Hypertension Silent Killer. What is the most effective treatment in lowering high blood pressure?

by zaheer17 (student)

Tanbir Islam 12AS2

Hypertension

What is the most effective treatment in lowering high blood pressure?

The Problem

Research has shown that high blood pressure is the main cause of Strokes and Coronary Heart Disease. It is of the most common disorders in the UK; this can be supported by many sources such as . Hypertension is regarded as a silent killer in many developed countries as statistics show; the “2008 overall death rate from HBP was 18.3%. Death rates were 16.5% for white males, 50.3% for black males, 15.3% for Hispanic males, 13.1% for American Indian/Alaska Native males and 14.5% for Asian/Pacific Islander males”.

(http://www.heart.org/idc/groups/heart-public/@wcm/@sop/@smd/documents/downloadable/ucm_319573.pdf)

Hypertension elevates the blood pressure in the arteries; which damages the artery wall by the high blood pressure exerting an extra strain on the endothelium layer. This causes an inflammatory response as the white blood cells move into the artery wall and accumulate cholesterol from the blood. The cholesterol builds up which lead to the formation of an atheroma, there is also a build up of calcium salts and fibres at the site which lead to a plaque formation on the inner wall of the artery. This causes the artery to become narrower which result in raised blood pressure.

Figure 1: Google Images

A blood clot may also form which can block the artery as a whole which reduces the flow of oxygenated blood back to the heart which can result in a heart attack. A blood clot can also cause stroke, pulmonary embolism and atrial fibrillation. Statistics show “69% of people who have a first heart attack, 77% of people who have a first stroke and 74% of people with chronic heart failure have high blood pressure”.

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Possible Solution – Antihypertensive drugs

Antihypertensive drugs are possible solutions to lowering blood pressure; these drugs have been tested thoroughly and are only prescribed to patients who suffer from extreme high blood pressure.

Examples of antihypertensive drugs are: ACE inhibitors (ACE stands for angiotensin converting enzyme), Diuretics, Beta blockers and Statins. ACE inhibitors block the production of angiotensin which causes arterial constriction and a rise in blood pressure; however the side effects are cough, dizziness, heart arrhythmia and impaired kidney. A combination of drugs is sometimes used if the blood pressure is not reduced for example: a doctor may prescribe Alpha blockers which reduces nerve impulse to the blood vessel, with ACE inhibitors to help lower the blood pressure.

To see how effective the drugs were, a randomised, double-blind placebo- controlled trial of the antihypertensive drug was conducted during a 4 week period; with “208 moderately hypertensive men aged between 35 to 60 years old, each individual received each of the four monotherapies in random order. Four week of placebo period was included before and between drug treatment periods. Antihypertensive responses were assessed with 24-h ambulatory”. Results show the blood pressure responses to “bisoprolol and losartan did not vary according to the variables. Amlodipine and hydrochlorothiazide responses were positively correlated with age, placebo blood pressure level, and lower night-time dipping on placebo”. ()

The benefit of a double blind study is a “double-blind study is an unbiased experiment which gives an accurate idea of the benefits of a drug. This is especially important when considering drug treatments that may have side effects or be otherwise detrimental to the patient”.

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Another randomised drug trial was conducted to investigate how effective antihypertensive drugs are. The placebo-controlled trial of ACE inhibitors “(four trials, 12,124 patients mostly with coronary heart disease) showed a risk reduction of 30% stroke and 20% coronary heart disease, the overview of placebo-controlled trials of calcium antagonists showed 39% risk reduction in stroke and 28% in major cardiovascular disease In the overview of trials comparing blood-pressure-lowering strategies of different intensity (three trials, 20,408 patients with hypertension), there were reduced risks of stroke (20% [2-35]), coronary heart disease (19% [2-33]), and major cardiovascular events (15% [4-24]) with more intensive therapy”.

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Figure 2

The graph shows a positive effect of ACE inhibitors and calcium antagonist has on strokes, coronary heart disease and major cardiovascular diseases; ACE inhibitors had a risk reduction of stroke by 30% and coronary heart disease by 20% while Calcium antagonist had a greater risk reduction of strokes by 39% and any major cardiovascular disease by 28%. This indicates antihypertensive drugs a more effective treatment and more favourable as they provide additional benefits to patients and have greater risk reduction in strokes, coronary heart disease and major cardiovascular diseases.

Ethical, Economic & Social Issues

Hypertension occurs more in developing countries such as: India, Bangladesh and Pakistan. Government in third world countries should develop comprehensive local programmes to promote healthy eating and exercise. This is one of the most prominent ways of preventing hypertension as the general public are aware of how to prevent themselves of getting hypertension by acknowledging how much salt to intake, to exercise on a regular basis and maintain a healthy weight.

One ethical issue is regarding drug trials on humans. Drug testing on humans is considered morally wrong as it breaches many ethical guidelines for example: right to withdraw and deception when considering placebo based drug trials. Drug trials can sometimes result in the death of the volunteers as statistics show 16 people were found dead due to drug trials in India.

(http://worldnews.nbcnews.com/_news/2012/08/18/13346829-report-211-die-during-drugs-trials-in-india?lite)

One economic issue regarding hypertension is the substantial economic cost burden; regarding the main consequences caused by hypertension as statistics show, coronary heart disease and stroke; have been calculated at a cost of about “£7.06 billion for Coronary heart disease and £5.77 billion for stroke”.

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Another economic issue is the cost of setting and running a drug trial. A drug trial can expand over a long period which can be very expensive and could even cost considerably more in marketing the product. Studies show the cost of running a drug trial can range from $500 million to $2 billion.

Benefits and risks of antihypertensive drugs

The advantage of using antihypertensive drugs like: ACE inhibitors to lower blood pressure can reduce the chance of stroke and coronary heart disease; as statistics show antihypertensive treatment can reduce the incidence of stroke by “30% and 20% coronary heart disease”. (www.ncbi.nlm.nih.gov/pubmed/11130523).

Unfortunately using antihypertensive drugs such as ACE inhibitors, Diuretics and Statins can result in side effects for example: using diuretics can induce nausea, muscle cramps, very occasional dizziness, impaired kidney function, the side effects can develop into other diseases for example: impaired kidney function can cause anaemia.

Another advantage of using antihypertensive drugs is it provides additional benefits to patients for example: “ACE inhibitors helps patients with heart failure by reducing the strain on the heart by decreasing the amount of fluid pumped around the body”. ()

A second disadvantage is antihypertensive drugs have to be taken on a daily basis, for example: “Some people who suddenly stop taking a calcium-channel blocker have a 'rebound' flare up of angina”.

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Alternative solutions

Diet

Hypertension can be controlled through lifestyle changes; such as diet, regular physical activity. These changes help to control high blood pressure.

People trying to control hypertension are advised to decrease their sodium intake, and maintaining a healthy weight. Reducing sodium is a prominent way of lowering the risk of hypertension especially for ethnic groups who have a greater risk of hypertension. The recommendation for daily sodium intake is “2.5 grams a day, on average people in the UK should consume about 9.5 grams salt”. (http://www.nhs.uk/chq/Pages/1138.aspx?CategoryID=51&SubCategoryID=167)

People with hypertension should aim to eat a diet that's rich in:

“Fruits
Vegetables
Whole-grain, high-fibre foods
Fat-free and low-fat (1 percent) dairy products
Beans
Skinless poultry and lean meats
Fish, especially fatty fish contain omega 3 fatty acids such as salmon, trout and herring (eat at least twice a week)”

“And low in:

Saturated and trans fats
Sodium”

“And limit:

Added
sugars”

Physical activity

Research has shown adults should aim to do at least “150 minutes of moderate intensity aerobic activity” for example: jogging, playing a sport, every week. This data is supported by many health organisations such as; National Health Service and American Heart Association. I can put a degree of trust in the information, as I have confirmed the validity of the data by comparing the information with other sources to see if it is reliable. Exercising on a regular basis helps to lower blood pressure by strengthening the heart and the cardiovascular system.

Exercising helps to reduce stress, as stress is a major cause of hypertension. Exercising also helps to reduce weight loss which gives the person an ideal healthy weight to control their blood pressure. A study on “10 269 male Harvard graduates aged between 45 and 84 showed that the men who increased their levels of physical activity had a 23% lower mortality after 20 years than their peers who did not exercise”. (Edexcel AS Biology Student Book)

Radiotherapy

New research has shown “directing short bursts of radio waves at nerves surrounding the kidney” which helps to lower blood pressure for a period between 6 months to a year. This type of treatment is used for people who failed to response to antihypertensive drugs. Using radiotherapy can cause side effects such as: tiredness, sore skin, and diarrhea etc. (http://newsroom.heart.org/news/radio-waves-to-kidneys-lower-persistent-241739)

Bibliography

Bravada DM,GO AS,Ford ES, et al. 2012 population fact sheets: a report from the American Heart Association. (http://www.heart.org/idc/groups/heart-public/@wcm/@sop/@smd/documents/downloadable/ucm_319573.pdf) (Assessed 27/12/12, available) () (Accessed 25/12/12, available)

, , , , , , , , , , .2007 March; Department of Medicine-University of Helsinki and Biomedicum Helsinki, Finland. (); (Assessed 21/12/12, available)

Ann Fullick, Patrick Fullick, Sue Howarth,- Edexcel A level Science Student Book Published 12/06/2008 (Edexcel AS Biology Student Book)

Henry Krum, Markus Schlaich, Murray Esler et al 17th December 2012. ()

Online website which provides medical, lifestyle and diseases information.

( 5/1/13- available)

Team of Doctors; Dr Adrian M Bonsall, Dr John P Cox, Dr Richard Draper et al. Website was launched in 1997

J L Y Liu, N Maniadakis, A Gray, M Rayner- 14 August 2002

(http://heart.bmj.com/content/88/6/597)(Avaliable)

() ( Accessed 24/1/13- available)

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() (Accessed 28/1/13-available)
Google Images (Accessed 28/1/13-available )

Evaluation of Sources

(); this source seems to be very reliable as it has taken many precautions to control any extraneous variable, affecting the results to ensure validity within the study; for example: checks had been made to ensure the participant had taken the antihypertensive drug on time.

(Edexcel AS Biology Student Book); this source would provide accurate information as its aim is to provide information to students. The author would also ensure the information is correct by double checking their sources.

(); this source is reliable a reliable source because, I have confirmed the reliability of the data by comparing the information with other sources to see if it is reliable.

(http://newsroom.heart.org/news/radio-waves-to-kidneys-lower-persistent-241739); the information provided is reliable as the information had been assessed by professor Murray Esler who is the senior director of the Baker IDI hearts and diabetes institute in Australia.

Useful Organisations