[Reduced resistin levels in patients with type 2 diabetes mellitus].

Objective: To measure the serum resistin level of patients with type 2 diabetes mellitus so as to examine whether there exists a relationship between resistin, obesity and diabetes.

Methods: ELISA was used to examine the fasting serum resistin, leptin, and true insulin and those 2-hours after taking 75-g glucose in 51 untreated type 2 diabetic patients, 30 males and 21 females, and 52 sex and age-matched normal control subjects. Blood glucose, blood pressure, height, weight, waist circumstance, hip girth were measured. Body mass index (BMI), waist to hip ratio (WHR), and quantitative insulin sensitivity check index (QUICKI) were calculated.

Results: In comparison with the control, the diabetic group had higher waist-to-hip ratio (WHR) and serum insulin levels (P < 0.05), but significantly lower resistin levels both in the fasting status (23 ng/ml +/- 15 ng/ml vs 30 ng/ml +/- 18 ng/ml, P < 0.05) and 2 hours after glucose loading (22 ng/ml +/- 11 ng/ml vs 31 ng/ml +/- 15 ng/ml, P < 0.001). The leptin level was not statistically different between the two groups (P > 0.05). The resistin level 2 hours after glucose loading was not significantly different between these 2 groups. Correlation analysis demonstrated that fasting resistin level was not correlated with sex, BMI, leptin, and blood pressure, but positively correlated with QUICKI (r = 0.30, P < 0.01) and negatively correlated with blood glucose (r = -0.21, P < 0.05).

Conclusion: The serum resistin level of patients with type 2 diabetes is reduced rather than increased in fasting status and 2 hours after glucose taking. Resistin may not be the major link between obesity and diabetes in human beings. Since human resistin level is positively correlated with insulin sensitivity, the use of term "resistin", originally for its resistance to insulin, may be somewhat premature.