Appetitive hormones, but not isoflavone tablets, influence overall and central adiposity in healthy postmenopausal women.
OBJECTIVE
One of the multiple health benefits of soy protein or its isoflavones may be their purported favorable effect on body composition. We examined the effect of isoflavones extracted from soy protein on overall and regional body composition, taking into account appetitive hormones as potential mediators, as well as the direct effect on appetitive hormones.


METHODS
This randomized, double-blind, placebo-controlled multicenter trial included 229 healthy postmenopausal women (age, 45.8-65 y; body mass index, 24.9 +/- 3.0 kg/m) who consumed placebo or soy isoflavone (80 or 120 mg/d) tablets for 12 months. We used intent-to-treat analysis to examine changes in body composition (whole-body lean mass, whole-body fat mass, androidal fat mass, and androidal-to-gynoidal fat mass ratio) and appetitive hormones (insulin, leptin, ghrelin, and adiponectin) in response to treatment.


RESULTS
Repeated-measures analysis of variance indicated that soy isoflavone treatment did not exert a significant effect on body composition measures (P value from 0.36 to 0.79) or appetitive hormone concentrations; the inclusion of covariates in statistical models did not alter these results. Independently of treatment, leptin and ghrelin related inversely to each body composition measure (P values from 0.044 to < or = 0.0001). Adiponectin related inversely to all fat measures (P values from 0.0004 to <0.0001). Time since last menstrual period related directly to all fat measures (P values from 0.06 to 0.0055). Dietary fat contributed to whole-body (P = 0.028) and androidal (P = 0.017) fat mass.


CONCLUSIONS
Our findings do not support a favorable effect of soy isoflavone tablets on body composition in healthy postmenopausal women.
School of Health, Physical Education, and Leisure Services, University of Northern Iowa, Cedar Falls, IA 50614-0241, USA. : oksana.matvienko@uni.edu
Oksana A
OA
Matvienko
D Lee
DL
Alekel
Ulrike
U
Genschel
Laura
L
Ritland
Marta D
MD
Van Loan
Kenneth J
KJ
Koehler
D052242:Adiponectin / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects; D000328:Adult; D001835:Body Weight / Q000187:drug effects*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D054439:Ghrelin / Q000378:metabolism; D006304:Health Status; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007529:Isoflavones / Q000008:administration & dosage* / Q000494:pharmacology; D020738:Leptin / Q000378:metabolism; D008875:Middle Aged; D036361:Peptide Hormones / Q000378:metabolism*; D017698:Postmenopause / Q000187:drug effects / Q000378:metabolism*; D012016:Reference Values; D030262:Soybean Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D016387:Women's Health
D052242:Adiponectin; D054439:Ghrelin; D007328:Insulin; D007529:Isoflavones; D020738:Leptin; D036361:Peptide Hormones; D030262:Soybean Proteins