Know your numbers for a healthy heart


Many people get the shock of their lives when they discover unexpectedly that their coronary arteries are blocked. Especially if they're fit and active, the surprise is even bigger.

Doctors often discover that patients are a walking timebomb; and that they have been suffering, albeit silently, from high cholesterol and blocked arteries (artherosclerosis) long before heart disease is diagnosed.

Sometimes artherosclerosis can be so severe, and the risk for heart attack so immense, that the patient has to undergo coronary artery bypass surgery as an emergency measure. But the news is not all bad: most recover from the surgery, and with cholesterol-lowering drugs, daily exercise, a low-fat eating plan, and regular check-ups, their heart disease is now controlled.

Many others are not as fortunate. Heart disease claims more than 12 million lives around the world each year, and South Africa has a very high rate: every eight minutes another South African has a heart attack. Every fourth one is fatal.

Are you (unwittingly) heading for a heart attack?

According to the Heart and Stroke Foundation of South Africa, the six main “health checks” that every South African should consider are:

  • blood pressure,
  • blood cholesterol levels,
  • BMI,
  • presence of diabetes,
  • whether you smoke or not, and
  • your physical activity level

High blood pressure, raised cholesterol and diabetes can develop without any symptoms, and are often only diagnosed after causing substantial damage to your health.

For good heart health, don’t smoke. Eat wisely: limit your intake of saturated fat and trans fatty acids, and eat at least five portions of fruit and vegetables daily. According to US Surgeon General recommendations, 30 minutes of exercise that increases the heart rate, every day of the week, would prevent most heart disease, and would improve the health status of a person who already suffers from atherosclerosis. The exercise need not be continuous, you could do five-minute walks six times a day - as long as it adds up to 30 minutes per day.

This is a good start, but not enough. You should also know your numbers:

1. Blood pressure should be lower than 120/80mmHg
One out of four people suffers from high blood pressure (hypertension). Two-thirds of people have no symptoms. Never rely on how you feel as an indicator of blood pressure or cholesterol – the term "silent killer" hasn't been coined for nothing.

All adults should know what their blood pressure is, and should have it checked at least every five years, preferably more often. People with a family history of heart disease, stroke or high blood pressure need to be tested every year.

Blood pressure can be measured relatively cheaply at clinics and pharmacies. It is expressed as the systolic blood pressure over the diastolic blood pressure in millimetres of mercury (mmHg).

According to the latest classifications, blood pressure can be graded as follows:

 Systolic pressure Diastolic pressure
Normal120 80
Pre-hypertension120-139 80-89
Hypertension Stage 1140-159OR90-99
Hypertension Stage 2160OR>100

A blood pressure reading of over 130/85 would most certainly warrant a visit to the doctor.

American researchers have determined that increased blood pressure is directly related to an increased risk of heart disease. The following statistics prove this relationship:

  • Any blood pressure reading of higher than 115/75mmHg is associated with a higher risk of heart disease. The risk of heart attack and stroke doubles for every 20-point increase in systolic pressure or every 10-point rise in diastolic pressure.
  • People with blood pressure readings of 135/85mmHg have twice the risk of heart disease of those with low blood pressure of 115/75mmHg.
  • People with blood pressure higher than 140/90mmHg have four times the risk of heart disease as people with a low blood pressure of 115/75mmHg.
  • Almost 90 percent of people over the age of 55 will develop high blood pressure, even if they have normal blood pressure up until the age of 55.

High blood pressure can be treated with medication and lifestyle changes such as weight loss, a balanced diet, restricted use of salt, regular exercise and stress management.

2. Cholesterol levels should be lower than 5
High cholesterol levels are often only diagnosed after having caused substantial damage to your health, according to heart specialists.

If a patient finds out about a high cholesterol reading earlier, preventative treatment and measures can limit the extent of fatty deposits in the arteries and the resultant blockages.

It's advised that you ask your doctor to do a full fasting liopogram test. Pharmacy testing isn't a good idea, as this doesn't give you an accurate picture of your cholesterol profile.

The Heart and Stroke Foundation recommends that your total cholesterol reading should be below 5mmol/l. The value for HDL (considered "good" cholesterol), should be greater than 1,2mmol/l, and the value for LDL, ("bad" cholesterol) should be less than 3mmol/l.

Note, however, that these values only apply if you have no known risk factors for heart disease. It's also worth noting that the ratio between the two figures is considered the most accurate predictor of future problems - speak to your doctor about this.

A cholesterol reading of over 7mmol/l could indicate a need for immediate lifestyle changes (mainly dietary) and perhaps medication, and certainly warrants a visit to a doctor.

Yearly checks are advised if you have high cholesterol.

Raised blood cholesterol levels can be treated with medication and/or dietary changes. Research has shown that lowering intakes of saturated fats and trans-fatty acids could be beneficial. Maintaining a healthy weight will enable you to control your blood cholesterol levels with greater ease, and daily exercise is also recommended for bringing cholesterol down.

3. A BMI of below 25kg/m2 is ideal
Being overweight can lead to high blood pressure, raised cholesterol levels and diabetes. It also puts undue strain on the workload of the heart.

It is important to check your weight and to shake off a few kilos if you are overweight or obese.

The body mass index (BMI) is a useful tool in determining if you have a weight problem. To work out your BMI, take your weight (in kg) and divide it by your height in metres squared, or click here for our BMI Calculator. This is what the figures mean:

  • <18,5 kg/m2 – underweight
  • 18,5-25 kg/m2 – normal weight
  • 26-30 kg/m2 – overweight
  • >30 kg/m2 – obese

For example, the BMI of a person of 1,7m, weighing 75kg, is 25,95, indicating overweight. Try your best to keep your BMI below 25.

Keep in mind that fad diets don't work in the long run. Start to make healthier food choices immediately and increase the amount of exercise you do.

4. Presence of type 2 diabetes
High blood glucose levels can damage the blood vessels of the heart. For this reason, diabetics are more inclined to develop atherosclerosis of the coronary arteries, which could lead to angina, a heart attack or heart failure. Keeping blood glucose levels under control helps prevent atherosclerosis.

Normal blood glucose readings are between 3,3 and 6mmol/l, while fasting blood glucose (blood glucose measured before breakfast) of over 7.8mmol/l, or a 2-hour post-prandial blood glucose of over 11.1mmol/l, is reason for concern.

All people with a family history of diabetes, who are overweight or obese, and who have high blood pressure or elevated cholesterol levels, should have their glucose levels tested.

Diabetes can be controlled with medication and lifestyle changes. These may include weight loss, a structured exercise programme and a low glycaemic-index diet.

- (Carine van Rooyen, Health24, updated February 2012)

Read more:

Slideshow: Think red for heart health
Slideshow: 10 celebrities with diabetes

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