空腹血糖受损患者KCNB1基因rs1051295位点多态性与特异组织胰岛素抵抗的关系

目的探讨空腹血糖受损患者KCNB1基因rs1051295位点多态性与特异组织胰岛素抵抗的关系。方法选择76例空腹血糖受损患者,进行口服糖耐量试验,计算特异组织胰岛素抵抗指数即肝脏组织胰岛素抵抗指数(Hepa-IRI)、骨骼肌组织胰岛素敏感指数(Mus-ISI);采集血液标本,采用焦磷酸测序法检测KCNB1基因rs1051295位点多态性。比较KCNB1基因rs1051295位点不同基因型的Hepa-IRI和Mus-ISI,采用多重线性回归模型分析各基因型和Hepa-IRI、Mus-ISI的相关性。结果空腹血糖受损患者中,Hepa-IRI和Mus-ISI在KCNB1基因rs1051295位点TT基因型高于TC、CC、TC+CC基因型(P均<0.05)。在校正性别、年龄和BMI后,基因型TT与Hepa-IRI存在正相关(TT vs TC:b=0.24,95%CI为0.01~0.48;TT vs CC:b=0.27,95%CI为0.01~0.52;TT vs(TC+CC):b=0.25,95%CI为0.04~0.47),与Mus-ISI存在负相关(TT vs TC:b=-0.18,95%CI为-0.35~-0.01;TT vs CC:b=-0.29,95%CI为-0.51~-0.08;TT vs(TC+CC):b=-0.21,95%CI为-0.37~-0.06)。结论空腹血糖受损患者KCNB1基因rs1051295多态位点TT基因型携带者肝脏和肌肉组织胰岛素抵抗风险显著升高。

FoxOs转录因子对机体代谢的调控

Forkhead box O(FoxOs)转录因子在调控机体代谢中发挥重要作用,在种属间高度保守,并受胰岛素信号控制。FoxOs在胰岛素敏感组织如肝脏、胰腺、骨骼肌和胃肠道中表达。在机体能量摄入受限或饥饿状态下,FoxOs位于细胞核内,激活相关基因转录,增加肝脏葡萄糖产生,减少胰岛素分泌,增加采食量,引起骨骼肌降解,为葡萄糖异生提供底物;然而在能量摄入过多或胰岛素抵抗时FoxOs被激活,失去转录调节活性;同时,FoxOs还参与调控细胞分化、增殖和细胞存活。本文综述了FoxOs转录因子控制胰岛素敏感组织中相关基因表达,从而调控机体代谢和组织发育。了解FoxOs转录因子的功能和作用机制,将为调控激素敏感组织发育和机体能量代谢提供依据。

A correlation study of the expression of resistin and glycometabolism in muscle tissue after traumatic brain injury in rats

Objective： To investigate the expression pattern of resistin （RSTN） in skeletal muscle tissue and its influence on glycometabolism in rats with traumatic brain injury （TBI）. Methods： Seventy-eight SD rats were randomly divided into traumatic group （n=36）, RSTN group （n=36） and sham operation group （n=6）. Fluid percussion TBI model was developed in traumatic and RSTN groups and the latter received additional 1 mg RSTN antibody treatment for each rat. At respectively 12 h, 24 h, 72 h, 1 w, 2 w, and 4 w after operation, venous blood was collected and the right hind leg skeletal muscle tissue was sampled. We used real-time PCR to determine mRNA expression of RSTN in skeletal muscles, western blot to determine RSTN protein expression and ELISA to assess serum insulin as well as fasting blood glucose （FBG） levels. Calculation of the quantitative insulin sensitivity check index （Q value） was also conducted. The above mentioned indicators and their correction were statistically analyzed. Results： Compared with sham operation group, the RSTN expression in the skeletal muscle as well as serum insulin and FBG levels revealed significant elevation （P〈0.05）, and reduced Q value （P〈0.05） in traumatic group. Single factor linear correlation analysis showed a significant negative correlation between RSTN expression and Q values （P〈0.001） in traumatic group. Conclusion： The expression of RSTN has been greatly increased in the muscular tissue of TBI rats and it was closely related to the index of glycometabolism. RSTN may play an important role in the process of insulin resistance after TBI.

The role of visceral adipose tissue on improvement in insulin sensitivity following Roux-en-Y gastric bypass:a study in Chinese diabetic patients with mild and central obesity

Background:Most Chinese patients with type 2 diabetes mellitus(T2DM)have mild obesity and central obesity.Central obesity is combined with insulin resistance.The aim of this study was to assess the effect of abdominal adipose tissue on insulin-sensitivity improvement after Roux-en-Y gastric bypass(RYGB)in Chinese diabetic patients with mild and central obesity.Methods:Seventeen T2DM patients with a mean body mass index of 30.3 kg/m^(2) were scheduled for laparoscopic RYGB.A hyperinsulinemic-euglycemic clamp and dual-energy X-ray absorptiometry were performed prior to surgery and 3 months after RYGB.The primary end points were the correlations between insulin sensitivity and abdominal adipose tissue,including visceral adipose tissue(VAT)and subcutaneous adipose tissue(SAT),before and 3 months after RYGB.Results:Indices of peripheral insulin sensitivity,including glucose-disposal rate(M value)and glucose infusion rate,were significantly increased after RYGB.Body-fat mass,VAT and SAT were significantly reduced after RYGB.The pre-operative M value was significantly correlated with VAT mass(r=–0.57,P=0.02),but not correlated with SAT mass.M value changes after RYGB were highly correlated with changes in VAT mass(r=–0.59,P=0.01),percentage of VAT mass(r=–0.66,P<0.01),VAT area(r=–0.56,P=0.02)and percentage of VAT area(r=–0.57,P=0.02).Conclusions:A significant correlation was observed between increased peripheral insulin sensitivity and decreased VAT following RYGB in Chinese patients with mild and central obesity.VAT and SAT were significantly decreased with improved insulin sensitivity after RYGB.VAT mass may be considered as an indication for gastric bypass during patient selection.