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.