Objective:To examine the combined effect of low glycemic load(LGL)and corn oil on glycemic control and vascular reactivity in type 2 diabetes mellitus. Methods:The study was a parallel design and randomized trial involved 110 participants with type 2diabetes mellitus treated from September 2013 to February 2014 in endocrinology department of the First Affiliated Hospital of Liaoning Medical University. Participants were provided with dietary advice on either LGL with corn oil given as a canola oil-enriched wheat rolls supplement(test group

55 participants)or a whole-grain diet given as a whole-wheat rolls supplement(control group

55participants). Fasting plasma glucose(FPG)

serum lipids

glycosylated hemoglobin A1c(GHb A1c)

cardiovascular disease(CVD)risk score and reactive hyperemia index(RHI)were detected. Based on the per-protocol(PP)principle

data of participants who had completed the test were statistically analyzed. Results:After 12 weeks intervention

a decrease of FPG[7.2(6.6

7.6)]

GHb A1 c [6.8(6.2

7.3)]

and CVD risk score[7.3(5.4

10.8)] was observed in the control group(P=0.000

0.037 and 0.046). FPG[7.0(6.5

7.5)]

GHb A1c[6.5(6.1

7.1)] and CVD risk score[6.1(5.2

7.5)] were significantly lower than before the intervention(P =0.001

0.000 and0.000) in the test group

whereas RHI [1.86(1.62

2.13)] increased(P=0.005). In the test group

GHb A1 c reduction was the greatest benefit(F =266.514

P =0.000) observed in those with higher systolic blood pressure(SBP). There were greater reductions in GHb A1 c

total cholesterol(4.73 ±0.97)

low-density lipoprotein [2.63(2.15

3.10)]

triglycerides [1.30(0.73

1.85)] and CVD risk score in the test group than in the control group(P=0.035

0.000

0.013

0.004 and 0.041)

whereas the high density lipoprotein cholesterol [1.42(1.28

1.60)] and RHI increased significantly(P=0.006 and 0.039). Conclusion:A cron oil-enriched LGL diet regulates blood lipid

reduced CVD risk

and improves glycemic control in type 2 diabetes mellitus particularly in participants with raised SBP and vascular reactivity. Furthermore

combined LGL diet of whole-wheat foods and corn oil may have synergistic effect on glycemic control and CVD risk factors reduction in type 2 diabetes mellitus.