Objective        To determine the effects of irbesartan on insulin resistance and islet β-cell function in the pat

ients with type2 diabetes mellitus (T2DM) complicated with hypertension.       Methods        Ninety-four patients with newly diagnosed T2DM complicated with hypertension admitted in our hospital from November 2011 to March 2012 were prospectively enrolled in this study. They were randomly assigned into 2 groups and received either irbesartan (150 to 300 mg/d) or amlodipine (5 to 10 mg/d) treatment for 12 weeks. The clinical characteristics

such as body mass index (BMI)

waist circumference (WC)

blood pressure (BP)

fasting plasma glucose (FBG) and insulin (FINS)

and serum levels of glycosylated  hemoglobin (HbA1c)

triglyeride (TG)

total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) were collected before and after treatment. Homeostasis model assessment (HOMA) was used to calculate the insulin resistance index (HOMA-IR=fasting serum insulin fasting serum glucose/22.5) and insulin secretion index (HOMA-β=fasting serum insulin×20/ fasting glucose-3.5).       Results        After 12 week treatment

the BP

FBG and HbA1c were decreased

while the insulin secretion index was significantly increased in both groups (

P

0.05). There was no significant difference in the WC

BMI

TC

LDL-c and HDL-c in the 2 groups before and after the treatment (

P

0.05). The insulin resistance index was obviously decreased in irbesartan group after the treatment [3.79 (2.51 to 4.99) vs 4.58 (3.38 to 5.94)

P

0.05

]

while there was no obvious alteration in the amlodipine group [3.90 (2.52 to 5.26) vs 3.90 (2.52 to 5.26)

P

0.05

]

.       Conclusion        While effectively controlling the blood pressure

irbesartan can improve the insulin resistance in T2DM patients.