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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 3, May/June 2018
AFRICA
185
mean values of Cr, BMI, SBP, DBP, TC, TG, HDL-C, LDL-C
and prevalence of CVRFs are shown in Table 1. The prevalence
of carotid plaque among the study participants was 16.1%, and
87 (53.7%) of the subjects had increased CIMT (
≥
0.9 mm).
Mean values of CIMT were significantly increased with
advancing age and in subjects with individual CVRFs compared
with subjects without CVRFs (
p
<
0.05) (Table 2). CIMT was
however not significantly different between male and female
subjects. There was a significant association between increased
CIMT and other traditional CVRFs (Table 3). However, age
≥
50 years, hypertension, obesity, dyslipidaemia and alcohol
intake remained independently associated with increased odds
of increased CIMT (Table 3).
CP was associated with age
≥
50 years (
p
<
0.001), obesity (
p
=
0.002), hypertension (
p
<
0.001) and dyslipidaemia (
p
=
0.001)
(Table 4). Age
≥
50 years and hypertension were the independent
predictors of increased odds of CP (Table 4). Mean values of
CIMT increased with increasing number of CVRFs, as shown
in Fig 1.
Discussion
The commonest traditional CVRFs besides age (51.2% of study
sample were
≥
50 years in age) in this study were dyslipidaemia
(68.5%), hypertension (49.4%) and obesity (34.2%). Previous
studies in Nigeria have sought to describe the prevalence of
CVRFs in different populations, such as hypertensives, diabetics,
and elderly and apparently healthy adult Nigerians.
Similar to our results, Akintunde
et al.
,
14
in a cross-sectional
study in the south-western region of Nigeria among apparently
healthy university staff aged 27 to 73 years, with a mean age of
45.27
±
7.87 years, found dyslipidaemia (49.5%), generalised
obesity (44.7%) and hypertension (40.8%) to be the most
prevalent CVRFs in their study population. Another population-
based cross-sectional study by Sani
et al
.
15
in the north-western
region of Nigeria among 300 apparently healthy Nigerians
between 18 and 75 years, with mean age of 37.6
±
10.6
years, found dyslipidaemia (28.3%), hypertension (25.7%) and
generalised obesity (21.3%) most prevalent.
Despite our study being hospital-based among subjects with
CVRFs, the commonest traditional risk factors in our study are
similar to these two non-hospital-based studies among apparently
healthy adult Nigerians. From these reports and ours, it appears
that dyslipidaemia, hypertension and obesity rank highest in
frequency among traditional CVRFs in Nigeria. This requires
confirmation in larger population studies. The differences in
CVRF frequencies between our study and other Nigerian
studies may be due to age differences, lifestyle and environmental
factors, as well as differences in clinical characteristics.
In our study, more than half of the subjects (53.7%) had
increased CIMT (
≥
0.9 mm) and one in six (16.1%) had CP.
Even though each of our study subjects had at least one CVRF,
46.3% of them still had CIMT within normal limits. A possible
explanation for this finding is that the subjects with normal
CIMT values probably had had risk factors for a shorter time,
since CIMT has been shown to worsen with longer exposure to
CVRFs.
16
Table 1. Clinical, laboratory and anthropometric
characteristics of the study sample
Variables
Statistics
Age (years) (mean
±
SD)
51.96
±
15.09
BMI (kg/m
2
) (mean
±
SD)
27.98
±
5.59
Gender (male),
n
(%)
80 (49.4)
SBP (mmHg) (mean
±
SD)
141.27
±
29.95
DBP (mmHg) (mean
±
SD)
89.49
±
21.00
FBS (mmol/l) (median (Q1–Q3)
4.00 (3.80–5.53)
Cr (µmol/l) (mean
±
SD)
100.13
±
24.26
TC (mmol/l) (mean
±
SD)
5.34
±
1.25
TG (mmol/l) (median (Q1–Q3)
1.96 (1.50–3.61)
HDL-C (mmol/l) (mean
±
SD)
1.23
±
0.31
LDL-C (mmol/l) (mean
±
SD)
3.59
±
1.03
Age
≥
50 years,
n
(%)
83 (51.2)
Hypertension,
n
(%)
80 (49.4)
Diabetes mellitus,
n
(%)
45 (27.8)
Dyslipidaemia,
n
(%)
111 (68.5)
Obesity,
n
(%)
56 (34.6)
Alcohol,
n
(%)
45 (27.8)
Smoking,
n
(%)
25 (15.4)
Chronic kidney disease
n
(%)
32 (19.8)
CIMT (mm) (median (Q1–Q3)
1.10 (0.70–1.40)
Increased CIMT,
n
(%)
87 (53.7)
Presence of plaque,
n
(%)
26 (16.1)
BMI: body mass index, SBP: systolic blood pressure, DBP: diastolic blood
pressure, FBS: fasting blood sugar, Cr: serum creatinine, TC: serum total
cholesterol, TG: serum triglycerides, HDL-C: serum high-density lipoprotein
cholesterol, LDL-C: serum low-density lipoprotein cholesterol, CIMT: carotid
intima–media thickness, SD: standard deviation, CVRFs: cardiovascular risk
factors.
Table 2. Mean CIMT by CVRFs
Risk factors
No of cases,
total
=
162
CIMT (mean
±
SD)
(mm)
p
-value
Age (years)
<
40
41
0.75
±
0.23
<
0.001
41–50
42
1.08
±
0.43
51–60
30
1.20
±
0.34
61–70
24
1.23
±
0.33
>
70
25
1.10
±
0.32
Gender
Male
80
1.12
±
0.40
0.574
Female
82
1.08
±
0.42
Smoking
Present
25
1.26
±
0.30
0.038
Absent
137
1.07
±
0.43
Hypertension
Present
80
1.34
±
0.32
<
0.001
Absent
82
0.87
±
0.36
Diabetes
Present
45
1.26
±
0.36
0.003
Absent
116
1.04
±
0.42
Dyslipidaemia
Present
111
1.23
±
0.41
<
0.001
Absent
51
0.81
±
0.24
Alcohol
Present
45
1.31
±
0.37
<
0.001
Absent
117
1.02
±
0.40
CKD
Present
130
1.25
±
0.40
0.027
Absent
32
1.07
±
0.41
Obesity
Present
56
1.34
±
0.39
<
0.001
Absent
106
0.98
±
0.37
CIMT: carotid intima–media thickness, CVRFs: cardiovascular risk factors,
CKD: chronic kidney disease.