Virtual Medical Centre

Hypertension (High blood pressure)

• What is Hypertension?
• Who gets Hypertension?
• Predisposing Factors
• Progression
• Probable Outcomes
• How Will Hypertension Affect Me?
• Clinical Examination
• How is Hypertension Diagnosed?
• How is Hypertension treated?
• Hypertension References
• Drugs/Products Associated with Hypertension

What is Hypertension?

Hypertension is defined as elevated blood pressure and is the leading cause globally of death and disability. It is the major risk factor for heart attack and stroke, and is also a significant risk factor for for chronic kidney disease and chronic heart failure. Because individuals with hypertension usually don't have any symptoms, it is a disease that is often under-diagnosed. Diagnosis relies upon routine blood pressure screening to monitor and detect affected individuals. 

Who gets Hypertension?

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Blood Pressure

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The Australian Diabetes, Obesity and Lifestyle Study (AusDiab) conducted in 1999–2000 reported that 30% of Australians (32% of males and 27% of females) over 25 years of age, or 3.7 million Australians, were hypertensive (blood pressure > 140/90 mmHg).

In general, males are more likely to have hypertension than females, except for between the ages of 45 and 64, when females are at equal risk to males.

The incidence of hypertension is three times higher in Indigenous Australians compared to non-indigenous Australians.

Predisposing Factors

Approximately 95% of hypertension cases are classified as essential or primary hypertension, in which the underlying cause is unknown. The remaining cases are classified as secondary hypertension, in which there is an identifiable cause (e.g. renal artery stenosis). 

Major studies have identified the following factors as key predisposing factors for hypertension:

• Prehypertensive systolic state (115–139 mmHg);
• Age-dependent increase in diastolic state;
• Female gender;
• Increasing BMI beyond a value of 25;
• Smoking; and
• Parenteral hypertension.

Factors that have been identified in the Australian 2008 National Heart Foundation Hypertension Guidelines include:

• Sedentary lifestyle;
• Smoking;
• Waist measurement > 94 cm in men and 80 cm in women, or BMI > 25;
• High dietary salt intake; and
• Alcohol consumption.

Progression

If hypertension remains uncontrolled, it ultimately leads to end organ damage. Hence, uncontrolled hypertension is the major risk factor for coronary artery disease and stroke – two important endpoints in the disease process.

Similarly, chronic renal failure, diabetes, eye disease, erectile dysfunction and chronic heart failure are also significant diseases associated with the progression of uncontrolled or poorly controlled hypertension.

General Cardiovascular Disease 10-Year Risk Calculator

This risk assessment tool is based on data from the Framingham Heart Study to estimate 10-year risk for general cardiovascular disease outcomes (coronary death, myocardial infarction, coronary insufficiency, angina, ischaemic stroke, haemorrhagic stroke, transient ischaemic attack, peripheral artery disease, heart failure). This tool is designed to estimate risk in adults aged 30-74 years of age without CVD at baseline examination. Use the calculator below to estimate 10-year risk.

Predictors

Age		years
		Male	Female
Gender
		Yes	No
Have you been diagnosed with Type II diabetes?
Are you a smoker?*
Are you prescribed medication to lower your blood pressure?
If you do not know the following blood pressure and cholesterol parameters ask your General Practitioner on your next visit.
Systolic blood pressure**		mmHg
Total cholesterol***	mmol/L      OR	mg/dl
HDL cholesterol****	mmol/L      OR	mg/dl

Results

Significant (> 20%)
Elevated (10–20%)
Mild risk (< 10%)
You have a significant risk of future cardiovascular disease requiring aggressive risk factor modification. You should see a health professional to ensure appropriate management.

• If diabetic, your sugar levels should be well controlled.
• Continue to avoid tobacco use or if you are a smoker, consider stopping this is something your General Practitioner can help you with.
• Blood pressure should be monitored closely. If elevated you should consider either lifestyle modification or appropriate medication. Your general Practitioner can advise you on this.
• Cholesterol levels should be assessed at least annually. Depending on your level, you might be advised to commence lifestyle changes or medication.

Significant (> 20%)
Elevated (10–20%)
Mild risk (< 10%)
You have an elevated risk of future cardiovascular disease requiring risk factor modification. You should see a health professional to ensure appropriate management.

• If diabetic, you should aim for your sugar levels to be well controlled.
• Continue to avoid tobacco use or if a smoker, consider stopping this is something your general practitioner can help you with.
• Blood pressure should be monitored closely. If elevated you should consider either lifestyle modification or appropriate medication. Your general Practitioner can advise you on this.
• Cholesterol levels should be assessed at least annually. Depending on your level you might be advised to commence lifestyle changes or medication.

Significant (> 20%)
Elevated (10–20%)
Mild risk (< 10%)
You have a mild risk of future cardiovascular disease, consider risk factor modification. You may like to see a health professional to ensure appropriate management.

• If diabetic, you should aim for your sugar levels to be well controlled.
• Continue to avoid tobacco use or if a smoker, consider stopping this is something your general practitioner can help you with.
• Blood pressure should be monitored closely. If elevated you should consider either lifestyle modification or appropriate medication. Your general Practitioner can advise you on this.
• Cholesterol levels should be assessed at least annually. Depending on your level you might be advised to commence lifestyle changes or medication.

^*For these purposes "smoker" means any cigarette smoking in the past month.
^**Use current blood pressure, regardless of whether the person is on antihypertensive therapy.
^***Total cholesterol values should be the average of at least two measurements obtained from lipoprotein analysis.
^****HDL cholesterol values should be the average of at least two measurements obtained from lipoprotein analysis.

References:

1. D'Agostino RB, Vasan RS, Pencina MJ, Wolf PA, Cobain M, Massaro JM, Kannel WB. General cardiovascular risk profile for use in primary care: the Framingham Heart Study. Circulation 2008; 117: 743-753.
2. National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation 2002; 106: 31433421.
3. Stancoven A, McGuire DK. Preventing macrovascular complications in Type 2 Diabetes Mellitus: glucose control and beyond. American Journal of Cardiology 2007; 99: 5H-11H.