Cardiovascular Journal of Africa: Vol 31 No 3 (May/June 2020)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 31, No 3, May/June 2020 AFRICA 145
to adulthood, the findings suggest that a significant proportion
of our participants are at high risk of becoming hypertensive
in adulthood.34 We did not observe an urban–rural difference
in the prevalence of hypertension. However, our participants
from the rural school were significantly older than their urban
counterparts, making it difficult to compare the two populations.
Both hypertension and pre-hypertension were more common
in the male students than the females in our study. Our finding
may be explained by the fact that male students were significantly
older than their female colleagues. Results from the most recent
meta-analysis on hypertension in adolescents in Africa however
showed no difference between boys and girls in the prevalence of
hypertension.30,35-37
Similar to other studies, overweight/obesity was associated
with up to a four-fold increased risk of hypertension among
our participants.5, 29,35,36,38-41 A similar link between obesity and
CVD has been established among adults.42 Overweight/obesity
and hypertension are some of the components of the metabolic
syndrome, an indicator of high risk for CVD as well as type 2
diabetes.43
The burden of overweight and obesity among our
participants is consistent with reports from other SSA countries
where between 2.5 and 10.6% of adolescents are overweight or
obese.2,39,41,44 There is evidence that the increase in overweight/
obesity is associated with urbanisation.2 Although we did not see
a rural–urban difference in the prevalence of overweight/obesity,
earlier data from urban students in Botswana reported a higher
proportion of overweight and obesity.45 Consistent with other
studies, overweight/obesity affected more girls than boys.29
Although none of the students was found to have diabetes
mellitus, 1.6% of participants had IFG. As for the other
components of the metabolic syndrome, IFG is a cardiovascular
risk factor.43 This is in contrast to findings from Cote d’Ivoire
where 0.4 and 14.5% of adolescents had diabetes mellitus and
IFG, respectively.46 The reasons for this discrepancy are not clear.
A small proportion of both rural and urban students reported
using tobacco. This is lower than earlier data from Botswana, in
which 10% of the students were current tobacco smokers, and
up to 29% reported having tried smoking.47 Our findings are also
inconsistent with the Global Youth Tobacco Survey (GYTS),
which reported a prevalence of 10–33% among 13–15-year-
olds.48 Tobacco use was more common among males than
females, consistent with a previous study in Botswana.32 The
lower prevalence of tobacco use among our participants was
possibly due to under-reporting of tobacco use because of its
prohibited use within schools in Botswana.
Only about 9% of our students reported using alcohol.
The figure is lower than what would be expected in a country
where nearly half (48.4%) of adults are said to consume alcohol
regularly,32 and again may be due to under-reporting. Similar to
a study in Australia, our urban students were more likely to use
alcohol than their rural counterparts.49 It is possible that urban
students have more access to alcohol than those in the rural
setting, contributing to these findings.
We observed a lower level of physical activity among rural
than urban students. This finding was unexpected, most likely
explained by the fact that rural students were in a boarding
school therefore had minimal travelling distance to their classes.45
There are some limitations. The study had a small sample size
and relied on some self-reported variables that were prone to
recall bias. We measured blood pressure on only two visits. More
than two readings would have been needed to provide the best
estimate of blood pressure.
Conclusion
This study has shown that hypertension, overweight/obesity
and alcohol intake were common among these senior secondary
school students in Botswana. Strategies to prevent the risk
factors of CVD should be developed and implemented to avoid
CVD-related morbidity and mortality in the future. These
strategies are being advanced and will be the subject of future
research.
This work was supported by the University of Botswana Office of Research
and Development (ORD) Post-graduate Internal Funding (Round 6). The
datasets used and/or analysed during the current study are available from the
corresponding author on reasonable request.
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