7.FEB.2018 4 MIN READ | 4 MIN READ

High blood pressure officially affects 27.3% of Singapore’s population. But in reality, that number is likely to be far greater. How can we go about treating this silent killer?

Dr Kenneth Guo, cardiologist at Mount Elizabeth Novena Hospital, explains how hypertension (high blood pressure) is treated. 

First things first, what is high blood pressure?

Well, as the name suggests, high blood pressure (also known as hypertension) is the force of blood pushing against the walls of your blood vessels. If you have high blood pressure, this force is stronger, which means your heart needs to work extra hard to transport blood around your body. 

Doctors measure both systolic pressure (the pressure in the arteries as the heart contracts) and diastolic pressure (the pressure in the arteries as the heart relaxes) to determine an accurate blood pressure reading. Normal blood pressure is generally considered to be a systolic pressure of less than 120mmHg and a diastolic pressure of less than 80mmHg.

Why is high blood pressure known as the ‘silent killer’?

Hypertension, the silent killer
Most patients with high blood pressure have few or no symptoms, so it can be hard for them to a) recognise they have a problem and b) know whether treatment is working. Symptoms like light-headedness, facial flushing or headaches might only set in when systolic blood pressure rises higher than 160 mmHg or above. 

According to the American Heart Association, you should have a high blood pressure screening during every visit to the doctor, or at least every 2 years, from the age of 20. You’ll need more regular screenings if your blood pressure is higher than 120/80 mmHg. 

What happens if high blood pressure goes untreated?

High blood pressure increases your risk of heart attack, stroke, heart failure and kidney disease. A 40-year-old obese male with a blood pressure of about 141/91 mmHg, for example, will be 6.8 times more likely to have a stroke than a healthy individual. 

While the risks increase the worse that high blood pressure gets, they generally improve with treatment. That’s why it’s so important to go for regular check-ups, and seek treatment early. 

So, how is high blood pressure treated?

How is hypertension treated
Lifestyle changes can be a huge factor when it comes to treating high blood pressure, as is evident by the Ministry of Health’s suggestions for a healthier heart:

Lifestyle measure Expected decrease in systolic blood pressure (mmHg)

Limiting alcohol intake to less than 1 unit/day for females and less than 2 units/day for males

2 – 4 

Regular walks for 30min, 5 times a week

4 – 9 

Minimising salt intake

2 – 8 

Weight management

1 – 2 per kg weight loss 

Quitting smoking

1 – 5 

The Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC) released new guidelines in 2014 for the proper management of high blood pressure. 

They analysed evidence worldwide to recommend treatment goals for patients living with high blood pressure. For most people, the goal is 140/90mmHg. However, for elderly people, this is usually slightly higher at 150/90mmHg. 

Your doctor will help you to set a treatment goal and regularly monitor your progress to help you stay on target.

Which medications are used to treat high blood pressure?

Various medication combinations can be used to help treat high blood pressure. These may include:

  • Diuretics, which help to reduce the amount of fluid in your arteries
  • Calcium channel blockers, which help to relax your arteries and slow your heart rate
  • ACE-inhibitors, which help to relax your arteries and decrease blood volume
  • Angiotensin Receptor Blockers (ARBs) which help to enlarge your arteries

The combination and concentration of these medications depends entirely on your needs and body type. Some examples of treatment plans include:

  • Starting on one drug, with your doctor slowly adjusting the dosage for maximum benefit, before adding a second drug
  • Starting on one drug and then adding a second drug, before your doctor slowly adjusts each dosage for maximum benefit
  • Starting two drugs at the same time, either taking 2 separate pills or a single pill combination

The JNC recommends combination therapy for patients with a high blood pressure over 160/100 mmHg, or for elderly patients with a high blood pressure over 170/110mmHg. This has been shown to get the patient on board with their treatment quicker, as well as help them to achieve their treatment goals faster. 

What about beta-blockers?

What about beta blockers
You’ve probably heard of beta-blockers – they’re the little pills that help to slow your heart rate by blocking the effects of certain hormones in your system.   

But nowadays, they’re not the first port of call when it comes to high blood pressure. This is partly due to a recent study that compared the effects of ARB and beta-blockers in patients aged between 55 and 80 years old, which found that ARB are 13% more effective at reducing the risk of death or stroke. 

In some parts of the world, like England and Canada, beta-blockers are still a popular first-treatment option for patients under 80. They are also useful for treating other conditions, including: 

  • Heart disease
  • Chronic heart failure
  • Atrial fibrillation (irregular heartbeat)
  • Thyrotoxicosis (caused by an overactive thyroid gland)
  • Liver cirrhosis (alcohol-related liver disease)
  • Migraines

How is high blood pressure treated in the elderly?

An uncommonly high systolic pressure together with an uncommonly low diastolic pressure might give a blood pressure reading like 150/70mmHg. This is known as isolated systolic hypertension, and it is particularly common in the elderly. 

The most common cause is arteries stiffening with age, but it can also be caused by:

  • Anaemia (not enough healthy red blood cells in the body)
  • Hyperthyroidism (an overactive thyroid gland)
  • Arteriovenous fistula (an abnormal connection between an artery and vein)
  • Severe aortic regurgitation (leaking valves in the heart)

A doctor will explore each of the possible causes before treating the condition. They will also be careful to avoid dropping the diastolic pressure too low with medication. 

It’s worth noting that elderly individuals are especially prone to postural hypotension, ie. low blood pressure that occurs when standing up after sitting or lying down. It normally doesn’t last long, but it can make them feel dizzy or even faint. One study found that elderly individuals have a 43% higher risk of hip fracture if they fall within the first 45 days of taking high blood pressure medication. If you are worried an elderly relative may be at risk, speak to your doctor. 

 

References

Armstrong, C. (2014). JNC8 Guidelines for the Management of Hypertension in Adults. American Family Physician 90(7):503-4. 

Austin, P.C, Butt, D.A., Glazier, R.H., Gomes, T., Mamdani, M. & Tu, K. (2012). The Risk of Hip Fracture After Initiating Antihypertensive Drugs in the Elderly. Archives of Internal Medicine 172(22):1739-44. 

Bakris, G.L., Black, H.R., Chobanian, A.V., Cushman, W.C., Green, L.A., Izzo, J.L. et al. (2003). Seventh report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 42(6):1206-52. 

Bangalore, S., Kamalakkannan, G., Messerli, F.H & Parkar, S. (2007). Fixed-dose Combinations Improve Medication Compliance: a Meta-analysis. The American Journal of Medicine 120(8):713-9.

Beevers, G., Dahlof, B., de Faire, U., Devereux, R.B., Julius, S., Kjeldsen, S.E. et al. (2002). Cardiovascular Morbidity and Mortality in the Losartan Intervention for Endpoint Reduction in Hypertension Study (LIFE): a Randomised Trial Against Atenolol. Lancet 359(9311):995-1003. 

Burt, V., Gu, Q., Nwankwo, T. & Yoon, S.S. (2013). Hypertension Among Adults in the US: National Health and Nutrition Examination Survey, 2011-2012. National Center for Health Statistics.

Corrao, G., Heiman, F., Merlino, L., Nicotra, F., Parodi, A., Zambon, A. et al. (2011). Cardiovascular Protection by Initial and Subsequent Combination of Antihypertensive Drugs in Daily Life Practice. Hypertension 58(4):566-72.

Crikelair, N., Glazer, R., Levy, D., Meng, X., Rocha, R. & Weir, M.R. (2007). Time to Achieve Blood-Pressure Goal: Influence of Dose of Valsartan Monotherapy and Valsartan and Hydrochlorothiazide Combination Therapy. American Journal of Hypertension 20(7):807-15. 

Duh, M.S., Falvey, H., Gradman, A.H., Lafeuille, M.H, Lefebvre, P. & Parise, H. (2013). Initial Combination Therapy Reduces the Risk of Cardiovascular Events in Hypertensive Patients: A Matched Cohort Study. Hypertension 61(2):309-18. 

Khan, N. & McAlister, F.A. (2006). Re-Examining the Efficacy of Beta-Blockers for The Treatment Of Hypertension: a Meta-analysis. Canadian Medical Association Journal 174(12):1737-42. 

7.FEB.2018
img
Guo Wei Qiang Kenneth
Cardiologist
Mount Elizabeth Hospital

Dr Kenneth Guo is a cardiology specialist practising at Mount Elizabeth Novena Hospital, Mount Elizabeth Hospital, Gleneagles Hospital and Parkway East Hospital, Singapore. His clinical interests are treating patients with congenital heart disease, pulmonary arterial hypertension, chronic thrombolembolic pulmonary hypertension and right heart failure.

View Profile | See Articles