单纯性肥胖症患者外周血ghrelin、obestatin的水平变化及其临床意义

Study on circulating levels of ghrelin and obestatin in human simple obesity

目的探讨单纯性肥胖症患者餐前、餐后外周血肥胖抑制素(obestatin)水平的变化及其与ghrelin(一种脑肠肽激素)间的关系。方法采用放射免疫法(RIA)检测16例单纯性肥胖症患者和14例正常对照者餐前1h及其中各10例餐后2h外周血ghrelin、obestatin水平;同时采用酶联免疫分析法(ELISA)检测餐前胰岛素水平并监测体质量指数(BMI)、腰臀比、血糖、血脂、白细胞及超敏C反应蛋白。结果单纯性肥胖症患者餐前外周血ghrelin和obestatin水平均低于正常对照组(均P<0.01),但ghrelin/obestatin比值却明显高于正常对照组(P<0.01)。单纯性肥胖症组和正常对照组餐后ghrelin/obestatin比值均明显低于其餐前(分别P<0.05,P<0.01),但两组间差异无统计学意义。相关分析显示餐前ghrelin/obestatin比值与BMI(r=0.54,P<0.01)、腰围(r=0.39,P<0.05)、总胆固醇(r=0.40,P<0.05)和低密度脂蛋白胆固醇(r=0.41,P<0.05)呈正相关;与其它指标间相关性无统计学意义。结论餐前外周血ghrelin、obestatin间比例失衡可能是单纯性肥胖症的发病机制之一。

AIM To investigate preprandial and postprandial changes of circulating ghrelin and obestatin levels in simple obesities. METHODS Plasma ghrelin and obestatin concentrations 1 hour before meal were measured by radioimmunoassay in 16 simple obese adolescents and 14 normal controls. Body mass index, waist-hip ratio, plasma glucose, plasma insulin, blood lipids, white blood cells count and high sensitive C-reactive protein were measured. Plasma ghrelin and obestatin concentrations 2 hours after meal were measured in 10 of the simple obese adolescents and 10 of the controls. RESULTS Although both prepramdial plasma ghrelin （ P 〈 0. 01 ） and obestatin （ P 〈 0. 05 ） concentrations decreased in simple obesities as compared with those in normal controls （ both P 〈 0. 01 ） , their ratios of ghrelin to obestatin were increased （P 〈 0.01 ） even after adjustment for gender and age. The ratios of postprandial ghrelin to postprandial obestatin decreased both in simple obesities （P 〈 0. 05 ） and normal controls （P 〈 0. 01 ） compared with their preprandial ratios, but the postprandial ratios were similar between simple obesities and normal controls. There were significant positive correlations respectively between prepramdial ghrelin/obestatin and BMI （r =0. 54, P 〈0. 01 ）, waist circumference （r =0. 39, P 〈0. 05）, total cholesterol （r =0. 40, P 〈0. 05）, low-density lipoprotein cholesterol （r =0.41, P 〈0.05）. CONCLUSION The imbalance of prepramdial circulating ghrelin and obestatin may play a role in the pathogenesis of human obesity.