CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 7, August 2012
AFRICA
371
Social drift of cardiovascular disease risk factors in
Africans from the North West Province of South Africa:
the PURE study
PT PISA, R BEHANAN, HH VORSTER, A KRUGER
Abstract
Objective:
This study examined whether the association
between socio-economic status (SES) and cardiovascular
disease (CVD) risk factors in black South Africans from
the North West Province had shifted from the more affluent
groups with higher SES to the less affluent, lower SES groups
over a period of nine years.
Method:
Cross-sectional baseline data of 2 010 urban and
rural subjects (35 years and older) participating in the
Prospective Urban and Rural (PURE) study and collected
in 2005 were analysed to examine the relationship of level of
education, employment and urban or rural residence with
dietary intakes and other CVD risk factors. These relation-
ships were compared to those found nine years earlier in
the Transition and Health during the Urbanisation of South
Africans (THUSA) study conducted in the same area.
Results:
The results showed that urban women had higher
body mass index (BMI), serum triglyceride and fasting
glucose levels compared to rural women and that both urban
men and women had higher blood pressures and followed a
more Westernised diet. However, rural men and women had
higher plasma fibrinogen levels. The more highly educated
subjects (which included both urban and rural subjects)
were younger than those with no or only primary school
education. Few of the risk factors differed significantly
between education groups, except that more highly educated
men and women had lower BMIs, and women had lower
blood pressure and triglyceride levels. These women also
followed a more prudent diet than those with only primary
school education. Employed men and women had higher
BMIs, higher energy intakes but lower plasma fibrinogen
levels, and employed women had lower triglyceride levels.
No significant differences in total serum cholesterol values
were observed.
Conclusion:
These results suggest a drift of CVD risk factors
from groups with higher SES to groups with a lower SES
from 1996 to 2005, indicating that interventions to prevent
CVD should also be targeted at Africans living in rural
areas, those with low educational levels, and the unemployed.
Keywords:
CVD risk factors, social drift phenomenon, socio-
economic status, dietary intakes, PURE baseline study, North
West Province, South Africa, serum lipids
Submitted 4/4/11, accepted 5/3/12
Cardiovasc J Afr
2012;
23
: 371–378
DOI: 10.5830/CVJA-2012-018
The escalating global burden of cardiovascular disease
(CVD) is related to the rapid health transition that developing
countries are experiencing.
1
Adoption of high-energy, high-fat,
Westernised diets and diminished physical activity contribute
to the accelerating epidemic of CVD.
2
South Africa, an
emerging economy, is currently undergoing a health transition,
characterised by the triple burden of disease consisting of a high
prevalence of under-nutrition-related infectious diseases, the
emergence of non-communicable chronic diseases (NCDs), and
the human immunodeficiency virus/acquired immune deficiency
syndrome (HIV/AIDS) pandemic.
3
The rate of urbanisation in the North West province of South
Africa has dramatically increased, characterised by high rates
of rural-to-urban migration, increased numbers of industrial
companies, improved economic activity and an increased
population in urban settings. Concurrently these economic
changes have led to changes in the quality of food intake, from
the traditional prudent dietary patterns and nutrient intake to
modern, imprudent fast foods, which seem to play a major role
in increasing the rate of NCDs.
The THUSA study, conducted from 1996 to 1998 in the
North West Province of South Africa, indicated that Africans
with a higher socio-economic status (SES) had higher risk
factors for CVD than those with a lower SES.
4
Many studies
have shown that in developing countries, during the early phases
of the health transition, the NCD/CVD burden is usually higher
in the higher SES class.
2,5,6
In developed countries, the burden has
shifted to the poor.
7-11
This phenomenon of a shift of the burden
of CVD in a population from the rich to the poor can be seen as
a social drift in CVD risk.
However, some studies found that the usual pattern is not
always followed. In certain developing countries, higher CVD
risk factors were seen in lower SES groups.
12-15
A study from a
developed country
16
showed that higher CVD risk factors were
found in higher SES groups. These studies illustrate a dynamic
drift of the burden of CVD risk factors between groups of
different SES within countries.
As mentioned above, the health transition in developing
countries is closely related to the transition from prudent,
low-energy, low-fat diets traditionally followed in rural areas to
the more Westernised high-energy, high-fat diets
3
followed in
urban areas. There is convincing evidence that this Westernised
dietary pattern increases the risk of CVD and other NCDs
Centre of Excellence for Nutrition (CEN), North-West
University, Potchefstroom, South Africa
PT PISA, PhD,
R BEHANAN, BSc
HH VORSTER, DSc
Africa Unit for Transdisciplinary Health Research (AUTHeR),
North-West University, Potchefstroom, South Africa
A KRUGER, PhD
