Association Of Plasma Leptin Level, Insulin Resistance And Leptin Receptor Gene Polymorphism With Cerebrovascular Disease

To investigate the association of plasma leptin level, insulin sensitivity and leptin receptor gene polymorphism with Cerebrovascular disease. Methods:Two mutations at A668G in exon 6 and G3057A in exon 20 of leptin receptor (LR) gene were analyzed in 81 patients with atherothrombotic cerebral infarction (ACI), 75 patients with lacunar infarction (LI), 35 patients with cerebral hemorrhage (CH) and 36 healthy controls by a combination of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The plasma concentration of insulin and leptin in 31 patients with ACI, 30 patients with LI and 21 healthy controls were measured by means of radioimmunoassay and ELISA. Results:Compared with those in the controls, there were elevation of plasma insulin level and reduction of ISI in the ACI patients. The plasma leptin level related negatively to ISI(t=3.124,P=0.03). Though the plasma leptin level showed no significant difference between the patients with cerebral infarction and healthy controls, there was a significant elevation of plasma leptin level in male patients who have essential hypertension compared with that in the male controls. We did not find any association between leptin receptor gene polymorphism and plasma leptin level in patients with cerebral infarction(t = 0.488, P = 0.627; M).002, P = 0.998). There were no differences in genotype conformation among all groups(p>0.05). When individuals homozygous for the more common allele of two polymorphisms were grouped (genotype: 668GG and3057GG), which had significantly higher CHO and LDL compared to the subjects with all other genotype combinations(t = 2.045, P = 0.043; t=2.508,P = 0.014). Conclusions:Insulin resistance is a risk factor for ACI, and increased plasma leptin level plays an important role in the pathogenesis of insulin resistance. It is possible that plasma leptin associate with ACI indirectly by taking part in insulin resistance. Synergy between leptin and essential hypertension can act to predispose an individual to developing cerebral infarction. Neither leptin receptor gene A668G nor G3057A mutation is sufficient for cerebrovascular disease to develop. However, in combination two genes mutation may act to lipid abnormalities.