Management of Hypertension – Bangladesh Perspective

Dr. Mohammad Farhad Uddin

MD (Cardiology)

Interventional Cardiologist

NICVD, Dhaka.

 

Introduction:
Blood pressure is a very important physiologic component in human body. In fact no one can survive without maintaining his or her blood pressure. By definition it is the pressure of blood over the blood vessel while flowing through it.  Blood pressure has two components namely systolic and diastolic which have their own normal ranges. Either of these two separately or together can go up above these normal ranges. If it is a persistent rise- blood pressure turns to hypertension.

Hypertension is a long-term medical condition in which the blood pressure in the blood vessels is persistently elevated. When this persistent rise is in the arteries then it is called Arterial Hypertension. Though other vessels like veins, pulmonary arteries can have hypertension too but the term “Hypertension” usually refers to arterial hypertension if not specified otherwise.

Epidemiology:

Hypertension is a global problem, let alone Bangladesh. It is one of the largest non-communicable disease as around 25% of the world population is suffering from it.  The bad news is its increase in prevalence.  A large number of these people live in developing countries.

Bangladesh has no large scale data but those so far found, have come up with around 26.4% overall prevalence with female preponderance. Another study by Islam et.al. depicted that incidence of hypertension increases with age as 40-65% of elderly people suffer from hypertension. A  large number of hypertensive patients live in the rural areas according to these studies. Chowdhury et,al. has shown in their study  that hypertension in Bangladesh community is associated  with older age, sex, education, place of residence, working status, wealth status BMI and diabetes. 

Types and risk factors of hypertension

Primary or essential hypertension

The exact cause of hypertension is not known among almost 95% of hypertensive patients and it is termed as primary or essential hypertension. However, there are some risk factors that are linked to developing hypertension in this group. These are lack of physical activity, obesity, recent weight change, dietary habit, smoking, positive family history. All these risk factors are getting more prominent among our people putting them at more risk to develop hypertension.

Secondary hypertension:

This is the type of hypertension that develops secondary to a disease that cause is known. Only 5% of the hypertensive patients experience secondary hypertension. Common causes are renal disease, thyroid disorder, due to some drugs and sleep disorder.  Recently some studies have found relation in-between hypertension and arsenicosis which has common cause of water pollution in parts of Bangladesh. Hypovitaminosis D might be another cause that might play a role in causing hypertension among Bangladesh people.

Coexistence with other Diseases

Though at the younger ages and at initial stages hypertension may remain alone but in course of time it may coexist with other diseases. These are commonly, kidney disease, cardiovascular disease, cerebrovascular disease, lipid disorder, metabolic syndrome, COPD,  eclampsia. In all these comorbid situations, management of hypertension becomes complicated and choice of antihypertensive is driven by the compelling indication.

 Stages of Blood pressure

Since Bangladesh doesn’t have any of its own guideline on Hypertension, therefore, we follow the other guidelines, namely those of  JNC 7, European Society of Hypertension and British Hypertension Society.  All have categorized hypertension almost similarly with slight differences. JNC 7, the most popular of these have categorized blood pressure in the following way:

Table: Stages of Hypertension: JNC 7

Stage of Blood Pressure ( BP)	Systolic BP	Diastolic BP
Normal	<  120	And <80
Prehypertension	120-139	80-89
Stage 1 Hypertension	140-159	90-99
Stage2 Hypertension	≥160	≥100

 

The majority of the people in Bangladesh, especially those living in the rural areas  have no idea about these numbers. Those with more education have  some conception about the ranges, but very few of us know regarding ‘Prehypertension’ and its importance. Though not today’s focus of discussion, our community deals with another blood pressure related complain which is termed by the patients “ Low Pressure”.
 
Complications

Hypertension though a silent disease by itself can invite  various complications for the body, more rapidly when it is not well controlled by the patient. Ischemic heart disease, acute coronary syndrome, left ventricular failure, cardiomyopathy, arrhythmia, chronic kidney disease, cerebrovascular disease ( brain stroke) retinopathy, peripheral vascular disease, dementia etc.  are recognized complications of hypertension. Our hypertensive patients do not know well about these complications. So, many of the hypertentensive patients attend the physicians  with the clinical features of the complication and come to know about their hypertension status for the first time.

A group of hypertensives may fall into conditions like resistance hypertension, hypertensive urgency and hypertensive emergencies warranting more vigorous treatment, urgent hospitalizations and management.

Diagnosis

Hypertension initially is largely a silent disease, therefore, remain undiagnosed in many patients. In a large group of patients hypertension is  asymptomatic while in others there are nonspecific symptoms like headache, weakness, palpitation, breathlessness, nasal bleeding, vision disturbance and so forth. As the disease progresses silently there comes a time when body’s vital organs are damaged and symptoms of complications surface.

This is relatively a common phenomenon in Bangladesh; hypertensive patients presenting with complications. Health System in Bangladesh is not supported by widespread health insurance and health checkup is not routinely practiced here. 

Lack of education, health awareness is also responsible for non-diagnosis or late diagnosis of hypertension. People come to know about their hypertension while measuring blood pressure somewhere or attending a health facility for some other reasons.  

Trend of Measuring Blood Pressure

Blood pressure measurement is the key way to diagnose hypertension. In Bangladesh, blood pressure measurement is available in health facilities like hospitals, clinics, chambers.

Now a days, beside such office BP measurement out of office BP measurement in pharmacies (medicine stores) is commonly seen.  Road side temporary facilities with blood pressure machine , glucometer and weight machine  in and around places where people visit for regular exercise are also seen now a days. 

Home BP monitoring (HBPM) is getting popularity in this country. However there should be definite scientific and logical approach to home blood pressure monitoring. Otherwise, misuse or overuse of HBPM  produces confusion, anxiety and lead the patient and family members to wrong treatment.

All these approaches in spite of their limitations have positive impact in the diagnosis and management of hypertension.

Types of Sphygmomanometer  (Blood Pressure Machines):

Aneroid BP Machine: The most popular type is the aneroid sphygmomanometer due to its availability, cost efficacy, easy handling.  In addition to its use in office BP measurement it is widely used in home BP monitoring.

The Mercury BP Machine:  Many people still unaware of the fact that mercury sphygmomanometer is losing its position as the gold standard because of chance of mercury toxicity.

Automated Digital BP Machine: People have doubt about the measurement efficacy of automated digital blood pressure machine though it is the sphygmomanometer that has been advocated by recent guidelines. Compared to other auscaltatory methods this automated digital BP machines measure blood pressure by means of oscillometry. Therefore, it can be operated alone. Excessive cost is another reason for its less use in Bangladesh community.

Ambulatory blood pressure monitor: Though it has an important role in the diagnosis of hypertension but its use is still very limited in our community due to unavailabity, higher cost and unawareness- even among the physicians.

Other investigations

Diagnosis and assessment of hypertension status include some other investigations like creatinine, urine, lipids, ECG, Echo, which the patients are reluctant to do due to unawareness and expenses.

Treatment

Treatment of blood pressure comprises of life style modification and antihypertensive medication. For all groups of hypertensive patients, life style modification is an inevitable component and in prehypertensives and stage1 without compelling indication it is infact the initial and only treatment. 

 Life style modification

Life style modification comprises of diet, reduction of obesity, regular exercise, cessation of smoking, abstinence from alcohol and stress management.

Diet

Diets include healthy eating habit like Dietary approach to stop hypertension (DASH), Mediterranean diet etc. All diets have a common basic concept that is a diet with required calorie according to patient’s body weight, rich in vegetable, fruit, fiber and less in animal fat, carbohydrate and no added salt (that is low in sodium) and rich in potassium. But it’s a common practice in Bangladesh to indulge in a diet rich in carbohydrate and extra salt.

So as a part of management of hypertension our diet needs healthy change – diet that is amicable with our culture as well as healthy enough to control hypertension. The traditional practice of taking extra salt, specially among the rural people must be discouraged by different approaches of health awareness program. Mass awareness campaign should also be launched to lower down the consumption of excess salt. Salt low in sodium is widely available in developed countries and should be instituted in Bangladesh.

Obesity Reduction:

With the growing economy, obesity in Bangladesh is expanding  as well. Our community should have more institutional facility like health center, counselor , nutritionist, treatment facility for morbid obesity, drugs to reduce obesity for obesity reduction.

Exercise:

No doubt, awareness for doing exercise has increased among Bangladesh people though a lot more needed to control no communicable diseases. Facilities like roads, pavements, parks friendly enough for walking and other exercises   are not at all enough for us and should be increased at any cost. Exercise should also include mental relaxation techniques like prayer, meditation, yoga etc.

First Line Antihypertensive Drugs	Diuretcs
	ACE Inhibitors (ACEI)
	Angiotensin II Receptor blocker (ARB)
	Calcium Channel Blocker (CCB)
Combination Antihypertensive	ACEI OR ARB +Diuretics
	ARB+ CCB
	CCB+ BB
	BB+ Diuretics
Second Line Antihypertensive Drugs	Beta blocker (BB)
	Alpha Blocker
	Hydralazine
Drugs used in Hypertensive Emergency	Hydralazine, Nitroprusside, Labetalol, Clonidine, Methyldopa,Furosemide, Nitrate

Treatment with Antihypertensive Drugs

One of the mentionable developments that Bangladesh has achieved in local production of almost 95% of the drugs used in health sector, thanks to the booming

pharmaceutical sector. Almost all types of antihypertensive drugs are locally produced and marketed cost effectively by the pharmaceutical industries. These are the combination drugs also available here making the treatment more patient-friendly. Antihypertensives are even crossing the border as pharmaceuticals are now a days exporting these drugs to other countries

South Asians respond to antihypertensive therapy in similar manner with the others. Since it is a lifelong treatment, most patients find comfort with cost effective  antihypertensives. Single daily dose is preferred to twice daily dosing and increases patient’s compliance with the treatment. In most cases, at least two drugs are needed at one stage of treatment to control hypertension.

Calcium-channel blockers (45%) and beta blockers (40%) are the two most popular drugs used for hypertension treatment in Bangladesh. Still the age old beta blockers are on popularity list though recent guidelines have discouraged the use of beta blockers due to its inability to lower down central blood pressure. Side-effects are sometimes troublesome for the patients and another reason for noncompliance with drug treatment. Prescription survey study found irrational drug prescribing, lack of quality in prescribing, dosing and biasness due to the influence by the pharmaceuticals.

Misconception regarding Antihypertensive drugs:

There are several misconceptions regarding treatment of hypertensive patients in Bangladesh. Many people believe regarding treatment, there is no other option but to take antihypertensive drugs. Some do not want to start antihypertesnsives because they believe it is not required since the disease is not producing any symptom. Some do not start the drug because they think it cannot be stopped once started so it’s better not to start at all.

Some people  discontinue the drug once the blood pressure is normalized because they think the drug is no more needed. In a study, non-adherence to antihypertensive treatment was found in 85% of cases. Many people keep taking the drug continuously without attending the physician further or measuring there blood pressure  from time to time.

Factors determining non-adherence included lower level of education, low family income, duration of illness, perception related to the disease, lack of accompanying person, and insufficient information from the service provider.

Prevention

The primary prevention of hypertension include healthy lifestyle in such a manner so that blood pressure remains in normal range. The secondary prevention includes good control of blood pressure among the hypertensive patients and avoidance of complications. Lifestyle modification, antihypertensive drugs, regular health checkup, health education all these in concert can achieve the purpose of prevention. Bangladesh needs its own guideline, strong health policy, robust strategy, large scale research works,  mass awareness program to achieve its target on management of hypertension.