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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 4, July/August 2017
236
AFRICA
ingested can contribute to the development of many diseases,
including obesity and diabetes, and thereby CVD. It appears
that fatty acids could be implicated in the pathogenesis of
these diseases; either by altering the composition of membrane
phospholipids, or by modulating the expression of genes.
9
Plasma omega-3 fatty acid levels were correlated to the
eating habits in the three European countries investigated.
10
The consumption of palm oil, which is rich in saturated fatty
acids, is a well-recognised risk factor for cardiovascular and
metabolic diseases; palm oil induces a larger increase in plasma
concentrations of total cholesterol and low-density lipoprotein
cholesterol.
11
It has been suggested that a 20% increase in the tax
on palm oil in India would reduce mortality rates from CVD by
1.3% and reduce total cholesterol levels by 0.08 mmol/l without
substitution of palm oil with other oils.
12
Furthermore, if palm
oil could be substituted by an oil rich in polyunsaturated fatty
acids, total cholesterol levels would then be reduced by 0.10
mmol/l. A reduction of 0.009 mmol/l in cholesterol level has
been considered clinically significant, with a noticeably beneficial
impact on health.
13
In this context, the impact of dietary lipids on the development
of CVD represents the focus of current health concerns, not only
in economically developed countries but also in developing
countries. While eating behaviours differ between the north
and south of Cameroon, the energy intake remains comparable
between the two regions, 3 241 kcal/day in the north and 2 721
kcal/day in the south.
8
The aim of this study was therefore
to evaluate whether the risk factors for CVD are similar in
north and south Cameroonians displaying different food habits
(regarding fat intake) but characterised by equivalent average
energy intake.
Methods
This study was performed on 192 volunteers, composed of 101
women and 91 men aged 35 to 65 years. They were distributed
between 89 volunteers from the north (45 men and 44 women)
and 103 volunteers from the south (46 men and 57 women). The
volunteers answered a questionnaire concerning their lifestyle.
In addition, their anthropometrics and biochemical parameters
were measured.
This study (P2013/164) was approved by the ethics committee
of the Université Libre de Bruxelles, Erasme University Hospital
and was conducted in compliance with the Declaration of
Helsinki. All volunteers gave written informed consent before
participation.
The sample size was calculated using the following standard
formula: [
n
=
t
²
×
p
×
(1–
p
)/
m
2
] where
n
is the minimum sample
size to obtain significant results for an event and a fixed level of
risk;
t
is the confidence level (typical value of the confidence level
of 95% is 1.96);
p
is the estimated prevalence of CVD, based on
the literature (14% mortality rate due to CVD in Cameroon
14
)
and
m
is the margin of error (usually set at 5%).
Due to logistical and financial reasons, the biochemical
parameters were measured in 50 randomly selected volunteers
(25 north, 25 south, with equal numbers of men and women
from the different cities). Anthropometric and blood pressure
measurements were performed on all 192 volunteers.
All volunteers were living in the urban zone from different
cities of the south (S): Douala, Yaoundé, Bafang and Dschang;
and the north (N): Garoua and Ngaoudéré. All volunteers
belonged to the working and middle social classes. The volunteers
were randomly recruited in their home or work place.
Basic information was collected and included the following:
gender: female (F) and male (M); age: volunteers were grouped
by age: 35–50 and 51–65 years; tobacco consumption: defined
as never smoked (no); former smoker or smoker (yes); alcohol
consumption: defined as no consumption (none); consumption
once or twice a week (occasionally); consumption more
than twice a week (regularly); physical activity (sport and
professional) was defined as sport: never practice (no); practice
intense or moderate activity once or more than once a week
(yes); for profession, domestic workers, farmers and traders
were considered physically active, whereas office workers were
considered intellectual; oil consumption: the oils mostly used for
cooking were recorded.
Various anthropometric parameters were collected for all
volunteers. Height was collected from the ID card and weight
was measured using an electronic scale. Body mass index (BMI)
was calculated using the formula: weight (kg)/height
2
(m) and
BMI categories were defined as underweight with BMI
≤
18.5
kg/m
2
; normal was BMI 18.5–24.9 kg/m
2
; overweight was
BMI 25–29.9 kg/m
2
; and obese was BMI
≥
30 kg/m
2
.
15
Waist
circumference (WC) was measured with a tape measure at the
navel while standing. The recommended WC thresholds for
assessing abdominal obesity for sub-Saharan African was:
women
≥
80 cm; men
≥
94 cm.
15
Systolic and diastolic blood pressure measurements were
performed on all volunteers in a seated position at rest and
monitored for at least five minutes using an electronic medical
wrist blood pressure monitor (Omron M2 Basic; Omron
Electronics SA, Knokke-Heist, Belgium). Two measurements
were performed on each subject and the mean value was used.
Blood pressure ranges were for systolic blood pressure (SBP):
normal
<
140 mmHg, and high
≥
140 mmHg; for diastolic blood
pressure (DBP): normal
<
90 mmHg, and high
≥
90 mmHg.
16
Biochemical parameters such as blood glucose (BG), total
cholesterol (TC), high-density lipoprotein cholesterol (HDL-C)
and triglycerides (TG), were measured in 50 randomly selected
volunteers, using an equal number of men and women from
different cities, who were advised to fast prior to and up to the
time of measurement (not having eaten and/or drunk during the
last 12 or eight hours, respectively).
Disposable test strips were used with a Cardio Chek
Analyser (Polymer Technology systems Inc, Indianapolis, USA).
Low-density lipoprotein cholesterol (LDL-C) was calculated
using Fridewald’s formula: LDL-C = TC – (HDL-C + TG/5).
Blood glucose values were defined as normal
<
100 mg/dl
(5.55 mmol/l); limit 100–125 mg/dl (5.55–6.94 mmol/l); diabetic
>
125 mg/dl (
>
6.94 mmol/l).
TC ranges were defined for women as normal: 155–255 mg/
dl (4.01–6.6 mmol/l); hypocholesterolaemia:
<
155 mg/dl (
<
4.01
mmol/l) and hypercholesterolaemia: 255 mg/dl (
>
6.6 mmol/l).
TC ranges were defined for men as normal: 130–250 mg/dl
(3.37–6.48 mmol/l); hypocholesterolaemia:
<
130 mg/dl (
<
3.37
mmol/l) and hypercholesterolaemia:
>
250 mg/dl (
>
6.48 mmol/l).
HDL-C ranges were defined for women as normal: 50–92 mg/
dl (1.3–2.38 mmol/l); hypocholesterolaemia:
<
50 mg/dl (
<
1.3
mmol/l), and hypercholesterolaemia:
>
92 mg/dl (
>
2.38 mmol/l).
HDL-C ranges were defined for men as normal: 37–65 mg/