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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 31, No 3, May/June 2020
142
AFRICA
Prevalence of hypertension and selected cardiovascular
risk factors among adolescents in selected rural and
urban secondary schools in Botswana
Matshidiso Mokgwathi, Julius Chacha Mwita
Abstract
Background:
Adolescent hypertension and other cardiovascu-
lar risk factors tend to track into adulthood. Consequently,
there is a need to determine the prevalence of hypertension
and pre-hypertension, and its co-existence with glycaemia,
obesity, tobacco and alcohol use among senior secondary
school students in Botswana.
Methods:
A cross-sectional study was undertaken between
December 2015 and March 2016 among students in select-
ed rural and urban senior secondary schools in Botswana.
Data were collected through a self-administered questionnaire,
measurements and fasting blood glucose testing. Participants
were asked about cigarette smoking, alcohol use and levels
of physical activity. Body weight, height, waist circumference,
blood pressure and fasting blood glucose levels were measured.
Hypertension, pre-hypertension, overweight and obesity were
defined based on gender, age and height from normative tables.
Results:
A total of 252 students with a mean age (stand-
ard deviation) of 17.1 (0.9) years participated in the study.
Rural students were older than urban students (17.5 vs 16.7
years;
p
< 0.001). The prevalence of hypertension and pre-
hypertension were 13.1 and 15.5%, respectively. Physical
inactivity (37.7%), overweight/obesity (10.3%) and alcohol
intake (9.1%) were also prevalent. Cigarette smoking was rare
(2.0%). Impaired fasting glucose levels were found in 1.6% of
participants, and none had diabetes mellitus. Hypertension (
p
< 0.001) and cigarette smoking (
p
= 0.019) were more preva-
lent among male than female participants. Female students
were more likely to be overweight or obese than male students
(
p
< 0.001). There were no urban–rural differences in hyper-
tension, pre-hypertension and smoking. Urban students were
more likely to drink alcohol than rural students (
p
= 0.008)
Conclusion:
Hypertension, overweight/obesity and alcohol
intake were common among these adolescents in Botswana.
Strategies to reduce the risk factors of cardiovascular diseases
should be urgently developed and implemented to prevent cardi-
ovascular disease-related morbidity and mortality in the future.
Keywords:
hypertension, cardiovascular risk factors, adolescents,
Botswana
Submitted 8/11/18, accepted 16/10/19
Published online 27/11/19
Cardiovasc J Afr
2020;
31
: 142–146
www.cvja.co.zaDOI: 10.5830/CVJA-2019-062
Demographic and epidemiological changes in sub-Saharan Africa
(SSA) have resulted in an increase in non-communicable diseases,
including hypertension, leading to concerns and activities to reduce
rising rates.
1-4
In children and adolescents, hypertension is often
underdiagnosed and may progress into adulthood.
5-8
The prevalence
of hypertension among children in developed countries is 1–5%.
9
By contrast, the prevalence of hypertension in SSA paediatric
populations is 0–12.5 and 0–21.5% for boys and girls, respectively.
10
Hypertension is usually found in constellation with obesity,
smoking, alcohol intake and physical inactivity.
10
All these
may track from childhood to adulthood and are predictive of
cardiovascular risk later in adult life.
10
The prevalence of all the
above risk factors has been increasing among children, mainly
as a consequence of urbanisation and changes in lifestyle.
11-13
Urbanisation has led to an increase in the use of tobacco and
alcohol, poor diet and physical inactivity.
14-16
For a country with a high burden of HIV/AIDS, the increase
in non-communicable diseases, including cardiovascular disease
(CVD) and diabetes, poses a challenge for health policymakers
and providers to the already stretched health system and
progress towards the development of millennium goals.
17-19
This
is particularly important in Botswana with its high rate of HIV/
AIDS, alongside the wish to maintain universal healthcare.
There is evidence that early identification and modification
of risk factors during childhood decreases the occurrence and
magnitude of associated complications due to CVD.
10,20
However,
data on the burden of hypertension and other cardiovascular
risk factors among adolescents in Botswana are currently scarce.
Consequently, the objective of this study was to determine
the prevalence of hypertension and co-existing selected
cardiovascular risk factors among secondary school students in
Botswana and to use the findings, if pertinent, to guide future
strategies in Botswana.
Methods
This cross-sectional study was conducted from December 2015
to March 2016 among students in the rural Shakawe senior
secondary school and the urban St Joseph’s College in Botswana.
Shakawe is the only senior secondary school in the Okavango,
a sub-district with a population of 2 529 inhabitants, mostly
subsistent farmers and pastoralists.
21
St Joseph’s College is located
in Gaborone, the capital city, with a population of 231 592.
21
The two schools were conveniently selected based on their
ease of accessibility and to provide widely different populations.
There were 36 and 42 classes at St Joseph’s College and Shakawe
senior secondary school, respectively. Four classes were selected
from each school using a simple random-sampling technique.
All students in the selected classes were invited to participate
in the study and were provided with a written description of
Department of Internal Medicine, Faculty of Medicine,
University of Botswana; Department of Internal Medicine,
Princess Marina Hospital, Gaborone, Botswana
Matshidiso Mokgwathi, MD, FCP, MMED
Julius Chacha Mwita, MD, MMed, MSc,
jmwita@gmail.com