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RESEARCH ARTICLE
SA JOURNAL OF DIABETES & VASCULAR DISEASE
62
VOLUME 16 NUMBER 2 • NOVEMBER 2019
Plasma phospholipid fatty acid patterns are associated
with adiposity and the metabolic syndrome in black
South Africans: a cross-sectional study
ALICE ACHIENG OJWANG, HERCULINA SALOME KRUGER, MANJA ZEC, CRISTIAN RICCI, MARLIEN
PIETERS, IOLANTHÉ MARIKE KRUGER, EDELWEISS WENTZEL-VILJOEN, CORNELIUS MATTHEUS SMUTS
Correspondence to: Alice Achieng Ojwang
Centre of Excellence for Nutrition, North-West University, Potchefstroom,
South Africa
e-mail:
ojwangaa@gmail.comManja Zec, Cristian Ricci, Marlien Pieters, Edelweiss Wentzel-Viljoen,
Cornelius Mattheus Smuts
Centre of Excellence for Nutrition, North-West University, Potchefstroom,
South Africa
Herculina Salome Kruger
Medical Research Council Hypertension and Cardiovascular Disease
Research Unit, North-West University, Potchefstroom, South Africa
Iolanthé Marike Kruger
Africa Unit for Transdisciplinary Health Research, North-West University,
Potchefstroom, South Africa
Previously published in
Cardiovasc J Afr
2019;
30
: 228–238
S Afr J Diabetes Vasc Dis
2019;
16
: 62–71
Abstract
Background:
Diets rich in
n
-6 polyunsaturated fatty acids
(PUFAs) and saturated fatty acids (SFA) have been associated
with increased risk of obesity and the metabolic syndrome
(MetS), but the evidence is inconsistent, whereas diets high
in
n
-3 long-chain (LC)-PUFAs are associated with lower risk.
There is limited information about the association of plasma
phospholipid fatty acids (FAs) with obesity and the MetS
among black South Africans.
Objective:
To investigate the association of dietary FAs and
plasma phospholipid FApatterns, respectively, withmeasures
of adiposity (body mass index, waist circumference, waist-to
height ratio) and the MetS in black South Africans.
Methods:
Factor analysis was used to identify FA patterns
from 11 dietary FAs and 26 individual plasma phospholipid
FAs. Cross-sectional association of the identified patterns
with measures of adiposity and the MetS was investigated.
A random sample of 711 black South African adults aged
30 to 70 years (273 men, 438 women) from the North West
Province was selected from the South African leg of the
Prospective Urban and Rural Epidemiology (PURE) study.
Sequential regression models adjusted for confounders
were applied to investigate the association between dietary
FAs and plasma phospholipid FA patterns with measures of
adiposity and the MetS.
Results:
Two patterns were derived from dietary FAs and
six patterns from plasma phospholipid FAs that explained
the cumulative variance of 89 and 73%, respectively. The
association of FA patterns with adiposity and the MetS was
weaker for dietary FA patterns than for plasma phospholipid
FA patterns. The plasma phospholipid FA pattern with high
loadings of saturated FAs (high-Satfat) and another with
high loadings of
n
-3 very-long-chain PUFAs (
n
-3 VLC-PUFAs)
were positively associated with measures of adiposity
and the MetS, while patterns with positive loadings of LC
monounsaturated fatty acids (
n
-9 LC-MUFA) and a positive
loading of
n
-3 essential FAs (
n
-3 EFA) showed inverse
associations with the MetS and some measures of adiposity.
Conclusions:
The
n
-9 LC-MUFA and
n
-3 EFA patterns seemed
to provide possible protective associations with adiposity
and the MetS, whereas the high-Satfat and
n
-3 VLC-PUFA
patterns were associated with adiposity and the MetS in our
study participants. The results are reflective of the metabolic
difference between overweight and obese compared to lean
individuals.
Keywords:
phospholipid fatty acid patterns, dietary fatty acid
patterns, adiposity, metabolic syndrome, waist:height ratio
South Africa is currently experiencing rapid nutritional, economic,
demographic and epidemiological transitions with likely
consequences for lifestyle and health.
1
The prevalence of overweight
and obesity in South Africa in 2012 was 31% in men and 64% for
women.
2
This increased in 2016 to 68% in women but remained
the same for men.
3
Abdominal obesity among black South African
women is particularly associated with elevated blood pressure (BP),
lower high-density lipoprotein cholesterol, higher serum triglycerides,
and elevated fasting plasma glucose, indicative of insulin resistance.
4
Unhealthy diet is a major risk factor associated with the rising
prevalence of obesity and the metabolic syndrome (MetS).
5,6
Fat intake among the black urban population of South Africa
has increased from 16.4 to 26.2% of total energy over the past
50 years.
7
The transition from more traditional to Western diets,
characterised by an increase in
n-
6 polyunsaturated fatty acids
(PUFA), saturated fatty acids (SFA), industrial trans fatty acids (FAs),
8
as well as a decrease in
n-
3 PUFA intake, is also prevalent in this
population.
9
Diets high in percentage energy from animal protein
and total fat intake may increase the risk of no
n-
communicable
diseases in rural and urban black South Africans,
10
and this may be
related to meat intake, which is a major source of both MUFAs and
SFAs in South Africans.
11
By contrast with this, however, a study
that investigated dietary intake of carbohydrate and SFAs in 18
countries undergoing rapid nutritional transition documented that
SFA intake was associated with lower risk of mortality.
12