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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 3, May/June 2017
148
AFRICA
Ethical approval was obtained from the ethics committees of
the participating countries and the patients gave written consent
before enrollment. The study complied with the Declaration of
Helsinki.
Data were collected simultaneously in all study centres of
the participating countries, using a standardised case report
form (CRF). The following variables were collected: socio-
demographic characteristics (age, gender, educational level,
alcohol consumption, tobacco use and employment type),
history of hypertension, diabetes status and systolic and diastolic
blood pressure (BP, in mmHg).
BP was measured using an automated BP machine (Omron
750 IT) in the seated position after the participant had been
at rest for five to 10 minutes. Three measurements were taken
on the right arm and the average of the last two was retained.
12
Weight, height, and waist and hip circumference were measured
using standard procedures and equipment following WHO
guidelines.
13
Weight was measured to the nearest 0.5 kg and
height to the nearest 0.5 cm. Body mass index (BMI, kg/m
2
) was
calculated as body weight in kg divided by the square of the
height in metres. The waist circumference (WC) was measured
with a tape midway between the lower rib margin and iliac crest.
Waist-to-hip ratio was calculated as waist circumference (cm)
divided by hip circumference (cm).
Fasting capillary glucose concentration was obtained using
a standardised glucometer (Accu-chek Aviva; Hoffmann-
LA Roche, Ltd, Germany) in all the settings. Fasting total
cholesterol, high-density lipoprotein (HDL-C) and low-density
lipoprotein cholesterol (LDL-C), triglycerides, uric acid and
serum creatinine concentrations were acquired using locally
available routine standard techniques and procedures.
Hypertension was diagnosed in the presence of systolic or
diastolic blood pressure
≥
140 or 90 mmHg or ongoing blood
pressure-lowering medications over the past 15 consecutive days.
Uncontrolled hypertension was defined as blood pressure
≥
140/90 mmHg in participants on BP control agents for the last 30
consecutive days. Duration of hypertension was defined as date
of survey minus date of diagnosis of hypertension.
Hyperglycaemia was defined as fasting capillary glucose
level
≥
6.1 mmol/l (110 mg/l) and diabetes was defined as
fasting capillary glucose level
≥
7.1 mmol/l (126 mg/dl) or
physician-documented history of diabetes, or patient on glucose-
controlling agents (oral or insulin) for the last 15 consecutive
days. Impaired fasting glycaemia was defined as fasting capillary
glucose levels between 6.1 and 7.1 mmol/l (110–126 mg/dl).
Overweight and obesity were defined using BMI and WHO
criteria,
14
i.e. normal: 18.5 kg/m
2
≤
BMI
≤
24.99 kg/m
2
; overweight:
25 kg/m
2
≤
BMI
≤
29.99 kg/m
2
; obesity: 30 kg/m
2
≤
BMI
≤
39.99
kg/m
2
, morbid obesity: BMI
≥
40 kg/m
2
. Hypercholesterolaemia
was defined as a total cholesterol level
>
5.18 mmol/l.
The metabolic syndrome (MS) was defined according to the
International Diabetes Federation (IDF) consensus criteria:
15
central obesity plus any two of the following: raised triglyceride
levels
≥
150 mg/dl (1.7 mmol/l) or specific treatment for this lipid
abnormality, reduced HDL-C
<
40 mg/dl (1.03 mmol/l) in men
and
<
50 mg/dl (1.29 mmol/l) in women or specific treatment for
this lipid abnormality, raised blood pressure (
≥
130/85 mmHg) or
treatment of previously diagnosed hypertension, raised fasting
plasma glucose level
≥
100 mg/dl (5.6 mmol/l) or previously
diagnosed type 2 diabetes.
15
Increased waist circumference was defined as
>
102 cm
for men and
>
88 cm for women. With a BMI
>
30 kg/m
2
,
central obesity was assumed without measurement of waist
circumference.
15
Alcohol consumption was categorised as low-to-moderate
consumption (less than or equal to one local beer daily for women
and two local beers for men) and excessive consumption (more
than two local beers daily).
16
Smoking status was determined as
current smokers, former smokers (having smoked in the past
but having stopped for two or more weeks prior to the survey,
however, those who had stopped within two weeks of the survey
were considered current smokers), and never smoked.
Statistical analysis
Data analysis was done using the Statistical Package for
Social Sciences (SSPS Inc, Chicago, IL) software version 20.0.
Categorical variables were summarised as counts and percentages
while continuous variables were summarised as means, median,
standard deviation (SD) and percentiles where appropriate.
Group comparisons used the chi-squared or Fisher’s exact tests
for categorical variables, and the Student
t
-test for continuous
variables. A
p
-value
<
0.05 was considered statistically significant.
Results
Table 1 shows the general characteristics of the study population.
A total of 844 adults (57.4% were women and overall mean age
was 52.6
±
11.6 years) were included in the study, among whom
154 and 216, respectively, were from Cameroon and Nigeria, 240
from the DRC and 240 from Madagascar. The majority (76.6%)
of the study participants were urban dwellers. The men were
more likely to be employed and to be educated than the women
(both
p
<
0.001). The women were more likely to be overweight,
obese or morbidly obese than the men (
p
<
0.001). The men had
a significantly higher mean triglyceride levels than the women
(2.9 vs 2.2 mmol/l;
p
=
0.019) and lower mean HDL-C levels (1.6
vs 1.8 mmol/l;
p
=
0.004). Men also had higher mean normal
values of serum creatinine (90.8 vs 75.7
µ
mol/l,
p
<
0.001) and
uric acid (295.0 vs 233.2
µ
mol/l,
p
<
0.001) than the women. Men
and women had similar mean systolic (149.5 vs 149.5 mmHg)
and diastolic (91.9 vs 90.6 mmHg) blood pressures, respectively.
The overall prevalence of hypertension [previously aware/
diagnosed (48.1%) and newly diagnosed (26%)] was 74.1%
[Cameroon (91.5%), Nigeria (66.8%), DRC (99.1%) and
Madagascar (45.0%)]. The overall prevalence of diabetes in
the study was 15.7% and ranged from 24.8% in Nigeria, 15.6%
in Cameroon and 15.0% in DRC, to 8.7% in Madagascar (
p
=
0.003). Excessive alcohol consumption was reported in 25.6%
of study participants, with the highest prevalence in Cameroon
(36.6%), and the lowest in Nigeria, where all participants
reported low-to-moderate consumption (
p
=
0.007).
Of the study participants, 17.3% were either current or
former smokers. A significant difference (
p
<
0.001) in prevalence
of smoking across the countries was noted, with the highest
prevalence in Madagascar (32.9%), followed by Cameroon
(13%), then DRC (10.9%), and Nigeria (10.0%) being the lowest.
Of the study participants, 32.3 and 36.3%were overweight and
obese (obesity 31.8%), or morbidly obese (4.5%), respectively.
Overweight was highest in Madagascar (39.2%) and lowest in