High blood pressure - the 'silent killer'

It is the most prevalent cardiovascular disease worldwide and is a major risk factor for both illness and death. Globally, it is estimated to affect 30% of adults and to account for 30% of all cardiovascular-related deaths. The prevalence in sub-Saharan Africa varies between 10 - 29%, depending on the country. In developed countries, less than 27% of patients with high blood pressure have their condition under control. Untreated hypertension shortens life expectancy by approximately five years.

Using criteria of blood pressure =160/95 mmHg or persons aged >18 years receiving antihypertensive medication, the 1998 South African Demographic and Health Survey estimated that there were 3.3 million people with hypertension in the country. Acceptance of the international definition of hypertension (BP =140/90 mmHg) adds a further 2.7 million people. Hypertension is a major and costly contributor to cardiovascular disease: it accounted for R4-5 billion in direct and indirect expenditure in 1991, and was previously shown to constitute 7.5% of the direct total healthcare spend in South Africa.

The good news is that the treatment of hypertension has been one of medicine's major successes of the past half-century. Treatment with medication has shown a 30-45% reduction in stroke, a 20-25% reduction in heart attack and a more than 50% reduction in heart failure. European guidelines recommend the use of at least two agents and fixed drug combinations have been shown to offer several advantages over the separate prescription of individual drugs.

In addition to medication, the adoption of certain lifestyle modifications has also been shown lower blood pressure effectively. These modifications include weight control, exercise, dietary salt restriction and potassium enhancement, and moderation of alcohol intake. The Dietary Approaches to Stop Hypertension (DASH) eating plan emphasises a high intake of fruits, vegetables, complex carbohydrates, and low-fat dairy products with restriction of saturated fats.

"High blood pressure is a 'silent killer' in that it can be present for a long time with no symptoms. Because people feel well, they don't realise they have a dangerous condition that can have serious long-term health consequences," says Pretoria-based cardiologist, Dr Adriaan Snyders. "It's therefore critical to know your numbers and to get treated if your readings are above the 'normal' cut-off point of 140/90. Some newer data even suggest that 130/75 is the more desirable target, with yet lower readings advised for diabetics, who often have co-existing high blood pressure."

While a diagnosis of hypertension is inevitably distressing, Dr Snyders feels that there is a positive spin-off. "You now have the opportunity to take control of and responsibility for your health," he concludes. "High BP is treatable and once it's under control, patients can live long, healthy lives."

Seven things you should know about high blood pressure:

• High blood pressure is a major risk factor for illness and death
  
• High blood pressure often has no symptoms. Just because you feel well, doesn't mean you don't have hypertension
  
• It is critical to have your blood pressure checked regularly - the more so if you have a family history of high blood pressure
  
• High blood pressure can be controlled with the right medication(s) and some lifestyle modifications
  
• Your doctor can guide you as to the right medication(s) for you
  
• Lifestyle modifications include increased physical activity, high intake of fruits, vegetables, complex carbohydrates and low-fat dairy products along with dietary salt restriction
  
• With your blood pressure under control, you can live a long and healthy life