Effect of weight reduction on concentration of plasma total homocysteine in obese Japanese men

Objective: To test whether weight reduction would lower tHcys concentration, and whether adding exercise training to dietary weight reduction would further reduce tHcys concentration over diet alone. Design: A randomized, controlled, prospective, 14-week weight-loss intervention. Setting and participants: Forty-eight obese Japanese men aged 27-66 years were assigned to 2 subgroups depending on the type of treatment: diet alone (DA) and diet plus exercise training (DE). Concentration of tHcy was measured in frozen plasma samples by an HPLC method. Results: Body weight decreased significantly for both groups: DA -7.8 +/- 3.2 kg and DE -9.1 +/- 3.6 kg. A significant decrease was found in tHcys concentration of the DE group (-2.3 +/- 5.0 mu mol/L) but not of the DA (-0.3 +/- 2.7 mu mol/L). For subjects with hyperhomocysteinemia (>= 15 mu mol/L, n=17), tHcys concentration decreased from 20.1 +/- 7.0 to 13.9 +/- 3.0 mu mol/L (p<0.01) for the DE group (n = 8) but did not change for the DA group (16.6 +/- 1.9 mu mol/L -> 15.4 +/- 2.3 mu mol/L, n=9). Furthermore, to consider a statistical phenomenon "regression to the mean", we excluded two subjects with the highest two tHcys values of the DE group. The DE group (n=7) still displayed a significant reduction after the exclusion. Conclusions: A weight reduction with diet alone did not improve tHcy levels. Adding aerobic exercise training to a dietary weight-reduction program may be effective for a reduction in tHcy. (C) 2007 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.