Effects of soy protein isolate supplementation on biomarkers of cardiovascular disease in type 2 diabetic patients at public health center 66, health department, Bangkok metropolitan administration

Abstract

Cardiovascular disease (CVD) accounts for the majority of morbidity and mortality in type 2 diabetic patients. This study evaluated the effects of soy protein isolate (SPI) supplementation on biomarkers of CVD in type 2 diabetic patients at Public Health Center 66. Thirty-six type 2 diabetic patients were recruited. They received nutrition counseling and were randomized into 2 groups: SPI group (supplemented with 30 g/day of SPI containing 32 mg of isoflavones for 6 weeks) and control group (no SPI supplementation). Blood pressure and biomarkers of CVD, which included blood glucose, glycosylated hemoglobin (HbA1c), lipid profile, total homocysteine (tHcy), folate, vitamin B12 and C-reactive protein (hs-CRP) were examined at baseline and at the end of week 6 of the study. The results showed that there was no significant difference in blood pressure and biomarkers of CVD between the SPI and control groups. However, after SPI supplementation, HbA1c and tHcy levels were significantly decreased and folate level was significantly increased from baseline (p < 0.01). The concentrations of TC, LDL-C and TG were decreased greater in SPI group than those in control group, but there were no significant differences from baseline. Furthermore, plasma tHcy level was significantly negatively correlated with plasma folate (r = -0.47), vitamin B12 (r = -0.39) and renal function (GFR) (r = -0.47), but it was significantly positively correlated with age (r = 0.59). The serum level of hs-CRP was significantly negatively correlated with GFR (r = -0.36) and significantly positively correlated with age (r = 0.40) and HbA1c (r = 0.35). This study indicated that supplementation of SPI with isoflavones improves some biomarkers of CVD and may be beneficial on cardiovascular events in type 2 diabetic patients.