脂粘素的研究现状

脂粘素 (Adiponectin,GBP2 8,ap M1)是最近发现的一种由脂肪组织分泌的胶原样蛋白质 ,其编码基因位于人染色体 3q2 7,称 ap M1基因。初步研究显示 :脂粘素具有抗动脉粥样硬化、改善胰岛素抵抗、抗炎等作用 ,血浆脂粘素水平降低与动脉粥样硬化、肥胖症、2型糖尿病的发病相关 ,但其具体作用机制尚未明确     

脂联素与动脉粥样硬化

脂联素为脂肪组织分泌的一种细胞因子,实验证实其具有改善胰岛素抵抗、抗动脉粥样硬化、抗炎等作用.脂联素与动脉粥样硬化具有明显相关性,低脂联素血症与初始的动脉粥样硬化相关,是动脉粥样硬化严重程度的重要标志.本文综述了现阶段脂联素与动脉粥样硬化的最新研究进展.     

脂联素基因R221S、H241P多态性与2型糖尿病的关系

[目的]探讨中国延边地区朝鲜族和汉族人群脂联素基因(apM1)第3外显子R221S、H241P和+1711C>T、+1795A>G、+1833C>A的单核苷酸多态性与2型耱尿病的关联性.[方法]选取377例无亲缘关系的延边地区朝鲜族和汉族人,其中195例糖耐量正常者(NGT)与182例2型糖尿病患者(T2DM),采用聚合酶链反应-单链构象多态性(PCR-SSCP)方法对apM1的多态性进行分析并对变异条带进行基因测序.[结果]脂联素基因的R221S多态在汉族NGT组和朝鲜族T2DM组各发现1例;H241P多态仅在汉族的2型糖尿病组发现1例:未发现脂联素基因3ˊ-UTR区1+1711C>T、+1795A>G、*+1833C>A位点的多态性.[结论]脂联素基因R221S、H241P可能不是延边朝鲜族和汉族群体2型糖尿病的易感位点.脂联素基因3ˊ-UTR区+1711C>T、+1795A>G、+1833C>A位点不属于中国延边地区的汉族及朝鲜族群体的SNPs.     

血清脂联素对心血管疾病的诊断价值

联素是主要由脂肪组织分泌的一种活性蛋白质，已经证实其通过直接作用于内皮细胞而起到抗动脉粥样硬化的作用。实验研究结果表明，脂联素具有抗动脉硬化、抗炎和抗糖尿病等特性。尽管脂联素作为一种重要的治疗手段还需要临床进一步地研究，但它可能成为预防和治疗冠状动脉疾病的重要手段。     

脂联素在胰岛素抵抗中的作用

胰岛素抵抗是代谢综合征、糖尿病和动脉粥样硬化的共同病理基础,对胰岛素抵抗发生机制的研究已成为当今的重要课题。脂联素是脂肪细胞分泌的特异性细胞因子,越来越多的研究证实脂联素能够改善胰岛素敏感性,具有拮抗胰岛素抵抗、抗炎和抗动脉粥样硬化等作用,而且脂联素还被认为是脂肪组织所表达和分泌的多种产物中与胰岛素抵抗关系最紧密的一个特异性细胞因子。现就脂联素在胰岛素抵抗中的作用及可能的作用机制作一综述。     

071 脂联素在胰岛素抵抗中的作用

胰岛素抵抗是代谢综合征、糖尿病和动脉粥样硬化的共同病理基础,对胰岛素抵抗发生机制的研究已成为当今的重要课题.脂联素是脂肪细胞分泌的特异性细胞因子,越来越多的研究证实脂联素能够改善胰岛素敏感性,具有拮抗胰岛素抵抗、抗炎和抗动脉粥样硬化等作用,而且脂联素还被认为是脂肪组织所表达和分泌的多种产物中与胰岛素抵抗关系最紧密的一个特异性细胞因子.现就脂联素在胰岛素抵抗中的作用及可能的作用机制作一综述.     

脂联素及相关疾病的研究进展

脂联素是白色脂肪组织合成和分泌最多的激素蛋白,健康成年人血浆脂联素浓度范围1.9 ～ 17.0 mg/L.脂联素具有胰岛素增敏、调脂、抗炎、抗动脉粥样硬化及抗肿瘤等作用.大量流行病学研究表明,在糖尿病、肥胖、心血管、肿瘤及生殖系统等疾病状态下,脂联素水平明显降低.本研究查阅相关文献,就脂联素与各种相关疾病的关系总结如下.     

脂联素与胎儿生长发育关系的研究进展

脂联素是由脂肪细胞产生和分泌的一种含有244个氨基酸的蛋白激素,具有重要的调节胰岛素敏感性、抗炎和抗动脉粥样硬化的作用.目前的研究已经发现,妊娠期胎盘有脂联素及其受体的表达,推测胎盘是妊娠期产生脂联素的重要来源[1];由于脂联素是调节胰岛素和糖代谢的关键因子,而胎儿的生长发育受胰岛素和糖代谢的影响,因此,脂联素可能是调节胎儿宫内发育的候选因子之一[2].现将脂联素与胎儿生长发育的关系综述如下.     

血清脂联素与慢性肾功能衰竭患者营养状态的关系

慢性肾功能衰竭患者中常存在营养不良-炎症-动脉粥样硬化综合征,可影响患者的生存质量和预后.脂联素是近年来发现的由脂肪细胞分泌的新型激素,具有抗炎和抗动脉粥样硬化等作用.     

血清脂联素与慢性肾功能衰竭患者营养状态的关系

慢性肾功能衰竭患者中常存在营养不良-炎症-动脉粥样硬化综合征,可影响患者的生存质量和预后.脂联素是近年来发现的由脂肪细胞分泌的新型激素,具有抗炎和抗动脉粥样硬化等作用.     

大于胎龄儿脐血脂联素水平测定及意义

目的探讨血脂联素水平与大于胎龄儿的关系。方法选取大于胎龄儿（LGA）和适于胎龄儿（AGA）各30人。应用酶联免疫吸附法测定脐血和母血脂联素浓度,用免疫比浊法测定血脂水平;并分析脐血脂联素水平与母血脂联素、新生儿性别、出生体质量、体质指数（BMI）、胎盘重量和血脂水平的相关性。结果大于胎龄儿脐血浆脂联素水平低于适于胎龄儿,差异有统计学意义（P〈0.01）;2组新生儿血脂水平差异无统计学意义（P〉0.05）。大于胎龄儿血浆脂联素水平与新生儿出生体质量、BMI、胎盘重量、脐血甘油三酯水平均呈显著负相关（r分别为-0.848,-0.785,-0.835,P〈0.001）。大于胎龄儿男婴和女婴脐血浆脂联素、血脂各成分水平比较,差异均无统计学意义（P〉0.05）。结论血脂联素水平的变化与大于胎龄儿的发生有关,测定脐血脂联素水平有助于判断大于胎龄儿的发展趋势。     

足月新生儿出生体重与母婴脂联素水平的相关性研究

目的探讨足月孕妇和新生儿脐静脉血中脂联素（Adiponectin）水平特点及其与新生儿体重的关系。方法采用放射免疫法测定36例健康育龄期妇女（对照组）和31例正常足月孕妇（妊娠组）及其新生儿脐静脉血（新生儿组）的血清胰岛素及脂联素水平,并进行统计学分析。结果足月孕妇血清脂联素水平最低（11．10±5．72）g／ml;新生儿脐血脂联素水平为（30．71±12．77）g/ml,妊娠组高于对照组妇女（16．52±6．87）g/ml;妊娠组脂联素水平与FINS、HOMA—IR呈负相关（r=-0．411、-0．393,P〈0．05）;新生儿脐血脂联素水平与新生儿出生体重正相关（r=0．416,P〈0．05）;母亲血清脂联素水平与新生儿脐血脂联素及出生体重无相关性。结论（1）新生儿组脂联素水平显著高于对照组及妊娠组;（2）新生儿脐血脂联素水平与其出生体重正相关,表明新生儿脂联素可能与胎儿宫内发育有关;（3）足月孕妇脂联素水平与新生儿脂联素水平、出生体重无相关性。     

Adipokines as uremic toxins

The adipose tissue has pleiotropic functions far beyond the mere storage of energy, and it secretes a number of hormones and cytokines, called adipokines, which have biological effects that impact heath and disease. Adipokines are markedly elevated in the plasma of uremic patients, mainly due to decreased renal excretion. They have pluripotent signaling effects on inflammation/oxidative stress (leptin, adiponectin, resistin), protein-energy wasting (leptin, adiponectin), insulin signaling (adiponectin, leptin, visfatin), endothelial dysfunction (visfatin), and vascular damage (adiponectin, leptin, resistin), which are prevalent in uremic patients. Obesity superimposed to uremia may further aggravate hyperadipokinemia, with the exception of adiponectinemia, which is mitigated by adiposity. Among adipokines and until more data become available, only leptin may be considered as a full uremic toxin owing to adverse effects on protein-energy wasting, cardiovascular damage, inflammation, and the immune system, which have been documented both clinically and experimentally. Resistin and visfatin display some features of uremic toxins, but more data are needed to consider these adipokines as true uremic toxins. In contrast, high levels of adiponectin and chemerin seen in uremia appear to be beneficial. Further research is needed to investigate whether selective removal of leptin, resistin, and visfatin and increments of adiponectin and chemerin levels may have clinical relevance in uremic patients.     

子痫前期患者血浆及腹壁脂肪组织脂联素mRNA水平测定及意义

目的:通过检测子痫前期患者血浆及腹壁脂肪组织脂联素mRNA水平及空腹血糖、胰岛素水平,探讨脂联素在子痫前期发病机制中的作用。方法:以子痫前期重度患者40例为研究组,40例同期健康晚期妊娠妇女为对照组。采用ELISA法检测血浆脂联素。葡萄糖氧化酶法测定血糖水平,放射免疫法测定胰岛素水平,Real-timePCR技术检测母体脂肪组织(皮下、网膜)中脂联素基因mRNA表达水平。结果:研究组血浆脂联素水平明显低于对照组(P0.05)。两组孕妇体重指数(BMI)无统计学差异(P0.05)。研究组出现胰岛素抵抗,血糖和HOMA-IR显著升高,与对照组比较有统计学差异(P0.05);皮下和网膜脂肪组织脂联素基因mRNA的表达水平无统计学差异(P=0.11),两者的表达水平呈显著正相关(r=0.32,P=0.04)。研究组皮下及网膜脂肪组织脂联素基因mRNA的表达水平明显低于对照组(P0.05)。结论:子痫前期患者血浆脂连素及腹壁脂肪组织脂连素mRNA表达水平降低,提示脂连素可能参与子痫前期的发生。     

Adiponectin, the missing link in insulin resistance and obesity

Obesity and insulin resistance have been recognised as leading causes of major health issues, particularly diabetes type 2 and metabolic syndrome. Although obesity, defined as excess body fat, is frequently accompanied by insulin resistance, diabetes, metabolic syndrome and cardiovascular diseases, the molecular basis for the link between obesity and those diseases has not yet been clarified. Adipose tissue expresses various secretory proteins, including leptin, tumour necrosis factor-alpha and adiponectin, which may be involved in the regulation of energy expenditure, lipid metabolism and insulin resistance. The aim of this study is to provide an overview of the metabolic alterations occurring in insulin resistance as well as to review the biological roles of adiponectin, particularly in the regulation of fatty acid oxidation and insulin action. Adiponectin is the most abundant gene product in adipose tissue and accounts for 0.01% of total plasma protein. Plasma adiponectin level is decreased in obesity, both in children and adults, and it is negatively associated to plasma insulin and positively associated to plasma triglycerides. Low levels of adiponectin decreases fatty acid oxidation in muscle. Recent data have demonstrated that adiponectin effects are mediated by the interaction with muscle and hepatic receptors through activation of AMP kinase, the cellular "fuel gauge", which in turn inhibits acetyl CoA carboxylase and increases fatty acid beta-oxidation. Since there is no available recombinant adiponectin for human use, its direct effects on human metabolism remain unknown, but this hormone appears to be promising in the treatment of obesity an related metabolic disorders.     

Association between lifestyle factors and plasma adiponectin levels in Japanese men

Background  

Adiponectin is an adipocyte-specific protein that plays a role in obesity, insulin resistant, lipid metabolism, and anti-inflammation. Hypoadiponectinemia may be associated with a higher risk for type 2 diabetes and cardiovascular disease. Some studies suggest that adiponectin levels are modulated by lifestyle factors, but little is known about the associations between lifestyle factors and plasma adiponectin levels in Japanese people. We therefore investigated the associations between lifestyle factors and plasma adiponectin levels in general Japanese men.     

Association between dietary factors and plasma adiponectin concentrations in men

BACKGROUND: Adiponectin, an adipocyte-derived peptide, improves insulin sensitivity, has antiinflammatory and antiatherogenic effects, and is associated with a lower risk of ischemic heart disease (IHD) and type 2 diabetes. However, little is known about dietary predictors of plasma adiponectin concentrations in humans. OBJECTIVE: Our objective was to examine cross-sectionally the association between dietary factors and plasma adiponectin in men. DESIGN: Our study included 532 male participants of the Health Professionals Follow-Up Study who were selected as control subjects for an investigation of biological predictors of IHD. Diet, lifestyle, and anthropometric data were assessed by questionnaires. RESULTS: After multivariable adjustment, adiponectin was significantly inversely related to glycemic load (-1.3 mg/L per 1-SD increase; P = 0.02) and tended to be positively associated with total fat intake (0.7 mg/L per 0.5% of energy from fat instead of carbohydrates; P = 0.06). We also found a significant nonlinear association between plasma adiponectin concentrations and alcohol intake (P for quadratic trend = 0.01). Thus, whereas nondrinkers had mean plasma adiponectin concentrations of 16.48 mg/L, those who consumed 0.1-4.9, 5.0-14.9, 15.0-29.9, or >/=30 g alcohol/d had mean concentrations of 16.79 (P = 0.77 compared with nondrinkers), 18.97 (P = 0.02), 19.11 (P = 0.01), and 18.39 (P = 0.10) mg/L, respectively. CONCLUSIONS: Moderate alcohol intake is associated with higher adiponectin concentrations, whereas a carbohydrate-rich diet with a high glycemic load is associated with lower adiponectin concentrations in men with no history of cardiovascular disease. Although the strength of these associations was modest, our observations highlight the hypothesis that dietary factors may modulate plasma adiponectin concentrations-a potential mediator related to a reduced IHD risk.     

Relationship between plasma adiponectin levels and metabolic risk profiles in Taiwanese children

OBJECTIVE: Adiponectin, a novel adipokine with antiinflammatory and insulin-sensitizing properties, has an important role in glucose metabolism and is negatively correlated with body fat amount in adults. The purpose of this study was to evaluate the association of plasma adiponectin level with metabolic risk profiles and insulin resistance status among Taiwanese children. RESEARCH METHODS AND PROCEDURES: We enrolled 1,248 children (608 boys and 640 girls) to ascertain their demographic, anthropometric, and cardiovascular risk factors distribution in Taipei. We measured plasma insulin, adiponectin, and leptin levels by radioimmunoassay (Linco Research Inc, St. Charles, MO). We calculated an insulin resistance index (IRI) using the Homeostasis Model Assessment model and also calculated an insulin resistance syndrome (IRS) summary score for each individual by adding the quartile ranks from the distribution of systolic blood pressure, serum triglyceride, high-density lipoprotein-cholesterol (HDL-C) (inverse), and insulin levels. RESULTS: In general, the boys had larger BMI, higher systolic blood pressure, serum total cholesterol, and triglyceride, and lower plasma leptin and adiponectin levels than girls. Plasma adiponectin levels were correlated negatively with BMI, leptin, insulin, IRI, and IRS summary score but positively correlated with HDL-C in both boys and girls. In multivariate regression analyses, adiponectin was negatively associated with insulin (girls only), IRI (girls only), and IRS score, and positively associated with HDL-C in both genders even after adjusting for age, BMI, plasma leptin level, and other potential confounders. DISCUSSION: These data suggest that plasma adiponectin levels were negatively associated with metabolic risk profiles that may have played a protective role in the development of insulin resistance among Taiwanese school children.     

冠心病患者中脂联素在冠状动脉损害中的意义

目的探讨冠心病患者血浆脂联素水平与冠状动脉粥样硬化病变的关系。方法根据选择性冠状动脉造影结果将142例患者分为冠心病组和对照组。冠心病组根据临床诊断分为稳定型心绞痛（SAP）组和急性冠脉综合征（ACS）组；根据冠状动脉病变类型分为A型病变、B型病变和C型病变组；根据冠状动脉病变程度分为轻度病变、中度病变和重度病变组。血浆脂联素浓度通过ELISA方法测定。结果冠心病组脂联素浓度明显低于对照组（（6．09±1．85）μg／ml vs （10．25±1．51）μg/ml，P〈0．001），ACS组脂联素浓度又明显低于SAP组（5．45±1．53）μg／ml vs（7．60±1．67）μg／ml，P〈0．001）。随冠状动脉病变类型和病变程度的加重，脂联素浓度逐渐降低，各组间差异有统计学意义（P〈0．001）。结论脂联素是冠状动脉粥样硬化的负调控因子，低脂联素血症可以做为预测冠状动脉粥样硬化病变情况及斑块稳定性的一个指标。     

Plasma adiponectin levels and metabolic factors in nondiabetic adolescents

OBJECTIVES: The relationship of plasma adiponectin levels with various anthropometric and metabolic factors has been surveyed extensively in adults. However, how plasma adiponectin levels are related to various anthropometric indices and cardiovascular risk factors in adolescents is not as vigorously studied. In this study, we investigated this among healthy nondiabetic adolescents. RESEARCH METHODS AND PROCEDURES: Two hundred thirty nondiabetic subjects (125 boys and 105 girls, approximately 10 to 19 years old) were included. The plasma adiponectin, fasting plasma glucose, insulin, lipids and anthropometric indices including body height, weight, waist circumference, and hip circumference were examined. Body fat mass (FM) and percentage were obtained from DXA scan. The homeostasis model assessment was applied to estimate the degree of insulin resistance. RESULTS: The plasma adiponectin levels were significantly higher in girls (30.79 +/- 14.48 micro g/mL) than boys (22.87 +/- 11.41 micro g/mL). The plasma adiponectin levels were negatively related to BMI, FM, FM percentage, waist circumference, waist-to-hip ratio, insulin resistance, plasma insulin, triglycerides, and uric acid levels, but positively with high-density lipoprotein cholesterol (HDL-C) with the adjustment for age and gender. Using different multivariate linear regression models, only age and HDL-C were consistently related to the plasma adiponectin levels after adjustment for the other variables. DISCUSSION: The relationship between plasma adiponectin and various anthropometric indices and metabolic factors, especially HDL-C, previously reported in adults was present in the healthy nondiabetic adolescents. Whether variation of plasma adiponectin levels in healthy nondiabetic adolescents may influence their future coronary artery disease risk warrants further investigation.