Ethnic in SSA and CVD in SSA, 1-s2.0-s00194832).

Ethnic Variation in
Hypertension Prevalence in Nigeria: The Implication of MicroRNA

The prevalence of non-communicable
diseases (NCDs) otherwise known as chronic diseases has been on the increase
with an estimated annual world mortality rate of about 40 million (1) with greater
mortality seen in low- and middle-income countries (LMICs) (2). Although
communicable diseases are currently the leading cause of death in sub-Saharan
Africa, NCDs has been projected to take the lead by 2030 (ncds-africa-policy)
accounting for about 46% death (ab). Some of the diseases classified under the NCDs
category include cardiovascular disease, cancers, chronic respiratory diseases
and diabetes.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

Although the different
diseases classified under the NCD contributes significantly to the overall
mortality rate, cardiovascular disease (CVD) accounts for more than 55% of
total death from NCDs and the leading cause of death globally except in Africa
(aa). CVD including coronary heart disease and stroke is one of the major global
public health concern with an estimation of about 17.7 million death in 2015
(1). Meanwhile, more than 75% of death from CVD occur in Low- and middle-income
countries (1), increasing health care costs with resultant negative impact on
the poverty reduction initiatives in these countries (4).

While CVDs prevalence
has been on the increase in LMICs, it has been on the decrease in high income
and developed countries. These increasing risks has been attributed to four
major risk factors which include tobacco use, physical inactivity, harmful use
of alcohol and unhealthy diets (http://www.who.int/ncds/introduction/en/)
that lead to four metabolic/physiological changes that include raised blood
pressure, glucose and cholesterol including overweight/obesity with these risks
being responsible for more than 90% of the CVDs (10 of CVD in SSA and CVD in
SSA, 1-s2.0-s00194832).

Hypertension and raised
high blood pressure has been identified as the major risk factor for CVD
including heart diseases and stroke (www.cdc.gov/dhdsp/data) and the leading
risk for death and disability (http://www.thelancet.com/pdfs/journals/landia/PIIS2213-8587(15)00319-8.pdf)
with an estimated global death rate of about 9.4 million per year (Norvatis).
About one billion people worldwide are currently living with hypertension with
a projection of about 1.56 billion adults in 2025 (ac). It kills nearly 8
million people yearly (ac). Africa is the most affected continent in the world
with more than 40% of the adult population in many African countries estimated
to have raised blood pressure (http://www.who.int/mediacentre/news/releases/2012/world_health_statistics_20120516/en/).
Estimating from the population standpoint of more than 170 million Nigerians,
more than 68 million people will be affected placing Nigeria as one of the most
affected countries of the world.

In Nigeria, a wide
variation range in adult hypertension ranging from 2.1% to 47.2% has been
reported (PlosOne_HBP). These wide variations have been blamed on some factors
including ethnicity. Ethnicity has been identified as an important factor in
the observed differences in BP prevalence, management and control (ethnic diff
in BP control). Even differing responses to antihypertensive medications have
been attributed to ethnic implications. Several studies have investigated the
implications of this ethnic difference in order to explain the observed
variation in blood pressure mortality and morbidity. In Suriname, high blood
pressure was observed between the ethnic groups in the country similar to what
was observed in Nigeria with the Suriname study concluding on the need for
ethnic specific research, prevention and intervension programme on blood
pressure (ethnicity suriname).

In Kenya, hypertension
was high among Kikuyus compared to Kalenjins and this was not adjusted with
socio-demographic variables and other CVD risk markers (ethnicity Kenya)

Meanwhile, genetic and
gene expression differences have been observed in different ethnic populations.
These gene expression are been regulated by microRNAs (miRNAs). miRNAs are
non-coding small RNAs that are significantly involved in gene expression
post-transcriptionally and they regulate about one-third of human gene
(ethnicity yoruba). miRNA are involved in RNA silencing and regulation of the
expression of target genes by attaching to the 31 untranslated region of target
mRNAs and are transcribed either by RNA from polymerase II from their own genes
or from introns. They are involved in many physiological human cell functions
and hence, the pathogenesis of various human diseases including hypertension has
been associated with their dysfunctions.

Assessing and
understanding genetic implications of the wide variation will be useful in
implementing strategies to combat this disease including drug regimen design
and use.

There are more than 250
ethnic groups in Nigeria (NPC; ICF Macro, 2009) with diverse geographical and
sociopolitical landscape which is basically divided into 6 geo-political zones.
These ethnic groups have different customs, traditions and languages that bring
them together. However, there are currently six major ethnic groups
representing six-political regions in the country. The Hausa-Fulani stands for
the Northwest, Yoruba for Southwest, Igbo for Southeast, Tiv for Northcentral,
Ijaw for Southsouth and Kanuri for Northeast.

Written by