Effect of exercise training and isoflavones on hepatic steatosis in overweight postmenopausal women

ABSTRACT

Objectives Postmenopausal women are particularly inclined to an increased risk of developing non-alcoholic hepatic steatosis. The purpose of this study was to investigate whether adding isoflavone supplementation to exercise training could reduce the risk.

Methods In a 6-month, double-blind, randomized, controlled trial, 54 healthy overweight-to-obese (body mass index 28–40 kg/m2) postmenopausal women were randomly assigned to one of the following groups: (1) exercise and isoflavones (Ex-Iso; n = 26), (2) exercise and placebo (Ex-Pla; n = 28). Exercise training consisted of three weekly sessions of mixed training. We examined the plasma level of specific hepatic enzymes (alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, and alkaline phosphatase) as a reflection of fatty liver along with the calculation of the fatty liver index. All measures were obtained at baseline and after the 6-month intervention.

Results Following the intervention, a lower fatty liver index (p <0.01; 29% in Ex-Iso, 18% in Ex-Pla) and plasma γ-glutamyltransferase (p <0.01; 22% in Ex-Iso, 16% in Ex-Pla) were observed in both groups, with a higher reduction in the Ex-Iso group. On the other hand, for all other hepatic enzymes, there was no change.

Conclusions Our results show that exercise training appears to bring favorable changes in the plasma level of hepatic enzymes, possibly due to the lowering of liver fat content. While postmenopausal women can benefit from this intervention to decrease the risk of developing non-alcoholic hepatic steatosis, it seems that the addition of isoflavones to exercise training provides some additional effects to those provided by exercise alone.

Key words::

• NON-ALCOHOLIC FATTY LIVER DISEASE
• PHYTOESTROGENS
• HEPATIC ENZYMES
• ESTROGENS
• MIXED EXERCISE TRAINING
• MENOPAUSE

ACKNOWLEDGEMENTS

We thank all the participants in the present study, with very special thanks to Martine Fisch (Research nurse), Karine Perreaut (Research coordinator), and all kinesiologists supervising the exercise training protocol for their valuable professional assistance. The contributions of the authors are as follows: Razieh Barsalani (conception, study design, data analysis, data interpretation and manuscript preparation), Éleonor Riesco (manuscript revision and data analysis), Jean-Marc Lavoie (manuscript revision) and Isabelle J. Dionne (study design and manuscript revision). All authors approved the final version for publication.

Conflict of interest The authors report no conflict of interest. The authors alone are responsible for the content and writing of this paper.

Source of funding This work was supported by grants from Canadian Institute of Health Research (CIHR).