New research reveals that South Africa has the highest rate of high blood pressure reported among people aged 50 and over for any country in the world, at any time in history.
Analysis of data from a major survey found that 78 per cent of those who took part in South Africa tested positive for high blood pressure, or hypertension. Less than one in 10 people were effectively controlling their condition with medication.
The data comes from the Study on Global Ageing and Adult Health (SAGE), conducted by the World Health Organisation (WHO), which surveyed more than 35,000 people aged 50 and over in South Africa, China, Ghana, India, Mexico and Russia.
The findings of the analysis are published in the February issue of the International Journal of Epidemiology and will be presented today in South Africa by Peter Lloyd-Sherlock, professor of social policy and international development at the University of East Anglia. The study aims to fill a crucial gap in understanding about the prevalence, awareness, possible causes and treatment of high blood pressure - the leading cause of death globally - in low and middle-income countries.
Prof Lloyd-Sherlock and his co-authors, from WHO, the Neuroscience Institute in Padua, Italy, and London School of Hygiene and Tropical Medicine in the UK, warn of potentially "catastrophic" consequences for people's health and well-being if global and national efforts to tackle the impact of high blood pressure are not transformed immediately.
They say the rates of hypertension in low and middle-income countries are striking and that levels of treatment and control are inadequate, despite half those sampled being aware of their condition.
Prof Lloyd-Sherlock said: "In many countries public awareness about hypertension remains very low, and the condition is not prioritised by national governments or development agencies. Unless this changes quickly, avoidable deaths and disability resulting from hypertension are set to soar. Interventions should include awareness raising, prevention and treatment. Ideally, we should persuade people to adopt healthier diets and lifestyles, but in the short run we should at least ensure they have access to effective treatment."
High blood pressure increases people's risk of experiencing stroke, heart disease and other forms of serious illness, with those over the age of 50 at significantly increased risk. In the past, it was associated with rich, developed countries or with wealthier sectors of society. Today, high blood pressure is a condition that affects the majority of society, rich or poor, rural or urban.
Those who took part in the SAGE survey were categorised as hypertensive if the mean of two measurements was equal or greater than 140mmHg (systolic blood pressure) or 90mmHg (diastolic blood pressure), or if they were taking treatment for hypertension. The rates of high blood pressure ranged from 78 per cent in South Africa to 32 per cent in India, with consistently higher levels for women.
In all six countries, national prevalence was strongly associated with age and weight. India achieved the highest rate of treatment effectiveness (55 per cent); the lowest rate of condition control was in Ghana (four per cent); the lowest treatment effectiveness was in Russia (17 per cent), which had the second highest rate of hypertension (71 per cent). South Africa had the highest rates for the 'lifestyle' risk factors of obesity (45 per cent) and low physical activity (59 per cent).
In South Africa the study involved 3,820 people. Only 38 per cent of those who tested positive for hypertension were aware of their condition. Most people who were aware were on treatment, but it was only effective in 24 per cent of cases. Limited awareness and ineffective treatment meant that only eight per cent of people with hypertension had their condition under control, compared to a rate of 14 per cent in India, the highest of the six countries studied. For poorer people living in rural districts rates of control were particularly low.
The SAGE survey was funded by the US National Institute on Aging and the data analysis was part-funded by the UK's Economic and Social Research Council (ESRC). Prof Lloyd-Sherlock will present the research findings today at a seminar in Pretoria organised by the Human Sciences Research Council (HSRC), which conducted the South Africa survey.
'Hypertension among older adults in low and middle-income countries: prevalence, awareness and control', Peter Lloyd-Sherlock (School of International Development, UEA), John Beard (Department of Ageing and Life Course, WHO), Nadia Minicuci (National Research Council, Neuroscience Institute), Shah Ebrahim (London School of Hygiene and Tropical Medicine) and Somnath Chatterji (Department of Health Statistics and Informatics, WHO), is published in the International Journal of Epidemiology, volume 43, issue 1, February 2014.