RESEARCH ARTICLE
SA JOURNAL OF DIABETES & VASCULAR DISEASE
108
VOLUME 7 NUMBER 3 • SEPTEMBER 2010
Hypertensive subjects and controls were well matched in age
and gender distribution. Hypertension was diagnosed as systolic
blood pressure of
≥
140 mmHg and/or diastolic blood pressure
≥
90 mmHg taken twice after at least five minutes of rest at the clinic,
according to standardised criteria. Subjects with mild hypertension
were asked to return after two weeks for confirmation. Those with
moderate and severe hypertension (JNC 7 stage 2) were recruited
for the study immediately.
Patients with chronic kidney disease, known diabetics, those with
clinical evidence suggestive of coronary heart disease and pregnant
patients were excluded from the study. Clinical and demographic
data were taken using a structured data form.
Laboratory analyses performed included fasting plasma glucose,
urinalysis, ultrasound, fasting serum plasma lipids, electrolytes, urea
and creatinine. All subjects had 12-lead resting electrocardiography.
Patients and controls were recruited after an informed consent.
Ethical approval was obtained for the study from the Ethics Board
of LAUTECH Teaching Hospital, Osogbo, Nigeria.
Statistical analyses were performed using the Statistical Package
for Social Sciences 16.0. Quantitative variables were summarised as
means
±
standard deviation while qualitative data were summarised
using proportions and percentages. Intergroup comparison was
done using the
t
-test and chi square as appropriate;
p
<
0.05 was
taken as statistically significant.
Results
One hundred and forty hypertensive subjects and 70 controls
were recruited for this study. The mean age of the patients and
the controls was 55.14
±
10.83 years (range 23–82) and 54.67
±
10.89 years (range 35–75), respectively. There was no statistically
significant difference between the mean ages of the subjects and
controls (
p
>
0.05).
The demographic and clinical parameters of the study participants
are shown in Table 1. When compared with control subjects, the
hypertensive subjects had a higher mean systolic blood pressure
(147.18
±
26.47 vs 115.06
±
13.11 mmHg,
p
<
0.005), diastolic
blood pressure (89.25
±
17.04 vs 70.96
±
9.67 mmHg,
p
<
0.005),
pulse pressure (57.93
±
24.38 vs 44.75
±
10.25 mmHg) and fasting
plasma glucose (5.6
±
1.9 vs 4.0
±
1.3 mmol/l,
p
<
0.005) although
the mean fasting plasma glucose levels were both within normal
limits. Also, the waist circumference of the hypertensive subjects
was significantly higher than the controls (93.89
±
11.96 vs 83.82
±
9.0 cm,
p
<
0.05).
Table 2 shows the biochemical profile of the study population.
The hypertensive subjects had significantly higher mean fasting
plasma glucose levels (5.6
±
1.9 vs 4.0
±
1.3 mmol/l,
p
<
0.05).
The lipid profile analysis of the study population is shown in
Table 2. Hypertensive subjects had a significantly lower HDL-C
compared to control subjects (1.06
±
0.36 vs 1.29
±
0.46 mmol/l,
p
<
0.05). Although mean total cholesterol, low-density lipoprotein
cholesterol (LDL-C) and triglyceride levels were higher among
hypertensive subjects than controls, they were not statistically
significant.
Hypertensive subjects with the metabolic syndrome were older
and were more likely to be female than those without the MS. They
also had a higher body mass index, systolic blood pressure, fasting
plasma glucose level and increased prevalence of left ventricular
hypertrophy, as shown in Table 3.
Table 4 shows that hypertension combined with obesity
and low HDL-C was the commonest pattern of combination of
cardiovascular risk factors among hypertensive subjects, followed
by a combination of hypertension, obesity and impaired glucose
tolerance.
Discussion
The frequency of occurrence of the metabolic syndrome in this
study was 31.4% in the hypertensive subjects, compared to 15.7%
in the control group. A similar report by Okpechi
et al
.
18
among
Table 2.
Biochemical parameters of the study population
Parameter
Hypertensive
subjects
(
n
=
140)
Control
subjects
(
n
=
70)
p
-value
Mean sodium (mmol/l)
135.9
±
4.7
133.7
±
2.4
>
0.05
Mean potassium (mmol/l)
3.8
±
0.5
3.1
±
0.4
<
0.05*
Mean urea (mmol/l)
5.8
±
2.2
3.2
±
1.7
>
0.05
Mean creatinine (μmol/l)
84.2
±
12.6
68.4
±
10.8
>
0.05
Mean FBS (mmol/l)
5.6
±
1.9
4.0
±
1.3
<
0.005*
Mean LDL-C (mmol/l)
2.49
±
1.41
2.35
±
0.63
>
0.05
Mean HDL-C (mmol/l)
1.06
±
0.36
1.29
±
0.46
<
0.05*
Mean TG (mmol/l)
1.33
±
0.59
1.18
±
0.41
>
0.05
Mean TC (mmol/l)
4.84
±
1.69
4.23
±
1.29
>
0.05
FBS: fasting blood sugar; LDL-C: low-density lipoprotein cholesterol; HDL-C:
high-density lipoprotein cholesterol; TG: triglycerides; TC: total cholesterol.
* Statistically significant.
Table 1.
Clinical and demographic parameters of study participants
Parameters
Hypertensive
subjects
(
n
=
140)
Control
subjects
(
n
=
70)
p
-value
Age (years)
55.14
±
10.83 54.67
±
10.89
>
0.05
Gender
Female (%)
75 (53.6)
37 (52.9)
>
0.05
Family history of diabetes
mellitus
5
7
>
0.05
Mean WC (cm)
Male
92.5
±
13.4
84.0
±
7.3
<
0.005*
Female
94.3
±
11.5
84.6
±
10.7
<
0.005*
Mean HC (cm)
100.15
±
11.63 92.79
±
9.92
>
0.05
Mean WHR
0.94
±
0.082 0.91
±
0.054
>
0.05
Mean BMI (kg/m
2
)
26.89
±
5.31 23.86
±
3.46
>
0.05
Mean SBP (mmHg)
147.18
±
26.47 115.06
±
13.11
<
0.005*
Mean DBP (mmHg)
89.25
±
17.04 70.96
±
9.67
<
0.005*
Mean PP (mmHg)
57.93
±
24.38 44.75
±
10.25
<
0.005*
WHR: waist–hip ratio, BMI: body mass index, SBP: systolic blood pressure,
DBP: diastolic blood pressure, PP: pulse pressure, HC: hip circumference.
* Statistically significant.
