Effect of genistein supplementation on metabolic indicators and oxidative stress in postmenopausal women with type-2 diabetes mellitus: Randomized Control Clinical Trial

Abstract

Background: Type 2 diabetes is the most common metabolic disorder characterized by an increase in blood glucose levels. Decreased ovarian function and estrogen deficiency during menopause play an important role in the development of metabolic disorders in postmenopausal women. Isoflavones in some foods such as soy can play an important role in reducing the risk of cardiovascular disease and type 2 diabetes. Genistein is the most abundant soy isoflavones. The aim of this study was to evaluate the effects of genistein supplementation on blood glucose indices, lipid profile and oxidative stress status in postmenopausal women with type 2 diabetes. Methods: This randomized, double-blind, placebo-controlled clinical trial was conducted on 54 postmenopausal women with T2DM. The selected patients were randomly assigned to experimental and control groups with matched on body mass index (BMI) and age. Written consent was obtained from all participants at the beginning of the study. Information about demographic characteristics, physical activity levels, and dietary intake of subjects were gathered for all subjects. Anthropometric measurements including weight, height, BMI, waist circumference, hip circumference, and waist to hip ratio were assessed, and blood samples were collected for biochemical measurements at baseline and at the end of the study. Patients in the intervention group (n=30) received two capsules per day each containing 54 mg genistein for 12 weeks. The control group (n=30) received two placebo capsules per day for a similar duration. Questionnaires and measurements were performed again at the end of the study. Assessment of dietary intake was also repeated in the middle and at the end of the study. Data analysis was performed using SPSS-22 software. Independent t-test, paired t-test, Mann-whitney U-test, chi-squared test and covariance analysis were used to analyze the data. P < 0.05 was considered to be significant. Results: Genistein supplementation significantly reduced serum levels of fasting blood glucose, hemoglobin A1C, serum triglyceride and malondialdehyde and increased total antioxidant capacity compared to the placebo group at the end of the study (P < 0.05, for all). Serum high density lipoprotein-cholesterol and quantitative insulin sensitivity check indices significantly increased within genistein group. Changes in anthropometric indices and other variables were not significant in any of the groups. Conclusion: The results of this study showed that genistein supplementation had favorable effects on some glycemic indexes, serum lipid profile and antioxidant status in studied subjects, and may be useful in the management of metabolic status in postmenopausal women with T2DM.