Cardiovascular Journal of Africa: Vol 25 No 6 (November/December 2014)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 6, November/December 2014 AFRICA 269
Prevalence of hypertension in the Gambia and Sierra
Leone, western Africa: a cross-sectional study
Morcos Awad, Andrea Ruzza, James Mirocha, Saman Setareh-Shenas, J Robert Pixton,
Camelia Soliman, Lawrence SC Czer
Abstract
Background: Hypertension (HTN) is one of the causes of
cardiovascular disease (CVD) in Africa, and may be associat-
ed with lower socio-economic status (SES). The prevalence of
HTN is not well established in the Gambia or in Sierra Leone.
Methods: A cross-sectional, population-based study of adults
was conducted in the Gambia in 2000 and in Sierra Leone
from 2001 to 2003 and in 2009. The study was conducted as
part of the annual visit to countries in western Africa spon-
sored by a medical delegation from California. People from
the Gambia and Sierra Leone were examined by the medical
delegation and blood pressures were measured.
Results: A total of 2 615 adults were examined: 1 400 females
and 1 215 males. The mean systolic blood pressure (SBP) of
the females was 134.3 ± 29.7 mmHg, mean diastolic blood
pressure (DBP) was 84.5 ± 17.5 mmHg, and 46.2% were
hypertensive. The mean SBP of the males was 132.8 ± 28.5
mmHg, mean DBP was 82.8 ± 16.2 mmHg, and 43.2% were
hypertensive. Overall prevalence of HTN in the subjects was
44.8%. Mean SBP, mean DBP and HTN prevalence increased
with age decade, both in males and females. In addition, after
age adjustment (known age), females had higher mean SBP
( p = 0.042), mean DBP (p = 0.001) and rate of occurrence of
HTN (p = 0.016) when compared with males.
Conclusions: Prevalence rates of HTN in the Gambia and
Sierra Leone were higher than 40% in males and females, and
may be a major contributor to CVD in both countries. Due to
the association of HTN with low SES, improvements in educa-
tional, public health, economic, non-governmental and govern-
mental efforts in the Gambia and Sierra Leone may lead to a
lower prevalence of HTN. The cause of the higher prevalence
in women may be due to post-menopausal hormonal changes.
Keywords: hypertension, the Gambia, Sierra Leone, prevalence,
sodium, age, gender
Submitted 2/3/14, accepted 8/9/14
Published online 16/10/14
Cardiovasc J Afr 2014; 25: 269–278
DOI: 10.5830/CVJA-2014-058
Hypertension (HTN) is a chronic, slowly progressive disease
affecting about one billion people globally and leading to about
7.1 million deaths annually. People of African origin may be
particularly susceptible to hypertension.1-3 Defined as a sustained
systolic blood pressure (SBP) above 140 mmHg, a diastolic
blood pressure (DBP) above 90 mmHg or both, the aetiology
of HTN can be classified as primary or secondary. While there
is no known cause for primary (essential) HTN, which accounts
for 90–95% of cases, the remaining 5–10% of cases is defined
as secondary HTN and is caused by other disease conditions,
which may affect the renal, circulatory, endocrine or other organ
systems.
Many factors are associated with, and may contribute to the
development and persistence of primary HTN, including obesity,
stress, smoking,4 low potassium intake, high sodium (salt) and
alcohol intake,5,6 familial and genetic influences,7,8 and low birth
weight.9 On the other hand, hyperthyroidism, hypothyroidism and
other conditions causing hormonal changes may be associated
with primary pulmonary HTN.10,11 Regardless of the cause,
the consequences of HTN include renal failure, heart failure,
myocardial infarction, pulmonary oedema and stroke.12
Given these undesirable outcomes, treatment and prevention
have assumed increasing emphasis in the management of HTN.
Modification of risk factors can be achieved by reducing body
weight and decreasing sugar intake, along with lowering alcohol
consumption,13,14 as well as reducing salt intake and increasing
potassium intake.15,16 Secondary HTN is managed by treating
the underlying cause. Drugs available for the treatment of HTN,
whether primary or secondary, include calcium-channel blockers
(CCB), angiotensin converting enzyme inhibitors (ACEI),
angiotensin receptor blockers (ARB), diuretics, α-blockers and
β-blockers.
Race and ethnicity may influence pathogenesis, prevalence
and treatment of HTN,17 perhaps through genetic influences.
As a consequence, HTN remains one of the most common
CVDs in Africa and one of the most frequent causes of death
in the sub-Saharan African region. 18,19 In 2000, the rate of
HTN in sub-Saharan Africa was reported to be 26.9% in males
and 28.3% in females.20 Low socio-economic status (SES) may
additionally play an important role in the high prevalence of
HTN in western and sub-Saharan Africa.
A cross-sectional survey in Tanzania revealed that treatment
rates for HTN were very low, especially among people with low
SES.21 Low SES led to inadequate education levels as a factor
Division of Cardiology, Cedars-Sinai Heart Institute, Los
Angeles, California
Morcos Awad, BS
Saman Setareh-Shenas, MS
J Robert Pixton, BS, Camelia Soliman, BS
Lawrence SC Czer, MD,
Division of Cardiothoracic Surgery, Cedars-Sinai Heart
Institute, Los Angeles, California
Andrea Ruzza, MD, PhD
Section of Biostatistics, Cedars-Sinai Medical Center, Los
Angeles, California
James Mirocha, MS