CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 7, August 2013
AFRICA
265
Association of homocysteinaemia with hyperglycaemia,
dyslipidaemia, hypertension and obesity
DUDU SENGWAYO, MPHO MORABA, SHIRLEY MOTAUNG
Abstract
Aim:
Hyperhomocysteinaemia and the metabolic syndrome
are associated with increased cardiovascular risk. We inves-
tigated whether there is a link between the metabolic
syndrome or its components and homocysteine levels in a
population without cardiovascular disease.
Methods:
From the population sample of 382 participants
(286 females and 96 males) we isolated those reflecting the
metabolic syndrome and determined their homocysteine
levels. We then evaluated the association of homocysteine
with hyperglycaemia, hypertriglyceridaemia, hypercholester-
olaemia, hypertension and obesity, using a significance level
of
p
=
0.05. Enzymatic methods were used for all biochemical
parameters.
Results:
We found the statistical relationship between homo-
cysteine and the metabolic syndrome as follows: hyper-
glycaemia (
p
=
0.175), hypertriglyceridaemia (
p
=
0.442),
hypercholesterolaemia (
p
=
0.480), obesity (
p
=
0.080); and
hypertension: systolic pressure (
p
=
0.002) and diastolic pres-
sure (
p
=
0.033).
Conclusion:
We found no statistically significant association
between baseline plasma homocysteine levels and the meta-
bolic syndrome, except for hypertension.
Keywords:
hyperglycaemia, hypertriglyceridaemia, hypercho-
lesterolaemia, hypertension, obesity, homocysteine
Submitted 17/4/13, accepted 14/8/13
Cardiovasc J Afr
2013;
24
: 265–269
DOI: 10.5830/CVJA-2013-059
Diabetes mellitus is a group of metabolic diseases characterised
by hyperglycaemia, resulting from defects in insulin secretion,
insulin action or both. It is associated with several cardiovascular
disorders, including angiopathy and platelet hyperactivity, which
are major causes of morbidity and mortality in type 2 diabetes
mellitus.
1
Atherosclerosis is substantially more prevalent and
progresses rapidly in diabetes mellitus.
2
There are an estimated 23.6 million people in the USA (7.8%
of the population) with diabetes.
1
The vascular complication
of diabetes mellitus, at its earliest stage, is manifested as
endothelial dysfunction,
3
decreasing the bioavailability of nitric
oxide, which protects blood vessels from endogenous injuries.
4
Hyperglycaemia inhibits fibrinolysis by decreasing the activity
of plasminogen activator and enhances coagulation by activating
procoagulants into thrombosis.
5
Homocysteine is an amino acid derived from methionine.
The latter is an intermediate in the conversion of homocysteine
to cysteine. Homocysteine is metabolised via two pathways:
remethylation, in which homocysteine is converted into
methionine, and transulphuration, in which homocysteine is
converted into cysteine. In the former pathway, homocysteine
acquires a methyl group, either from the conversion of
5-methyltetrahydrofolate into hydrofolate or from the conversion
of betaine into the N
′
N-dimethylglycine.
6
Vitamins B
12
and B
6
are important in the conversion of 5-methyltetrahydrofolate into
hydrofolate and therefore for the remethylation pathway and the
metabolism of homocysteine into methionine.
7
Epidemiological studies suggest hyperhomocysteinaemia to
be an independent risk factor for developing atherothrombotic
vascular disease.
8
Mechanisms by which hyperhomocysteinaemia
causes vascular disease include promotion of atherosclerosis by
damaging the inner lining of arteries and promoting thrombosis
through pathological collagen activation of the intrinsic pathway,
9
impairment of thrombolysis, increased production of hydrogen
peroxide, endothelial dysfunction, and increased oxidation of
low-density lipoproteins.
8
Some of the complications of arterial thrombosis following
hyperhomocysteinaemia include coronary heart disease,
myocardial infarction, stroke, peripheral vascular disease,
miscarriage, pulmonary embolism, retinal embolism and neural
tube defect (spina bifida).
9
The homocysteine level may be
increased in hypertensive, overweight and obese subjects.
10
Homocysteine is thought to help regulate glucose metabolism
and insulin absorption.
11
Homocysteine has been suggested to
contribute to the atherosclerotic process of diabetes mellitus.
High homocysteine levels have been reported in diabetic
patients,
2,12
and elevated levels are a strong risk factor in these
patients.
1
The elevation occurs particularly in patients with type
2 diabetes, as well as in individuals in prediabetic states who
exhibit insulin resistance.
13
The levels of homocysteine in such
individuals are also influenced by their insulin concentrations,
and therapy with insulin and medications such as metformin and
glitazones that can either raise or lower homocysteine levels.
12
The effect of hyperhomocysteinaemia on diabetes and
insulin resistance has been reported with unclear synergism.
12
Homocysteine levels have been reported as either low or elevated
compared to non-diabetic subjects, reflecting the potential role of
homocysteine in the development of macro- and microvascular
disease in diabetic patients.
13,1
Shaikh
et al
. found that 58% of
their diabetic participants had elevated homocysteine levels and
males were predominant in this group.
1
This finding is consistent
with that of Schalinske’s study.
14
These authors reported a strong association between
atherosclerosis, hyperhomocysteinaemia and type 2
Department of Medical Science, Health Public and Health
Promotion, School of Health Sciences, Faculty of Health
Sciences, University of Limpopo (Turfloop Campus),
Sovenga, South Africa
MPHO MORABA, DTech
Department of Biomedical Sciences, Faculty of Science,
Tshwane University of Technology, Pretoria, South Africa
DUDU SENGWAYO, MTech
SHIRLEY MOTAUNG, DTech,
