SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
VOLUME 7 NUMBER 3 • SEPTEMBER 2010
107
Metabolic syndrome among newly diagnosed non-diabetic
hypertensive Nigerians: prevalence and clinical correlates
AA Akintunde, OE Ayodele, PO Akinwusi, JO Peter, OG Opadijo
Abstract
B
ackground:
Hypertension is the most common
cardiovascular risk factor worldwide. Clustering of
cardiovascular risk factors has been noted to increase
the risk of developing type 2 diabetes mellitus and
cardiovascular diseases. Reports of the metabolic syndrome
among African hypertensive subjects are scarce.
Methods:
One hundred and forty newly diagnosed
hypertensive subjects and 70 apparently healthy controls
were recruited consecutively for this study. Demographic
and clinical parameters were assessed using a pre-tested
data-collection form. Fasting blood sugar and fasting serum
lipid level were determined. The metabolic syndrome was
defined according to NCEP ATP III criteria. Statistical analyses
were performed using SPSS 16.0. Intergroup comparisons
were done using the
t
-test and chi square as appropriate.
Results:
Hypertensive and control subjects were similar in
age (55.14
±
10.83 vs 54.67
±
10.89 years,
p
=
0.8) and gender
distribution [female 75 (53.6%) vs male 37 (52.9%),
p
=
0.3].
The metabolic syndrome was diagnosed in 44 (31.4%) of the
hypertensive subjects and 11 (15.7%) of the controls. Systolic
blood pressure, body mass index and prevalence of left
ventricular hypertrophy were higher among subjects with
the metabolic syndrome than those without it. Prevalence of
the metabolic syndrome increased with age and was more
common among female subjects.
Conclusion:
This study showed that the prevalence of the
metabolic syndrome was high among newly diagnosed
hypertensive subjects in Osogbo, Nigeria. It was however
lower than that described among many Caucasian
populations. The presence of the metabolic syndrome in
Nigerian hypertensive subjects is closely related to and
influenced by demographic and clinical factors.
Keywords:
metabolic syndrome, prevalence hypertension, Nigeria,
diabetes, impaired glucose tolerance
Systemic hypertension affects about one billion people and
accounts for about 7.1 million deaths per year worldwide.
1
It is the
commonest non-communicable disease in Nigeria with prevalence
rates ranging from seven to 20%, according to published
studies.
2-4
Hypertension is commonly associated with many other
cardiovascular risk factors such as obesity, dyslipidaemia, impaired
glucose tolerance (or hyperglycaemia) and hyperuricaemia.
5-9
The metabolic syndrome (MS) is defined as a clustering of
components that reflects the expanding waistlines of the world.
Although there are different criteria for the definition of the MS as
recommended by the various working groups, the core components
of the syndrome, which include increased waist circumference,
impaired glucose tolerance, dyslipidaemia and hypertension,
are commonly required by the various groups for diagnosis.
10
The prevalence of the metabolic syndrome varies in different
populations and is influenced by race, gender, differing socio-
economic status, work-related activities and cultural views on body
fat.
10
Reported prevalence rates in different countries vary between
two and 66.9%.
10
Reports also showed that the prevalence of the
MS is increasing to epidemic proportions, not only in the USA and
other developed countries but also in developing nations.
10
The clustering of cardiovascular risk factors is associated with
increased risk of the development of cardiovascular diseases (CVD),
such as coronary heart disease (CHD) and stroke, as well as an
increase in all-cause mortality. The metabolic syndrome has been
shown to predict the development of diabetes. Various studies
have demonstrated that the presence of multiple risk factors
confers greater risk than a single factor.
11-16
In the Kuopio Ischaemic
Heart Disease Risk Factor study, Finnish men without CVD were
followed up for approximately 11 years, and those with the MS
were three to four times more likely to die of CHD, 2.6 to three
times more likely to die of CVD and twice as likely to die from
all causes.
12
The age-adjusted relative risks for CVD and CHD in
men with the MS were 2.88 and 2.54, respectively, and 2.55 and
1.54 in women, respectively, using the Framingham data base.
13
Information on the prevalence of the metabolic syndrome among
Nigerian hypertensive subjects is scarce.
Methods
The metabolic syndrome was defined in this study as the presence
in patients of three or more of five cardiovascular risk factors,
according to the National Cholesterol Education Programme
Adult Treatment Panel III criteria. These include fasting plasma
glucose
>
6.1 mmol/l, fasting plasma triglycerides
>
150 mg/dl (1.7
mmol/l), fasting plasma high-density lipoprotein cholesterol (HDL-
C) levels for men
<
1.04 mmol/l, fasting plasma HDL-C levels for
women
<
1.29 mmol/l, blood pressure
≥
130/85 mmHg and waist
circumference for men
>
102 cm and for women
>
88 cm.
17
This was a cross sectional study and 140 newly diagnosed,
non-diabetic, hypertensive subjects and 70 normotensive controls
were recruited consecutively from the cardiology clinic of LAUTECH
Teaching Hospital, Osogbo, Nigeria. Control subjects were patients’
relatives and hospital staff who voluntarily gave their consent to
participate in the study.
Correspondence to: Adeseye A Akintunde
Department of Medicine, Cardiology Unit, Eberhard Karls’ University,
Tübingen, Germany
Tel: +49 15227790146
e-mail:
AA Akintunde, OE Ayodele, PO Akinwusi, JO Peter, OG Opadijo
Department of Internal Medicine, Division of Cardiology, Ladoke Akintola
University of Technology Teaching Hospital, Osogbo, Nigeria
S Afr J Diabetes Vasc Dis
2010;
7
: 107–110
