The Significance Of Detecting Leptin And Neuropeptid Y Level Of Blood In Gastic Cancer And Ulcer Patients

BackgroundLeptin, a Product of the ob gene, is a 16 kDa Protein synthesised by adipose tissue . Recently leptin is found in the gastric epithelium and to accelerates Proliferation of gastric epithelium cell. Neuropeptide Y (NPY), a 36-amino acid peptide, is abundant in the brain. Leptin and NPY play an important role in the regulation of appetite and energy expenditure. Leptin is also related to proliferation and differentiation of some cancer cells, including mastocarcinoma and carcinoma of prostate et al. NPY acts on the gastric microvasculature to induce vasoconstriction and can induce acute mucosal damage. It has been revealed that the two substances take part in the pathogenesis of cancer-related anorexia and cachexia by studying tumor-bearing animals. But there is little study of their effects on the gastric ulcer patients and clinical anorexia ..and cachexia of gastric cancer patients.ObjectiveTo study the significance of detecting leptin and neuropeptid Y level of gastic cancer and ulcer patients' blood.Methods and materialsThere were 48 gastric ulcer patients, 71 gastric cancer patients and 79 normal controls in this study. Eight parameters, including gender, age, body height, body weight, body mass index, percent body fat(fat%), level of serum leptin and plasm NPY, were examined in all subjects. The volume of gastric cancer patients' serum leptin and plasm NPY was detected again 1 day and 7day after surgery. Fat% was detected by body composition analyzer. Leptin and NPY were detected by radioimmunoassay. The data was analyzed with the SPSS10.0 statistical Package. We considered differences significant at P<0.05.ResultsThe level of serum leptin was positively correlated with percent body fat. The leptin level of gastric cancer patients' was significantly lower than that of normal controls' ( P =0.400, P=0.003; P =0.678, p=0.000; P =0.557, P=0.000) , but there was no difference in leptin/fat% among the two groups(1.83ng/ml vs 2.98ng/ml, P=0.000). There was no relationship between leptin and histological type proliferation, lymph nude metastasis and stage of gastric cancer(P>0.05). The level of gastric ulcer patients' leptin and leptin/fat% was significantly lower than that of gastric cancer patients' and normal controls'(P<0.05). The NPY level of gastric ulcer patients was also significantly lower than that of normal controls(207.84pg/ml vs 226.01pg/ml, P=0.005), but had no difference than that of gastric cancer patients(P>0.05). There was no relationship between NPY and histological type, lymph nude metastasis and stage of gastric cancer(P>0.05). But NPY level of middle-low differentiation of gastric cancer patients was lower than that of low differentiation(165.16pg/ml vs 235.22pg/ml, P=0.018). Serum leptin ascended quickly after surgery, but recovered in one week(2.20ng/ml vs 4.79ng/ml vs 1.90ng/ml). The level of plasm NPY kept low in a week after surgery(228.25pg/ml vs 211.49pg/ml vs 213.63pg/ml).ConclusionsLeptin deosn't take Part in gastric cancer formation. The low level of gastric cancer patients' leptin is associated with their Poor nutrition. Low level of leptin and NPY perhaps is a factor for gastric ulcer. Gastric cancer weight loss/cachexia perhaps is due to maladjustment of leptin and NPY, but more studies should be done in the future. The leptin level increases and the NPY level decreases because of surgery.