Background: In the past 37 years, increased efforts have been directed toward a better understanding of the importance of Hcy in disease and it has now become clear that hyperhomocysteinemia is a major independent risk factor for CVD. Extensive research on the influence of vitamin supplementation leading to reductions in Hcy levels and improvements in cardiovascular function has been done. The importance of exercise in the lowering of cardiovascular risk factors, as well as its favourable influence on cardiovascular function has also been indicated in
several studies, however, the limited number of studies investigating the effect of exercise on
Hcy concentrations revealed contradicting results. Furthermore, a relationship between Hcy
concentration and cardiovascular function with the intervention of an exercise training and a
vitamin supplementation programme respectively has also not been investigated.
Objective: The objective of this study was to examine the effect of a 12-week exercise training and a
12-week vitamin supplementation intervention respectively on tHcy concentrations and
cardiovascular function, and whether the change in tHcy concentration within the different
interventions correlated with the change in cardiovascular function.
Methods: In a randomised controlled cross-over intervention study, 52 men matched for age, cardiorespiratory
fitness levels and cardiovascular risk factors were randomly assigned to one of 3
groups (Group A = exercise training programme, 20-30min. at 70-80% of HRmax; Group B = 400
g folic acid and 25 g vitamin B12 supplement; Group C = control). Group A and B were
crossed over for phase 11, and Group C remained the control. The questionnaires were
completed, and the body composition variables (BMI, WHR and body fat percentage),
cardiovascular function (Finometer), tHcy concentrations and VO2max, were measured before and
after each 12-week intervention period. A 6-week washout period separated the crossovers. Results: The ANCOVA, adjusted for age and BMI, showed that the percentage change from baseline to
end, corrected for baseline of the tHcy concentration increased significantly (p ≤ .05) by 9.7%
with the exercise training intervention and decreased significantly (p ≤ .05) by 12.9%, with the
vitamin supplementation intervention. The ANCOVA of the percentage change from baseline to
end in cardiovascular function showed that the vitamin supplementation intervention resulted in
improvements in cardiovascular function (decreased resting MAP, TPR and increased resting
SV, CO, Cw) in comparison to the impairment in cardiovascular function with the exercise
training intervention (increased resting DBP, MAP and TPR). The relationship between the
tHcy concentration and cardiovascular function at baseline and within each of the different
interventions were assessed by partial correlations adjusted for age, BMI and VO2max.
Significant (p ≤ .05) relationships only occurred within the vitamin supplementation
intervention, where decreased percentage change in tHcy concentration significantly correlated
with increased percentage change of resting SV and CO and decreased percentage change of
resting TPR.
Conclusion: The general conclusion that can be drawn is that a 12-week vitamin supplementation intervention
showed increased health related results, e.g. a significant reduction in tHcy concentration, an
improvement in cardiovascular function and a significant positive relationship between these b o
factors, in comparison to the 12-week exercise training intervention that significantly increased
the tHcy concentration and did not show increased health related results. Due to inadequate
compliance to the exercise training intervention, no conclusion can be drawn with regard to the
effect of exercise training on tHcy concentrations and cardiovascular function. / Thesis (M.Sc. (Human Movement Science))--North-West University, Potchefstroom Campus, 2007
| Identifer | oai:union.ndltd.org:NWUBOLOKA1/oai:dspace.nwu.ac.za:10394/1365 |
| Date | January 2006 |
| Creators | Nel, Rumada |
| Publisher | North-West University |
| Source Sets | North-West University |
| Detected Language | English |
| Type | Thesis |
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