Association of prediabetes by fasting glucose and/or haemoglobin A1c levels with subclinical atherosclerosis and impaired renal function: observations from the Dallas Heart Study

Can prediabetes diagnosed using HemoglobinA1c or oral glucose tolerance test predict presence and severity of coronary artery disease in symptomatic patients?

We investigated whether prediabetes diagnosed by hemoglobinA1c (HbA1c) or oral glucose tolerance test (OGTT) could predict presence and severity of coronary artery disease (CAD) in symptomatic patients. The presence of plaque, stenosis, plaque characteristics, and coronary artery calcium (CAC) were evaluated by coronary CT angiography in 702 patients with suspicion of CAD. Patients were classified by glycemic status using the American Diabetes Association criteria for HbA1c and OGTT, and compared to their respective normal ranges. Prediabetes was observed in 24% by HbA1c and 72% by OGTT. Both prediabetes classifications were associated with increased presence of plaque, stenosis, calcified plaques, CAC >400, and a lower frequency of zero CAC compared to their respective normal range (all, p < 0.05). After adjusting for potential confounders, patients with HbA1c-prediabetes had an odds ratio of 2.1 (95% CI: 1.3-3.5) for CAC >400 and 1.5 (95% CI: 1.0-2.4) for plaque presence, while none of the associations for OGTT-prediabetes were significant. The receiver operating characteristic-curve for HbA1c-prediabetes showed an area under the curve of 0.81 for CAC >400 and 0.77 for plaque presence. Prediabetes defined by HbA1c predicts presence and severity of CAD. Although OGTT identified more patients with prediabetes, their risk of CAD were not explained by prediabetes using these diagnostic-criteria.

Sex differences in the risk of arterial stiffness among adults with different glycemic status and modifications by age

BACKGROUND

Studies indicate lower, comparable, and higher cardiovascular risks in women vs men in normal glucose regulation (NGR), prediabetes, and diabetes, respectively. However, this sex difference is uncertain and aging might play a part. We aimed to estimate sex differences in arterial stiffness in NGR, prediabetes, or diabetes and the potential modifications by age.

METHODS

We used baseline data of 9618 participants aged ≥40 years in a large community-based cohort study in Shanghai. Glycemic status was determined by history of diabetes, fasting and 2-h post-load glucose levels, and hemoglobin A1c levels. Arterial stiffness was examined by brachial-ankle pulse wave velocity (ba-PWV). Multivariable linear regression analysis was conducted to examine the associations between sex and ba-PWV levels in glycemic and age categories.

RESULTS

Before adjustment for age, women had lower, comparable, and higher ba-PWV vs men in the NGR, prediabetes, and diabetes groups, respectively. In participants aged 40-59 years, women were associated with lower ba-PWV levels in generally all glycemic strata after adjustment for age and other confounders. In participants aged ≥60 years, women were associated with significantly higher ba-PWV levels (β coefficient = 71.5; 95% confidence interval = 23.4, 119.7) and the sex difference was attenuated in the groups of prediabetes and diabetes with a borderline significant interaction between sex and glycemic status (p for interaction = .068).

CONCLUSIONS

The sex difference in cardiovascular risks in adults with NGR, prediabetes, or diabetes was dependent on age. Our findings provide new evidence for prioritizing preventive treatment against atherosclerosis in men vs women with different glycemic status.

Persistence or regression of prediabetes and coronary artery calcification among adults without diabetes

OBJECTIVE

The effect of changes in glycemic status on subclinical atherosclerosis is uncertain. We assessed the association of persistence, regression, or progression of prediabetes with coronary artery calcium score (CACS) as a measure of subclinical atherosclerosis.

DESIGN

A cross-sectional study, comprising 126 765 adults, and longitudinal sub-study, comprising 40 622 adults (with baseline and at least 1 follow-up computed tomography scan to assess changes in CACS), were undertaken.

METHODS

Changes in glycemic status over 1.5 years (interquartile range, 1.0-2.0) before the first CACS assessment were categorized according to 6 groups: persistent normoglycemia (reference), normoglycemia to prediabetes, normoglycemia to diabetes, prediabetes to normoglycemia, persistent prediabetes, and prediabetes to diabetes. Logistic regression was used to calculate the odds ratios (ORs) and 95% CIs for prevalent coronary artery calcification (CAC). Mixed models with random intercepts and random slopes were used to estimate 5-year CAC progression rates.

RESULTS

Mean (SD) age was 41.3 (7.0) years (74.7% male) (n = 126 765). Multivariable-adjusted OR for prevalent CAC was 1.13 (95% CI, 1.08-1.18) for persistent prediabetes, 1.05 (0.98-1.12) for regression to normoglycemia, and 1.46 (95% CI, 1.27-1.67) for progression from prediabetes to diabetes, compared with persistent normoglycemia. Coronary artery calcification progression increased significantly in all prediabetes groups. Multivariable-adjusted ratio of 5-year CAC progression rates was 1.19 (95% CI, 1.16-1.22) (persistent prediabetes), 1.11 (1.07-1.14) (regression to normoglycemia), and 1.63 (95% CI, 1.26-2.10) (progression from prediabetes to diabetes).

CONCLUSIONS

Unfavorable changes in glycemic status, including persistence of prediabetes or progression to diabetes from prediabetes, were associated with increased risk of CAC.

Addressing the Continuum of Dysglycaemia and Vascular Complications in Prediabetes and Type 2 Diabetes: Need for Early and Intensive Treatment

The onset of type 2 diabetes increases the risk of vascular complications and death. We know now that that this risk begins long before the diabetes diagnosis. Prediabetes and type 2 diabetes are not separate entities in practice and exist within a continuum of dysglycaemia and vascular risk that increases in severity over time. This excess risk requires early intervention with lifestyle therapy supported with pharmacologic antidiabetic therapy, intensified promptly where necessary throughout the duration of the diabetes continuum. Metformin is an evidence-based treatment for preventing prediabetes and improves cardiovascular outcomes in people with type 2 diabetes from diagnosis onwards. Newer agents (SGLT2 inhibitors and GLP-1 agonists) are appropriate for people presenting with type 2 diabetes and significant cardiovascular comorbidity. Additional therapies should be used without delay to achieve patients' individualised HbA1c goals and to minimise cardiovascular risk.

Prediabetes diagnosis is associated with the progression of coronary artery calcification: The Kangbuk Samsung Health Study

AIM

To investigate the associations between prediabetes defined by different diagnostic criteria and coronary artery calcification (CAC) and its progression over time.

MATERIALS AND METHODS

This cross-sectional study included 146 436 Korean adults without diabetes who underwent CAC estimation computed tomography (CT) during health examinations from 2011 to 2019. We used multinomial logistic regression models. The longitudinal study comprised 41 100 participants with at least one follow-up cardiac CT and annual CAC progression rates and ratios were estimated. Prediabetes was categorized into three groups: isolated glucose prediabetes (fasting blood glucose [FBG] 100-125 mg/dl, HbA1c < 5.7%), isolated HbA1c prediabetes (FBG < 100 mg/dl, HbA1c 5.7%-6.4%) and prediabetes meeting both FBG and HbA1c criteria (FBG 100-125 mg/dl, HbA1c 5.7%-6.4%).

RESULTS

After adjusting for covariates, the prevalence ratios (95% CI) for CAC scores of more than 100 comparing isolated glucose prediabetes, isolated HbA1c prediabetes and prediabetes fulfilling both criteria with those of normoglycaemia were 1.12 (0.99-1.26), 1.24 (1.11-1.39) and 1.31 (1.18-1.45), respectively. The multivariable-adjusted ratio (CIs) of annual CAC progression rates comparing the corresponding groups with the normoglycaemia group were 1.031 (1.023-1.039), 1.025 (1.019-1.032) and 1.054 (1.047-1.062), respectively.

CONCLUSIONS

CAC risk and CAC progression were consistently highest in individuals meeting both glucose and HbA1c criteria, while all three prediabetes types showed a significantly increased risk of CAC progression. Atherosclerosis risk reduction management is necessary for prediabetes, especially in patients meeting both criteria.

Vascular complications in prediabetes and type 2 diabetes: a continuous process arising from a common pathology

The term, "prediabetes", describes a state of hyperglycaemia that is intermediate between true normoglycaemia and the diagnostic cut-offs for indices of glycaemia that are used to diagnose type 2 diabetes. The presence of prediabetes markedly increases the risk of developing type 2 diabetes. Numerous randomized, controlled evaluations of various agents have demonstrated significant prevention or delay of the onset of type 2 diabetes in subjects with prediabetes. Intensive lifestyle interventions and metformin have been studied most widely, with the lifestyle intervention being more effective in the majority of subjects. The application of therapeutic interventions at the time of prediabetes to preserve long-term outcomes has been controversial, however, due to a lack of evidence relating to the pathogenic effects of prediabetes and the effectiveness of interventions to produce a long-term clinical benefit. Recent studies have confirmed that prediabetes, however defined, is associated with a significantly increased risk of macrovascular and microvascular complications essentially identical to those of diabetes, and also with subclinical derangements of the function of microvasculature and neurons that likely signify increased risk of compilations in future. Normoglycaemia, prediabetes and type 2 diabetes appear to be part of a continuum of increased risk of adverse outcomes. Long-term (25-30 years) post-trial follow up of two major diabetes prevention trials have shown that short-term interventions to prevent diabetes lead to long-term reductions in the risk of complications. These findings support the concept of therapeutic intervention to preserve long-term health in people with prediabetes before type 2 diabetes becomes established.

Risk of Macrovascular and Microvascular Disease in Diabetes Diagnosed Using Oral Glucose Tolerance Test With and Without Confirmation by Hemoglobin A1c: The Whitehall II Cohort Study

BACKGROUND

It is unclear whether replacing oral glucose tolerance test (OGTT) with hemoglobin A1c (HbA1c) measurement for diagnosing diabetes is justified. We aimed to assess the proportion of OGTT-diagnosed diabetes cases that can be confirmed by HbA1c and to examine whether individuals with OGTT diagnosis but nondiagnostic HbA1c are at higher risk of macrovascular and microvascular disease.

METHODS

Participants were 5773 men and women from the population-based Whitehall II prospective cohort study in the United Kingdom. New OGTT diabetes cases diagnosed in clinical examinations in 2002 to 2004 and 2007 to 2009 were assessed for HbA1c confirmation (≥6.5%) in these and subsequent clinical examinations in 2012 to 2013 and 2015 to 2016. All participants were followed up for major cardiovascular events through linkage to electronic health records until 2017 and for incident chronic kidney disease (estimated glomerular filtration rate <60 mL·min^-1·1.73 m^-2) until the last clinical examination. In analysis of vascular disease risk, new OGTT-diagnosed diabetes cases with and without diagnostic HbA1c and preexisting diabetes cases were compared with diabetes-free participants.

RESULTS

Of the 378 (59.3%) participants with OGTT-diagnosed diabetes, 224 were confirmed by HbA1c during 4.1 years (SD, 4.1 years) of follow-up. We recorded 942 cardiovascular events over 12.1 years. After adjustment for nonmodifiable risk factors and compared with the 4997 diabetes-free participants, 371 participants with new HbA1c-confirmed diabetes and 405 participants with preexisting diabetes had increased risk of cardiovascular disease (hazard ratio, 1.53 [95% CI, 1.12-2.10] and 1.85 [95% CI, 1.50-2.28], respectively). The corresponding hazard ratios in the analysis of incident chronic kidney disease (487 cases; follow-up, 6.6 years) were 1.69 (95% CI, 1.09-2.62) for 282 participants with new HbA1c-confirmed diabetes and 1.67 (95% CI, 1.22-2.28) for 276 participants with preexisting diabetes. In both analyses, OGTT cases with nondiagnostic HbA1c (n=149 and 107) had a risk (hazard ratio, 0.99-1.07) similar to that of the diabetes-free population.

CONCLUSIONS

More than 40% of OGTT-diagnosed diabetes cases were not confirmed by HbA1c during an extended follow-up. However, because these individuals have a risk of cardiovascular disease and chronic kidney disease similar to that of the diabetes-free population, replacement of OGTT with HbA1c-based diagnosis appears justified.

Impaired fasting blood glucose is associated with incident albuminuria: Data from a Chinese community-based cohort

OBJECTIVE

Growing evidence links hyperglycemia in the diabetic range to albuminuria, while the association between impaired fasting glucose (IFG) and albuminuria is not well established. The study intends to explore whether IFG is longitudinally associated with incident albuminuria in a non-diabetic Chinese community-based cohort.

METHODS

Participants with urine albumin creatinine ratio (UACR) both in 2014 and 2018 from the atherosclerotic cohort were included. A total of 1649 non-diabetic subjects were ultimately included in the analysis after ruling out participants with UACR≥30 mg/g and self-reported history of renal diseases at baseline. Fasting blood glucose (FBG) was assessed by Roche C8000 Automatic Analyzer and UACR was measured with Unicel DxC 800 Synchron biochemistry analyzer using spot morning urine sample. Incident albuminuria was defined as an advance from normal to microalbuminuria or macroalbuminuria. Multivariable logistic regression model was used to investigate the relationship between FBG and incident albuminuria.

RESULTS

During a mean follow-up of 4.38 years, 82 (4.97%) participants developed incident albuminuria. Logistic regression analysis showed that after adjustment, the risk of incident albuminuria increased by 71% (OR = 1.71, 95%CI: 1.11-2.62, P = 0.014) for every 18 mg/dl (1 mmol/l) increase of FBG level. Besides, FBG level was independently and gradably associated with incident albuminuria. Compared with the FBG < 100 mg/dl (5.6 mmol/l) group, the risk increased 1.63-fold for incident albuminuria (OR = 2.63, 95%CI:1.42-4.87, P = 0.002) in the FBG 110-126 mg/dl (6.1-7.0 mmol/l) group while the association between FBG 100-110 mg/dl (5.6-6.1 mmol/l) group and the outcome was not significant. Subgroup and interaction analyses were performed and no significant modification effect was found.

CONCLUSION

IFG was independently associated with incident albuminuria in Chinese community-based population. The higher the FBG level, the higher the risk of incident albuminuria, which may suggest that screening for albuminuria should be emphasized in population with IFG so as to prevent and treat it in an early stage.

LDL-Cholesterol versus Glucose in Microvascular and Macrovascular Disease

BACKGROUND

The causal relationships between increased concentrations of low density lipoprotein (LDL)-cholesterol and glucose and risk of ischemic heart disease are well established. The causal contributions of LDL-cholesterol and glucose to risk of peripheral micro- and macrovascular diseases are less studied, especially in prediabetic stages and in a general population setting.

CONTENT

This review summarizes the current evidence for a causal contribution of LDL-cholesterol and glucose to risk of a spectrum of peripheral micro- and macrovascular diseases and reviews possible underlying disease mechanisms, including differences between vascular compartments, and finally discusses the clinical implications of these findings, including strategies for prevention and treatment.

SUMMARY

Combined lines of evidence suggest that LDL-cholesterol has a causal effect on risk of peripheral arterial disease and chronic kidney disease, both of which represent manifestations of macrovascular disease due to atherosclerosis and accumulation of LDL particles in the arterial wall. In contrast, there is limited evidence for a causal effect on risk of microvascular disease. Glucose has a causal effect on risk of both micro- and macrovascular disease. However, most evidence is derived from studies of individuals with diabetes. Further studies in normoglycemic and prediabetic individuals are warranted. Overall, LDL-cholesterol-lowering reduces risk of macrovascular disease, while evidence for a reduction in risk of microvascular disease is inconsistent. Glucose-lowering has a beneficial effect on risk of microvascular diseases and on risk of chronic kidney disease and estimated glomerular filtration rate (eGFR) in some studies, while results on risk of peripheral arterial disease are conflicting.

Diagnosing type 2 diabetes using Hemoglobin A1c: a systematic review and meta-analysis of the diagnostic cutpoint based on microvascular complications

AIMS

Diabetic microvascular complications of retinopathy, nephropathy and neuropathy may occur at hemoglobin A1c levels (HbA1c) below the 6.5% (48 mmol/mol) diagnostic threshold. Our objective was to assess the validity of the HbA1c diagnostic cutpoint of 6.5% based upon published evidence of the prevalence of retinopathy, nephropathy and neuropathy as markers of diabetes.

METHODS

Data Sources PubMed, Embase, Cochrane, Scopus and CINAHL from 1990-March 2019, grey literature sources. Study Selection All studies reported after 1990 (to ensure standardized HbA1c values) where HbA1c levels were presented in relation to prevalence of retinopathy, nephropathy or neuropathy in subjects not known to have diabetes. Data Extraction Studies were screened independently, data abstracted, and risk of bias appraised. Data Synthesis Data were synthesized using HbA1c categories of < 6.0% (< 42 mmol/mol), 6.0-6.4% (42-47 mmol/mol) and ≥ 6.5% (≥ 48 mmol/mol). Random-effects meta-analyses were conducted for retinopathy, nephropathy and neuropathy prevalence stratified by HbA1c categories. Random-effects multivariable meta-regression was conducted to identify predictors of retinopathy prevalence and sources of between-study heterogeneity.

RESULTS

Pooled mean prevalence was: 4.0%(95% CI: 3.2-5.0%) for retinopathy, 10.5% (95% CI: 4.0-19.5%) for nephropathy, 2.5% (95% CI: 1.1-4.3%) for neuropathy. Mean prevalence when stratified for HbA1c < 6.0%, 6.0-6.4% and ≥ 6.5% was: retinopathy: 3.4% (95% CI: 1.8-5.4%), 2.3% (95% CI: 1.6-3.2%) and 7.8%(95% CI: 5.7-10.3%); nephropathy: 7.1% (95% CI: 1.7-15.9%), 9.6% (95% CI: 0.8-26.4%) and 17.1% (95% CI: 1.0-46.9%); neuropathy: 2.1% (95% CI: 0.0-6.8%), 3.4% (95% CI: 0.0-11.6%) and 2.8% (95% CI: 0.0-12.8%). Multivariable meta-regression showed HbA1c ≥ 6.5% (OR: 4.05; 95% CI: 1.92-8.57%), age > 55 (OR: 3.23; 95% CI 1.81-5.77), and African-American race (OR: 10.73; 95% CI: 4.34-26.55), to be associated with higher retinopathy prevalence. Marked heterogeneity in prevalence estimates was found across all meta-analyses (Cochran's Q-statistic p < 0.0001).

CONCLUSIONS

The prevalence of nephropathy and moderate retinopathy was increased in subjects with HbA1c values ≥ 6.5% confirming the high specificity of this value for diagnosing T2DM; however, at HbA1c < 6.5% retinopathy increased at age > 55 years and, most strikingly, in African-Americans, suggesting there may be excess microvascular complication prevalence (particularly nephropathy) in individuals below the diabetes diagnostic threshold.

The association of subclinical atherosclerosis with prediabetes is stronger in people with dyslipidaemia than in those with normoglycaemia: A cross-sectional study in Chinese adults

BACKGROUND

Prediabetes is associated with a high risk of cardiovascular disease (CVD) and often occurs with dyslipidaemia. The present study investigated the association between subclinical atherosclerosis profiles and prediabetes with and without dyslipidaemia.

METHODS

This cross-sectional analysis included 4786 participants (1441 subjects with prediabetes and 3345 healthy controls). Prediabetes was defined by fasting plasma glucose (FPG) 5.6-6.9mmol/L or HbA1c 5.7-6.4% without antidiabetic drugs. Different markers of subclinical atherosclerosis were analysed: the carotid intima-media thickness (CIMT), carotid plaques (CP), and brachial-ankle pulse wave velocity (baPWV).

RESULTS

Subclinical atherosclerosis was significantly more prevalent in prediabetic subjects than in normoglycaemic subjects (P<0.001). Only individuals with prediabetes in the dyslipidaemic group had significantly elevated adjusted odds ratios for subclinical atherosclerosis profiles. When stratified by FPG-only, HbA1c-only or both, the three subcategories in combination with dyslipidaemia shared a similarly increased risk of subclinical atherosclerosis compared to normoglycaemia without dyslipidaemia (P<0.05). The risk profile increased directionally from FPG-only to HbA1c-only to both overall.

CONCLUSION

Our data suggest that subclinical atherosclerotic changes in the prediabetic state are mainly seen in dyslipidaemic subjects. Thus, strategies to prevent atherogenic changes might focus on persons with prediabetes combined with dyslipidaemia, especially for the prediabetes-both subcategory, because of potential effects on CVD risk.

Is it possible to predict atherosclerosis in the ascending aorta by the patient's lipid panel?

INTRODUCTION

Atherosclerosis is a chronic inflammatory event characterized by stiffness and thickening of the vascular walls. In our daily practice, we assume the atherosclerotic potential of the patient by following the total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglyceride levels (lipid panel). We aimed to understand the relation between the HDL, LDL, cholesterol levels and the atherosclerosis in large vascular structures such as the ascending aorta.

MATERIAL AND METHODS

We have searched for atherosclerosis in the aortic tissue samples from 48 patients. It is a study in which we examine the correlation of preoperative cholesterol values (HDL, LDL, triglyceride, total cholesterol) by dividing the patients into two groups according to the presence of plaque.

RESULTS

Forty-three (89.6%) male and 5 (10.4%) female patients between 39 and 81 years of age were included in the study. There was no statistically significant difference between the patients' preoperative cardiovascular risk assessments. The free T3 values were within the normal range in all patients, but there was a difference that patients in the non-atherosclerosis group had lower values. There was no statistically significant difference between the two groups' HDL, LDL, total cholesterol, or triglyceride parameters.

CONCLUSIONS

As a result, in our study, no significant difference was found between HDL-C, LDL-C, triglyceride, total cholesterol values and the pathological process of aortic atherosclerosis. As a result of this study, we believe that it was necessary to correct the error margins of these parameters. In addition, it required the need for a clearer laboratory parameter to demonstrate atherosclerosis.

Risk of chronic kidney disease defined by decreased estimated glomerular filtration rate in individuals with different prediabetic phenotypes: results from a prospective cohort study in China

OBJECTIVE

We aimed to investigate the effects of prediabetes and its phenotypes of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycated hemoglobin A1c (EHbA1c) on chronic kidney disease (CKD) occurrence, and define the cut-off point of each glycemic index that significantly increases the risk of CKD.

RESEARCH DESIGN AND METHODS

In this prospective cohort study, 6446 non-diabetic subjects aged 40 years and over were followed over a period of 3 years to track the new onset of CKD. Cox regression was used to assess the association of prediabetes and its phenotypes with CKD. Receiver operating characteristic curves were used to define the cut-off point of each glycemic index that significantly increases the occurrence of CKD. Population attributable risk percent was calculated to estimate the contribution of prediabetes to CKD.

RESULTS

Compared to subjects with normal glucose tolerance, patients with prediabetes significantly increased the risk of development of CKD (HR=2.33 (1.19-4.55)). Specifically, this increased risk of CKD development was observed in patients with IFG, IGT and EHbA1c. The cut-off points shown to significantly increase the risk of CKD are fasting plasma glucose of 5.63 mmol/L, 2-hour plasma glucose of 6.80 mmol/L and HbA1c of 5.6%. The contribution of prediabetes to CKD occurrence in the study population was 60.6%.

CONCLUSIONS

This result suggests that the stricter criteria might be needed to define normal plasma glucose level in China that would not be predisposed to diabetic complications, particularly CKD.

Association between Prediabetes and Renal Dysfunction from a Community-based Prospective Study

Objective: Our study aimed to evaluate the association between prediabetes and renal dysfunction, and further assess which of glycemic indices of fasting plasma glucose (FPG), postprandial plasma glucose (PPG) and hemoglobin A1c (HbA1c) has a higher risk of renal dysfunction. Methods: This was a community-based prospective cohort study, which included 7015 participants from Beijing and Taian between May and October in 2015. The outcome was the renal dysfunction defined as estimated glomerular filtration rate (eGFR)<60 mL/min/1.73 m². Univariate and multivariate logistic regression model was performed, and calculated the odds ratio (OR) and 95% confidence interval (95%CI) of renal dysfunction. Receiver operating curve (ROC) analysis was used to predict renal dysfunction for glycemic indices. Results: 121 renal dysfunction cases were identified. We found that the adjusted ORs (95%CI) of renal dysfunction were 1.72 (1.11-2.38), 1.48 (1.09-1.93), 1.97 (1.27-2.89) and 1.35 (1.07-2.13), respectively, for those with prediabetes, impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated HbA1c, compared with individuals with normal glucose tolerance. And IGT presented a higher risk of renal dysfunction than other glycemic indices. The similar results were obtained by performing the subgroup analysis. ROC analysis revealed the PPG had a higher predictive value for renal dysfunction. Conclusion: We found prediabetes was positively associated with the risk of renal dysfunction and PPG had a higher risk and predictive value of renal dysfunction than other glycemic indices of FPG and HbA1c.

Association of insulin, C-peptide and blood lipid patterns in patients with impaired glucose regulation

BACKGROUND

To investigate any associations between blood glucose (BG) and lipid levels in patients with different glucose tolerance statuses, including type 2 diabetes (T2DM) and impaired glucose regulation (IGR) cases as well as normal glucose tolerance (NGT) individuals.

METHODS

A total of 354 participants were recruited to this study including 174 in the T2DM group, 112 in the IGR group and 68 in the NGT group. We compared BG, insulin and C-peptide (CP), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) serum levels during a 3 h oral glucose tolerance test (OGTT) in the 3 groups.

RESULTS

Basic overall HbA1c serum concentration percentages were 5.52, 6.33 and 9.76% for the NTG, IGR and T2DM cases. During the OGTT, insulin secretion in the IGR group was almost double that of the T2DM group. CP levels were highest in the IGR patients and OGTT related BG concentrations were highest in the T2DM group followed by IGR, but in the IGR group hyperglycemia was less pronounced than in T2DM patients (P <  0.001). Compared to the NGT group, TC, TG and LDL-C serum concentrations were significantly higher (P ≤ 0.001) and HDL-C concentrations were significantly lower (P ≤ 0.001) in IGR and T2DM cases compared to the NTG group.

CONCLUSIONS

IGR led to similar unfavorable blood lipid patterns compared with T2DM patients and an imbalance of insulin and CP serum concentrations during an OGTT.

Glycemic Markers and Subclinical Cardiovascular Disease: The Jackson Heart Study

Background We investigated the associations of glycemic markers (HbA1C [hemoglobin A1C], fasting plasma glucose, and insulin resistance-homeostasis model assessment of insulin resistance) with subclinical cardiovascular disease (CVD) among blacks. Methods We included 4303 community-dwelling blacks (64% women; mean age, 54.5 years) without prevalent CVD. Subclinical CVD was defined as ≥1 of the following: any coronary artery calcification (CAC), elevated carotid intima-media thickness (cIMT), left ventricular (LV) hypertrophy, LV ejection fraction <50%, and peripheral artery disease (ankle-brachial index, <0.90). Estimates of cross-sectional associations of glycemic markers (fasting plasma glucose, HbA1C, and homeostasis model assessment of insulin resistance) with subclinical CVD measures were adjusted for traditional CVD risk factors. Results Each 1% increment in HbA1C was associated with higher odds of CAC, abnormal cIMT, and subclinical CVD (all P <0.001). Adjusted mean values of LV mass (LVM), LVM index, relative wall thickness, CAC, and cIMT were increasingly abnormal with worsening HbA1C categories (all P<0.05). Each 10-mg/dL increase in fasting plasma glucose was associated with higher odds of LV hypertrophy, CAC, abnormal cIMT, and subclinical CVD (all P <0.005). Adjusted mean values of LVM, LVM index, relative wall thickness, CAC, ankle-brachial index, and cIMT were more abnormal across categories of worsening fasting plasma glucose (all P <0.05). Each unit increment in log-transformed homeostasis model assessment of insulin resistance conferred a higher odd of having LV hypertrophy ( P<0.01). Across quartiles of homeostasis model assessment of insulin resistance, we observed progressively abnormal adjusted mean values of LVM, LVM index, relative wall thickness, and ankle-brachial index (all P <0.01). Conclusions Among blacks, glycemic markers were differentially associated with various measures of subclinical CVD.

Elevated haemoglobin A1c but not fasting plasma glucose conveys risk of chronic kidney disease in non-diabetic individuals

AIMS

To compare impact of elevated HbA1c and fasting plasma glucose (FPG) on incident chronic kidney disease (CKD) in a non-diabetic cohort.

METHODS

Data from diabetes- and CKD-free 25,109 health examinees were retrospectively analysed with a mean observation period of 5.3 years. Prediabetes was diagnosed by the ADA and WHO criteria, and CKD by estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² and/or dipstick proteinuria. Cox proportional hazards model was applied with sex, age, insulin sensitivity, systolic blood pressure, eGFR and serum alanine aminotransferase level as covariates.

RESULTS

For incident CKD (n = 2483), high HbA1c but not FPG was an independent risk: adjusted hazard ratio (AHR, 95%CI) for HbA1c 1% and FPG 1 mmol/L, 1.91 (1.70-2.16) and 0.85 (0.60-1.20), respectively. Prediabetes by the ADA and WHO criteria were both risk for CKD with AHR (95%CI), 1.21 (1.12-1.32) and 1.31 (1.16-1.48), respectively. Prediabetes diagnosed by 'elevated HbA1c irrespective of FPG', either by the ADA and the WHO definition, was a risk with AHR (95%CI), 1.48 (1.36-1.61) and 1.51 (1.31-1.74), respectively. In contrast, prediabetes diagnosed by 'raised FPG irrespective of HbA1c' was not a CKD risk.

CONCLUSIONS

Elevated HbA1c, but not FPG, identified CKD risk in non-diabetic individuals.

Association between coronary artery atherosclerosis and plasma glucose levels assessed by dual-source computed tomography

Background

To assess the association between coronary artery atherosclerosis (CAA) and plasma glucose parameters in a randomly selected cohort of asymptomatic, community-dwelling, Chinese adults by dual-source computed tomography (DSCT).

Methods

We randomly selected participants and classified them into three groups based on their plasma glucose levels: normal glucose regulation (NGR), pre-diabetes, and diabetes mellitus (DM). The participants underwent DSCT, and those identified with CAA were divided into four groups according to the severity of their coronary artery stenosis. We analyzed the composition of plaques in all coronary artery segments according to the American Heart Association's (AHA) guidelines. We compared the severity of coronary artery stenosis and the plaque composition with plasma glucose parameters among participants.

Results

Out of a total of 335 participants, 118 were found to have CAA. The prevalence of CAA was highest (P value for trend =0.031) in the diabetic group (67.7%) followed by the pre-diabetic group (35.1%) then the NGR group (27.7%). Both calcified and mixed plaques were found in the coronary arteries of the diabetic group while mixed and non-calcified plaques predominated in the pre-diabetic and the NGR groups. When data from all subjects with CAA were analyzed, blood glucose parameters, fasting plasma glucose (FPG), 2-hr postprandial plasma glucose (PPG), and hemoglobin A1c (HbA1c), exhibited a positive correlation with the severity of coronary stenosis (P<0.05). Multivariable logistic regression models indicated a significantly higher risk of CAA among the diabetic patients. Triglyceride levels were positively correlated with the blood glucose parameters among the three groups while LDL-C was elevated in the DM group but not in the pre-diabetic group compared to the NGR group.

Conclusions

The severity of CAA exhibited a direct correlation with the blood glucose parameters, FPG, PPG, and HbA1c. DSCT can accurately detect the presence and distribution of CAA in asymptomatic, community-dwelling subjects. DSCT is a useful screening tool for coronary artery disease (CAD).

Normal LDL-Cholesterol Levels Are Associated With Subclinical Atherosclerosis in the Absence of Risk Factors

BACKGROUND

Absence of cardiovascular risk factors (CVRFs) is traditionally considered low risk for atherosclerosis; however, individuals without CVRFs, as currently defined, still have events.

OBJECTIVES

This study sought to identify predictors of subclinical atherosclerosis in CVRF-free individuals.

METHODS

Participants from the PESA (Progression of Early Subclinical Atherosclerosis) study (n = 4,184) without conventional CVRFs were evaluated (n = 1,779; 45.0 ± 4.1 years, 50.3% women). CVRF freedom was defined as no current smoking and untreated blood pressure <140/90 mm Hg, fasting glucose <126 mg/dl, total cholesterol <240 mg/dl, low-density lipoprotein cholesterol (LDL-C) <160 mg/dl, and high-density lipoprotein cholesterol ≥40 mg/dl. A subgroup with optimal CVRFs (n = 740) was also defined as having blood pressure <120/80 mm Hg, fasting glucose <100 mg/dl, glycosylated hemoglobin <5.7%, and total cholesterol <200 mg/dl. We evaluated ultrasound-detected carotid, iliofemoral, and abdominal aortic plaques; coronary artery calcification; serum biomarkers; and lifestyle. Adjusted odds ratios (with 95% confidence interval) and ordinal logistic regression models were used.

RESULTS

Subclinical atherosclerosis (plaque or coronary artery calcification) was present in 49.7% of CVRF-free participants. Together with male sex and age, LDL-C was independently associated with atherosclerosis presence and extent, in both the CVRF-free and CVRF-optimal groups (odds ratio [×10 mg/dl]: 1.14 to 1.18; p < 0.01 for all). Atherosclerosis presence and extent was also associated in the CVRF-free group with glycosylated hemoglobin levels.

CONCLUSIONS

Many CVRF-free middle-aged individuals have atherosclerosis. LDL-C, even at levels currently considered normal, is independently associated with the presence and extent of early systemic atherosclerosis in the absence of major CVRFs. These findings support more effective LDL-C lowering for primordial prevention, even in individuals conventionally considered at optimal risk. (Progression of Early Subclinical Atherosclerosis [PESA] Study; NCT01410318).

Glycemic status and chronic kidney disease in Chinese adults: Findings from the REACTION study

BACKGROUND

Diagnosed diabetes has been associated with chronic kidney disease (CKD). However, the association between non-diabetic hyperglycemia and CKD remained uncertain. The aim of the present study was to investigate the association between different glycemic status and CKD in Chinese adults and to assess the prevalence and control of diabetes among individuals with CKD.

METHODS

In all, 250 752 adults aged ≥40 years were selected from the baseline cohort of the Risk Evaluation of cAncers in Chinese diabeTic Individuals: a lONgitudinal (REACTION) study. Plasma glucose concentrations and biochemical and other clinical data were collected; CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min per 1.73 m² .

RESULTS

The prevalence of CKD increased gradually with deterioration of glucose metabolic status in both men and women ( P _trend  < 0.001 for both). Compared with individuals with normal glucose regulation, men with prediabetes and diabetes had higher risks of prevalent CKD (prediabetes odds ratio [OR] 1.15, 95% confidence interval [CI] 1.02-1.32; newly diagnosed diabetes OR 1.27, 95% CI 1.08-1.49; previously diagnosed diabetes OR 2.05, 95% CI 1.78-2.35). Similar results were observed in women, but not among those with prediabetes. In male CKD patients with diabetes, 52.1% received antidiabetic treatment and 41.8% of those treated had effective glycemic control, higher than values for females.

CONCLUSIONS

Prediabetes and diabetes were associated with an increased risk of CKD in Chinese men. Control of diabetes among Chinese CKD patients is far from optimal.

Progression of coronary artery calcification is stronger in poorly than in well controlled diabetes: Results from the Heinz Nixdorf Recall Study

AIM

To assess associations between HbA1c and progression of coronary artery calcification (CAC) in persons with and without diabetes.

METHODS

In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany (N=3453, aged 45-74years), CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. At baseline, participants were divided into five groups: poorly (HbA1c≥7.0%) and well (HbA1c<7.0%) controlled previously known diabetes (group I/II); no previously known diabetes with HbA1c ≥6.5% (group III), HbA1c 5.7-6.4% (group IV), and HbA1c <5.7% (group V). We fitted linear, logistic and robust Poisson regression models to assess associations between diabetes group and PF₅ (factor by which CAC after 5-year follow-up is larger than baseline CAC), and categories of CAC change, respectively.

RESULTS

Relative to group V, adjusted percentage increase of the geometric mean of PF₅ (95% CI) was: 69.1% (33.9%;113.6%), 15.4% (-5.6%;41.1%), -4.1% (-22.2%;18.2%), 4.2% (-5.4%;14.8%) for groups I-IV, respectively. The corresponding odds ratios for annual CAC increase ≥100 Agatston units (reference: <10) were 10.0 (4.8;20.6), 4.0 (2.1;7.6), 1.5 (0.7;3.2), and 1.1 (0.7;1.8).

CONCLUSIONS

In known diabetes, CAC progression was stronger in poor diabetes control. For newly detected diabetes diagnosed by HbA1c ≥6.5%, associations with CAC progression were weak.

Association between markers of glycemia and carotid intima-media thickness: the MARK study

BACKGROUND

Carotid intima-media thickness (C-IMT) is a reliable predictor of cardiovascular events. We Investigated the relationship between markers of glycemia and C-IMT in intermediate-risk cardiovascular patients.

METHODS

This study analyzed 427 subjects, aged 35 to 74 years (mean, 60.3 ± 8.5 years), 55 % women, enrolled into the MARK study. Including 231 subjects defined as normal glucose, 104 subjects classified as prediabetes and 92 with type 2 diabetes mellitus. Carotid ultrasound was used to measure C-IMT and the presence of plaques. Fasting plasma glucose (mg/dl) and glycated hemoglobin (%) (HbA1c) were measured using standard enzymatic automated methods. Postprandial glucose (mg/dl) was self-measured by patients at home 2 h after meals (breakfast, lunch and dinner) for 1 day.

RESULTS

The C-IMT shows a positive correlation with fasting plasma glucose, postprandial glucose and HbA1c. Multiple linear regression analysis showed a positive association between HbA1c and C-IMT, with a 0.016 mm and 0.019 mm increase in mean and maximum C-IMT per 1 % increase in HbA1c. In addition, an association between fasting plasma glucose and C-IMT was found with an increase of 0.004 and 0.005 mm in mean and maximum C-IMT per 10 mg/dl in fasting plasma glucose. We also observed a graded association between fasting plasma glucose, postprandial glucose and HbA1c and the presence of carotid target organ damage (TOD), with an odds ratio of 1.013, 1.010 and 1.425, respectively.

CONCLUSION

The results of this study suggest that the fasting plasma glucose and HbA1c, but not postprandial glucose, are associated with C-IMT media and maximum. The patients who present with a metabolic glucose alteration have more risk of developing carotid TOD.

TRIAL REGISTRATION

ClinicalTrials.gov; Identifier: NCT01428934 .

HbA1c Levels Are Associated with Chronic Kidney Disease in a Non-Diabetic Adult Population: A Nationwide Survey (KNHANES 2011-2013)

BACKGROUND

Many studies have reported an association between glycated hemoglobin A1c (HbA1c) and metabolic syndrome (MetS) in non-diabetes patients. Each component of MetS is in fact related to chronic kidney disease (CKD) incidence and progression. Therefore, HbA1c in non-diabetic mellitus (DM) may be intrinsically associated with the prevalence of CKD. The hypothesis of the present study was that high HbA1c in non-DM patients is associated with CKD.

PATIENTS AND METHODS

The total number of participants in this study was 24,594. The participants were divided into three groups according to their HbA1c levels: a Low group (<5.7% or <39 mmol/mol), a Middle group (5.7-6.0% or 39-42 mmol/mol), and a High group (>6.0% or >42 mmol/mol). The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

The number of participants allocated to the Low, Middle, and High groups was 8,651, 4,634, and 1,387, respectively. Linear regression analyses were performed to evaluate the association between variables. Standardized β ± standard error was 0.25 ± 0.22 for waist circumference, 0.44 ± 0.20 for fasting glucose, -0.14 ± 0.30 for high-density lipoprotein cholesterol levels, 0.15 ± 2.31 for triglyceride levels, 0.21 ± 0.00 for systolic blood pressure, 0.10 ± 0.00 for diastolic blood pressure, and -0.22 ± 0.42 for eGFR (P < 0.001 for all variables). eGFR in non-diabetes participants was inversely associated with the HbA1c level, where eGFR decreased as HbA1c levels increased. Standardized βs were -0.04 ± 0.42 in multivariable analysis (P < 0.001). The proportion of participants with only MetS, only CKD, or both MetS and CKD was higher in the High group than in the Low and Middle groups.

CONCLUSION

High HbA1c in non-DM patients may be associated with CKD. Renal function in patients with high HbA1c levels may need to be monitored.

Carotid atherosclerosis severity in relation to glycemic status: a cross-sectional population study

OBJECTIVE

Intima-media thickness (IMT) is increased in subjects with prediabetes or newly diagnosed diabetes. However, no previous studies have evaluated the relationship between the severity of carotid atherosclerosis, assessed by the presence of carotid plaques or stenosis, and the glycemic status, assessed either by fasting glucose, an oral glucose tolerance test (OGTT) or A1C levels.

METHODS

Cross-sectional analysis of 1475 subjects (mean age 62 years, 44% males), randomly selected from the population. A fasting blood sample was obtained to determine glucose, lipids, and A1C levels. An OGTT was performed in non-diabetic subjects. Carotid atherosclerosis was evaluated by echo-doppler.

RESULTS

A 10.5% of the population had a previous diagnosis of diabetes. Of the 1320 non-diabetic participants, 349 (26.4%) had normal fasting glucose, normal glucose tolerance and A1C < 5.7%, and were considered controls. Prediabetes was diagnosed in 850 subjects (64.4%), and diabetes was newly diagnosed in 121 (9.2%). The prevalence of patients with carotid plaques was 34.2% in controls, 45.1% in prediabetics, 64.2% in newly diagnosed diabetics, and 72.9% in established diabetic patients. These numbers were 0.3%, 1.1%, 5.0% and 7.7% for carotid stenosis, respectively. In multivariate analysis, glycemic status remained significantly associated with the prevalence of carotid plaques after adjusting for age, sex, statin treatment, and cardiovascular risk factors.

CONCLUSIONS

Glycemic status is associated with all grades of carotid atherosclerosis, from early signs, as demonstrated by the IMT, to intermediate degrees, as demonstrated by the presence of carotid plaques, to advance atherosclerosis, as established by the presence of carotid stenosis.

Circulating cell-free mitochondrial DNA as the probable inducer of early endothelial dysfunction in the prediabetic patient

Recent evidence has shown that 346million people in the world have diabetes mellitus (DM); this number will increase to 439million by 2030. In addition, current data indicate an increase in DM cases in the population between 40 and 59years of age. Diabetes is associated with the development of micro- and macro-vascular complications, derived from chronic hyperglycemia on the endothelium. Some reports demonstrate that people in a prediabetic state have a major risk of developing early endothelial dysfunction (ED). Today, it is accepted that individuals considered as prediabetic patients are in a pro-inflammatory state associated with endothelial and mitochondrial dysfunction. It is important to mention that impaired mitochondrial functionality has been linked to endothelial apoptosis and release of mitochondrial DNA (mtDNA) in patients with sepsis, cardiac disease, or atherosclerosis. This free mtDNA could promote ED, as well as other side effects on the vascular system through the activation of the toll-like receptor 9 (TLR9). TLR9 is expressed in different cell types (e.g., T or B lymphocytes, mastocytes, and epithelial and endothelial cells). It is localized intracellularly and recognizes non-methylated dinucleotides of viral, bacterial, and mitochondrial DNA. Recently, it has been reported that TLR9 is associated with the pathogenesis of lupus erythematosus, rheumatoid arthritis, and autoimmune diabetes. In this work, it is hypothesized that the increase in the levels of circulating mtDNA is the trigger of early ED in the prediabetic patient, and later on in the older patient with diabetes, through activation of the TLR9 present in the endothelium.

All-cause mortality and estimated renal function in type 2 diabetes mellitus outpatients: Is there a relationship with the equation used?

BACKGROUND

We investigated the relationship between serum creatinine (SCr) and estimated glomerular filtration rate (eGFR), evaluated by different formulae, and all-cause mortality (ACM) in type 2 diabetes mellitus (T2DM) outpatients.

METHODS

This observational cohort study considered 1365 T2DM outpatients, who had been followed up for a period of up to 11 years. eGFR was estimated using several equations.

RESULTS

Seventy subjects (5.1%) died after a follow-up of 9.8 ± 3 years. Univariate analysis showed that diagnosis of nephropathy (odds ratio (OR): 2.554, 95% confidence interval (CI): 1.616-4.038, p < 0.001) and microvascular complications (OR: 2.281, 95% CI: 1.449-3.593, p < 0.001) were associated with ACM. Receiving operating characteristic (ROC) curves showed that the areas under the curve for ACM were similar using the different eGFR equations. eGFR values were predictors of ACM, and the hazard ratios (HRs) of the different equations for eGFR estimation were similar.

CONCLUSION

In our cohort of T2DM outpatients, different eGFR equations perform similarly in predicting ACM, whereas SCr did not.