Variable effects of soy protein on plasma lipids in hyperlipidemic and normolipidemic hemodialysis patients.
BACKGROUND
Hyperlipidemic factors contribute to the high cardiovascular risk in hemodialysis patients. Soy protein has decreased some atherogenic lipid concentrations in subjects with normal renal function. This study evaluates the effect of soy protein on serum lipid profiles in hyperlipidemic and normolipidemic hemodialysis patients.


METHODS
Nineteen hyperlipidemic and 18 normolipidemic hemodialysis patients were enrolled in a randomized, double-blind, placebo-controlled, clinical trial. After a 4-week run-in phase, subjects in each category were randomly assigned to 2 groups. Thirty grams of isolated soy protein or milk protein was consumed daily as a beverage at breakfast or postdialysis for 12 weeks.


RESULTS
In hyperlipidemic subjects, soy protein intake significantly decreased total cholesterol levels by 18.6% (95% confidence interval [CI], -11.4 to -25.8; P = 0.04), triglyceride levels by 43.1% (95% CI, -34.0 to -52.2; P = 0.02), non-high-density lipoprotein cholesterol levels by 23.6% (95% CI, -14.7 to -32.5; P < 0.01), apolipoprotein B levels by 15.4% (95% CI, -5.4 to -25.4; P = 0.01), and insulin levels by 49.8% (95% CI, -23.3 to -66.1; P < 0.01). Low-density lipoprotein cholesterol concentration was decreased significantly (-25.8%; 95% CI, -8.3 to -42.7; P = 0.01), and high-density lipoprotein cholesterol level was increased significantly (17%; 95% CI, 2 to 32.0; P = 0.03), but there was no significant difference compared with the milk protein group (-5.5% +/- 16.9% and 7.0% +/- 11.8%, respectively). There were no significant changes in serum lipid and lipoprotein concentrations in normolipidemic subjects.


CONCLUSIONS
These results indicate soy protein substitution has lipid-lowering effects in hyperlipidemic hemodialysis patients. However, soy protein intake had little effect on plasma lipid levels in normolipidemic hemodialysis patients.
Chen
Shu-Tzu
ST
Department of Nutrition and Health Sciences, Taipei Medical University, Cathay General Hospital, Taipei, Taiwan.
Ferng
Shyang-Hwa
SH
Yang
Chwei-Shiun
CS
Peng
Sheng-Jeng
SJ
Lee
Huei-Rong
HR
Chen
Jiun-Rong
JR
D000368:Aged; D001055:Apolipoproteins B / Q000032:analysis; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D004044:Dietary Proteins / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood / Q000150:complications / Q000178:diet therapy*; D007328:Insulin / Q000097:blood; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications* / Q000628:therapy; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D008894:Milk Proteins / Q000008:administration & dosage / Q000627:therapeutic use; D006435:Renal Dialysis; D030262:Soybean Proteins / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome; D014280:Triglycerides / Q000097:blood
D001055:Apolipoproteins B; D004044:Dietary Proteins; D007328:Insulin; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008894:Milk Proteins; D030262:Soybean Proteins; D014280:Triglycerides; D002784:Cholesterol