Effects of soy isoflavones on glycemic control and lipid profile in patients with type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials

Abstract

The aim of the report was to investigate the impact of soy protein and isoflavones on glucose homeostasis and lipid profile in type 2 diabetes. The studies used in this report were iden-tified by searching through the MEDLINE and EMBASE databases (up to 2020). Meta-regression and subgroup analyses were performed to explore the influence of covariates on net glycemic control and lipid changes. Weighted mean differences and 95% confidence intervals (CI) were calculated by using random-effect models. Changes in the lipid profile showed statistically signif-icant decreases in total cholesterol and LDL-C concentrations: −0.21 mmol/L; 95% CI, −0.33 to −0.09; p = 0.0008 and −0.20 mmol/L; 95% CI, −0.28 to −0.12; p < 0.0001, respectively, as well as in HDL-C (−0.02 mmol/L; 95% CI, −0.05 to 0.01; p = 0.2008 and triacylglycerols (−0.19 mmol/L; 95% CI, −0.48 to 0.09; p = 0.1884). At the same time, a meta-analysis of the included studies revealed statistically insignificant reduction in fasting glucose, insulin, HbA1c, and HOMA-IR (changes in glucose metabolism) after consumption of soy isoflavones. The observed ability of both extracted isoflavone and soy protein with isoflavones to modulate the lipid profile suggests benefits in prevent-ing cardiovascular events in diabetic subjects. Further multicenter studies based on larger and longer duration studies are necessary to determine their beneficial effect on glucose and lipid metabolism.