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

Summary 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 μmol/L) but not of the DA (−0.3 ± 2.7 μmol/L). For subjects with hyperhomocysteinemia (≥15 μmol/L, n = 17), tHcys concentration decreased from 20.1 ± 7.0 to 13.9 ± 3.0 μmol/L ( p < 0.01) for the DE group ( n = 8) but did not change for the DA group (16.6 ± 1.9 μmol/L → 15.4 ± 2.3 μmol/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.