Cardiovascular Journal of Africa: Vol 27 No 3 (May/June 2016)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 3, May/June 2016 AFRICA 177
Associations between body fat distribution, insulin
resistance and dyslipidaemia in black and white South
African women
Dheshnie Keswell, Mehreen Tootla, Julia H Goedecke
Abstract
Aim: The aim was to examine differences in body fat distribu-
tion between premenopausal black and white South African
(SA) women and explore the ethnic-specific associations with
cardiometabolic risk.
Methods: Body composition, using dual-energy X-ray absorp-
tiometry (DXA) and computerised tomography, insulin resist-
ance (HOMA-IR) and lipid levels were assessed in 288 black
and 197 white premenopausal SA women.
Results: Compared to the white women, black women had
less central and more peripheral (lower-body) fat, and lower
serum lipid and glucose concentrations, but similar homeo-
stasis models for insulin resistance (HOMA-IR) values. The
associations between body fat distribution and HOMA-IR,
triglyceride and high-density lipoprotein cholesterol concen-
trations were similar, while the associations with fasting
glucose, total and low-density lipoprotein cholesterol levels
differed between black and white women.
Conclusion: Ethnic differences in body fat distribution are
associated, in part, with differences in cardiometabolic risk
between black and white SA women.
Keywords: body fat distribution, ethnicity, cardiometabolic risk,
dual X-ray absorptiometry, visceral adipose tissue, subcutaneous
adipose tissue
Submitted 9/9/15, accepted 14/11/15
Published online 25/5/16
Cardiovasc J Afr 2016; 27: 177–183
DOI 10.5830/CVJA-2015-088
Recent studies have shown that non-communicable diseases
(NCDs) account for the majority of deaths globally (65.5%), and
that 80% of the deaths attributed to NCDs each year are in low-
middle-income countries.1 Within South Africa (SA), NCDs,
such as cardiovascular disease (CVD) and type 2 diabetes (T2D)
were the second highest cause of death in 2000.2 Obesity, a major
risk factor for CVD and T2D,3,4 is extremely common in SA
women, particularly in black women.5 However, fat distribution
rather than the amount of body fat has been shown to be a
greater predictor of CVD and T2D risk factors, such as insulin
resistance (IR) and dyslipidaemia.6-8 There is growing evidence
indicating that not all fat stores contribute equally to CVD and
T2D risk factors.9
Studies in predominantly white populations have shown that
central fat mass (FM) [measured as trunk fat on the dual-energy
X-ray absorptiometry (DXA) scan] or waist circumference,9-11 and
more specifically visceral adipose tissue (VAT),12,13 is positively
associated with IR and dyslipidaemia. Conversely, lower-body
(gluteo-femoral) subcutaneous adipose tissue (SAT) has been
shown to be negatively associated with these cardiometabolic risk
factors.9-11,14 Some, but not all of these studies have demonstrated
that central and lower-body fat have independent effects on
metabolic risk.9-11
The relationship between fat distribution and IR appears to
be altered by ethnicity. Studies in the USA and SA have shown
that compared to white women, black women have less VAT
and more gluteo-femoral FM, but are more insulin resistant.15-19
Less VAT in the black women may, however, explain their more
favourable lipid profile compared to white women.20 However,
SA studies have been performed in only small samples of women
( n = 10–15) and focused only on abdominal fat distribution.
To date, most studies that have explored ethnic-specific
associations between whole-body fat distribution (central and
peripheral) and cardiometabolic risk have been undertaken in the
USA or Europe, with no studies to our knowledge, examining
the independent associations between central and peripheral
fat distribution and cardiometabolic risk in African women.
Therefore, the aim of this study was to examine differences in
whole-body fat distribution between premenopausal black and
white women and to explore the ethnic-specific associations
with cardiometabolic risk. We also set out to determine whether
central versus peripheral fat were independently associated with
cardiometabolic risk, and to examine which body composition
variable was most closely associated with cardiometabolic risk
in black and white women, taking into account other lifestyle
factors that have been shown to alter body composition, such
as physical activity, use of contraception, smoking and alcohol
consumption.
Methods
The study population consisted of 288 black and 197 white SA
women who were recruited by advertisement and from local
church groups, community centres and universities in Cape
Town, as previously described.21 Inclusion criteria were: age
18–45 years; no known diseases or not taking any medication
Division of Exercise Science and Sports Medicine,
Department of Human Biology, University of Cape Town,
Cape Town, South Africa
Dheshnie Keswell, PhD
Mehreen Tootla, MSc
Julia H Goedecke, PhD
Non-communicable Disease Research Unit, South African
Medical Research Council, Cape Town, South Africa
Julia H Goedecke, PhD,