CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 7, August 2012
AFRICA
389
Different lipid profiles according to ethnicity in the Heart
of Soweto study cohort of
de novo
presentations of
heart disease
KAREN SLIWA, JASMINE G LYONS, MELINDA J CARRINGTON, SANDRINE LECOUR, A DAVID MARAIS,
FREDERICK J RAAL, SIMON STEWART
Abstract
Background:
Historically, sub-Saharan Africa has reported
low levels of atherosclerotic cardiovascular disease (CVD).
However as these populations undergo epidemiological
transition, this may change.
Methods:
This was an observational cohort study performed
at Chris Hani Baragwanath Hospital in Soweto, South
Africa. As part of the Heart of Soweto study, a clinical
registry captured detailed clinical data on all
de novo
cases
of structural and functional heart disease presenting to
the Cardiology unit during the period 2006 to 2008. We
examined fasting lipid profiles in 2 182 patients (of 5 328 total
cases) according to self-reported ethnicity. The study cohort
comprised 1 823 patients of African descent (61% female,
aged 56
±
16 years), 142 white Europeans (36% female, aged
57
±
13 years), 133 Indians (51% female, aged 59
±
12 years)
and 87 of mixed ancestry (40% female, aged 56
±
12 years).
Results:
Consistent with different patterns in heart disease
aetiology, there were clear differences in total cholester-
ol (TC), low-density lipoprotein cholesterol (LDL-C) and
triglycerides across ethnicities (
p
<
0.001): patients of African
descent had the lowest TC and LDL-C levels and Indians the
highest. However, there were no significant differences in
high-density lipoprotein cholesterol (HDL-C) levels between
ethnicities (
p
=
0.20). Adjusting for age, gender and body
mass index, patients of African descent were significantly
less likely to record a TC of
>
4.5 mmol/l (OR 0.33, 95% CI:
0.25–0.41) compared to all ethnic groups (all
p
<
0.001).
Conclusions:
These data confirm important blood lipid
differentials according to ethnicity in patients diagnosed
with heart disease in Soweto, South Africa. Such disparities
in CVD risk factors may justify the use of specialised preven-
tion and management protocols.
Keywords:
Africa, heart disease, lipids, ethnicity/race, epide-
miologic transition
Submitted 3/2/12, accepted 2/5/12
Cardiovasc J Afr
2012;
23
: 389–395
DOI: 10.5830/CVJA-2012-036
The historical distribution of risk and communicable versus
non-communicable forms of cardiovascular disease (CVD),
particularly its major component heart disease, reflects the
influence of cultural and ethnic factors.
1
Historically, low
levels of atherosclerotic CVD in populations of African descent
were, in part, attributed to low levels of total cholesterol (TC),
low-density lipoprotein cholesterol (LDL-C) and triglycerides
(TGs) and high levels of high-density lipoprotein (HDL-C).
2,3
Indeed, it appears a great deal of the burden of CVD in those
of African descent can be attributed to hypertension, rather than
dyslipidaemia.
4
However, other ethnic groups, such as South
Asians, have been shown to be more prone to the high levels
of TC and TG and low HDL-C dyslipidaemia, associated with
atherosclerotic forms of CVD.
5
While a significant proportion of the excess risk of CVD
in certain ethnic groups can be explained by environmental,
nutritional and lifestyle factors, they do not fully account for
such disparities. In order to apply appropriate CVD preventative
and management strategies, it is crucial to understand the
underlying processes that vary between ethnic groups, especially
in settings where the burden of CVD is rapidly increasing.
In sub-SaharanAfrican communities, such as the urban enclave
of Soweto, SouthAfrica, there is clear evidence that the historical
balance between communicable and non-communicable forms
of heart disease is in epidemiological transition.
6
The Heart
of
Soweto study of more than 5 000
de novo
presentations of heart
disease to the Baragwanath Hospital involved patients from an
eclectic mix of cultural and ethnic backgrounds and the pattern
of heart disease differed accordingly.
We sought to determine if there were differences in the lipid
profiles (and other major CVD risk factors) of patients with
de novo
presentations of heart disease in Soweto, South Africa
according to ethnicity and whether these were independent of
socio-economic profile.
Hatter Institute for Cardiovascular Research in Africa and
IIDMM, Faculty of Health Sciences, University of Cape Town,
South Africa
KAREN SLIWA, MD, PhD
SANDRINE LECOUR, Pharm D, PhD
Soweto Cardiovascular Research Unit, Chris Hani
Baragwanath Hospital, University of the Witwatersrand,
Johannesburg, South Africa
KAREN SLIWA, MD, PhD
MELINDA J CARRINGTON, PhD
SIMON STEWART, PhD
Baker IDI Heart and Diabetes Institute, Melbourne, Australia
JASMINE G LYONS, BA, BSc (Hons)
MELINDA J CARRINGTON, PhD
SIMON STEWART, PhD,
Department of Internal Medicine, Groote Schuur Hospital,
Observatory, Cape Town, South Africa
A DAVID MARAIS, FCPSA
Carbohydrate and Lipid Metabolism Research Unit,
University of the Witwatersrand, Johannesburg, South Africa
FREDERICK J RAAL, MD, PhD
