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RESEARCH ARTICLE
SA JOURNAL OF DIABETES & VASCULAR DISEASE
54
VOLUME 14 NUMBER 2 • DECEMBER 2017
and Nigeria.
20
These differences could be accounted for by the
differences in study types (hospital based vs community based) and
also geographical variations in the populations studied. However,
the high prevalence of IFG among the participants is significant, as
this represents a group of individuals at increased risk for transition
to higher cardiovascular risk and the eventual development
of diabetes if not properly controlled with lifestyle and dietary
modifications.
Recent publications have highlighted the rapidly increasing
prevalence of hypertension, coupled with under-diagnosis,
undertreatment and low control rates in SSA.
4,20,21
The high
prevalence of hypertension in our hospital-based study and the fact
that 25.8%of these patients were newly diagnosed or undiagnosed
cases is therefore not surprising. The situation was similar with
diabetes mellitus, with an overall prevalence of 15.7%, with 6.9%
being undiagnosed cases, as previously described.
22
In a recent meta-analysis that focused on the burden of
hypertension in Africa,
4
the pooled prevalence was 30%. Our
prevalence is equivalent to the highest prevalence of 70% in
the pooled studies. Another recent population-based study in
Cameroon
21
reported a prevalence of 47.5%, which was lower
than reported in our cohort.
The CLARIFY registry, which explored geographical variations
in cardiovascular risk factors among coronary artery disease (CAD)
patients, reported a high prevalence of hypertension of 48% in
Eastern Europe.
23
The differences observed in these studies and
others could be due to differences in populations studied and
methodologies employed. Previous regional-based studies using
similar methodology to ours are non-existent, therefore limiting the
possibility for adequate comparison.
The high prevalence of diabetes in our study (15.7%) was
slightly below the 17% noted among CAD patients in Eastern
Europe but far lower than the 60% in the Middle East.
23
While
we acknowledge the dearth of African regional data on diabetes,
some national studies are worth noting. The highest prevalence of
diabetes among participating countries was from Nigeria, with a
prevalence rate of 24.8%. This was lower than the 28.2% noted
in a community-based study in South Africa,
19
but higher than the
10.1% reported in a self-selected population study in Cameroon.
22
Variations in degree of urbanisation, and differences in lifestyle,
environmental factors and study settings (population vs hospital
based) as well as sample sizes most likely account for the differences
seen in these studies.
Overall mean BMI of our study participants was 28.5 kg/m
2
,
which was higher than reported in Benin,
8
although it was lower
than reported in Ghana among hypertensive subjects.
17
About one
in three of the study participants was overweight or obese. This is
likely to be explained by the increasing adoption ofWestern lifestyles,
especially in urban areas (which were in the majority in our study),
limited physical activity and increased sedentary lifestyles, which
are wrongly attributed to good living. Similarly, a high prevalence of
obesity has been reported in other parts of Africa,
8,17,24
in relation to
urbanisation and high socio-economic status.
25
A community-based
study in Cameroon by Fezeu and colleagues in 2010 demonstrated
the influence of ethnicity and urbanisation on abdominal adiposity
and obesityrelated abnormalities.
26
A quarter of participants reported excessive alcohol consumption,
and approximately one in five was either a current or former smoker.
This is similar to the 19% smoking prevalence reported in Eastern
Europe.
23
These are well-established drivers for CVD,
27
metabolic
and other NCDs and most likely account in part for the high rates
of hypertension, diabetes and obesity in our cohort. Our findings
are supported by a recent meta-analysis of prospective studies on
the association of alcohol consumption and CVD risk and mortality,
where it was found that low-to-moderate alcohol consumption
was inversely significantly associated with the risk of CVD and all-
cause mortality among hypertensive patients.
27
Risk profiles of the participants were examined according to
hypertension status. A high prevalence of diabetes (17.7%) was
noted among the hypertensive subjects, compared to 10% in
non-hypertensives. This was half that reported in Ghana among
hypertensive subjects,
17
although higher than the 13.5% reported
in Cameroon.
28
Hypertensive patients were also more likely to
be overweight and obese than non-hypertensive subjects, with
prevalence rates of 33.1 and 42.8%, compared to 30.5 and 16.8%,
respectively.
All other studied risk factors, such as hypercholesterolaemia,
abdominal adiposity (WC > 88 cm for women and 102 cm for men),
and excessive alcohol consumption were more prevalent among
hypertensive subjects, except for smoking. The high prevalence
of cardiometabolic risk factors reported in our study is similar to
reports by Akintunde
et al
. among university staff in Nigeria.
20
Besides factors such as a high-salt diet, low physical activity and
high socio-economic status (not examined in our study), these are
established risk factors for hypertension, which in itself is a major
risk for CVD. Urbanisation, among other determinants, has largely
been queried.
8,19,29
Our study showed that all risk factors studied were most
prevalent among participants with diabetes. About three out of four
diabetic subjects had hypertension. Other studies have reported a
high prevalence of high blood pressure among diabetic subjects in
Table 4.
Risk factors according to diabetes status in the study partici-
pants
Non-
Diabetes diabetes Total
Variable
n
(%)
n
(%)
n
(%)
p
-value
Tobacco smoking (
n
= 834)
Current
07 (5.3)
66 (9.4) 73 (10.6)
Former
19 (14.4) 54 (7.9) 73 (10.6) 0.019
Never
106 (80.3) 582 (82.7) 688 (78.8)
Alcohol consumption (
n
= 308)
Low to moderate
30 (69.7) 199 (75.0) 229 (75.1) 0.456
Excessive
13 (30.2) 66 (25.0) 79 (24.9)
Obesity (
n
= 839)
Normal
37 (28.0) 228 (32.2) 265 (31.6)
Overweight
42 (31.8) 228 (32.2) 270 (32.2) 0.462
Obese
44 (33.3) 222 (31.6) 266 (31.7)
Morbidly obese
09 (6.9)
29 (4.0)
38 (4.5)
Waist circumference
Men (> 102 cm) (
n
= 359)
10 (29.4) 85 (26.1) 95 (26.4) 0.685
Women (> 88 cm) (
n
= 478) 29 (76.3) 319 (72.5) 348 (72.8) 0.706
Hypertension (n = 839)
Yes
110 (83.3) 509 (71.9) 619 (73.7) 0.007
No
22 (16.7) 198 (28.1) 220 (26.3)
Hypercholesterolaemia (
n
= 809)
Yes
15 (22.1) 161 (21.7) 176 (21.8) 0.949
No
53 (77.9) 580 (78.3) 633 (78.2)
Diabetics = participants with diabetes mellitus; non-diabetics = participants
without diabetes mellitus;
p
-values = comparison of variables between both
groups.