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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 4, July/August 2019
234
AFRICA
‘non-marine’ FA pattern. The second pattern was named the
‘marine’ FA pattern because it was characterised by high positive
loadings of eicosapentaenoic acid (C20:5n-3) and C22:6n-3.
The six plasma phospholipid FA patterns are discussed in
the order in which they were derived. The first pattern presented
with positive loadings of LC-SFAs, C18:0, C20:0, C22:0 and
C24:0 and very high negative loadings of C16:1n-7, C18:1n-7
and C18:1n-9; we named it the ‘high-Satfat’ pattern. The second
pattern was named ‘n-3 VLC-PUFA’ and presented with high
positive loadings of docosapentaenoic acid (C22:5n-3), C22:6n-3
and C20:5n-3, as well as C20:4n-6. The third pattern presented
the highest positive loadings of C18:2n-6 and eicosadienoic
acid (C20:2n-6) and was named accordingly as the ‘high-LA’
pattern. The fourth pattern was named ‘n-6 VLC-PUFA’
since
it was characterised with high positive loadings of adrenic acid
(C22:4n-6), C22:2-n6 and C20:3n-6. The fifth pattern extracted
was named the ‘n-9 LC-MUFA’ pattern and presented with
positive loadings of C24:1n-9 and gondoic acid (C20:1n-9).
The sixth and last pattern had a positive loading of one FA, i.e.
C18:3n-3, and we named it ‘n-3 EFA’ pattern.
Dietary FA patterns were weakly associated with measured
outcomes (Table 4). The non-marine FA pattern showed marginal
positive associations with WC in the crude model and the
association remained marginal after adjusting for age and gender
(
β =
0.06, 95% CI
=
–0.01–0.13,
p
=
0.09). The association was lost
after adjustment for lifestyle variables and energy intake. On the
other hand, we did not find any associations with the marine FA
pattern (Table 4). Neither pattern revealed any association with
BMI, WHtR or the MetS. Further adjustment to the regressions
for total fat, fibre, carbohydrates and added sugar did not result
in any significant associations. The variables in the adjusted
models explained 0.02 to 27% of the variation in measures of
adiposity and 0.4 to 20% of the variation in the MetS.
Plasma phospholipid FA patterns resulted in stronger
associations with measures of adiposity and the MetS (Table
5). The high-Satfat and n-3 VLC-PUFA patterns were positively
associated with all measures of adiposity and the MetS. The
associations remained significant in the fully adjusted model.
The omega-6 VLC-PUFA pattern showed marginal and positive
associations with WC and WHtR in the crude model, but
associations were lost after further adjustments. This pattern
also showed higher odds for having the MetS and remained
significantly associated in the fully adjusted model (odds ratio,
OR
=
1.25, 95% CI
=
1.02–1.54,
p
=
0.03).
The n-9 LC-MUFA pattern was inversely associated with
WC and WHtR in the crude model as well as after adjustment
for age and gender. The associations were, however, lost after
adjustments for lifestyle variables and energy intake. This pattern
also showed lower odds for having the MetS and remained
significantly associated in the fully adjusted model (OR
=
0.61,
95% CI
=
0.50–0.75,
p
≤
0.0001).
The omega-3 EFA pattern showed an inverse association with
BMI, WC and WHtR, but in the fully adjusted model marginal
significance remained for BMI only. This pattern also showed
lower odds for having the MetS and remained significantly
associated in the fully adjusted model (OR
=
0.81, 95% CI
=
0.66–0.99,
p
=
0.04). The variables in all the adjusted models
explained 14 to 34% of the variation in measures of adiposity,
and 18 to 31% of the variation in the MetS.
We further adjusted all regression models for use of
contraceptives and intakes of total fat, fibre, carbohydrates,
and energy from added sugar in association with plasma
phospholipid FAs. Additional adjustment for these variables
did not result in different associations with anthropometric
indices. The association between high-LA pattern and the MetS
remained marginally significant after adjusting for additional
variables, whereas the associations with the n-6 VLC-PUFA and
n-3 EFA patterns were lost.
Discussion
The results of this study add new information about identified
FA patterns both in diet and plasma phospholipids among a
selected group of black South Africans from the North West
Province. We identified for the first time two dietary FA patterns
and six plasma phospholipid FA patterns (Table 3) by means
of factor analysis in this group of black adults. The dietary
non-marine FA pattern showed a weak positive association with
WC, whereas the marine pattern did not show any associations
with outcomes measured.
On the other hand, two plasma phospholipid FA patterns
(high-Satfat and n-3 VLC-PUFA) were positively associated
with all measures of adiposity and the MetS. The omega-6
VLC-PUFA pattern showed a positive association with the MetS,
but not with measures of adiposity. The n-9 LC-MUFA and the
n-3 EFA patterns showed an inverse association with the MetS in
fully adjusted models and tended to be negatively associated with
some measures of adiposity. The high-LA pattern was neither
associated with measures of adiposity nor the MetS. Our findings
indicate that dietary FA patterns were weakly associated, whereas
plasma phospholipid FA patterns were more strongly associated
with measures of adiposity and the MetS.
Previous studies have reported FA patterns, derived from
different components of blood and tissue in association with
obesity
29
and the MetS,
22,30
but not with dietary patterns. These
patterns were generated by varying numbers of FAs ranging
from nine to 34 FAs,
22,29,30
and some included estimated desaturase
activities,
30
by means of use of factor
29,30
and cluster
22
analysis.
Consequently, these derived patterns differed from that obtained
in our study.
A dietary pattern, consisting of SFAs, PUFAs, MUFAs and
other nutrients, was not associated with obesity among Iranian
adults.
45
On the contrary, a multiracial study in the USA reported
a positive association of intakes of total fat, total saturated fat,
LC-SFAs, myristic acid (C14:0), C16:0 and C18:0, and MUFAs
with BMI.
46
Furthermore, a study investigating the association
of dietary patterns with the MetS concluded that a pattern high
in meat products was associated with a higher prevalence of the
MetS.
47
In our study, the dietary non-marine FA pattern showed
marginal and positive associations with WC, but not with other
measures of adiposity or the MetS. The non-marine FA pattern
had positive loadings of FAs from SFAs, MUFAs and PUFAs,
specifically from two SFAs (C16:0 and C18:0), two MUFAs
(C16:1n-7, C18:1n-9) and two PUFAs (C18:2n-6 and C18:3n-3).
The dietary marine FA pattern showed no association with
outcomes measured.
Our results are in agreement with a study in the USA that
also found no associations of n-3 LC-PUFAs with BMI due to
low intakes of these FAs in their participants.
46
In our study and