BP: Know your numbers

By: Dr A. T. Kumararajah, Sunday Star, February 3, 2008

It is vital that your blood pressure is controlled to an optimum level so as to reduce the risk of diseases such as cardiovascular diseases, diabetes, and so on.

THE lower the better, and that’s not a prediction for the punters in the financial markets.

That is the war cry of physicians treating hypertension, by far the most common disease affecting the population at large, where it is estimated to affect about 4.3 million Malaysians.

Add to the fact that only 8% of the patients who are hypertensive have their blood pressures (BP) below the optimum level of 140/90mmHg paints a pretty bleak picture.

The data that comes from the 3rd National Health and Morbidity survey done in 2006 and recently published by the Health Ministry puts things into perspective for the hypertensive population in Malaysia.

There are many strategies that have been proposed to improve the overall management of hypertension (to bring more patients to treatment goals).

The patient should be viewed as an increasingly important stakeholder in the overall management of hypertension.

In order to achieve our aims, we will have to empower the patients with certain basic knowledge of their hypertension management and what all those numbers mean.

I have attempted to do this in a frequently asked questions format.

If you are a hypertensive patient, do you know what level should your BP be at and what is the treatment target your physician has planned for you?

If you don’t know your numbers – it is time to ask.

How do I know what grade my hypertension is?

Grading of hypertension helps the physician to attach appropriate risk stratification to their hypertension.

Grade 1 is systolic BP (SBP) of 140-159 mmHg or diastolic BP (DBP) of 90-99mmHg.

Grade 2 is SBP of 160-179mmHg or DBP of 100-109mmHg and grade 3 is SBP of = 180 mmHg or DBP of = 110 mmHg.

What if my SBP and DBP are not in the same grade?

The rule is the grading of whichever is higher will apply. For example, if a patient has a SBP of 165mmHg and a DBP of 92mmHg, the patient will still be classified as Grade 2.

How does my doctor determine my risk level?

There are many matrixes that have been developed and validated in clinical trials for hypertension risk stratification.

One of the latest comes from the European medical fraternity and clearly assigns the appropriate risk level by both computing the BP numbers and the associated risk factors.

Unfortunately, most hypertensive patients do not present with elevated BP levels alone and most often have other concomitant diseases that amplify their cardiovascular risk dangerously.

These reversible risks are smoking and cholesterol, and diseases that also confer a higher risk for hypertensive patients, including diabetes and renal disorders.

At what level must I get my blood pressure treated?

You should be on medication with anything above a BP of 140/90mmHg even in the absence of any confounding factors.

All patients diagnosed with hypertension should immediately be on life style modifying (LCM) interventions.

In grade 2 hypertension with no risk factors or with only moderate risk, then LCM can be initiated for several weeks, failing which pharmacological treatment must be started.

In grade 1 hypertension, the time delay to allow LCM can be up to several months, but again the patients must be started on some pharmacological agents to lower their BP if LCM does not result in definite BP lowering.

What are the accepted normal BP levels?

If you have normal BP, then it should be 120/80mmHg or lower.

Yes, that may sound like it is too low or not common. But there are many studies that have stratified that to be the lowest risk.

In fact, some even point lower to 115/75mmHg, but for all practical purposes, your normal BP is = 120/80mmHg.

What if my BP is above 120/80mmHg but below 140/90mmHg?

The people who fall into this group are known as pre-hypertensive.

If you don’t have any confounding factors, then your physician will probably ask you to go on a lifestyle modification regime.

Lifestyle regimens are centred mainly on the tripartite of diet modification (lower dietary salt intake, lower intake of foods laden with fat), weight reduction and smoking cessation.

If we could reduce our weight by 10kg, then we can reduce our systolic BP anywhere between 5-20mmHg.

That is an impressive lowering provided that weight gain can be achieved and maintained.

I am only pre-hypertensive but on treatment with anti-hypertension drugs. Why?

Pre-hypertensive patients who have additional risks such as diabetes, established cardiovascular disease or renal diseases should necessarily be on the appropriate pharmacological agent.

What is the evidence that shows that reduction in BP leads to lower cardiovascular risk, morbidities and mortalities?

The primary goal of treatment of the hypertensive patient is to achieve the maximum reduction in the long-term total risk of cardiovascular morbidity and mortality.

These also include the treatment of all the reversible risk factors identified including smoking, diabetes, cholesterol and its associated parameters and abdominal obesity along with the treatment of hypertension per se.

There is lots of evidence that looking for the optimal level of reduction of BP will confer the lowest CV risk. A recent hypertension study exemplified this.

Subjects with BP of 138.1/82.3 mmHg had a 28% lower incidence of cardiovascular mortality, stroke and coronary events compared to subjects whose average BP was 141.6/83.9 mmHg.

A large study which pooled analysis from 61 different anti-hypertensive clinical trials showed that a mere 2mmHg reduction in systolic BP reduces the risk of mortality with heart attacks and stroke by 7% and 10% respectively.

In the same analysis, it was concluded that for every 20mmHg rise in SBP or 10mmHg rise in DBP, the risk of cardiovascular morbidities and mortalities tend to double.

What are the target levels for my BP?

Target BP for those in the general hypertensive population is less than140/90mmHg.

In hypertensive patients with diabetes or considered to be at high risk (hypertensive patients with stroke, heart attacks, evidence of protein in the urine or renal dysfunction), the target level to be achieved is lower than 130/80 mmHg.

In patients with renal failure and having massive amounts of proteins in the urine, the target BP level that should be aimed for is below 125/75 mmHg.

Patients must be very sure of what their current BP levels are and what target levels their physicians are aiming for.

They also should be very sure of the types of medications that they have been prescribed.

Carry a record of this with you, it might just save you your life!

If you don’t know your numbers, ask your doctor.

This article is courtesy of sanofi-aventis. For further information, e-mail starhealth@thestar.com.my. The information provided is for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.