Cardiovascular Journal of Africa: Vol 30 No 3 (May/June 2019)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 3, May/June 2019 142 AFRICA
Ellisras Longitudinal Study 2017: the association of fat
patterning with blood pressure in Polokwane private
school children aged five to 15 years (ELS 22)
Mbelege Rosina Nkwana, Kotsedi Dan Monyeki, Suzan Mafoloa Monyeki, Tlou Thomas Makata,
Judas Mponthseng Lentenne Monyeki
Abstract
Background: Obesity is a risk factor for non-communicable
diseases and is a global public health concern.
Objectives: The main objectives of this study were to inves-
tigate the association of fat patterning and blood pressure
among five- to 15-year-old black children attending private
schools in Polokwane, South Africa, and to determine the
prevalence of obesity and hypertension.
Method: A total of 1 665 subjects (846 boys and 819 girls),
aged five to 15 years and attending three private schools in
Polokwane, were included in the study. All anthropometric
measurements were taken according to standard proce-
dures of the International Society for the Advancement of
Kinanthropometry. All data were analysed using SPSS.
Results: Girls showed a higher prevalence of over-fatness
(10.2–12.3%) and hypertension (1.4–33.0%) than boys (7.3–
10.3, 3.6–21.3%, respectively). The sum of four skinfolds,
trunk skinfolds relative to limb skinfold, and body mass index
(BMI) were positively associated with systolic and diastolic
blood pressure (p < 0.01). There was a significant positive
( p < 0.001) association between over-fatness and hyperten-
sion, both unadjusted (OR = 3.11; 95% CI = 2.17–4.46) and
adjusted for age and gender (OR = 3.29; 95% CI = 2.22–4.86).
Conclusion: These Polokwane private school children with
high body fatness were at risk for developing high blood
pressure.
Keywords: skinfolds, African children, hypertension, obesity, fat
patterning
Submitted 10/4/18, accepted 31/10/18
Published online 24/5/19
Cardiovasc J Afr 2019; 30: 142–145
DOI: 10.5830/CVJA-2018-058
Obesity is a risk factor for non-communicable diseases and is
of global public health concern. It is estimated that more than
one billion adults are overweight, of which at least 300 million
are obese.1 Over-fatness, measured by means of the sum of the
triceps and subscapular skinfold thicknesses greater than the
85th percentile, increased significantly in girls after menarche
and peaked at 17 years, with 11% of girls being overweight.1,2
Additionally, it is known that late childhood is an important
period for the development of a central patterning of body fat,
which predisposes to coronary heart disease at a later age.3 It is
also suspected that essential hypertension may have its inception
in childhood.4
Monyeki et al.5 reported a low incidence of hypertension and
overweight in rural school children living in the Ellisras area. The
association between fat patterning and hypertension has received
little attention in urban school children. Therefore the main
objectives of this study were to investigate the association of fat
patterning and blood pressure among five- to 15-year-old black
children attending private schools in Polokwane, South Africa,
and to determine the prevalence of obesity and hypertension.
Methods
A total of 1 665 subjects (846 boys and 819 girls), aged five
to15 years attending all three private schools in Polokwane,
a city in the Limpopo Province, participated in the survey.
Generally, children attending private schools in South Africa
fall within the middle and high socio-economic groups of the
population. All children attending school on the days of the
survey participated in the study. Informed consent had been
obtained from the parents and/or guardians prior to the survey
and ethical approval for the study was obtained from the Ethics
Committee of the University of Limpopo. The survey was
undertaken at the schools over a period of 20 days.
All children underwent a series of anthropometric
measurements, including weight, height and skinfolds [(supra-
iliac (SPIL), subscapular (SSCP), triceps (TRCP) and biceps
(BCP)]. A Martin anthropometer was used to measure height
to the nearest 0.1 cm and an electronic scale measured weight to
the nearest 0.1 kg. A slim skinfold caliper was used to measure
skinfolds.
All training and measurements were carried out in accordance
with the standard procedures of the International Society
for the Advancement of Kinanthropometry.6 The fieldworkers
underwent testing for reliability of measurements as part of their
training, in order to achieve a technical error of measurement
within the accepted limits. 6
The sum of four skinfolds (SPIL + SSCP + TRCP + BCP)
was used as an indicator of total body fatness. The proportion
of body fat on the trunk relative to that on the limbs was used as
an indicator of the central pattern of body fat (visceral fat). This
was calculated by two formulae:7,8
Department of Physiology and Environmental Health,
University of Limpopo, Polokwane, South Africa
Mbelege Rosina Nkwana, BSc Hons
Kotsedi Dan Monyeki, PhD, MPH,
Suzan Monyeki Mafoloa, MPhil
Tlou Thomas Makata
Judas Monyeki Mponthseng Lentenne