This represents about a third of the adult population and is a major risk for heart disease and stroke, as well as kidney disease. Known as the 'silent killer' this symptomless disease is a leading cause of death in South Africa, second only to HIV/AIDS.
"One of the ways in which to improve the diagnosis of high blood pressure in South Africa through more accurate readings is to use ambulatory blood pressure monitoring (ABPM). This technique uses a cuff connected to a microchip that measures and records blood pressure levels at regular intervals during a 24-hour period. The small device takes measurements every 30 minutes day and night, during one's normal routine," says Rayner.
He explains that sporadic blood pressure checks are not as accurate as frequent readings taken throughout the day.
"About 20% of patients who are consistently hypertensive in their doctor's office or clinic don't have high blood pressure the rest of the day. This phenomenon, called 'white coat hypertension' reflects the anxiety often caused by a visit to the doctor. ABPM is an important diagnostic tool for detecting this. Data from ABPM devices show that although office readings routinely over-diagnose hypertension, they sometimes under-diagnose it. The flip side of white coat hypertension is called masked hypertension - office readings are normal, but those taken outside the office using ABPM are high. About 10% of people whose blood pressure appears normal in the office have hypertension and their disease goes undetected."
Despite the obvious advantages of ABPM, its use remains low in South Africa, due to its associated costs. To address this need, Cipla Medpro, one of South Africa's leading pharmaceutical companies has recently launched a national pharmacy based 24-hour ABPM service called BP Watch. The service, which will initially be offered through Dis-Chem clinics, will be expanded through independent pharmacies to broaden the footprint and make the service available to more doctors and their patients.
Rayner says the UK recently introduced guidelines under the National Institute for Health and Care Excellence (NICE) stating that a diagnosis of primary hypertension should be confirmed using 24-hour ABPM. Research that informed the guidelines found that implementation of a diagnostic strategy for hypertension using ambulatory monitoring would reduce misdiagnosis and be cost saving for the country's National Health Service (NHS).
"In South Africa we loosely follow international guidelines such as those prescribed by NICE, so we are very encouraged by the recommendation of ABPM being included in the UK and hope that South Africa will follow suit. As the number of people affected by hypertension goes up, we do strongly encourage that doctors and patients consider 24-hour ABPM," he concludes.
