CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 6, November/December 2010
AFRICA
321
tively with BMI, waist circumference and truncal skin folds in
the girls. Among the boys, no significant positive correlation was
found, but there was a trend towards an association in the same
direction. Using multiple regressions with both physical activity
and body composition variables, waist circumference was posi-
tively associated with serum CRP levels in the girls.
Also in line with previous reports, there was a trend towards
an inverse correlation between fitness and percentage body fat in
the boys in this study.
1,28
Obesity and central body fat distribution
are related to an adverse risk profile in the youth, and reports
suggest that physical activity exerts a positive effect on risk
factors for chronic disease. A higher degree of cardio-respiratory
fitness has also been shown to relate to a healthier metabolic
profile in children.
10
Rapid urbanisation and westernisation are becoming the
norm in South Africa and this may be causal to the notion that
overweight in childhood could become a public health issue.
8,9
Lobstein
et al.
2
and Simon
et al.
33
emphasised that children from
socio-economically deprived environments in most westernised
societies, such as the subjects of low socio-economic status in
this study, have a greater risk of obesity than those from more
affluent groups.
Findings in this study have broad implications, especially
with regard to the link between body composition, cardiovascu-
lar risk and the metabolic syndrome. Many obese children, and
especially adolescents, tend to become obese or overweight as
adults and it has been suggested that 33% of adult obesity starts
in childhood.
1,3
Obesity during childhood seems to increase the
risk of subsequent morbidity, whether or not obesity persists into
adulthood,
1,34
with obese children being at an increased risk of
metabolic and cardiovascular disorders later in life.
3,5
Limitations of this study include the fact that the age range of
children recruited from one high school class varied between 13
and 22 years. Learners older than 18 years were excluded from
the analysis and the remaining children were therefore not all at
the same stage of physical development, with resulting effects on
their body composition. Not all recruited children gave consent
for taking blood samples, so the sample size was relatively small
when the groups of children were compared.
Conclusion
This study showed a statistically significant association between
serum CRP levels and physical activity in the girls, and an
inverse correlation between serum CRP levels and fitness in
the boys. Waist circumference was a significant predictor of
serum CRP levels in the girls. These associations indicate a link
between body fat, physical activity and inflammation. Obesity
should be discouraged in South African children by encouraging
physical activity.
This work is based on research supported by the National Research
Foundation (NRF) of South Africa. Any opinions, findings and conclusions
or recommendations expressed in this article are those of the authors and
the NRF does not accept any liability in regard thereto. The North-West
University of Potchefstroom, South Africa, also provided financial support.
The authors thank the children from the two township schools in Ikageng,
South Africa, who participated in this study. We also acknowledge the
contribution of the PLAY research team, particularly Prof Anita Pienaar for
supervision of physical activity and fitness testing and Dollien Naudé for
body composition measurements.
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