Motivation:
Cardiovascular disease (CVD) is one of the leading causes of mortality and morbidity
in South Africa and worldwide. Various investigations have confirmed the hypothesis
that elevated plasma homocysteine (Hcy) levels may be linked to vascular disease,
and it has become clear that hyperhomocysteinemia is an independent risk factor for
atherosclerosis and atherothrombosis. Extensive research on the influence of
vitamin supplementation leading to the lowering of homocysteine levels has been
done, but extensive research on the effect of physical activity on high homocysteine
levels is lacking. The interaction of vitamin supplementation in combination with
physical activity has also not been investigated. If a conditioning exercise programme
can demonstrate a lowering effect on elevated homocysteine levels, it will confirm the
importance of physical activity as a less expensive alternative for a better lifestyle
that can also continue to lower morbidity and mortality rates.
Objective:
This study examined the effect of a conditioning program, vitamin supplement and a
combination of both on Hcy levels in men with coronary heart disease risk factors.
Methods:
In a randomized, placebo-controlled, blinded crossover study, 84 men matched for
physical activity (PA) levels, age and risk factors were randomly assigned to one of 4
groups [A = physical conditioning, 20-30 min; 70-80% (THR), 8 = physical
conditioning + supplement, C = supplement (12,5 ug vitamin 812; 200 ug folic acid)
or D = control). Groups A, B, and C were crossed over according to the Latin square
design. Total plasma homocysteine, maximal oxygen consumption (V02max) and
body composition (BMI & Fat %) were measured before and after each 12-week
intervention period. A 6-week washout period separated the crossovers.
Results:
The experimental and control groups presented similar baseline characteristics and
the profile analysis of the V02max values and Hcy concentrations indicated positive
results (multivariate p-value <0.0001), due to the fact that the four groups repeated
measurements, presented different patterns. A phase effect for the V02max values
and a phase and interaction effect for the Hcy concentrations were indicated, though
all the subjects were requested to maintain their normal daily routine (eating pattern,
PA levels and alcohol consumption) for the duration of the study. The lack of
compliance to the conditioning programme makes it impossible to draw conclusions
for V02max values. The poor compliance lead to a small sample size that eventually
leads to less statistical power.
Conclusion:
This study found that a 12-week conditioning programme had no effect on Hcy
concentrations. The results of this study make it impossible, due to poor compliance,
to suggest that the effect of increased PA on homocysteine may play an important
role in the prevention and treatment of CVD. It is, therefore, recommended that more
studies should be conducted to further investigate the effect of PA and vitamin
supplements on tHcy levels. / Thesis (M.Sc. (Human Movement Science))--North-West University, Potchefstroom Campus, 2006.
| Identifer | oai:union.ndltd.org:NWUBOLOKA1/oai:dspace.nwu.ac.za:10394/993 |
| Date | January 2005 |
| Creators | Herbst, Sara Johanna |
| Publisher | North-West University |
| Source Sets | North-West University |
| Detected Language | English |
| Type | Thesis |
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