Effect of soy protein-rich diet on renal function in young adults with insulin-dependent diabetes mellitus.
BACKGROUND
Diabetic nephropathy is the most frequent cause of end-stage renal disease in the Western world. Dietary intake, including protein amount and type, seems to affect the progression of renal disease. This pilot study tested the hypothesis that substituting soy protein for animal protein in the diets of diabetics would help correct glomerular hyperfiltration.


METHODS
Twelve young adults (aged 29.9 +/- 2.4 years) with type 1 diabetes mellitus (duration of diabetes 15.1 +/- 2.3 years) and hyperfiltration (glomerular filtration rate, GFR > 120 ml/min/1.73 m2) completed a crossover, dietary intervention trial. After a four-week assessment of baseline characteristics and dietary habits, subjects were assigned to either a control or soy diet for eight weeks after which each subject was crossed over to the alternative diet for another eight-week period.


RESULTS
Mean GFR was significantly reduced (p < 0.02) after eight weeks on the soy diet (143 +/- 7.4 ml/min/1.73 m2) compared with baseline (159 +/- 7.7 ml/min/ 1.73 m2) and control diets (161 +/- 10.0 ml/min/1.73 m2). Urinary excretion of the soy isoflavones was significantly higher (p < 0.01) at the end of the soy diet (genistein 1,014.6 +/- 274.1 nmol/h, daidzein 2,645.1 +/- 989.6 nmol/h) compared with baseline (genistein 53.7 +/- 31.1 nmol/h, daidzein 151.1 +/- 74.1 nmol/h) and control diets (genistein 41.1 +/- 13.3 nmol/h, daidzein 127.5 +/- 54.0 nmol/h). The soy diet significantly reduced total and LDL cholesterol by 7% and 9%, respectively.


CONCLUSIONS
Implementation of a soy-based diet appears to reduce the GFR and total and LDL cholesterol of young adults with type 1 diabetes and glomerular hyperfiltration, thus affecting positively their clinical profile.
Stephenson
T J
TJ
Division of Nutritional Science, College of Agriculture, University of Kentucky, USA.
Setchell
K D R
KD
Kendall
C W C
CW
Jenkins
D J A
DJ
Anderson
J W
JW
Fanti
P
P
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D008078:Cholesterol, LDL / Q000187:drug effects; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000178:diet therapy*; D003928:Diabetic Nephropathies / Q000000981:diagnostic imaging / Q000178:diet therapy*; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011877:Radionuclide Imaging; D030262:Soybean Proteins / Q000008:administration & dosage*; D016896:Treatment Outcome
D008078:Cholesterol, LDL; D030262:Soybean Proteins