Plasma interleukin-6 levels are increased in subjects with impaired glucose tolerance but not in those with impaired fasting glucose in a cohort of Italian Caucasians

BACKGROUND: While the relationship between impaired glucose tolerance (IGT) and circulating interleukin-6 (IL-6) is well established, there is no information whether IL-6 levels are elevated in impaired fasting glucose (IFG). METHODS: To this end, we examined the relationship between plasma IL-6 concentration and different degrees of glucose homeostasis in a cohort of 470 Italian Caucasian subjects comprising 236 normal glucose tolerant (NGT), 49 IFG, 51 IGT, and 134 type 2 diabetic subjects. RESULTS: We observed that IL-6, CRP and fibrinogen levels were higher in subjects with IGT or type 2 diabetes as compared with NGT and IFG subjects. Univariate correlations between IL-6 concentrations and metabolic variables in the whole cohort showed that IL-6 levels were positively correlated with age, BMI, waist, systolic and diastolic blood pressure, fasting plasma glucose, triglycerides, CRP, fibrinogen, and negatively correlated with insulin sensitivity, IGF-I and HDL. In a subgroup analysis including NGT, IFG and IGT (n = 336), IL-6 levels were positively correlated with age, BMI, waist, systolic and diastolic blood pressure, triglycerides, CRP, fibrinogen, fasting insulin, 2 h post-load glucose, and negatively correlated with insulin sensitivity, IGF-I and HDL. Stepwise linear regression analysis in a model including gender, age, BMI, waist, glucose tolerance status, fasting plasma glucose, 2 h post-load glucose, triglycerides, HDL, fasting insulin, and insulin sensitivity revealed that waist was the only independent variable associated with IL-6 levels accounting for 21.0% of its variation (P < 0.0001). CONCLUSIONS: These data show that IGT and type 2 diabetes, but not IFG, are associated with elevated plasma IL-6 levels.     

1193例住院高血压病患者胰岛素分泌和敏感性情况

目的用口服葡萄糖耐量试验中各点血糖和胰岛素的值来计算反映胰岛素敏感性及β细胞功能的参数,回顾性研究住院高血压病人糖代谢情况。方法根据WHO和美国糖尿病协会标准计算血糖分布情况,去除新诊断的糖尿病病人后,分成正常血糖(NGT)、单纯性空腹血糖升高(IFG)、单纯性餐后血糖升高(IGT)和空腹、餐后血糖均升高(IFG,／IGT)组进行比较。再分别以口服75g葡萄糖后30min或60min血糖正常值为标准对NGT组和IGT组进行分组。用HOMA-IR和Composite胰岛素敏感性指数(ISI)计算胰岛素敏感性,HOMA-B和△I／AG计算β细胞功能。结果1193例住院的原发性高血压病人中,新诊断的糖尿病病人为11．1％,其中57．9％仅有餐后血糖升高。IGT、和IFG／ICT组的HOMA-IR高于NGT组,Composite ISI和AI／AG低于NGT组。无论是否30min或60min血糖升高,IGT组的Composite ISI均低于30min和60min血糖正常的NGT组。30min和(或)60min血糖升高的NGT组△I／AG低于30min和60min血糖正常的NGT组。结论IGT或IFG／IGT的高血压患者同时存在空腹和总体胰岛素敏感性的下降和糖负荷后早期β细胞分泌功能的受损。30min和(或)60min血糖升高的NGT高血压病人存在糖负荷后早期β细胞分泌功能的受损。     

高血糖是高血压的独立危险因素？

作者分析糖耐量低减者（ＩＧＴ）２５０例及正常糖耐量者（ＮＧＴ）１７５例的资料。ＩＧＴ者中高血压所占比例明显高于ＮＧＴ者（分别为３０．１４％、１３．１７％，Ｐ＜０．００１）；Ｐｅｒｓｏｎ相关分析中，收缩压、舒张压、平均血压均与体重指数，空腹及服糖后２小时血糖和胰岛素呈显著正相关；应用多因素回归分析，在调整年龄、性别、体重指数、血浆总胆固醇、空腹胰岛素等因素后，收缩压、舒张压、平均血压仍与服糖后２小时血糖呈独立正相关。提示高血糖可能为高血压的独立危险因素。     

Tumor necrosis factor alpha and insulin resistance in obese type 2 diabetic patients

The relationship between basal serum tumor necrosis factor alpha (TNFalpha) levels and peripheral tissue (muscle) sensitivity to insulin was examined in 63 subjects with normal glucose tolerance (NGT), 18 subjects with impaired glucose tolerance (IGT), and 123 patients with type 2 diabetes mellitus (T2DM). The BMI was similar in NGT (28.8+/-0.7 kg/m(2)), IGT (31.1+/-1.0), and T2DM (30.0+/-0.4) groups. The fasting serum TNFalpha concentration in T2DM (4.4+/-0.2 pg/ml) was significantly higher than in NGT (3.1+/-0.2) and IGT (3.4+/-0.2; both P<0.05). In T2DM the fasting plasma glucose (FPG=183+/-5 mg/dl) and insulin (FPI=17+/-1 micro U/ml) concentrations were significantly higher than in NGT (FPG=95+/-1; FPI=10+/-1) and IGT (FPG=100+/-2; FPI=13+/-1; all P<0.01). The rate of total body insulin-mediated glucose disposal (Rd; 40 mU/m(2) min euglycemic insulin clamp in combination with (3)H-glucose) was reduced in T2DM (102+/-3 mg/m(2) min) compared with NGT (177+/-10) and IGT (151+/-14; both P<0.01). The serum TNFalpha concentration was inversely correlated with Rd (r=-0.47, P<0.0001) and positively correlated with both FPG (r=0.32, P=0.004) and FPI (r=0.32, P=0.004) in NGT plus IGT. No correlation was observed between serum TNFalpha and Rd (r=-0.02), FPG (r=0.15), or FPI (r=0.15) in T2DM. In stepwise multiple regression analysis using age, sex, BMI, FPG, FPI and serum TNFalpha concentration as independent variables, only BMI and serum TNFalpha concentration were significant and independent predictors of Rd (r(2)=0.29, P<0.0001) in the NGT plus IGT group, while FPG and FPI were significant and independent predictors of Rd (r(2)=0.13, P<0.0001) in T2DM. These results suggest that: (i) an increase in circulating TNFalpha concentration is associated with peripheral insulin resistance and increased plasma glucose and insulin levels prior to the onset of type 2 diabetes; and (ii) the further deterioration in peripheral insulin resistance in T2DM (compared with NGT and IGT) is unrelated to the increase in serum TNFalpha concentration.     

Pancreatic beta-cell function and insulin sensitivity in japanese subjects with impaired glucose tolerance and newly diagnosed type 2 diabetes mellitus

To clarify whether pancreatic beta-cell function and/or insulin resistance contributes to development of glucose intolerance in Japanese subjects, we investigated 551 subjects who underwent a 75-g oral glucose tolerance test (OGTT). Subjects were divided into 3 groups: normal glucose tolerance (NGT, n = 238), impaired glucose tolerance (IGT, n = 211), and newly diagnosed type 2 diabetes mellitus (n = 102). The diabetics were subdivided into 3 subgroups as follows: diabetes with normal fasting glucose (fasting plasma glucose [FPG] < 110 mg/dL), diabetes with impaired fasting glucose (FPG 110 to 125 mg/dL), and diabetes with diabetic fasting glucose (FPG >or= 126 mg/dL). Insulinogenic index as early-phase insulin secretion, homeostasis model assessment (HOMA-beta and HOMA-resistance), and 4 different formulas of insulin sensitivity index were assessed by plasma glucose and insulin concentrations obtained at fasting or during a 75-g OGTT. Both early-phase insulin secretion and insulin sensitivity were low even in the IGT stage compared with NGT. The transition from IGT to diabetes was accompanied by a progressive deterioration of insulin reserve as well as insulin resistance. During the further progression in diabetes, insulinogenic index decreased additionally, whereas declines in insulin sensitivity were relatively small. In conclusion, both impaired insulin secretion and insulin resistance may contribute to the underlying mechanisms of glucose intolerance in Japanese subjects.     

不同糖耐量水平人群血清真胰岛素和胰岛素原水平的临床意义

目的 探讨不同糖耐量者血清真胰岛素（ＴＩ）及胰岛素原（ＰＩ）水平的变化及临床意义。方法 用特异的单克隆抗体夹心放大酶联免疫分析法（ＢＡ－ＥＬＩＳＡ）检测１３５例正常糖耐量（ＮＧＴ）、８６例糖耐量低减（ＩＧＴ）及１０１例Ⅱ型糖尿病（ＤＭ）者口服葡萄糖耐量试验（ＯＧＴＴ）各点血清ＴＩ及ＰＩ水平。结果 ３组血清空腹ＴＩ差异无显著性（Ｐ〉０．０５）,免疫反应胰岛素（ＩＲＩ）Ⅱ型ＤＭ组明显升高（Ｐ〈０．０１     

中老年正常糖耐量人群胰岛β细胞功能分析

目的 分析中老年正常糖耐量人群血糖水平与胰岛B细胞分泌功能的关系.方法 选择上海市部分社区流行病学调研2095例居民,根据口服葡萄糖耐量试验(OGTT)、空腹血糖(FPG)和餐后2 h血糖(2 hPG)结果,将受检者分为正常糖耐量、糖耐量减低(IGT)、空腹血糖受损(IFG)、糖耐量减低合并空腹血糖受损(IFG/IGT)及糖尿病组.再将正常糖耐量者按年龄及空腹血糖值进行分组,观察稳态胰岛β细胞功能指数(HBCI),并对各组年龄、血糖与胰岛β细胞分泌功能指标进行统计学分析.结果 (1)随着年龄的增长,FPG逐渐升高,40～49岁、50～59岁及60～69岁组分别为(5.00±0.47)mmol/L、(5.09±0.44)mmol/L及(5.17±0.48)mmol/L,50～59岁组与40～49岁组比较(t=2.727,P<0.01)、60～69岁组与50～59岁组比较(t=2.303,P<0.05),均差异有统计学意义,但空腹胰岛素(FINS)值变化无明显规律;(2)随着年龄的增长,HBCI值呈下降趋势(F=33.75,P<0.05);(3)FPG≥5.0 mmol/L组较<5.0 mmol/L组HBCI值下降,分别为4.39±0.58和4.22±0.70,差异有统计学意义(t=2.974,P<0.05).结论 中老年正常糖耐量者随着年龄增长,空腹血糖增高;当空腹血糖≥5.0 mmol/L时,可能存在胰岛β细胞分泌功能异常.     

老年2型糖尿病和糖耐量受损患者血清铁蛋白与胰岛素抵抗和胰岛β细胞功能相关

目的 探讨60岁以上老年2型糖尿病和糖耐量受损(IGT)患者血清铁蛋白(SF)水平与胰岛素抵抗、胰岛β细胞功能之间的相关性.方法 入选2型糖尿病组患者1 143例,IGT组448例和正常糖耐量组(NGT)2 950名.测定身高、体重、血压、总胆固醇、甘油三酯(TG)、空腹血糖(FPG)、餐后2 h血糖(2hPG)、空腹胰岛素(FINS)和SF水平.采用稳态模型、QUICK来评估胰岛素抵抗,采用稳态模型和处置指数(DI)来评估胰岛β细胞功能.结果 2型糖尿病组SF水平高于NGT组(P<0.01);NGT、IGT和2型糖尿病组稳态模型评估的胰岛素抵抗指数(HOMA-IR)呈增高趋势(P<0.05),稳态模型评估的胰岛素β细胞功能指数(HOMA-β)、QUICK、DI呈递减趋势(均P<0.05).Spearman相关分析和偏相关分析显示,校正年龄和性别后,SF与FPG、2hPG、TG、FINS、HOMA-IR呈正相关,与HOMA-β、QUICK、DI呈负相关.多元逐步回归分析显示,QUICK、体重指数、TG是影响SF的独立危险因素.结论 老年2型糖尿病患者体内铁超负荷;随着SF的升高,胰岛素抵抗逐渐增加,而胰岛β细胞功能呈下降趋势.

Abstract：

Objective To investigate the relationship between serum ferritin and p-cell function,insulin resistance in elderly patients(age>60 years)with type 2 diabetes and impaired glucose tolerance.Methods Total 1143 patients with type 2 diabetes,448 patients with impaired glucose tolerance(IGT),and 2 950 subjects with normal glucose tolerance(NGT)were recruited for the measurments of height,weight,serum triglyceride(TG),total cholesterol,fasting plasma glucose(FPG),fasting insulin(FINS),postprandial 2 h plasma glucose(2hPG),and serum ferritin.Homeostasis model assessment of insulin resistance(HOMA-IR)and QUICK index were used to estimate insulin resistance,and homeostasis model assessment of β cell function(HOMA-p)and disposition index(DI)to evaluate p-cell function.Results The results showed that the level of serum ferritin was significantly higher in type2 diabetes mellitus group than NGT group(P<0.01).HOMA-IR was gradually increased,and HOMA-β,QUICK,and DI decreased from NGT to IGT,type 2 diabetes mellitus groups(all P < 0.05).Spearman and partial correlation analysis showed that partial adjustment for age and sex,serum ferritin was positively associated with FPG,2hPG,TG,FINS,and HOMA-IR,and negatively associated with HOMA-β,QUICK,and DI.Stepwise regression showed that serum ferritin was associated with QUICK,BMI,and TG.Conclusion The results suggest that iron overload exists in elderly patients with type 2 diabetes.With increasing serum ferritin level,insulin resistance increases and p-cell function decreases in the elderly patients with abnormal glucose metabolism.     

Hyperbolic correlation between insulin sensitivity and insulin secretion fades away in lean subjects with superb glucose regulation

The relationship between insulin sensitivity (Si) and insulin secretion (β) was analyzed in 533 health examinees. The subjects underwent a 75 g oral glucose tolerance test, with plasma glucose (PG) and immunoreactive insulin (IRI) determined at fasting, 30 min and 120 min, and were classified according to the current criteria as normal glucose tolerance (NGT, n=328), non-diabetic hyperglycemia (NDH, n=113) including impaired fasting glucose and impaired glucose tolerance, and diabetes mellitus (DM, n=72). NGT was subdivided by fasting PG (FPG) tertile, ≤4.9, 5.0-5.4 and 5.5-6.0 mM, into NGT(FPG1), NGT(FPG2) and NGT(FPG3), or by body mass index (BMI) tertile, ≤21.8, 21.9-24.4 and ≥24.5 kg/m2, into NGT(BMI1), NGT(BMI2) and NGT(BMI3). As an index of Si and β, Matsuda index=10,000/sqrt[FPG·FIRI·2hPG·2hIRI] and δIRI????/δPG????, were employed respectively: FIRI, 2hPG and 2hIRI denote fasting IRI, 2h-post glucose PG and IRI, respectively. Correlation between Si and β was evaluated by Spearman's rank correlation and the parameters for [β]=a·[Si](b) were obtained by standardized major axis (SMA) regression. Si-β correlation was strongest in NDH (Spearman's rho=-0.546, SMA regression r2=0.277), intermediate in DM (rho=-0.432, r2=0.193) and weakest in NGT (rho=-0.201, r2=0.039). Spearman's rho for the Si-β correlation was significantly lower in NGT than in NDH (p=0.003). Si-β correlation was significant in NGT(FPG3), NGT(FPG2) and NGT(BMI3), but not in NGT(FPG1), NGT(BMI2) and NGT(BMI1). The slope, b, was -1.184?-1.530 without significant differences between any groups. In conclusion, the hyperbolic Si-β correlation was weaker in NGT than in NDH and absent in NGT subjects belonging to the lowest FPG or BMI tertile.     

Hyperglycaemia after glucose loading is a major predictor of preclinical atherosclerosis in nondiabetic subjects

OBJECTIVE: Carotid intima-media thickness (IMT) has proved to be an independent marker of preclinical atherosclerosis. The aim of this study was to determine whether carotid IMT is associated with the plasma glucose concentration in the fasting state, after loading with oral glucose, or with the insulin sensitivity index (ISI) in nondiabetic subjects with different levels of glucose intolerance and insulin resistance. DESIGN: Cross-sectional study. PATIENTS: A total of 160 nondiabetic subjects (147 from our obesity-overweight clinic and 13 healthy normal subjects) were included in the present study, among them 33 had normal glucose tolerance (NGT), 13 had impaired fasting glucose (IFG), 80 had impaired glucose tolerance (IGT) and 34 had both IFG and IGT. MEASUREMENTS: Carotid IMT was assessed in the common carotid artery by a high-resolution B-mode ultrasound system. Plasma glucose was measured after fasting and at 30 min, 1, 2 and 3 h after a standard 75-g load of glucose. The ISI was calculated from the frequent sampling intravenous glucose tolerance test (FSIGT). Results The IMT values in the NGT group were lower than those in the IFG, IGT and IFG + IGT groups (P < 0.03). No statistical difference in IMT values was found among the latter three groups. Univariate correlation analyses showed that the IMT was positively associated with age, plasma glucose concentrations 1 and 2 h after glucose loading, and serum concentration of low density lipoprotein (LDL) cholesterol (r=0.39, 0.22, 0.25 and 0.18, respectively, P<0.05). Multiple regression analysis showed that only age, plasma glucose concentration 2 h after glucose loading, and LDL cholesterol appeared to be significant correlates of the IMT (P<0.0001), whereas the ISI was not. CONCLUSIONS: In nondiabetic subjects with various degrees of glucose intolerance, there was a significant increase in IMT in those with IFG and IGT. Significant determinants of IMT, an indicator of preclinical atherosclerosis, include hyperglycaemia 2 h after a glucose load, age and LDL cholesterol, whereas fasting glucose concentration and the ISI were not significantly associated with IMT.     

2型糖尿病患者非糖尿病后代心率变异性与血清脂联素水平的相关性研究

目的旨在探讨血清脂联素浓度降低是否与2型糖尿病(T2DM)患者非糖尿病后代心率变异性(heart rate variability,HRV)改变有关.方法31例(男16例,女15例)T2DM患者,所有子女(91例)排除已进行药物治疗的T2DM患者14例,其余空腹静脉取血测定血浆葡萄糖,排除≥7.0 mmol/L者3例,排除5.6~7.0 mmol/L之间者7例.选择其空腹血糖≤5.6 mmol/L后代行口服葡萄糖耐量试验,均未达到T2DM诊断标准,分为正常葡萄糖耐量组(NGT,n=32),葡萄糖耐量异常组(IGT,n=35),对照组(n=32)为无糖尿病家族史的健康查体者.行24 h动态心电图检查测定HRV,指标包括:全部正常窦性R-R间期值的标准差(SDNN);全程按5 min分成连续的时间段,先计算每5 min正常R-R间期的平均值,再计算所有平均值的标准差(SDANN);全部相邻R-R间期差的均方根(rMSSD);总功率(TP);低频功率(LF);高频功率(HF).ELISA法测定血清脂联素.结果T2DM非糖尿病后代血清脂联素水平与其体重指数(BMI)、空腹胰岛素负相关,与高密度脂蛋白胆固醇(HDL-c)、SDNN、SDANN、rMSSD、TP、LF、HF正相关.对照组、NGT组、IGT组之间血清脂联素逐渐降低、空腹胰岛素、SDNN、SDANN、rMSSD、TP、LF、HF逐渐升高.IGT组BMI、血清三酰甘油高于HDL-c,低于对照组和NGT组.结论自主神经平衡的改变与胰岛素抵抗和血清脂联素水平改变具有相关性.     

新疆汉、维民族糖调节受损人群胰岛素分泌功能和胰岛素作用功能的研究

目的 评估新疆汉、维民族在IFG,IGT及IGR阶段的胰岛素分泌功能和胰岛素作用功能。 方法 采用多中心研究进行横断面调查,行OGTT试验。用胰岛素抵抗指数（HOMA-IR）评估IR,胰岛β细胞功能指数（HOMA-β）评估基础胰岛素分泌;ΔI30/ΔG30评价胰岛素早相分泌,ΔI30/ΔG30/HOMA-IR评估葡萄糖处置指数（DI）。 结果 WC、BMI、血脂、FIns、2 hIns在汉、维民族不同糖代谢组差异有统计学意义。IFG组与NGT、IGT组比较,汉、维族人群的HOMA-IR差异有统计学意义。在汉族中NGT组与IGT、IGR组比较,HOMA-β差异有统计学意义（P=0.030、0.044）,而在维族只有IFG组与NGT组比较差异有统计学意义（P=0.001）。ΔI30/ΔG30、DI在两民族不同糖代谢组差异均无统计学意义。 结论 汉族人群IR在IFG阶段,胰岛素分泌功能在IGT阶段起主要作用。IR和胰岛素分泌功能在维族人群IFG阶段起重要作用。胰岛素早相分泌及葡萄糖处置功能在糖调节受损阶段作用不显著。     

IGT with fasting hyperglycemia is more strongly associated with microalbuminuria than IGT without fasting hyperglycemia

Previous studies have established that impaired glucose tolerance (IGT) patients with fasting hyperglycemia (IGT/FH: fasting plasma glucose (FPG) level 6.1-7.0 mmol/l and 2 h PG level of 7.8-11.1 mmol/l) exhibit higher insulin resistance than those with isolated IGT (FPG level <6.1 mmol/l and 2 h PG level of 7.8-11.1 mmol/l), but the association with microalbuminuria has not been determined. Here, we evaluate the prevalence of microalbuminuria in non-diabetic Japanese males 20-70 years of age. The subjects were classified into four groups based on the results of OGTT: normal glucose tolerance (NGT: n=71), impaired fasting glucose (IFG: n=24), isolated IGT (n=36), and IGT/FH (n=23). A urinary albumin-to-creatinine ratio (ACR) from 30 to 300 microg/mg creatinine was counted as microalbuminuria. The prevalence of microalbuminuria was higher in subjects with IGT/FH than in subjects with isolated IGT (26% versus 14%). Logistic regression analysis showed microalbuminuria to be more significantly associated with IGT/FH (OR=3.82, 95% CI 1.09-13.36) than with isolated IGT (OR=1.75, 95% CI 0.50-6.17). While insulin resistance (HOMA-IR) in isolated IGT was not significantly different from that in NGT, insulin resistance in IGT/FH was significantly higher (P<0.01). Regression analysis of ACR in IGT showed a significant correlation with insulin resistance (P=0.012). Accordingly, microalbuminuria is more strongly associated with IGT/FH than with isolated IGT, most likely due to the higher insulin resistance.     

Insulin secretion and sensitivity in non-obese and obese Japanese patients with coronary artery disease

In a cross-sectional study of 240 patients with angiographically documented coronary artery disease (CAD), we investigated whether obese and non-obese subjects differed as to the influence of insulin deficiency and insulin resistance on glucose intolerance and cardiovascular risk. Patients were classified according to a 75-g oral glucose tolerance test as having normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or diabetes mellitus (DM). We defined obesity as a body mass index (BMI) exceeding 25 kg/m(2). Early phase insulin secretion (insulinogenic index) declined with worsening glucose intolerance in non-obese (tau = -.216, P <.001; Kendall's correlation coefficient) and obese subjects (tau = -.392, P <.001). Total insulin secretion was higher in obese subjects with NGT or IGT than in controls and decreased in association with worsening glucose intolerance in obese subjects (tau = -.239, P <.001). Insulin sensitivity was calculated by 3 proposed indices. The first of these decreased in association with worsening in glucose tolerance in non-obese subjects (tau = -.137, P <.01). The second showed such a pattern in both groups (non-obese, tau = -.407, P <.001; obese, tau = -.311, P <.001), as did the third (non-obese, tau = -.512, P <.001; obese, tau = -.488, P < 0.001). Because even prediabetic Japanese subjects with CAD showed a latent insulin secretion defect in response to a glucose load, as well as impaired insulin sensitivity, compensatory hyperinsulinemia is not a sensitive indicator of coronary risk.     

Adipocytes in subjects with impaired fasting glucose and impaired glucose tolerance are resistant to the anti-lipolytic effect of insulin

Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) are two intermediate states in the transition from normal glucose metabolism to type 2 diabetes. Insulin clamp studies have shown that subjects with IGT have increased insulin resistance in skeletal muscle, while subjects with IFG have near normal muscle insulin sensitivity. Because of the central role of altered free fatty acid (FFA) metabolism in the pathogenesis of insulin resistance, we have examined plasma free fatty acid concentration under fasting conditions, and during OGTT in subjects with IGT and IFG. Seventy-one NGT, 70 IGT and 46 IFG subjects were studied. Fasting plasma FFA in IGT subjects was significantly greater than NGT, while subjects with IFG had similar fasting plasma FFA concentration to NGT. However, fasting plasma insulin concentration was significantly increased in IFG subjects compared to NGT while subjects with IGT had near normal fasting plasma insulin levels. The adipocyte insulin resistance index (product of fasting plasma FFA and FPI) was significantly increased in both IFG and IGT subjects compared to NGT. During the OGTT both IFG and IGT subjects suppressed their plasma FFA concentration similarly to NGT subjects, but the post-glucose loads were significantly increased in both IFG and IGT subjects. These data suggest that both subjects with IFG and IGT have increased resistance to the antilipolytic action of insulin. However, under basal conditions, fasting hyperinsulinemia in IFG subjects is sufficient to offset the adipocyte insulin resistance and maintain normal fasting plasma FFA concentration while the lack of increase in FPI in IGT subjects results in an elevated fasting plasma FFA.     

Comparison of serum concentrations of C-reactive protein, TNF-alpha, and interleukin 6 between elderly Korean women with normal and impaired glucose tolerance

This study was performed to compare concentrations of pro-inflammatory cytokines, such as interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha) as well as acute-phase protein, such as C-reactive protein (CRP) between subjects with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT). The purpose of this study was to verify whether the pro-inflammatory cytokine-induced acute-phase response is a pathogenic mechanism in type 2 diabetes in elderly Korean women. A total of 1737 elderly subjects aged over 60 years participated in a population based study in Seoul, Korea (SWS Study 1999). Amongst them, a total of 232 non-smoking and non-diabetic female subjects aged 60-89 years was randomly selected and compared with each other. Higher serum high-sensitivity CRP (hs-CRP) concentrations were shown in subjects with IGT than those with normal glucose tolerance (median 1.2 versus 0.9, P < 0.05). Moreover, a relationship between serum hs-CRP concentrations and many components of the metabolic syndrome were detected. Serum pro-inflammatory cytokine IL-6 or TNF-alpha concentrations, however, were neither increased in subjects with IGT nor closely correlated with the components of the metabolic syndrome. In multiple regression analysis with stepwise selection method using hs-CRP as a dependent variable, it was found that white blood cell (WBC) counts, body mass index (BMI), fasting insulin, post-load 2h glucose, hematocrit and LDL cholesterol were significant independent variables. Our study confirms that increased acute-phase reaction is associated with impaired glucose tolerance and the metabolic syndrome in elderly Korean women. However, the hypothesis that pro-inflammatory cytokine-induced systemic inflammation is an early metabolic defect prior to onset of type 2 diabetes, is not supported in our study of elderly Korean women.     

The role of non-esterified fatty acids in the deterioration of glucose tolerance in Caucasian subjects: results of the Paris Prospective Study

Summary Although an increased plasma non-esterified fatty acid (NEFA) concentration has been shown to increase insulin resistance (Randle cycle), decrease insulin secretion and increase hepatic gluconeogenesis, the effect of NEFA on the deterioration of glucose tolerance has not been studied prospectively in Caucasian subjects. Therefore, we investigated whether plasma NEFA may be regarded as predictors of deterioration of glucose tolerance in subjects with normal (NGT, n = 3671) or impaired (IGT, n = 418) glucose tolerance who were participants in the Paris Prospective study. The subjects were first examined between 1967 and 1972 and underwent two 75-g oral glucose tolerance tests 2 years apart with measurements of plasma glucose, insulin and NEFA concentrations. Glucose tolerance deteriorated from NGT to IGT or non-insulin-dependent diabetes (NIDDM) in 177 subjects and from IGT to NIDDM in 32 subjects. In multivariate analysis, high fasting plasma NEFA in NGT subjects and high 2-h plasma NEFA and low 2-h plasma insulin concentrations in IGT subjects were significant independent predictors of deterioration along with older age, high fasting and 2-h plasma glucose concentrations and high iliac to thigh ratio. When subjects were divided by tertiles of plasma NEFA concentration at baseline, there was an increase in 2-h glucose concentration with increasing NEFA in the subjects who did not deteriorate, but no effect of plasma NEFA in those who deteriorated. In subjects with IGT who deteriorated compared with those who did not 2-h plasma insulin concentration was lower but there was no evidence that this resulted from an effect of plasma NEFA. Our data suggest that a high plasma NEFA concentration is a risk marker for deterioration of glucose tolerance independent of the insulin resistance or the insulin secretion defect that characterize subjects at risk for NIDDM. [Diabetologia (1997) 40: 1101–1106] Received: 11 March 1997 and in revised form: 20 May 1997     

Insulin‐secretion capacity in normal glucose tolerance,impaired glucose tolerance,and diabetes in obese and non‐obese Japanese patients

Aims/Introduction: Pronounced reduction of insulin secretion in response to a rise in glucose level has been reported in Japanese patients compared with Caucasian patients, but the mean body mass index (BMI) is also lower in Japanese patients. As BMI is a determinant of insulin secretion, we examined insulin‐secretion capacity in obese and non‐obese Japanese patients. Materials and Methods: Using the oral glucose tolerance test (OGTT), we estimated the insulin‐secreting capacity in obese (BMI ≥ 25) and non‐obese (BMI < 25) Japanese patients, including 1848 patients with normal glucose tolerance (NGT), 321 patients with impaired glucose tolerance (IGT) and 69 diabetes (DM) patients. Results: The insulinogenic index (I.I.), calculated by dividing the increment in serum insulin by the increment in plasma glucose from 0 to 30 min during OGTT, decreased from NGT to IGT and to DM in patients with and without obesity. In patients with NGT, IGT and DM, the I.I. values of obese patients were higher than those of the non‐obese patients. The peak of insulin concentration in OGTT appeared at 60 min in NGT and at 120 min in IGT in both obese and non‐obese patients, but in DM it was observed at 120 min in obese patients and at 60 min in non‐obese patients. Conclusions: These results show that early‐phase insulin secretion in obese Japanese patients is higher than in non‐obese patients in all stages of glucose tolerance, and delayed insulin‐secretion capacity is also conserved in obese Japanese patients, even in IGT and DM, which is similar to Caucasian patients. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00180.x , 2011)     

Insulin secretion and insulin sensitivity in Japanese subjects with impaired fasting glucose and isolated fasting hyperglycemia

Impaired fasting glucose (IFG) is a subgroup of impaired glucose regulation exhibiting an elevated fasting glucose levels without elevated 2-h glucose levels on oral glucose tolerance test (OGTT). Diabetes mellitus with isolated fasting hyperglycemia (DM/IFH) is a similar subgroup of diabetes having higher fasting glucose levels with 2-h glucose levels within the non-diabetic range. The aim of this study is to profile the characteristics of these subgroups to estimate the factors involved in the development from normal glucose tolerance (NGT) via IFG to DM/IFH. Five hundred and sixty seven Japanese males were classified on the basis of 75 g OGTT into four groups, NGT, IFG, DM/IFH, and isolated impaired glucose tolerance (isolated IGT). Insulin secretion was evaluated by insulinogenic index, insulin sensitivity was evaluated by ISI composite, and insulin secretory patterns were compared additionally. IFG and DM/IFH subjects exhibited both lower insulin secretion and lower insulin sensitivity than NGT subjects. There was an insulin peak in NGT, IFG, and DM/IFH at 60 min, which did not occur in isolated IGT. Impaired early-phase and basal insulin secretion and decreased insulin sensitivity both are estimated as factors in progression from NGT via IFG to DM/IFH in these subjects. IFG and DM/IFH subjects have definite fasting hyperglycemia in contrast to isolated IGT subjects, 2-h glucose levels being maintained within the non-diabetic range partly by the insulin peak at 60 min.     

单纯空腹血糖受损和单纯空腹高血糖型糖尿病的代谢特征

目的评估初发的单纯空腹血糖受损（iIFG）和单纯空腹高血糖型糖尿病（IFH）患者的胰岛素分泌及胰岛素敏感性特征,进一步探讨进展为IFH的相关因素。方法2004—2005年瑞金医院内分泌科门诊初诊病人,隔夜空腹10h后行口服葡萄糖耐量试验,其中同时行胰岛素释放试验1852例。其中糖耐量正常（NGT）557例;iIFG221例;IFH81例。比较各组的代谢指标及胰岛素分泌和胰岛素敏感性指数。结果对1852例接受者操作特征曲线（ROC）分析确定的糖耐量异常（除外糖尿病）发生的最佳空腹血糖切点为5．590mmol／L,2型糖尿病发生的最佳空腹血糖切点为6．695mmol／L。从NGT→iIFD→IFH,早期相胰岛素分泌和胰岛素敏感性指数均逐渐降低。结论初发的iIFG和IFH均有显著的早期相胰岛素分泌缺陷和胰岛素敏感性降低。B细胞胰岛素分泌缺陷和胰岛素抵抗均是从NGT向iIFG向IFH的进展过程中的重要因素。