CHAPTER I: INTRODUCTION
According to the World Health Organization (WHO), hypertension
in adults is defined as a rise in blood pressure levels above normal limits
characterized by systolic blood pressure equal to or above 140mmHg and /or
diastolic blood equal to or above 90mmHg[1]. In children, the
National High Blood Pressure Education Program Working Group (NHBPEP) defined
hypertension in children as either systolic and/or diastolic blood pressure =
95th percentile measured on three or more
occasions''[2,3].
WHO estimates that, approximately 40% of adults aged 25 are
diagnosed as having hypertension; the number of people with the condition rose
from 600million in 1980 to 1 billion in 2008[1,4]. In
children, the prevalence as reported by various studies, ranges from 5.4% to
19.4%-'-''[2,5-8] with an increase in trends in the last two
decades.
Globally, cardiovascular disease accounts for approximately
17million deaths a year, nearly one third of the total[9]. Of
these, complications of hypertension account for 9.4million deaths every
year---------[10]. Several studies have provided evidence that
hypertension in adults has its origin from
childhood--'''''''''''''''-'[11-13].
Public health implications of hypertension in children are
overwhelming because many of these individuals will eventually face medical
sequelae in adulthood when undiagnosed, which can lead to death and
cardiovascular disability due to target organ damage: Left Ventricular
Hypertrophy (LVH), thickening of carotid vascular wall, retinal vascular
damage, kidney damage, cognitive impairment and death in worst
cases'-[6,7,12,14,15].
Overweight and obesity are strongly correlated risk factors to
primary hypertension in children-'[7,13,16-18]. Family history
of hypertension or cardiovascular disease, male sex, maternal smoking during
pregnancy and race(to a lower extent) are additional risk
factors[16,18]. In the same light, renal parenchymal disease
and renovascular diseases account for most cases of secondary hypertension
predominant in children and adolescents as compared to
adults[16,17].
According to the Task Force recommendations on blood pressure
control in children, every child 3 years and older should have his/her Blood
Pressure (BP) measured on every healthy/sick visit. This will lead to early
diagnosis and identification of those at risk is an important strategy for
public health control and prevention of cardiovascular
diseases[19].
In America, 65% of hypertensive children identified were
referred to a clinic for history of elevated blood pressure, amongst which, 43%
had essential hypertension and 57% had secondary hypertension. Those with
essential hypertension had a significantly older age at diagnosis and stronger
family history of hypertension[14].
Amritanshu et al in India in 2015, showed a prevalence of 4.7%
in children and adolescents aged 5 to 19 years of life which was significantly
associated with family history of hypertension, type of diet, and additional
salt intake and showed a gradual increase over age[20].
In Africa, particularly in urban Sudan, the prevalence of
hypertension in children was 4.9% and obesity was found out to be strongly
associated with hypertension in primary school children-[21].
Ugwuja et al in 2015 in a rural Agrarian community in Southeast Nigeria found a
prevalence of 23.2% and, showed that the age, the consumption of red meat, body
mass index and the number of children in the family were associated with
hypertension, in patients aged 18years and above[22]. For Okoh
Ba et al in 2012 in Nigeria, the prevalence of hypertension in primary school
children was 4.7% and a higher BMI was demonstrated significantly associated
with a higher prevalence of hypertension[23].
In Cameroon, studies carried out Bertoua, Yaounde and Buea
revealed that the prevalence among school children varied between 2.2 - 3.2%
and strongly associated with overweight but no significant association with
family history of
HTN-''''''''''''''''''''''''''''''''''''''''''''''''''''''`'''''''''''''[24-26].
A few studies on blood pressure in school children in the
Centre region were done in Yaounde, an urban setting and none in the rural
areas. We thus decided to undertake this study in the Mbankomo subdivision, a
rural area in theMefou and Akono division, in the Centre Region, to see
thetrends of high blood pressure in school children and assess the factors
which influence its occurrence in this setting.
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