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VOLUME 13 NUMBER 1 • JULY 2016
13
SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
The metabolic syndrome among newly diagnosed non-
diabetic hypertensive Nigerians: prevalence and clinical
correlates
Adeseye A Akintunde, OE Ayodele, P Olayinka Akinwusi, JO Peter, OG Opadijo
Correspondence to: Dr Adeseye A Akintunde
Division of Cardiology, Department of Internal Medicine, Ladoke Akintola
University of Technology Teaching Hospital, Osogbo, Nigeria
Cardiology Unit, Eberhard Karls University, Tübingen, Germany
e-mail:
iakintunde2@yahoo.comOlugbenga E Ayodele, Olayinka Akinwusi, JO Peter, George Opadijo
Division of Cardiology, Department of Internal Medicine, Ladoke Akintola
University of Technology Teaching Hospital, Osogbo, Nigeria
S Afr J Diabetes Vasc Dis
2016;
13
: 13–16
Abstract
Background:
Hypertension is the commonest 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. There are few
reports on the prevalence of the metabolic syndrome among
hypertensives African subjects.
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 pretested data-
collection form. Fasting blood glucose and fasting serum lipid
levels were determined. The metabolic syndrome was defined
according to NCEP ATP III. Statistical analysis was performed
using SPSS 16.0. Intergroup comparisons were done using
t
-test and chi-squared tests, as appropriate.
Results:
The hypertensive and control subjects were similar in
age (55.14 ± 10.83 years vs 54.67 ± 10.89 years,
p
= 0.8) and
gender distribution [females 75 (53.6%) vs males 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 in those without it. Prevalence
of the metabolic syndrome increased with age and was more
common among female subjects.
Conclusion:
This study shows that 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. Presence of
the metabolic syndrome in hypertensive Nigerian subjects
was closely related to and influenced by demographic and
clinical factors.
Keywords:
metabolic syndrome, prevalence hypertension, Nigeria,
diabetes, impaired glucose tolerance
Introduction
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, according to published studies, ranging from seven to
20%.
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 is defined as a clustering of
components that reflects the expanding waistlines of the world’s
populations. Although there are different criteria for the definition
of the metabolic syndrome, 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
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 show that prevalence of the metabolic
syndrome 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 indicated 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 metabolic syndrome 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 metabolic syndrome were 2.88
and 2.54, respectively, and 2.55 and 1.54 in women, respectively,
using the Framingham database.
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
of three or more of five cardiovascular risk factors in the patients,
according to the National Cholesterol Education Programme Adult
Treatment Panel III (NCEP ATP III). These include fasting plasma
glucose concentration > 6.1 mmol/l, fasting plasma triglyceride
level > 150 mg/dl (1.7 mmol/l), fasting plasma high-density