., Cushing’s syndrome, acrome­galy, pregnancy also show hypertension.

Classification of Blood Pressure:

A. Heredity:

a. Hypertension frequently affects several members of a family and there is a high correlation between the blood pressures of identical twins.

b. Individual susceptible to hypertension is related to decreased activity of (Na⁺, K⁺) ATPase, the enzyme that through the so­dium pump maintains intracellular concen­trations of Na⁺ and K⁺. The activity of the enzyme is genetically determined.

B. Obesity:

a. Hypertension commonly accompanies obesity though it may occur in thin peo­ple.

b. Obese patients with hypertension, if re­duce their weight to normal value, their blood pressure frequently returns to nor­mal without any other treatment. This in­dicates that in susceptible individuals obesity is a direct cause of hypertension.

C. High Salt Intake:

High salt intake in some countries causes hyper­tension; but in some other countries high salt in­take shows no effect. It is, therefore, assumed that there is a threshold for salt intake, as yet undefined, above which hypertension commonly arises in sus­ceptible individuals and that susceptibility is ge­netically determined.

D. Other Possible Risk Factors:

a. Stress, either mental or physical, raises the blood pressure immediately but this is only temporarily.

b. Environmental stresses may contribute to hypertension and of the theory that indi­viduals with a poor capacity for relaxa­tion are more prone to hypertension indi­cate that stress is not a major risk factor.

c. Inactivity may be a risk factor but is only a minor one.

d. Alcohol intake (> 3 units/day for men; > 2 units/day for women).

e. Physical activity.

f. Smoking.

g. Drags (e.g., NSAID, Oral contraceptives).

h. Renal diseases.

i. Pheochromocytoma.

j. Conn’s syndrome (tetany, muscle weak­ness, polyuria, hypokalemia).

Factors involved in pathogenesis of hypertension:

i. Laboratory Investigations:

Urine for protein, glucose and microscopic (RBCs/other segments) haemoglobin, fasting blood glucose, serum creatinine, potassium and total cho­lesterol.

ECG:

ii. Additional Investigations:

Lipid profile, Uric acid

Chest X-ray

Echocardiogram.

Treatment of Hypertension:

Non-Pharmacological Measures:

Life style measures:

a. Maintain normal weight for adults (body mass index 20-25 kg/m²).

b. Reduce salt intake to < 100 mmol/day (< 6 gm. NaCl or < 2.4 gm. Na⁺/d).

c. Limit alcohol consumption to < 3 units for men and < 2 units/day for women.

d. Aerobic exercise (e.g., walking, cycling, swimming) > 3 min/day (at least three days of the week).

e. Consume at least five portions/day of fresh fruits and vegetables. Fish consumption rather than meat should be recommended. High intake of fibres, grains, vegetables and fruits improve BP control.

f. Reduce the intake of total and saturated fat.

Pharmacological Measures:

a. Achieve gradual reduction of blood pres­sure.

b. Use low doses of antihypertensive drugs to initial therapy.

c. Choice of an antihypertensive agent is influenced by age, concomitant risk fac­tors, pressure of target organ damage, other coexistence diseases and socio-economic condition.

d. Use of long acting drugs providing 24 hr efficacy ensures smooth and sustained control of blood pressure. Once daily ap­plication also improves patient compli­ance.

Prevention of Hypertension:

a. The dietary restriction is the reduced in­take of salt.

b. It is advised widely not to use table salt and to use a minimum salt in home cook­ing. It is more important for the public to know that prepared meats contain about 20 times as much salt as is present in the original fresh meat.

Chips and crisp pota­toes are very rich sources of salts. Salted and canned fish are fine for an occasion but if eaten frequently may increase salt intake greatly. Many snack foods are rich in salt.

c. As a preservative, salt is added to manu­factured foods. But it should be such as to be ineffective. Manufacturers are not un­responsive to medical opinion and have greatly reduced the previously high salt content of infant foods when it was shown that this was a cause of hyperosmolar de­hydration, a serious disorder in infants.

A significant amount of salt is added to bread, butter and cheese. It is to be looked upon as medicinal products that low salt bread, butter and cheese are obtained eas­ily. If there is a popular demand for low salt foods of all sorts, manufacturers will produce and advertise them.

d. Legislation to restrict the addition of salt to foods will be difficult to enforce. A more practical approach will be to provide more money and support for appropriate health education.