Effects of soy consumption on oxidative stress, blood homocysteine, coagulation factors, and phosphorus in peritoneal dialysis patients.

OBJECTIVE

We studied the effects of soy consumption on oxidative stress, blood homocysteine, coagulation factors, and phosphorus in peritoneal dialysis patients.

DESIGN

This was an unblinded, randomized clinical trial.

SETTING

This study involved peritoneal dialysis centers in Tehran, Iran.

PATIENTS

We included 40 peritoneal dialysis patients (20 males and 20 females).

INTERVENTION

Peritoneal dialysis patients were randomly assigned to either a soy or control group. Patients in the soy group received 28 g/day textured soy flour (containing 14 g of soy protein) for 8 weeks, whereas patients in the control group received their usual diet, without any soy.

MAIN OUTCOME MEASURES

Blood oxidized low-density lipoprotein (ox-LDL), homocysteine, phosphorus, fibrinogen concentrations, and the activities of coagulation factors VII, IX, and X were measured at baseline and at the end of week 8 of the study.

RESULTS

The percentage of plasma coagulation factor IX activity decreased significantly by 17% in the soy group at the end of week 8 compared with baseline (P < .01), and the reduction was significant compared with the control group (P < .05). There were no significant differences between the two groups in mean changes of blood ox-LDL, homocysteine, phosphorus, fibrinogen concentrations, and the activities of coagulation factors VII and X.

CONCLUSION

Soy consumption reduces plasma coagulation factor IX activity, which is a risk factor for thrombosis in peritoneal dialysis patients.