Relationship between insulin resistance and erythrocyte insulin receptors in patients with cerebral infarction

Ming YU; Han CHEN; Qing ZHAO; Yingquan WU

ABSTRACT

BACKGROUND:

Epidemiologic studies have shown an association between higher insulin levels and coronary artery disease, and metabolic studies have associated insulin resistance and compensatory hyperinsulinemia with non-insulin-dependent diabetes mellitus, hypertension, obesity,and lipid disorders.

OBJECTIVE:

To investigate the relationship between insulin resistance (IR) and erythrocyte insulin receptors (EIRs) in the patients with cerebral infarction (CI).

DESIGN:

Case-control trial.

SETTING:

Department of Neurology, China-Japan Union Hospital of Jilin University.

PARTICIPANTS:

From January 2004 to October 2004, 40 patients with CI, who were in-patients in China-Japan Union Hospital of Jilin University,were selected for the study. Meanwhile, 30 healthy doctors or nurses were recruited as normal controls.

METHODS:

The levels of blood glucose and serum insulin under fasting and 2-hour after oral glucose tolerance test (OGTT) were detected in the 40 patients with CI and 30 healthy doctors or nurses. Fasting blood glucose multiplied by fasting serum insulin was insulin resistance index (IRI). The number of insulin receptors and their binding affinity on every erythrocyte were determined using modified Gambhir's method. The correlation between the number of EIRs and IRI was analyzed.MAIN OUTCOME

MEASURES:

Comparison of CI group with control

RESULTS:

Data of 40 patients with CI and 30 controls were analyzed, and under fasting and 2-hour after OGTT The level of serum insulin under fasting and blood glucose, serum insulin at 2-hour after OGTT in CI group were higher than those in normal group [(13.30±5.15), (9.85±4.36) mU/L,(8.27±1.65), (6.32±1.37) mmol/L, (75.21±21.12), (28.26±6.31)mU/L,P ＜ 0.01,EIRs The number of insulin receptors with high and low affinity and maximum specific binding rate in the patients with CI were significantly less than those in normal group [20.30±4.50, 23.80±4.10; 2 223.80±509.30,2 610.10±435.10; (10.62±3.55)%, (13.21±2.94)%, P ＜ 0.01]. Multiple linear regression analysis and correlation analysis showed the numbers of two types of EIRs in the patients with CI were negatively correlated with IRI (r=-0.458, -0.439, P ＜ 0.01, both).

CONCLUSION:

Insulin resistance can lead to cerebral infarction. Decrease in insulin receptors may play an importance role in cerebral infarction induced by insulin resistance.