Prestigious lecture series at Wits: cardiovascular disease in Africans and importance of lifestyle
Although cardiovascular disease and its major component, heart disease, exists in epidemic proportions in Western developed countries, it is also an increasing problem in Africa, contributing to significant morbidity and premature mortality in vulnerable populations. The overall burden of cardiovascular disease is predicted to rise by approximately 150% in the developing world within the next 20 years. In Africa alone, it is predicted that it will affect 1.3 million people per annum during this period. Even in low- to middle-income countries such as South Africa it is already responsible for close to 10% of healthy life years lost; being second only to HIV/AIDS in this regard.
Such data support the hypothesis that the overall health status of human societies is linked to economic development, and that globalisation could have a negative impact due to “Westernisation of lifestyle”. With industrialisation, the major causes of death have shifted from infectious diseases and nutritional deficiencies to more chronic disorders: a phenomenon with distinct stages known as “epidemiologic transition”. For example, there are strong indications that in South Africa this phenomenon is occurring even within a specific disease category of cardiovascular disease: rheumatic heart disease of the young. Although it is still prevalent, there is some evidence that it is giving way to hypertension, coronary artery disease and acute coronary syndromes including acute myocardial infarction (MI). All are common precursors of chronic heart failure.
As demonstrated by the recently published Heart of Soweto study (Sliwa et al. The Lancet, March 2008) South Africans are suffering a double or even triple burden within the cardiovascular disease group: a) a still high prevalence of disease linked to infections such as rheumatic heart disease or tuberculous pericarditis; b) an emerging epidemic of hypertension and coronary artery disease; and c) the cardiovascular consequences linked to the HIV epidemic and its pharmacological therapy.
In contrast to the decline in developed nations of common cardiovascular diseases such as stroke, myocardial infarction, and heart failure, there is a surprising increase in the prevalence of these diseases in emerging economies such as South Africa. This lecture presents the key drivers of this CVD epidemic, with examples of data obtained in three large cardiovascular studies being conducted in the Soweto, Nigeria and Africa.
The lecture ends with the following conclusion:
- A deadly overlap between infectious diseases and non-communicable diseases is occurring throughout South Africa, leading to a crisis of priorities for health systems already struggling with inadequate resources.
- Low community awareness of the dangers of cardiovascular disease makes the task of cardiovascular disease control more complex.
- This can be achieved by health promotion, including primary prevention focusing on five major risk factors for CVD, such as obesity, physical inactivity, incorrect diet, high blood pressure and smoking.
- Primordial prevention must be combined with programmes to reverse and reduce the risk factor elevations, especially in urban communities (primary prevention).
- Cost-effective methods must be established for timely diagnosis and management of manifest diseases (secondary and tertiary prevention).