The Role of Physical Activity Level and B-Vitamin Status on Blood Homocysteine Levels

• Autores: Lanae M. Joubert, Melinda M. Manore
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 40, Nº. 11, 2008, págs. 1923-1931
• Idioma: inglés
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• Resumen

  • Exercise increases methionine metabolism, which also increases its amino acid metabolic intermediate, homocysteine (Hcy). High Hcy levels increase cardiovascular disease (CVD) risk, whereas B-vitamins (folate, vitamins B6, and B12) can reduce Hcy. Research exploring the relationship between exercise and Hcy is equivocal.

    Purpose: To determine whether plasma Hcy values, independent of plasma B-vitamin concentrations, are higher in active (HighPA; >420 min[middle dot]wk-1) than less active (LowPA; <=420 min[middle dot]wk-1) males (M = 38) and females (F = 38).

    Methods: Subjects were healthy, young (26 +/- 5 yr), used no B-vitamin supplements in last 30 d, and reported being physically active for the last 5 yr. Physical activity (PA) groups were based on moderate- to high-intensity PA (min[middle dot]wk-1) using 7-d PA records. Dietary intakes of B-vitamins were assessed using 7-d weighed food records. The differences of Hcy between PA and gender were examined using ANCOVA, with plasma B-vitamins as covariates.

    Results: Mean PA was 220 min[middle dot]wk-1 for LowPA (n = 36; V[spacing dot above]O2max = 42.8 +/- 8.8 mL[middle dot]kg-1[middle dot]min-1) and 652 min[middle dot]wk-1 for HighPA (n = 40; V[spacing dot above]O2max = 54.2 +/- 9.7 mL[middle dot]kg-1[middle dot]min-1). Hcy ([mu]mol[middle dot]L-1) was not different between PA levels (LowPA = 7.5 +/- 1.6; HighPA = 7.7 +/- 1.6, P = 0.36) or sex (M = 7.8 +/- 1.7; F = 7.4 +/- 1.1; P = 0.13). Plasma folate was the only significant covariate (P<0.001). However, secondary analysis revealed that Hcy levels were significantly higher in the most active and fit (ExHighPA; range = 758-1085 min[middle dot]wk-1; n = 11; >90% V[spacing dot above]O2max) compared with the sedentary ones (ExLowPA; range = 9-130 min[middle dot]wk-1; n = 9; <70% V[spacing dot above]O2max; 8.6 +/- 1.8 vs 6.7 +/- 1.5 [mu]mol[middle dot]L-1; P = 0.007, respectively).

    Conclusion: Hcy, independent of plasma B-vitamin levels, was not different between PA levels in nonsupplementing young adults, unless PA was high (>758 min[middle dot]wk-1).