CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 7, August 2013
268
AFRICA
medication.
12
Control of these confounding factors in our study
may have improved the level of association.
We determined homocysteine levels in 39 hypertriglycerid-
aemic and 38 hypercholesterolaemic subjects. No statistically
significant association was found between homocysteine and
hypertriglyceridaemia (
p
=
0.442) and hypercholesterolaemia
(
p
=
0.480) (Table 2). Three hypertriglyceridaemic subjects had
hyperhomocysteinaemia (7.7%)while five hypercholesterolaemic
subjects had hyperhomocysteinaemia (13.1%) (Table 3). The
insignificant association was supported by the findings of Vayá
et al
.
15
However, Nabipour
et al
. found significant associations
between lower HDL cholesterol and high homocysteine levels.
20
Homocysteine levels were estimated in 72 subjects with
high systolic blood pressure and 84 subjects with high
diastolic blood pressure, a total of 156 hypertensive subjects.
Homocysteine was statistically significantly associated with
both systolic (
p
=
0.002) and diastolic (
p
=
0.033) blood
pressure (Table 2). Eleven hypersystolic subjects (15.3%)
were hyperhomocysteinaemic while 16 hyperdiastolic
subjects (19%) were hyperhomocysteinaemic (Table 3). These
findings are supported by various researchers, who found
hyperhomocysteinaemia to be significantly associated with
hypertension.
10,20-22
The association of homocysteine with hypertension may be
due to the fact that homocysteine induces arteriolar constriction,
renal dysfunction and increased sodium absorption, with
increased arteriolar stiffness.
18
It increases oxidative stress, which
causes oxidative injury to the vascular endothelium, diminishing
vasodilation by nitric oxide. It also stimulates the proliferation of
vascular smooth muscle cells and alters the elastic properties of
the vascular wall, leading to an increase in hypertension.
18
On the basis of our findings, the large body of supporting
evidence and the mechanisms of association, homocysteine levels
can be used to track blood pressure. Hyperhomocysteinaemia
reflects a causal effect rather than being concomitant to elevated
blood pressure.
In our present study we evaluated 95 obese subjects for
homocysteine association with obesity. We found a borderline
association (
p
=
0.080) (Table 2). Ten obese subjects were
hyperhomocysteinaemic (Table 3). The association was partly
supported by other researchers, who found increased prevalence
of hyperhomocysteinaemia in obese subjects.
10,15,36
Depending
on age and the pattern of obesity, homocysteine may be
significantly associated with obesity. This viewpoint is supported
by the findings of Vayá
et al
.
15
and El-Sammak
et al
.
37
Conclusion
We found no statistically significant relationship between baseline
plasma homocysteine levels and hyperglycaemia, dyslipidaemia
and obesity. There was, however, a significant relationship
between homocysteine levels and hypertension. According to our
cross-sectional study, high baseline plasma homocysteine level
is a major risk factor for hypertension and can be used in blood
pressure tracking in a large, community-based sample. The study
supported the hypothesis that plasma homocysteine is casually
related to elevated blood pressure.
Additional prospective investigations are recommended to
confirm these findings. A study evaluating the association
between plasma homocysteine levels and hyperglycaemia after
a few days of treatment withdrawal would probably yield better
and more reliable results. Unfortunately, withdrawing treatment
from diabetic subjects may be risky, especially in those with high
glucose levels. We plan in future to compare homomocysteine
levels between participants with and without the metabolic
syndrome.
We thank the Tshwane University of Technology and the University of
Limpopo (Turfloop campus) for financial assistance.
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TABLE 3. PREVALENCE OF HYPERHOMOCYSTEINAEMIA
WITH HYPERGLYCAEMIA, HYPERTRIGLYCERIDAEMIA,
HYPERCHOLESTEROLAEMIA, HYPERTENSIONAND OBESITY
Hyperhomocystein-
aemia
Metabolic disorder
Prevalence rate
(%)
n
=
3
Hyperglycaemia (
n
=
45)
6.7
n
=
3
Hypertriglyceridaemia (
n
=
39)
7.7
n
=
5
Hypercholesterolaemia (
n
=
38)
13.1
n
=
11
Systolic blood pressure (
n
=
72)
15.3
n
=
16
Diastolic blood pressure (
n
=
84)
19.0
n
=
10
Obesity (
n
=
95)
10.5
Prevalence of hyperhomocysteinaemia = number of hyperhomocysteinae-
mic subjects per number of subjects in the respective components of the
metabolic syndrome.
