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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 4, July/August 2019
AFRICA
231
for logistic regression. Linear regression results are presented
as standardised
β
and 95% confidence intervals (CI) with their
significance levels, and odds ratio and 95% CI with significance
levels for logistic regression. All analyses were performed using
SAS Version 9.4 (SAS Institute, Cary, NC, USA)
44
and
p
<
0.05
was considered significant.
Results
The baseline characteristics of the 711 participants are shown
in Table 1. The majority were women (61.6%) and the median
age was comparable between men and women. Men had higher
HDL levels and were more likely to smoke. By contrast, the
women had higher serum triglycerides, as well as higher levels
of measures of adiposity (
p
<
0.0001). The dietary intake data
revealed that men had higher total energy, total carbohydrate
and total protein intakes, whereas the women, on the other hand,
had higher total dietary fibre intake.
Table 2 shows that total intakes of fat, SFAs and MUFAs
were significantly higher in overweight/obese women compared
to lean women. Plasma phospholipid FAs within SFA, MUFA
and PUFA classes differed across BMI categories and gender.
In men, the plasma levels of SFAs, C18:0, C20:0, C22:0, C24:0
and n-6 PUFA C20:3n-6 were significantly higher in overweight
Table 2. Dietary intake of fats, individual fatty acids and plasma phospholipid fatty acid profile
by BMI categories and gender in 711 black South African adults
Variables
Men (
n
=
273)
Women (
n
=
438)
BMI
a
<
25 kg/m
2
(
n
=
233)
BMI
≥
25 kg/m
2
(
n
=
40)
p
-value
Effect
size
BMI
<
25 kg/m
2
(
n
=
191)
BMI
≥
25 kg/m
2
(
n
=
247)
p
-value
Effect
size
Median (Q
1
, Q
3
)
Median (Q
1
, Q
3
) Median (Q
1
, Q
3
)
Total energy, dietary fat intake
Total energy (kcal/day)
1856 (1374, 2599) 2052 (1370, 2681)
0.48
1579 (1139, 2188) 1651 (123, 2224.)
0.50
Total fat (g/day)
44.8 (28.5, 63.0)
46.8 (31.5, 66.9)
0.71
35.5 (22.8, 59.2)
44.9 (27.9, 68.0)
0.002
Total saturated fatty acids (g/day)
10.4 (6.5, 15.4)
12.4 (8.1, 16.3)
0.71
8.4 (4.7, 15.5)
10.8 (6.2, 17.1)
0.003
Total polyunsaturated fatty acids (g/day)
13.8 (8.8, 19.6)
12.8 (8.7, 18.7)
0.32
11.8 (7.0, 19.5)
13.5 (8.2, 20.9)
0.29
Total n-3 PUFAs (g/day)
0.4 (0.2, 0.6)
0.34 (0.2, 0.6)
0.58
0.3 (0.2, 0.5)
0.4 (0.2, 0.5)
0.09
Total n-6 PUFAs (g/day)
13.5 (8.7, 19.1)
12.4 (9.2, 19.8)
0.39
12.1 (6.9, 18.9)
13.4 (8.1, 20.2)
0.27
n-6/n-3 ratio
33.1 (24.4, 152.4)
34.2 (22.5, 53.1)
0.84
37.3 (27.57,49.73) 36.8 (26.1, 51.9)
0.76
Total mono-unsaturated fatty acids (g/day)
11.2 (6.8, 16.4)
13.4 (7.2, 19.7)
0.48
8.5 (5.0, 16.4)
12.0 (6.4, 19.4)
<
0.0001
Plasma phospholipid fatty acids (% total FAs)
c
Saturated fatty acids
Myristic acid (C14:0)
0.25 (0.2, 0.3)
0.25 (0.2, 0.3)
0.75
0.26 (0.2, 0.3)
0.27 (0.2, 0.3)
0.21
Palmitic acid (C16:0)
27.6 (25.2, 29.5)
26.3 (24.6, 28.0)
0.002 0.37 26.7 (24.8, 29.2)
25.7 (24.0, 27.6)
0.21
Stearic acid (C18:0)
14.0 (12.4, 15.5)
15.1 (14.4, 16.2)
<
0.0001 0.31 14.8 (13.5, 16.3)
15.5 (14.3, 17.0)
0.0004 0.38
Arachidic acid (C20:0)
0.27 (0.21, 0.34)
0.34 (0.27, 0.39)
0.02 0.33 0.30 (0.25, 0.37)
0.36 (0.30, 0.43)
<
0.0001 0.35
Behenic acid (C22:0)
0.94 (0.66, 1.17)
1.22 (0.97, 1.43)
0.0006 0.32 1.03 (0.78, 1.35)
1.27 (1.07, 1.54)
<
0.0001 0.35
Lignoceric acid (C24:0)
1.01 (0.81, 1.23)
1.13 (0.91, 1.36)
0.02 0.40 1.00 (0.81, 1.24)
1.07 (0.9, 1.27)
0.03 0.45
Mono-unsaturated fatty acids
Palmitoleic acid (C16:1n-7)
0.88 (0.5, 1.6)
0.6 (0.4, 0.8)
0.0007 0.34
0.8 (0.5, 1.2)
0.6 (0.4, 0.8)
0.003 0.40
Cis-
vaccenic acid (C18:1n-7)
1.46 (1.26, 1.69)
1.19 (1.01, 1.44)
0.002 0.30 1.41 (1.20, 1.65)
1.30 (1.12, 1.5)
0.03 0.41
Oleic acid (C18:1n-9)
10.0 (7.6, 13.0)
7.5 (6.2, 9.3)
0.0002 0.30 8.2 (7.0, 11.3)
7.16 (6.3, 8.3)
<
0.0001 0.35
Elaidic acid (C18:1n9t)
0.31 (0.20, 0.56)
0.27 (0.20, 0.5)
0.32
0.34 (0.21, 0.81)
0.32 (0.21, 0.61)
0.50
Gondoic acid (C20:1n-9)
0.11 (0.09, 0.12)
0.10 (0.08, 0.11)
0.04 0.36 0.11 (0.09, 0.12)
0.10 (0.09, 0.12)
0.02 0.42
Erucic acid (C22:1n-9)
0.06 (0.04, 0.08)
0.07 (0.04, 0.09)
0.29
0.06 (0.05, 0.09)
0.07 (0.05, 0.09)
0.50
Nervonic acid (C24:1n-9)
1.66 (1.44, 1.95)
1.61 (1.35, 1.95)
0.75
1.69 (1.42, 2.02)
1.88 (1.55, 2.21)
0.005 0.41
n-3 polyunsaturated fatty acids
α
-linolenic acid (c18:3n-3)
0.09 (0.07, 0.12)
0.08 (0.05, 0.10)
0.18
0.08 (0.06, 0.1)
0.1 (0.05, 0.1)
0.77
Eicosapentaenoic acid (C20:5n-3)
0.6 (0.5, 0.9)
0.6 (0.5, 0.9)
0.32
0.6 (0.4, 0.9)
0.6 (0.4, 0.8)
0.92
Docosapentaenoic acid (C22:5n-3)
0.5 (0.4, 0.7)
0.6 (0.4, 0.8)
0.51
0.6 (0.5, 1.0)
0.5 (0.4, 0.8)
0.92
Docosahexaenoic acid (C22:6n-3)
3.8 (3.0, 4.8)
4.29 (3.2, 5.6)
0.09
4.4 (3.5, 5.5)
5.0 (4.05, 5.8)
0.0008 0.39
n-6 and n-9 polyunsaturated fatty acids
Linoleic acid (C18:2n-6)
16.1 (13.6, 18.5)
16.4 (14.1, 18.6)
0.71
15.9 (12.8, 18.4)
16.0 (13.8, 18.7)
0.50
γ
-linolenic acid (C18:3n-6)
0.13 (0.1, 0.2)
0.10 (0.07, 0.14)
0.04 0.39
0.1 (0.1, 0.2)
0.10 (0.07, 0.13)
0.07
Eicosadienoic acid (C20:2n-6)
0.34 (0.29, 0.39)
0.35 (0.29, 0.4)
0.71
0.36 (0.31, 0.42)
0.38 (0.33, 0.44)
0.07
Dihomo-
γ
-linolenic acid (C20:3n-6)
2.7 (2.4, 3.3)
3.1 (2.7, 3.9)
0.006 0.32
2.8 (2.4, 3.2)
3.1 (2.72, 3.61)
<
0.0001 0.35
Arachidonic (C20:4n-6)
12.9 (11.5, 14. 3)
14.1 (12.6, 15.7)
0.08
13.5 (12.0, 15.0)
14.2 (12.7, 15.6)
0.007 0.44
Docosadienoic acid (C22:2-n6)
0.018 (0.013, 0.023) 0.018 (0.014, 0.022) 0.75
0.02 (0.014, 0.027) 0.025 (0.018, 0.032)
<
0.0001 0.37
Adrenic acid (C22:4n-6)
0.6 (0.5, 0.7)
0.6 (0.5, 0.7)
0.51
0.6 (0.5, 0.7)
0.6 (0.5, 0.7)
0.29
Osbond acid (C22:5n-6)
1.4 (1.2, 1.6)
1.4 (1.1, 1.7)
0.71
1.4 (1.2, 1.6)
1.4 (1.1, 1.6)
0.15
Mead acid (C20:3n-9)
0.3 (0.2, 0.4)
0.2 (0.1, 0.3)
0.09
0.2 (0.1, 0.3)
0.17 (0.1, 0.3)
0.0003 0.41
a
BMI, body mass index; PUFA, polyunsaturated fatty acids.
b
Median (Q
1
, Q
3
)
=
differences between FAs across BMI and gender were tested by independent
t
-test according to BMI
<
25 and BMI
≥
25 kg/m
2
. Data are presented as
median; Q
1
: lower interquartile range, Q
3;
upper interquartile range.
c
Plasma phospholipid fatty acids (% total FAs)
=
fatty acids are expressed as a percentage (%) of total FA. Significance levels of differences in parameters between men
and women based on Mann–Whitney tests.