Associations between whole blood trace elements concentrations and HbA1c levels in patients with type 2 diabetes

BioMetals - Previous researches have been conducted to study the associations of trace elements on Type 2 diabetes (T2D) risk. The present study focuses on the evaluation of potential associations...     

基于气相色谱法分析T2DM患者粪便中SCFAs水平与HbA1c的相关性

目的 研究2型糖尿病患者粪便中6种短链脂肪酸水平与糖化血红蛋白的相关性。 方法 采用气相色谱法检测粪便中短链脂肪酸的含量,并对方法学进行考察。选取2018年在本院查体的2型糖尿病患者57例,根据糖化血红蛋白水平将其分为高糖化组(糖化血红蛋白>7.0,28例)与低糖化组(糖化血红蛋白≤7.0,29例)。应用气相色谱法检测两组患者粪便中6种短链脂肪酸水平,并分析6种短链脂肪酸水平与糖化血红蛋白的相关性。 结果 低糖化组患者粪便中乙酸、丙酸、丁酸、戊酸水平显著高于高糖化组(均P0.05)。Pearson相关性分析结果表明:在2型糖尿病患者中,糖化血红蛋白与粪便中乙酸呈负相关(r=-0.540 1,P结论 2型糖尿病患者粪便中短链脂肪酸水平与糖化血红蛋白存在一定的相关性,短链脂肪酸水平的下降可能是影响血糖控制不佳的主要原因。     

Blood DNA methylation markers associated with type 2 diabetes,fasting glucose,and HbA1c levels: An epigenome-wide association study in 316 adult twin pairs

DNA methylation plays an important role in the development and etiology of type 2 diabetes; however, few epigenomic studies have been conducted on twins. Herein, a two-stage study was performed to explore the associations between DNA methylation and type 2 diabetes, fasting plasma glucose, and HbA1c. DNA methylation in 316 twin pairs from the Chinese National Twin Registry (CNTR) was measured using Illumina Infinium BeadChips. In the discovery sample, the results revealed that 63 CpG sites and 6 CpG sites were significantly associated with fasting plasma glucose and HbA1c, respectively. In the replication sample, cg19690313 in TXNIP was associated with both fasting plasma glucose (P = 1.23 × 10⁻¹⁷, FDR < 0.001) and HbA1c (P = 2.29 × 10^–18, FDR < 0.001). Furthermore, cg04816311, cg08309687, and cg09249494 may provide new insight in the metabolic mechanism of HbA1c. Our study provides solid evidence that cg19690313 on TXNIP correlates with HbA1c and fasting plasma glucose levels.     

Low plasma albumin levels are associated with increased plasma protein glycation and HbA1c in diabetes

Albumin is one of the most abundant plasma proteins and is heavily glycated in diabetes. In this study, we have addressed whether variation in the albumin levels influence glycation of plasma proteins and HbA1c. The study was performed in three systems: (1) streptozotocin (STZ)-induced diabetic mice plasma, (2) diabetic clinical plasma, and (3) in vitro glycated plasma. Diabetic mice and clinical plasma samples were categorized as diabetic high albumin plasma (DHAP) and diabetic low albumin plasma (DLAP) on the basis of their albumin levels. For the in vitro experiment, two albumin levels, high albumin plasma (HAP) and low albumin plasma (LAP), were created by differential depletion of plasma albumin. Protein glycation was studied by using a combination of two-dimensional electrophoresis (2DE), Western blotting, and LC-MS(E). In both mice and clinical experiments, an increased plasma protein glycation was observed in DLAP than in DHAP. Additionally, plasma albumin levels were negatively correlated with HbA1c. The in vitro experiment with differential depletion of albumin mechanistically showed that the low albumin levels are associated with increased plasma protein glycation and that albumin competes for glycation with other plasma proteins.     

Evaluation for fasting and 2-hour glucose and HbA1c for diagnosing diabetes based on prevalence of retinopathy in a Chinese population

Background

The glycemic thresholds for diabetes diagnosis have long been at the forefront of discussion. However, no information about glycemic cutoff points has been made available for the Chinese population. The aim of the present study was to examine the association of fasting plasma glucose (FPG), 2-h plasma glucose (2-h PG) and HbA₁c levels with diabetic retinopathy (DR) and determine the associated cutoff levels in a Chinese population.

Methodology and Principal Findings

In a cross-sectional population-based sample of 2551 Chinese (representing a population of 1,660,500 in a Beijing district) between 18–79 years of age, the three glycemic measures were measured in a 75 g oral glucose tolerance test, and DR was assessed by two 45° color digital retinal images. The prevalence of DR increased in the ninth decile of each variable, corresponding to an FPG of ≥7.2 mmol/l, a 2-h PG of ≥10.7 mmol/l, and HbA₁c of ≥6.4%, according to the Joinpoint regression method. After excluding individuals receiving antihyperglycemic medication, the prevalence significantly increased at an FPG of ≥6.8 mmol/l, a 2-h PG of ≥12.0 mmol/l, and HbA₁c of ≥6.7%. The area under the ROC curve for all three measures showed no significant differences for detecting DR. After excluding individuals receiving antihyperglycemic medication, the three measures also showed no significant differences.

Conclusions and Significance

A significant increase in retinopathy prevalence occurs among individuals with FPG ≥7.2 mmol/l, 2-h PG ≥10.5 mmol/and HbA₁c ≥6.4%; and measuring FPG or HbA₁c are equally reliable methods as measuring 2-h PG for the diagnosis of diabetes in the Chinese population.     

Relationship between HbA1c and Continuous Glucose Monitoring in Chinese Population: A Multicenter Study

Objective

Since there is a paucity of reference data in the literature to indicate the relationship between HbA1c, and 24 h mean blood glucose (MBG) from continuous glucose monitoring (CGM) in Chinese populations, we described the above relationship in adult Chinese subjects with different glucose tolerance status.

Methods

Seven-hundred-and-forty-two individuals without history of diabetes were included to the study at 11 hospitals in urban areas across China from 2007–2009 and data of 673 subjects were included into the final analysis. Oral glucose tolerance test (OGTT) classified the participants as nondiabetic subjects, including those with normal glucose regulation (NGR; n = 121) and impaired glucose regulation (IGR; n = 209), or newly diagnosed type 2 diabetes (n = 343). All participants completed testing for HbA1c levels and wore a CGM system for three consecutive days. The 24 h MBG levels were calculated. Spearman correlations and linear regression analyses were applied to quantify the relationship between glucose markers.

Results

The levels of HbA1c and 24 h MBG significantly increased with presence of glucose intolerance (NGR<IGR<type 2 diabetes; both, P<0.001). Analysis of the total population indicated that HbA1c was strongly correlated with 24 h MBG (r = 0.735). The correlation was also found to be significant for the subgroup of participants with newly diagnosed type 2 diabetes (r = 0.694, P<0.001). Linear regression analysis of the total study population yielded the following equation: 24 h MBG _mmol/L = 1.198×HbA1c–0.582 (24 h MBG _mg/dL = 21.564×HbA1c–10.476) (R² = 0.670, P<0.001). The model fit was not improved by application of exponential or quadratic modeling. When HbA1c was 6.5%, the calculated 24 h MBG was 7.2 (6.4–8.1) mmol/L (130 (115–146) mg/dL); and when HbA1c was 7.0%, the 24 h MBG was 7.8 (6.9–8.7) mmol/L (140 (124–157) mg/dL).

Conclusions

Our study provided the reference data of the relationship between HbA1c and CGM in Chinese subjects.     

Plasma resistin levels in patients with type 1 and type 2 diabetes mellitus and in healthy controls.

Resistin is a recently discovered hormone that is exclusively expressed in adipose tissue. Its expression in rodents was reported to be elevated or suppressed in genetic and diet-induced obesity, respectively. Resistin treatment impaired glucose tolerance and insulin action. Immunoneutralization of resistin improved insulin sensitivity, while thiazolidinedione treatment reduced resistin expression. Therefore, resistin could play a critical role in the development of obesity and type 2 diabetes. In this study were determined resistin plasma levels in humans suffering from type 1 and type 2 diabetes and in healthy controls. Plasma levels of resistin in healthy controls were 38.78 ng/ml. They were not statistically different in individuals with a broad BMI range. Resistin plasma levels in type 2 diabetes were 38.7 ng/ml, and 39.4 ng/ml in type 1 diabetes. Thiazolidinedione treatment did not influence resistin plasma levels. We conclude from our data: 1. resistin can be detected in human plasma, 2. plasma resistin levels are not different in type 1 and type 2 diabetes.     

Relationship between Hb and HbA2 concentrations in healthy and iron deficient subjects.

In 23 healthy subjects and in 115 patients with various degrees of chronic iron deficiency anaemia without congenital abnormalities of globin synthesis, Hb ranged from 3.4 to 16.3 g/100 ml. HbA2 ranged from 0.0550 to 0.5250 g/100 ml. Hb and HbA2 were statistically correlated, as shown by linear regression analysis (a equals --0.1387; b equals 0.0372; r equals 0.8198; P smaller than 0.001). The second degree parabola was not statistically different, but it gave a biologically preferable Figure for intercept (a equals --0.0006; b equals 0.0070; c equals 0.0015; r equals 0.8324; P smaller than 0.001). The second degree parabola was to be preferred also on the basis of previous literature results. Shortness of iron seems to reduce more the HbA2 than the Hb levels.     

格列吡嗪对2型糖尿病患者血糖、血脂的影响

目的:探讨格列吡嗪对2型糖尿病患者血清血糖及血脂水平的影响.方法:2型糖尿病患者120例.两组年龄、性别匹配,按随机双盲法分为治疗组(60例)和安慰剂组(60例),干预治疗16周后比较其血清血糖和血脂水平,同时测血压、身高、体重等指标,计算体重指数(BMI).结果:经格列吡嗪治疗后,患者血糖、血脂水平明显降低(P＜0.05).结论:格列吡嗪可能通过降低血糖和血脂水平改善2型糖尿病患者胰岛素抵抗从而改善血糖及血脂水平.     

Ethnic disparity in hemoglobin A1c levels among normoglycemic offspring of parents with type 2 diabetes mellitus

ObjectiveTo investigate the racial/ethnic disparities in hemoglobin A_1c levels among nondiabetic persons with similar parental history of type 2 diabetes mellitus.MethodsWe studied a community-based sample of adult offspring of parents with type 2 diabetes mellitus. Measurements included anthropometry, hematology assessments, serial fasting plasma glucose, oral glucose tolerance testing, plasma insulin, hemoglobin A_1c, insulin sensitivity, and b-cell function, using a homeostasis model assessment.ResultsThe study included 302 participants (135 white, 167 black). Compared with white participants, black participants had lower fasting plasma glucose levels (91.9 ± 0.51 mg/dL vs 93.6 ± 0.50 mg/dL, P = .015), lower area under the curve of plasma glucose during oral glucose tolerance testing (P = <.001), higher body mass index (31.1 ± 0.61 kg/m² vs 28.5 ± 0.57 kg/m², P = <.001), and similar insulin sensitivity and b-cell function. Hemoglobin A_1c was higher in black participants than in white participants (5.68 ± 0.033% vs 5.45 ± 0.028%, P <.001). The absolute black-white difference in hemoglobin A_1c level of approximately 0.22% persisted after adjusting for age, hemoglobin, hematocrit, body mass index, waist circumference, fasting plasma glucose, glucose area under the curve, and other covariates.ConclusionsAmong healthy offspring of parents with type 2 diabetes mellitus in this study, African American participants had higher hemoglobin A_1c levels than white participants after adjusting for age, adiposity, blood glucose, and known variables. Thus, plasma glucose level is more valid than hemoglobin A_1c for diagnosing prediabetes or diabetes in black persons. (Endocr Pract. 2012; 18:356-362)     

Identification of variables influencing resistin serum levels in patients with type 1 and type 2 diabetes mellitus.

BACKGROUND: Resistin, a peptide hormone, has been discussed controversially as a missing link between obesity and insulin resistance. In contrast to resistin mRNA expression in adipose tissue, data on human serum levels in obesity and diabetes mellitus is scarce. The physiological range of serum resistin levels, reference values or adjusted percentiles have not yet been determined, making the interpretation of serum resistin concentrations quite difficult. METHODS: Resistin serum concentrations were measured systematically by ELISA in 216 healthy controls, 555 patients with type 2 diabetes and 114 patients with type 1 diabetes. Mean values, median, and range were determined, and BMI-, gender-, and disease-adapted percentiles were calculated for all subgroups. RESULTS: Age and gender did not have any influence on resistin levels. BMI and resistin levels were positively correlated in healthy controls (p = 0.02), albeit with a weak correlation coefficient. This correlation was absent in patients with type 1 and type 2 diabetes. In both genders, healthy controls had significantly higher resistin levels than patients with type 1 and type 2 diabetes (7.9 +/- 0.2 ng/ml vs. 5.7 +/- 0.2 ng/ml and 5.5 +/- 0.1 ng/ml, respectively; p < 0.0001). There was no correlation between resistin levels and occurrence of diabetic retinopathy or nephropathy. CONCLUSIONS: Serum resistin levels can be measured by ELISA over a broad range from 0.6 ng/ml up to 27.7 ng/ml, suggesting that percentiles might be helpful in the interpretation of an individuals resistin value. While age and gender do not influence resistin levels, BMI and occurrence of diabetes have to be considered.     

Autophagic adaptations in diabetic cardiomyopathy differ between type 1 and type 2 diabetes

Little is known about the association between autophagy and diabetic cardiomyopathy. Also unknown are possible distinguishing features of cardiac autophagy in type 1 and type 2 diabetes. In hearts from streptozotocin-induced type 1 diabetic mice, diastolic function was impaired, though autophagic activity was significantly increased, as evidenced by increases in microtubule-associated protein 1 light chain 3/LC3 and LC3-II/-I ratios, SQSTM1/p62 (sequestosome 1) and CTSD (cathepsin D), and by the abundance of autophagic vacuoles and lysosomes detected electron-microscopically. AMP-activated protein kinase (AMPK) was activated and ATP content was reduced in type 1 diabetic hearts. Treatment with chloroquine, an autophagy inhibitor, worsened cardiac performance in type 1 diabetes. In addition, hearts from db/db type 2 diabetic model mice exhibited poorer diastolic function than control hearts from db/+ mice. However, levels of LC3-II, SQSTM1 and phosphorylated MTOR (mechanistic target of rapamycin) were increased, but CTSD was decreased and very few lysosomes were detected ultrastructurally, despite the abundance of autophagic vacuoles. AMPK activity was suppressed and ATP content was reduced in type 2 diabetic hearts. These findings suggest the autophagic process is suppressed at the final digestion step in type 2 diabetic hearts. Resveratrol, an autophagy enhancer, mitigated diastolic dysfunction, while chloroquine had the opposite effects in type 2 diabetic hearts. Autophagy in the heart is enhanced in type 1 diabetes, but is suppressed in type 2 diabetes. This difference provides important insight into the pathophysiology of diabetic cardiomyopathy, which is essential for the development of new treatment strategies.     

Heparanase levels are elevated in the urine and plasma of type 2 diabetes patients and associate with blood glucose levels

Heparanase is an endoglycosidase that specifically cleaves heparan sulfate side chains of heparan sulfate proteoglycans. Utilizing an ELISA method capable of detection and quantification of heparanase, we examined heparanase levels in the plasma and urine of a cohort of 29 patients diagnosed with type 2 diabetes mellitus (T2DM), 14 T2DM patients who underwent kidney transplantation, and 47 healthy volunteers. We provide evidence that heparanase levels in the urine of T2DM patients are markedly elevated compared to healthy controls (1162 ± 181 vs. 156 ± 29.6 pg/ml for T2DM and healthy controls, respectively), increase that is statistically highly significant (P<0.0001). Notably, heparanase levels were appreciably decreased in the urine of T2DM patients who underwent kidney transplantation, albeit remained still higher than healthy individuals (P<0.0001). Increased heparanase levels were also found in the plasma of T2DM patients. Importantly, urine heparanase was associated with elevated blood glucose levels, implying that glucose mediates heparanase upregulation and secretion into the urine and blood. Utilizing an in vitro system, we show that insulin stimulates heparanase secretion by kidney 293 cells, and even higher secretion is observed when insulin is added to cells maintained under high glucose conditions. These results provide evidence for a significant involvement of heparanase in diabetic complications.     

Recent HbA1c Values and Mortality Risk in Type 2 Diabetes. Population-Based Case-Control Study

This study aimed to evaluate mortality within 365 days of HbA1c values of <6.5% or >9.0% in participants with clinical type 2 diabetes mellitus. A matched nested case-control study was implemented, within a cohort of participants with type 2 diabetes from 2000 to 2008. Conditional logistic regression was used to model the odds ratio for mortality adjusting for comorbidity and drug utilisation. There were 97,450 participants with type 2 diabetes; 16,585 cases that died during follow up were matched to 16,585 controls. The most recent HbA1c value was <6.5% (48 mmol/mol) for 22.2% of cases and 24.2% of controls, the HbA1c was >9.0% for 9.0% of cases and 7.7% of controls. In a complete case analysis, the adjusted odds ratio (AOR) for mortality associated with most recent HbA1c <6.5% was 1.31 (95% confidence interval (CI): 1.21,1.42). After multiple imputation of missing HbA1c values the AOR was 1.20 (CI: 1.12,1.28). The complete case analysis gave an AOR for HbA1c >9.0% of 1.51 (CI: 1.33, 1.70), in the multiple imputation analysis this was 1.29 (1.17,1.41). The risk associated with HbA1c <6.5% was age dependent. In the multiple imputation analysis the AOR was 1.53 (CI: 0.84 to 2.79) at age<55 years but 1.04 (CI: 0.92, 1.17) at age 85 years and over. In non-randomised data, values of HbA1c that are either <6.5% or >9.0% may be associated with increased mortality within one year in clinical type 2 diabetes. Relative risks may be higher at younger ages.