CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 5, September/October 2010
AFRICA
269
complying with the inclusion criteria. They were selected from
one of the four Dr Kenneth Kaunda education districts of the
North West province, South Africa. To assimilate the sample,
the following exclusion criteria were proposed: users of
α
- and
β
-blockers, participants with body temperatures higher than
37.5°C, and those who had been vaccinated or had donated blood
three months prior to participation.
For the purpose of our sub-study, we included only 53 men
of the 101 SABPA black males after they had been classified
as clear high active (AC,
n
=
30) or passive coping (PC,
n
=
23)
responders, using the Amirkhan African validated coping style
indicator.
19
The North West Education Department supported by the
South African Democratic Teachers Union granted permission
for participation in the study. The Ethics Committee of the
North-West University approved the study and all the partici-
pants completed informed consent forms prior to cooperation.
We abided by the institutional guidelines and terms of the
Declaration of Helsinki when taking measurements and conduct-
ing procedures.
20
Experimental procedure
At 07:00 on four working days of the week, application of the
Cardiotens
®
for 24-hour blood pressure measurements and the
Actical
®
apparatuses commenced at their respective institu-
tions. Teachers thereafter resumed their normal daily activities
and at the end of the day, were transported to the North West
University’s research facility to overnight. They were each
welcomed, received their own rooms and were pre-counselled
regarding AIDS. Afterwards they were exposed to the experi-
mental set up to lessen anticipatory stress.
10
Completion of the psychosocial questionnaires followed,
supervised by registered clinical psychologists, with a dinner
break in between, and participants went to bed at 22:00, fast-
ing overnight. At 06:00 the following morning, disconnection
of the Cardiotens
®
occurred and an eight-hour collected fasting
urine sample was obtained from each volunteer. Anthropometric
measurements began, followed by a resting period of five to 10
minutes, and subsequently, blood sampling commenced.
On completion of the protocol, the participants were thanked
for their cooperation and each received feedback and post-coun-
selling for HIV (if tested positive) in the privacy of their rooms.
Transportation back to school followed breakfast and referral to
a physician, where applicable.
Questionnaires
The coping strategy indicator (CSI), developed by Amirkhan
(1990), was essential in predicting each participant’s predominant
orhabitualcopingstyle.
21
TheCSIisaself-reportmeasureofcoping
strategies, encompassing problem and avoidance strategies, and
seeking social support. This 33-item questionnaire, formulated
through a combination of deductive and inductive methodolo-
gies, is widely applicable and has been validated for Africans.
21
Participants rated the 33 items of the questionnaire on a three-
point Likert scale: a lot (3), a little (2), or not at all (1), with a
recent stressful event in mind. The higher scores were indicative
of preference for a specific coping style, with the cut-off points
for high use pertaining to: problem solving or AC (31), avoid-
ance or PC (23), and seeking social support (28).
21
Clear
high
responders were scrutinised,
21
and participants utilising both AC
and PC styles (
n
=
48) were excluded. Unfortunately this could
not be prevented and was a limitation of the sub-study.
The global physical activity questionnaire (GPAQ) as predic-
tor of the subjects’physical activity was completed and assessed.
22
Participants also completed the general socio-demographic and
health questionnaire regarding information such as medical
history, alcohol and smoking habits, caffeine intake, and socio-
demographic details.
Anthropometrics
Registered level II biokinetisists took measurements of each
participant in triplicate to ensure accuracy. Measurement of
waist circumference (WC) was perpendicular to the long axis of
the trunk, at the midpoint between the lower costal border and
iliac crest. The cut-off points for WC determining obesity were
values of
≥
94 cm (male) and
≥
80 cm (female).
13
The BMI was
calculated in kg/m
2
from the height and weight.
Actical
®
accelerometers (Mini Mitter Co, Bend, Oregon,
USA) on the waist measured physical activity (PAI) in kilocalo-
ries per 24 hours, and participants were classified as high activity
(PAI-3) according to their active energy expenditure. PAI-3 was
equivalent to strenuous activity for three days a week (achieving
a minimum of 1 500 MET-minutes), or any activity accruing at
least 3 000 MET-minutes for seven days a week.
22
Blood pressure
The Cardiotens
®
(Meditech, Budapest, Hungary) apparatus
obtained24-hour bloodpressuremeasurements.This programmed
apparatus measures ambulatory blood pressure oscillometrically
at intervals of 30 minutes during the day and 60 minutes at night.
A suitable obese or non-obese cuff of the Cardiotens
®
apparatus
was fastened to each subject’s non-dominant arm.
After overnight sleep and anthropometrical measurements,
two mercury sphygmomanometer blood pressure readings using
Korotkoff IV or V for diastolic BP followed while the partici-
pants rested for five minutes in the semi-fowler position, with a
three- to five-minute rest in between measurements. Participants
were defined as hypertensive with a 24-hour blood pressure of
>
125–130/
>
80 mm Hg, according to the ESH guidelines (2007).
23
Carotid intima–media thickness (CIMT)
A high-resolution ultrasound scan with CIMT images from at
least two optimal angles of the left and right common carotid
artery, carotid bulb and internal carotid arterial (ICA) segments
were obtained using a Sonosite Micromaxx ultrasound system
(SonoSite Inc, Bothell, WA, USA) and 6–13 MHz linear array
transducer using the Rudy Meijer protocol. The digitised images
were imported into the AMS automated software for analysis of
CIMT. A maximal 10-mm segment with good image quality was
chosen for analysis. The program automatically identifies the
borders of the CIMT of the near and far wall.
Biochemical analysis
Fasting resting serum and sodium fluoride (glucose) blood
samples were obtained by a registered nurse from the brachial
vein branches of the participant’s dominant arm, with a winged
infusion set. Blood samples were centrifuged at 3 700 revolu-
