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SA JOURNAL OF DIABETES & VASCULAR DISEASE
RESEARCH ARTICLE
VOLUME 14 NUMBER 1 • JULY 2017
33
Association of homocysteinaemia with hyperglycaemia,
dyslipidaemia, hypertension and obesity
DUDU SENGWAYO, MPHO MORABA, SHIRLEY MOTAUNG
Correspondence to: Shirley Motaung
Dudu Sengwayo
Department of Biomedical Sciences, Faculty of Science, Tshwane University of
Technology, Pretoria, South Africa
e-mail:
motaungsckm@tut.ac.zaMpho Moraba
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
Previously published in
Cardiovasc J Afr
2013;
24
: 265–269
S Afr J Diabetes Vasc Dis
2017;
14
: 33–37
Abstract
Aim:
Hyperhomocysteinaemia and the metabolic syndrome
are associated with increased cardiovascular risk. We
investigated 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 homo-
cysteine levels. We then evaluated the association of
homocysteine with hyperglycaemia, hypertriglyceridaemia,
hypercholesterolaemia, 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
homocysteine and the metabolic syndrome as follows:
hyperglycaemia (
p
= 0.175), hypertriglyceridaemia (
p
=
0.442), hypercholesterolaemia (p = 0.480), obesity (
p
= 0.080);
and hypertension: systolic pressure (
p
= 0.002) and diastolic
pressure (
p
= 0.033).
Conclusion:
We found no statistically significant association
between baseline plasma homocysteine levels and the
metabolic syndrome, except for hypertension.
Keywords:
hyperglycaemia, hypertriglyceridaemia, hypercholes-
terolaemia, hypertension, obesity, homocysteine
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 embolismand 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