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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 31, No 6, November/December 2020
AFRICA
309
WC and CIMT (
r
= 0.19;
p
= 0.02); TEE (
r
= 0.24;
p
= 0.00); and
PAL (
r
= 0.20;
p
= 0.02) was found. When partial correlation was
performed to control for age, gender, cholesterol, ambulatory
24-hour BP, CRP and WC, a significant inverse relationship
was found between CIMT and TEE (
r
= –0.31;
p
= 0.05), and
a borderline inverse relationship was found between CIMT and
AEE
(r = –
0.28;
p
= 0.07) in sedentary male teachers (Table 6).
Furthermore, a borderline significant relationship was found
between CIMT and mean seven-day METs (
r
= –0.19;
p
= 0.08),
controlled for age, gender, cholesterol, ambulatory 24-hour BP
and WC.
When CRP was added among the controlled variables, the
borderline significant correlation diminished, therefore CRP
was excluded in the analyses. No significant relationships were
observed between CIMT and PA for female teachers in the
sedentary group.
Discussion
This study aimed to investigate the relationship between
objectively measured PA and CIMT among teachers in South
Africa. A borderline negative association between CIMT and
Table 6. Partial correlation coefficient (
r
) for the relationship between CIMT and PA,
controlled for age group, waist circumference, CRP, 24-h SBP and cholesterol
Males (n
=
41)
Females (n
=
19)
Sedentary
Mean 7-day
awake METs
AEE
(kcal/wk)
TEE
(kcal/wk)
PAL
seven days
CIMT
(mm)
Mean 7-day
awake METs
AEE
(kcal/wk)
TEE
(kcal/wk)
PAL
seven-day
CIMT
(mm)
Mean seven-day awake METs
r
–
0.06
0.09
0.64
0.09
–
0.43
0.37
0.80
0.21
p
–
0.68
0.55
<
0.001*
0.58
–
0.05*
0.10
<
0.001*
0.35
AEE (kcal/wk)
r
0.06
–
0.95
0.40
–0.28
0.43
–
0.97
0.55
0.18
p
0.68
–
<
0.001*
0.01*
0.07
#
0.05*
–
<
0.001*
0.01*
0.44
TEE (kcal/wk)
r
0.09
0.95
–
0.28
–0.31
0.37
0.97
–
0.53
0.16
p
0.55
<
0.001*
–
0.06
#
0.05*
0.10
<
0.001*
–
0.01*
0.48
PAL seven-day
r
0.64
0.39
0.28
–
–0.08
0.80
0.55
0.53
–
0.09
p
<
0.001*
0.01*
0.06
#
–
0.59
<
0.001*
0.01*
0.01*
–
0.71
CIMT (mm)
r
0.09
–0.28
–0.31
–0.08
–
0.21
0.18
0.16
0.09
–
p
0.58
0.07
#
0.05*
0.59
–
0.35
0.44
0.48
0.71
–
Males (n
=
53)
Females (n
=
82)
Light PA
Mean 7-day
awake METs
AEE
(kcal/wk)
TEE
(kcal/wk)
PAL
seven days
CIMT
(mm)
Mean 7-day
awake METs
AEE
(kcal/wk)
TEE
(kcal/wk)
PAL
seven-day
CIMT
(mm)
Mean seven-day awake METs
r
–
0.66
0.64
0.95
0.02
–
0.50
0.37
0.88
–0.19
p
–
<
0.001*
<
0.001*
<
0.001*
0.90
–
<
0.001*
<
0.001*
<
0.001*
0.08
#
AEE (kcal/wk)
r
0.66
–
0.99
0.54
0.10
0.50
0.92
0.45
–0.03
p
<
0.001*
–
<
0.001*
<
0.001*
0.44
<
0.001*
–
<
0.001*
<
0.001*
0.75
TEE (kcal/wk)
r
0.64
0.99
–
0.50
0.12
0.37
0.92
–
0.38
–0.001
p
<
0.001*
<
0.001*
–
<
0.001*
0.38
<
0.001*
<
0.001*
–
<
0.001*
0.99
PAL seven-day
r
0.95
0.54
0.50
–
0.002
0.88
0.45
0.38
–
–0.16
p
<
0.001*
<
0.001*
<
0.001*
.
0.99
<
0.001*
<
0.001*
<
0.001*
–
0.14
CIMT (mm)
r
0.08
0.10
0.12
0.01
–
–0.19
–0.03
–0.001
–0.16
–
p
0.90
0.44
0.38
0.99
–
0.08
#
0.75
0.99
0.14
–
Sedentary
= ≤
1.5 METs; light PA
=
1.5–3 METs. AEE
=
activity energy expenditure; CIMT
=
carotid intima–media thickness; CRP
=
C-reactive protein; METs
=
meta-
bolic equivalent of task; PAL
=
physical activity level; SBP; systolic blood pressure; TEE
=
total energy expenditure. *Level of significance was set at
p
≤
0.05;
#
border-
line significance.
Table 5. Correlations matrix
rho
(
r
) for anthropometric
measurements, AEE and CIMT by activity group
Sedentary group
Light PA group
Variables
CIMT
(mm)
BMI
(kg/m
2
)
WC
(cm) WHtR
CIMT
(mm)
BMI
(kg/m
2
)
WC
(cm) WHtR
CIMT (mm)
r
1.00 –0.05 0.14 0.05 1.00 0.09 0.19* 0.12
p
– 0.66 0.25 0.70 – 0.27 0.02 0.14
AEE (kcal/wk)
r
–0.17 0.02 –0.02 0.04 0.11 –0.01 0.10 –0.05
p
0.15 0.86 0.86 0.75 0.20 0.88 0.24 0.54
Mean seven-day
awake METs
r
–0.20 0.07 –0.06 0.01 –0.02 0.05 0.12 0.04
p
0.11 0.57 0.64 0.93 0.81 0.58 0.16 0.66
TEE (kcal/wk)
r
–0.05 0.14 0.18 0.14 0.15 0.10 0.24** 0.06
p
0.66 0.23 0.13 0.24 0.08 0.25
<
0.001 0.45
PAL
r
–0.30
*
0.13 –0.02 0.14 –0.001 0.20* 0.19* 0.17*
p
0.01 0.30 0.89 0.24 0.99 0.02 0.02 0.04
AEE
=
activity energy expenditure; BMI
=
body mass index; CIMT
=
left carotid
intima–media thickness; METs
=
metabolic equivalent of task; TEE
=
total
energy expenditure; PAL
=
physical activity level; WC
=
waist circumference;
WHtR
=
waist-to-height ratio. *Level of significance is set at
p
≤
0.05. **Level of
significance is set at
p
≤
0.001