Effects of soy consumption on serum lipid and apoprotein levels in peritoneal dialysis patients

Lipid abnormalities, especially high serum Lp(a) concentration, is one of the major causes of cardiovascular diseases in peritoneal dialysis patients. The present study was designed to investigate the effects of soy consumption on serum lipid and apoprotein levels in peritoneal dialysis patients.

The study was a randomized clinical trial in which 40 peritoneal dialysis patients (20 males and 20 females) were randomly assigned to either a soy or a control diet. The patients in the soy group received 28 g/d textured soy flour (containing 14 g soy protein) for 12 weeks, while the patients in the control group consumed their usual diet without any soy. At the baseline and at the end of the period, from each patient 5 ml blood were collected after a 12- to 14-hour fast and serum triglyceride, total cholesterol, HDL-C, LDL-C, apoAI, apoB100, Lp(a), TNF-α, albumin, and phosphorus measured.

The serum Lp(a) concentration in more than 86% of the peritoneal dialysis patients was above the normal range. As compared to the baseline value, the mean serum Lp(a) concentration decreased significantly by 41% (P<0.01) in the soy group at the end of 8-week period, and the reduction was significant as compared to the control group (P<0.05). The mean serum Lp(a) concentration did not change significantly in the control group. There were no significant differences between the 2 groups with regard to mean changes in the serum triglyceride, total cholesterol, HDL-C, LDL-C, apoB100, apoAI, TNF-α, albumin or phosphorus levels.

The results of the present study indicate that soy consumption reduces serum Lp(a) concentration considerably in peritoneal dialysis patients. Therefore, it may be effective in preventing cardiovascular diseases in these patients.