title: The effects of soy protein on chronic kidney disease: a meta-analysis of randomized controlled trials.
abstract: OBJECTIVE
  There is a growing body of evidence to indicate that soy protein consumption may have a beneficial effect on kidney function. We performed a meta-analysis to evaluate the effects of soy protein consumption compared with animal protein consumption in patients with pre-dialysis chronic kidney disease (CKD).
  
  
  METHODS
  We conducted a structured electronic search of the databases PubMed, EMBASE, Cochrane Library and Chinese Biological Medicine for randomized controlled trials published up to March 2014. The outcome measures were serum creatinine (SCR), triglyceride (TG), total cholesterol (TC), calcium (Ca) and phosphorus concentrations. Weighted or standard mean differences were calculated for net changes using random-effects models.
  
  
  RESULTS
  The meta-analysis consisted of nine trials, comprising 197 subjects. Soy protein intake significantly reduced SCR and serum phosphorus concentrations. The mean difference was -6.231 μmol/l (95% confidence interval (CI): -11.109, -1.352 μmol/l) for SCR (P=0.012) and -0.804 (95% CI: -1.143, -0.464 μmol/l) for serum phosphorus (P=0.00). It also significantly reduced serum TG, with a pooled estimated change of -0.223 mmol/l (95% CI: -0.396, -0.051 mmol/l; P=0.011) after the exclusion of one trial indicated by sensitivity analyses. No statistically significant effects were observed for TC (-0.135 mmol/l (95% CI: -0.289, 0.019 mmol/l)) or Ca (0.023 mmol/l (95% CI: -0.016, 0.062 mmol/l)).
  
  
  CONCLUSIONS
  The meta-analysis suggested a protective effect of soy protein consumption on SCR and serum phosphorus concentrations in pre-dialysis CKD patients. It may also have a significant effect on lowering serum TG concentrations. However, nonsignificant effects on TC and Ca were observed. Evidence was limited because of the relatively small number of available trials and subjects.
authors.affiliation: Department of Nutrition, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Nutrition, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Nutrition, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: J
authors.initials: J
authors.lastname: Su
authors.affiliation: Department of Nutrition, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: F
authors.initials: F
authors.lastname: Tian
mesh_terms: D003404:Creatinine / Q000097:blood*; D004044:Dietary Proteins / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007668:Kidney / Q000187:drug effects*; D010758:Phosphorus / Q000097:blood*; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000178:diet therapy*; D030262:Soybean Proteins / Q000494:pharmacology / Q000627:therapeutic use*; D013025:Glycine max / Q000737:chemistry*; D014280:Triglycerides / Q000097:blood
chemical_list: D004044:Dietary Proteins; D030262:Soybean Proteins; D014280:Triglycerides; D010758:Phosphorus; D003404:Creatinine