Vol.2, No.7, 731-735 (2010)
Copyright © 2010 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
Prevalence, awareness, treatment and control of
hypertension in a nigerian population
Obinna Ikechukwu Ekwunife*, Patrick Obinna Udeogaranya, Izuchukwu Loveth Nwatu
Department of Clinical Pharmacy and Pharmacy Management, University of Nigeria Nsukka; Department of Pharmacy, Enugu State
Teaching Hospital Enugu State, Nigeria; *Corresponding Author: obinna.ekwunife@unn.edu.ng
Received 19 January 2010; revised 24 March 2010; accepted 26 March 2010.
Hypertension is a major public health problem.
Due to paucity of data, the burden of hyperten-
sion in Nigeria might be underestimated. Esti-
mating the prevalence of hypertension in popu-
lations of Nigeria would be useful in efforts to
control hypertension and prevent its conse-
quences. This survey aimed to assess the pr-
evalence, detection, treatment and control of
hypertension in Nsukka, a city located in South-
Eastern Nigeria. Hypertension prevalence, awa-
reness, treatment, and control (outcomes) were
examined in 756 adult participants (364 men and
392 women) aged 18 years and above. Blood
pressure (BP) of the participants was measured
and they also answered a detailed questionnaire.
Hypertension was defined as BP 140 for sys-
tolic BP and or 90 mm Hg for diastolic BP or
being on antihypertensive therapy. Prevalence
of hypertension was 21.1%. Men had higher
prevalence of high BP compared to women.
Systolic and diastolic BP increased with age in
both men and women. Detection of high BP in
participants with raised blood pressure was
40.3% and 24.7% for males and females respec-
tively. Only 23.7% and 17.5% of males and fe-
males respectively with high BP were on anti-
hypertensive treatment while 5.0% of males and
17.5% of females with hypertension were con-
trolled. Prevalence of hypertension was com-
parable with other studies in Nigeria and Africa.
The results showed a poor detection, treatment
and control of hypertension. This underscores
the need for comprehensive evaluation of the
prevalence of hypertension and other cardio-
vascular diseases in Nigeria.
Keywords: Hypertension; Prevalence;
Epidemiology; Nsukka
Hypertension is a major public health problem. World-
wide, prevalence estimates for hypertension is about 1
billion individuals [1]. It causes about 7.1 million deaths
per year [2] and 4.5% of the disease burden which trans-
lates to 64 million disability adjusted life years (DALYs)
[3]. The relationship between blood pressure (BP) and
risk of cardiovascular diseases events is continuous,
consistent, and independent of other risk factors. The
higher the BP, the greater is the chance of heart attack,
heart failure, stroke, and kidney diseases [4].
The burden of non-communicable diseases (NCDs)
such as hypertension is increasing in epidemic propor-
tions in Africa. According to the World Health Report
2001, NCDs accounted for 22% of the total deaths in the
region in the year 2000; cardiovascular diseases alone
accounted for 9.2% of the total deaths, killing even more
than malaria [2]. Major target-organ complications of
hypertension, such as left ventricular hypertrophy [5],
diastolic dysfunction [6], congestive heart failure [7],
ischemic heart disease [8], stroke [9], and renal failure
[10] have been established by various researchers in Ni-
Reducing the prevalence of hypertension would de-
crease mortality and disability in middle-aged and older
persons and lead to a better quality of life. Reduction of
hypertension prevalence could be achieved through risk
factor prevention programmes as well as using low-cost
management. However, in most countries of the African
region, implementation of these approaches and pro-
grammes is hampered by dearth of data on the preva-
lence and control levels of hypertension. Scarcity of data
is sometimes understood as non-existence of the prob-
lem [3]. There is paucity of hypertension prevalence in
many populations of Nigeria. Thus, burden of hyperten-
sion in these populations might be underestimated and
might leave the illness undiagnosed and untreated. Un-
controlled hypertension clearly places a substantial strain
on health care delivery system. Estimating the preva-
O. I. Ekwunife et al. / HEALTH 2 (2010) 731-735
Copyright © 2010 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
lence of hypertension in populations of Nigeria would be
useful in efforts to control hypertension and other NCDs.
This survey aimed to assess the prevalence, detection,
treatment and control of hypertension in Nsukka, a city
located in South-Eastern Nigeria.
2.1. Study Design and Population
This is a household survey with the objective of assess-
ing prevalence, awareness and control of hypertension in
Nsukka. Nsukka is a town located in South-Eastern Ni-
geria and has an estimated population of 117,086. Chris-
tianity is the main religion while farming, transportation
and trading are the major commercial activities. The
most prominent feature in Nsukka is the University of
Nigeria Nsukka, which attracts people of different ethnic
and linguistic group to the area. There are 19 public
health facilities and over 20 private health facilities in
2.2. Ethical Consideration
All procedures were carried out according to a study
protocol approved by the Local Ethics Committee of
University of Nigeria Teaching Hospital Enugu. Objec-
tives and nature of the study were explained to people
that agreed to participate. Informed consent was orally
obtained. The information about participant’s identity
was not included with the other data and only the prin-
cipal investigator had access to this information. No ref-
erence to the participant’s identity was made at any stage
during data analysis.
2.3. Sampling and Sample Size Calculation
A mixture of cluster and systematic random technique
was employed. Nsukka was grouped into 16 clusters
based on geographical locations as established by a map
designed by Nsukka Graduates Association. Six sections
or clusters were randomly selected from the sixteen
clusters using a random sampling technique. In each
section, the first house in each street was identified, fol-
lowed by systematic sampling of the next three houses.
Using “Statcalc” function of EPI INFO (Version 6, Cen-
tre for Disease Control, USA), it was determined that a
sample size of 400 was adequate to detect prevalence of
hypertension of 10% to 40% with 5% precision and 95%
confidence. However, a total of 800 persons were met in
the exercise after covering the selected clusters.
2.4. BP Measurement and Interview Procedure
The data collection tool was a questionnaire. The survey
was carried out from April to August of 2009. Partici-
pants that were included in the study were those from 18
years and above in each household identified. Those
who took caffeine, smoked or did an exercise prior to the
interview were excluded from the study. Participants
were interviewed and blood pressure was measured at
home. Data obtained were marital status, age, gender,
educational status, estimated income per month, family
history of hypertension, and co-morbidities. The inter-
view was in English or in Igbo (the local dialect) for
participants that could not understand English. Blood
pressure was measured twice by the trained final year
pharmacy students using mercury sphygmomanometers
and stethoscopes (Kris-Alloy®, Wuxi Medical Instru-
ment Factory, Wuxi City Jiangsu, China). Blood pressure
was measured after they were in resting state for 10
minutes and in sitting position in the right arm place at
the level of the heart. An appropriate-sized cuff (cuff
bladder encircling at least 80% of the arm) was used to
ensure accuracy [4]. High blood pressure was defined
using the WHO/ISH criteria of SBP 140 mmHg and/or
DBP 90 mmHg [11]. Prevalence of high BP was cal-
culated as percentage of participants with SBP and DBP
above WHO/ISH criteria, those that were known hyper-
tensive and those on hypertension medication (s). Hy-
pertension detection was defined as any prior diagnosis
of hypertension made by a health professional among the
population defined as having hypertension. Treatment of
hypertension was defined as use of recognized anti-
hypertensive medication among the population defined
as having hypertension, whereas control of hypertension
was defined as blood pressure of < 140/90 mmHg
among the population defined as having hypertension.
2.5. Data Analysis
Mean levels of BP were reported by gender (male versus
female) and age. Gender difference in blood pressure
was conducted using 2-sample t-test while gender dif-
ferences in detection, treatment and control rate was
assessed using χ2 test. All data analyses were conducted
using SPSS 13.0 (Chicago, IL) software. Data were dou-
ble checked by a staff of Clinical Pharmacy department,
University of Nigeria Nsukka for consistency. A two-
tailed significance level of 0.05 was used.
A total of 800 participants were encountered in their
homes but only 756 participants agreed to participate in
the study (94.5% response rate). Majority of those that
declined to participate were afraid to be diagnosed of
hypertension and would not want their blood pressure
measured. The rest did not want to participate because of
time the exercise will take. Three hundred and sixty four
O. I. Ekwunife et al. / HEALTH 2 (2010) 731-735
Copyright © 2010 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
(48.1%) were males while three hundred and ninety-two
(51.9%) were females. Majority of the participants
(about 60%) were married while the rest were single.
Only a few of the participant (< 1%) were divorced.
About 26% of the participants had a tertiary degree, 58%
had up to secondary school training while 3% had no
formal education. One half of the study population
earned less than $ 100 in a month and men significantly
earned more than women (T-test, p < 0.001). Details of
the demographic characteristics of the study population
are presented in Table 1.
Table 2 shows the details of clinical characteristics of
the study population. Among the participants, 23.5%
reported that they have a family history of hypertension.
Mean systolic blood pressure in the study population
was 129.8 ± 27.4 mmHg and mean diastolic blood pres-
sure 85.1 ± 9.9 mmHg. Males had a significantly higher
SBP compared to females –133.3 ± 14.3 mmHg vs 125.0
± 14.6 mmHg respectively (T-test, p < 0.001). DBP was
also significantly higher in males than in females –87.1
± 9.3 mmHg vs 83.2 ± 10.2 mmHg respectively (T-test,
p < 0.001). Prevalence of high blood pressure was
21.1%. Systolic and diastolic BP increased with age as
shown in Figure 1.
Detection of high BP in participants with raised blood
Table 1. Demographic characteristics of the study population
(n = 756).
Variable Mean ± SD, frequencies (%)
or median
[Interquartile range]
1. Age (y) 34.9 ± 13.9
Male 364 (48.1)
Female 392 (51.9)
Marital status
Single 297 (38.4)
Married 458 (59.2)
Divorced 6 (0.8)
Educational status
No formal education 23 (3.0)
Primary education 87 (11.2)
Secondary education 450 (58.1)
Graduate 206 (26.1)
5. Average Individual
Income ($/month) 83.3 [83.3 – 250]
Table 2. Clinical characteristics of the study population.
Variable Mean ± SD or
percentages (%)
1. Family history of hypertension 23.5
2. Systolic blood pressure (mm Hg) 129.8 ± 27.4
3. Diastolic blood pressure (mm Hg) 85.1 ± 9.9
4. Prevalence of BP 21.1
Figure 1. Systolic and diastolic BP by age group in Nsukka
urban, Nigeria. Results are shown as mean and standard devia-
pressure was significantly higher in males (40.3%)
compared to females (24.7%) (χ2 (1) = 4.2, p = 0.041).
Overall detection rate was 30%. Percentage of partici-
pants with high BP treated were 23.7% for males and
17.5% for males and females respectively. There was no
significantly difference in treatment rate between men
and women (χ2 (1) = 0.83, p = 0.36). On the total, 21%
of participants with high BP take medications. On con-
trol rate, 17.5% of the women were controlled while
5.0% of the men were controlled. There was significant
gender difference in control rate (χ2 (1) = 6.73, p = 0.01).
Overall control rate of BP amongst hypertensive was 9%
in the study population.
This study presents the prevalence estimate of hypertension
in Nsukka, an urban towngeria. in South-Eastern Ni
O. I. Ekwunife et al. / HEALTH 2 (2010) 731-735
Copyright © 2010 SciRes. http://www.scirp.org/journal/HEALTH/Openly accessible at
Table 3. Blood pressure by age group and gender.
Systolic BP (mm Hg) Diastolic BP (mm Hg)Systolic BP (mm Hg) Diastolic BP (mm Hg)
Age group (y) n
Men (n = 364)
Women (n = 392)
19 28 123 ± 10 81 ± 8 31 118 ± 8 82 ± 8
20-29 106 127 ± 9 85 ± 8 162 119 ± 9 80 ± 8
30-39 75 132 ± 12 88 ± 9 109 127 ± 13 85 ± 9
40-49 85 136 ± 15 88 ± 8 48 128 ± 16 86 ± 12
50-59 36 143 ± 15 89 ± 6 18 136 ± 17 88 ± 9
60 34 147 ± 17 94 ± 14 24 145 ± 25 90 ± 19
Results are presented mean ± standard deviation
Blood pressure showed a consistent increase with age in
both men and women. The survey showed that only 30%
of persons with raised blood pressure were detected,
21% were detected, while 9% were controlled.
Similar prevalence estimate have been documented in
the literature. In South-Eastern Nigeria, prevalence of
hypertension in a university community was as much as
21% [12]. Arterial hypertension was found in 25% of
examined motor bike riders in Benin City, Nigeria [13].
It has been speculated that about 20%-25% Nigerian
adults could be classed as hypertensive [14].
The consistent increase of blood pressure with age in
both men and women is a known occurrence and has
been reported elsewhere in Africa [15]. A recent study in
Nigeria (Kogi State) showed that blood pressures in-
creased with age and body mass index [16]. The age-
related rise in systolic blood pressure is primarily re-
sponsible for an increase in both incidence and preva-
lence of hypertension with age [17]. It has been stated
that the prevalence of hypertension increases with ad-
vancing age to the point where more than half of people
aged 60 to 69 years old and approximately three-quarters
of those aged 70 years and older are affected [1]. Though
blood pressure increased with age, men had a signifi-
cantly higher blood pressure than women in all the age
The survey showed that only 30% of persons with
raised blood pressure were detected, 21% were treated,
while 9% were controlled. In general, our results showed
a comparable level of detection, treatment and control of
hypertension with those that have been reported in other
surveys in Africa. For example in Ghana, it was reported
that only 34% were aware that their blood pressure was
high and 22.2% were taking antihypertensive medication,
but only 6.2% had optimal blood pressure control [18].
Although a recent survey in Nigeria by Omuemu et al.,
reported a lower detection rate of 18.5% compared to
30% obtained in this survey, treatment and control rates
in both surveys were comparable [19].
This study strengthens the fact that in sub-Saharan Af-
rica, level of detection, treatment and control are still far
less than results obtained in developed countries [20].
This poor level of detection, treatment and control has
been attributed to scarce resources and inadequate
healthcare provision [21,22]. The poor level of detection,
treatment and control of hypertension is a cause of con-
cern. As hypertension is an important cardiovascular risk
factor, many undetected hypertensive patients have a
high risk of suffering from cardiovascular disease con-
sequences such as myocardial infarction and stroke. As
was stated earlier, the burden of hypertension might be
underestimated in Nigeria.
This study had some limitations. Stratified sampling
technique would have been the best sampling method
which will ensure the generalizability of the prevalence
estimate. Also, since the blood pressure of the entire
residents’ ( 18 years) in the identified houses was
measured, clustering effect could have resulted diluting
the randomness of the sampling.
Prevalence of hypertension was comparable with other
studies in Nigeria and Africa. Our results also showed a
poor detection, treatment and control of hypertension
than has been reported in other surveys in Africa. This
underscores the need for comprehensive evaluation of
prevalence of hypertension and other cardiovascular
diseases in Nigeria. Information from this assessment
could demonstrate the need to urgently address this
emerging disease. It is also imperative to design cost-
effective strategies which could be implemented to im-
prove detection, adherence and control of hypertension
in Nigeria.
O. I. Ekwunife et al. / HEALTH 2 (2010) 731-735
Copyright © 2010 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
The authors wish to acknowledge the following final year pharmacy
students that took part in the field study: Ejike Onah, Ifeanyi Aduaka,
and Theresa Money.
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