Objective: Isoflavones and exercise have been shown to affect C-reactive protein (CRP) and body composition and to act synergistically on trunk and total fat mass (FM), glucose metabolism, and lean body mass in postmenopausal women with a body mass index higher than 25 kg/m2. We hypothesized that exercise and isoflavone supplementation (Ex + ISO) could reduce inflammation in the same subpopulation of women. The objective of this study was to investigate if 6 months of mixed exercise combined with isoflavones could have greater effects on specific inflammatory markers than exercise alone in overweight or obese postmenopausal women.
Methods: Thirty-four postmenopausal women aged 50 to 70 years were randomly assigned to exercise and placebo (Ex + PLA; n = 15) or Ex + ISO (n = 19). At baseline and after 6 months, waist circumference, hip circumference, total FM, trunk FM, leg FM, and muscle mass index (MMI; = total fat free mass [kg] / height2 [m]) were assessed (dual-energy x-ray absorptiometry). Inflammatory markers (CRP, tumor necrosis factor-α [TNF-α], and interleukin-6) were obtained by enzyme-linked immunosorbent assay. T tests were used to compare groups at baseline.
Results: The Ex + PLA group showed significant changes in MMI (+0.33 kg/m2, P ≤ 0.009) and FM compartments (waist circumference, −5.13 cm; % FM, −1.31%; P ≤ 0.001), whereas inflammation remained unchanged. However, the Ex + ISO group showed significant changes in total FM (−1.70 kg, P < 0.0001), FM compartments (hip circumference [−2.51 cm, P = 0.019], leg FM [−1.16 kg, P = 0.037], and trunk FM [−0.72 kg, P = 0.006]), MMI (+0.39 kg, P = 0.011), and inflammation (CRP, −1.14 mg/L, P = 0.029; TNF-α, +0.29 pg/mL, P = 0.010).
Conclusions: Despite an increase in TNF-α, the use of isoflavones—when body weight remains stable—seems to enhance the beneficial effects of mixed-exercise training on body composition and CRP in overweight or obese postmenopausal women.
From the 1Research Center on Aging, 2Faculty of Physical Education and Sports, and 3Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Québec, Canada.
Received September 9, 2013; revised and accepted October 30, 2013.
I.J.D. had full access to all data, is the guarantor of this work, and takes full responsibility for the integrity of the data and the accuracy of data analysis. J.L. wrote the manuscript and researched and analyzed the data. E.R. contributed to data collection and revised the manuscript. D.T. collaborated on study design and data collection and revised the manuscript.
Funding/support: I.J.D. and E.R. were supported by the Canadian Institutes of Health Research. I.J.D. and J.L. were supported by Fond de la Recherche en Santé du Quebec. The study was supported by the Canadian Institutes of Health Research.
Financial disclosure/conflicts of interest: None reported.
Address correspondence to: Isabelle J. Dionne, PhD, Research Center on Aging, 1036 Belvédère Sud, Sherbrooke, Québec, Canada J1H 4C4. E-mail: isabelle.dionne@USherbrooke.ca