Oral glucose tolerance test does not affect degree of hemoglobin glycation as measured by routine assay

BackgroundHemoglobin A1c (HbA1c) is an accurate index of fluctuation in glycemia over the 2-3 months prior to quantitative assessment. During this time, hemoglobin (Hb) slowly glycates until it shows the properties of advanced glycation end-products. Glycation kinetics is intensified by prolonged glucose exposure. In subjects undergoing oral glucose tolerance testing (OGTT), immediately after ingestion, glucose is ostensibly transported by the glucose transporter 1 (GLUT1) to erythrocyte corpuscular hemoglobin. The earliest significant measurable level of hemoglobin glycation associated with this transportation is still not clear.Subjects and methodsWe attempted to explore the early impact of short-term glucose load on HbA1c levels, because it is now known that transmembrane GLUT1-mediated glucose transport occurs immediately. A total of 88 participants (46 patients and 42 clinically healthy controls) underwent fasting plasma glucose quantitation during an OGTT. HbA1c, revealed by a monoclonal anti-glycation epitope antibody and adiponectin, was quantitated before (T0) and 2 hours (T120) after 80 g glucose ingestion.ResultsWilcoxon test revealed that the HbA1c values did not significantly vary (P = 0.15) during the OGTT, whereas glucose concentration varied strongly between T0 and T120.DiscussionIt is well known that quantitative estimation of HbA1c is informative for clinical care, independently of glucose level. The molecular mechanisms and dynamics by which glucose enters/exits red blood cells are incompletely known and may differ between individuals. We here show, for the first time, that HbA1c levels do not significantly increase during OGTT, supporting the view that non-enzymatic glycation of hemoglobin occurs slowly and that glycation during the 2 hours of an OGTT is insignificant.     

2型糖尿病下肢血管病变与脂联素及高敏C-反应蛋白关系的研究

目的观察单纯2型糖尿病(T2DM)和T2DM并下肢血管病变患者血浆脂联素及高敏C-反应蛋白(HsCRP)的变化,探讨其在糖尿病及下肢血管病变发生发展中的影响。方法入选研究对象115例,为2004年12月至2005年6月在内蒙古医学院第一附属医院内分泌科住院患者及门诊健康体检者。正常对照组30名;T2DM组85例,其中单纯T2DM组42例,并下肢血管病变组43例。用酶联免疫吸附试验(ELISA)法检测血浆脂联素,用散射比浊法检测HsCRP。结果正常对照组血浆脂联素高于T2DM组,单纯T2DM组高于并下肢血管病变组,组间比较差异有显著性意义(P<0.05);HsCRP水平则相反,差异也有显著性意义(P<0.05)。单因素相关分析显示脂联素与高密度脂蛋白胆固醇(HDL-C)呈正相关,与低密度脂蛋白胆固醇(LDL-C)、体重指数(BMI)、空腹血糖(FPG)呈负相关;HsCRP与LDL-C、BMI呈正相关,与HDL-C呈负相关;脂联素和HsCRP均与年龄、胰岛素抵抗指数(HOMA-IR)无相关;脂联素与HsCRP呈强负相关。结论脂联素、HsCRP与糖尿病及下肢血管病变的发生及发展相关。脂联素、HsCRP可作为早期诊断糖尿病下肢血管病变及预测其预后的参考指标。     

The prediction roles of asymmetric dimethyl-arginine,adiponectin and apelin for macroangiopathy in patients with impaired glucose regulation

Purpose

To investigate the effects of asymmetric dimethyl-arginine (ADMA), adiponectin (APN) and apelin in predicting macroangiopathy in impaired glucose regulation (IGR) patients.

Methods

A total of 210 patients undergoing oral glucose tolerance test were included in this study. They were classified to normal glucose tolerance (NGT, n = 42), impaired fasting glucose (IFG, n = 36), impaired glucose tolerance (IGT, n = 92, including 44 IGT1 and 48 IGT2 patients) and IFG + IGT (n = 40) groups. APN, apelin and ADMA levels, blood pressure, blood lipid, insulin, body mass index (BMI), and homeostasis model assessment of insulin resistance (HOMA-IR) were detected. The severity and extent of coronary atherosclerosis were determined by the Gensini score.

Results

The prevalence of coronary heart disease and Gensini scores in IGT and IFG + IGT groups were similar but both were higher than NGT and IFG groups (all P < 0.05). Lower APN, higher ADMA and apelin levels were witnessed in IGT and IGT + IFG groups compared with NGT and IFG groups (all P < 0.05). IGT2 group had higher 2-h PG and apelin levels and Gensini scores but lower APN levels than IGT1 group (all P < 0.05). Gensini score was positively correlated with apelin (r = 0.669) and ADMA (r = 0.764), but were negatively correlated with APN (r = –0.555, all P < 0.001). ADMA and APN were the independent factors affecting Gensini score.

Conclusion

ADMA and APN levels could be predictive factors for macroangiopathy in IGR patients, especially in IGT cases.     

冠心病患者载脂蛋白A5与脂联素和空腹胰岛素的关系研究

目的 探讨冠心病患者血清载脂蛋白A5(APOA5)与脂联素和空腹胰岛素(FINS)之间的关系.方法 检测2005年6月至12月在中南大学湘雅二医院心内科住院确诊的51例冠心病患者和同期在此院门诊进行健康体检的44名健康对照者血清APOA5、脂联素、FINS和血脂,并计算胰岛素抵抗指数(HOMA-IR).结果 冠心病组血清APOA5和脂联素显著低于健康对照组[(230.06±115.80)μg/L对(324.43±151.79)μg/L,(3.03±1.85)mg/L对(4.12±2.48)mg/L,P均＜0.05];冠心病组的FINS显著高于对照组[(9.85±5.94)mU/L对(7.85±3.04)mU/L,P＜0.05].APOA5与三酰甘油(TG)、FINS、HOMA-IR呈负相关,与高密度脂蛋白胆固醇(HDL-C)呈正相关,与脂联素不相关.结论 冠心病患者血清APOA5和脂联素降低,FINS增高.APOA5不但影响血脂代谢,而且可能与胰岛素抵抗有关.     

上海地区汉族健康人群血清脂联素水平分析

目的探讨上海地区汉族健康人群血清脂联素水平，分析其与年龄、性别、血脂浓度及胰岛素抵抗指数的关系。方法收集400名汉族健康体检者的血清标本，采用酶联免疫吸附双抗夹心（ELISA）法测定血清脂联素水平和血清空腹胰岛素（FINS）水平。结果上海地区汉族健康人血清空腹脂联素水平为（9．48±4．86）μg／ml，各年龄组间比较差异无统计学意义；男性脂联素浓度为（8．46±3．97）μg／ml，女性为（10．22±5．30）μg／ml，男性和女性相比脂联素浓度差异有统计学意义；女性绝经前后脂联素浓度分别为（11．89±4．78）μg／ml和（8．78±4．65）μg／ml，两者脂联素浓度差异有统计学意义。结论①血清脂联素浓度在各年龄段差异无统计学意义；女性脂联素浓度高于男性，差别有统计学意义（P〈0．05）；绝经前、后女性脂联素浓度差异有统计学意义（P〈0．05）。②血清脂联素水平与空腹胰岛素水平、体重、体重指数、腰臀比、收缩压、LDL—C等指标呈负相关，与HDL—C水平呈正相关。     

脂联素对糖尿病大血管病变保护作用的研究进展

脂联素是一种脂肪细胞特异性蛋白。脂联素及其基因多态性与糖尿病大血管病变等的发生有密切的关系,脂联素通过抑制血管内皮细胞炎症及黏附、巨噬细胞向泡沫细胞转化、血管平滑肌细胞的增殖移行以及改善糖脂代谢,影响动脉粥样硬化的形成,发挥心血管保护作用。     

老年高血压患者MMP-9、脂联素及踝臂指数与肥胖的关系

目的 研究老年原发性高血压患者血清基质金属蛋白酶-9(MMP- 9) 、 脂联素(ADP)水平及踝臂指数(ABI)的变化与肥胖的关系。方法 将入选的高血压患者分为高血压肥胖组和单纯高血压组,正常血压者分为单纯肥胖组和正常对照组。四组均采用ELISA法测定MMP-9及ADP,并测量ABI。比较四组MMP-9、ADP和ABI水平。结果 ①单纯高血压组、单纯肥胖组、高血压肥胖组BMI、LDL-C均较对照组升高( P < 0.05) ;单纯高血压组、高血压肥胖组FPG、SBP、DBP均较对照组增高( P < 0.05);单纯高血压组、高血压肥胖组SBP、DBP、FPG较单纯肥胖组增高( P < 0.05);单纯肥胖组、高血压肥胖组BMI、TG、TC、LDL-C较单纯高血压组增高(P< 0.05)。②MMP–9、ADP及ABI在对照组、单纯高血压组、单纯肥胖组和高血压肥胖组中逐渐增高或降低,且单纯高血压组、单纯肥胖组、高血压肥胖组和对照组比较,单纯肥胖组、高血压肥胖组和单纯高血压组比较,高血压肥胖组和单纯肥胖组比较,差异均有统计学意义( P < 0.05) 。③多元线性回归分析显示,MMP-9与SBP、LDL呈正相关。ADP与SBP、DBP、BMI呈负相关。ABI与SBP、DBP、TG呈负相关。结论 MMP-9、ADP、ABI在高血压、肥胖及动脉粥样硬化进程中有重要意义,对临床疾病评估具有一定指导意义。     

脂联素在大肠癌中的表达及意义

目的探讨脂联素在正常结肠组织和大肠癌组织中的表达变化及意义,研究其与大肠癌发生、发展的关系。方法结肠镜检查发现的大肠癌患者63例,以患者的大肠癌组织作为大肠癌组,以同一患者距癌组织5cm的远端正常结肠组织作为正常结肠组。应用免疫组化法检测脂联素在结肠组织中的表达及定位,并应用图象分析系统对其阳性表达结果进行半定量分析,采用配对设计定量资料的统计学方法比较两组间的变化特点。结果正常结肠组中脂联素均匀表达于结肠组织腺管的腺胞细胞膜及细胞浆,大肠癌组中脂联素在肿瘤细胞的胞膜及胞浆表达,阳性细胞呈散在、片状或灶状分布,其阳性区域面积占总面积百分比与正常结肠组比较差异具有统计学意义(P<0.001),在大肠癌组中,从高分化组到中分化组、低分化组,脂联素表达逐渐下降,各组间阳性区域面积占总面积百分比的比较,差异具有统计学意义(0.43411±0.03473vs0.58871±0.02653,0.43411±0.03473vs0.65673±0.03319,0.58871±0.02653vs0.65673±0.03319,P<0.05)。结论脂联素与大肠癌的发生密切相关。     

Adiponectin and insulin sensitivity in primary aldosteronism

BACKGROUND: A high prevalence of metabolic syndrome has been reported in primary aldosteronism. Low levels of adiponectin, an adipokine with insulin-sensitizing properties, are considered a hallmark of the metabolic syndrome. We evaluated the relationship between adiponectin and insulin sensitivity in primary aldosteronism, with and without metabolic syndrome, compared with essential hypertension. METHODS: Forty patients with primary aldosteronism and 40 matched patients with low-renin essential hypertension (LREH) were studied. Patients with type 2 diabetes were excluded. Each group was divided into two subsets: one including patients with metabolic syndrome and one including patients without metabolic syndrome (ie, hypertension alone or associated with another component of the syndrome). RESULTS: Insulin resistance, defined by increased homeostasis model assessment (HOMA index), was higher in patients with primary aldosteronism than in those with LREH only in the absence of metabolic syndrome (P<.01), whereas in the subsets bearing the syndrome it was similar. Adiponectin levels were lower in primary aldosteronism than in patients with LREH (P<.01). Like HOMA index, the difference was maintained (P<.01) only in the subsets without metabolic syndrome. Adiponectin levels were inversely correlated with HOMA index and positively correlated with potassium levels both in primary aldosteronism (P<.001) or in LREH (P<.05) groups. CONCLUSIONS: Lower adiponectin as well as lower insulin sensitivity in primary aldosteronism compared with LREH seem to result from both direct (aldosterone excess) and indirect (hypokalemia) mechanisms. Therapeutic interventions aimed at correcting both potassium and adiponectin levels by specific antihypertensive agents might improve insulin sensitivity, providing better cardiovascular protection in primary aldosteronism.     

妊娠糖尿病患者血清脂联素水平与胰岛素抵抗的关系

目的 研究妊娠糖尿病患者血清脂联素（APN）水平与胰岛素抵抗的关系,探讨妊娠糖尿病的致病机制.方法 检测2011年3月至2012年12月来我院就诊的正常糖耐量（NGT）孕妇50例以及妊娠糖尿病（GDM）患者40例的脂联素水平和空腹胰岛素水平,对两组检测结果进行比较分析.结果 GDM组患者APN水平（7.3±6.2） mg/L明显低于NGT组孕妇APN水平（11.9 ±3.9） mg/L,HOMA-IR又较NGT组孕妇显著升高（均P＜0.01）.结论 脂联素不足增加了炎性反应,导致胰岛素抵抗的发生和发展,从而导致妊娠糖尿病的发生.