HbA1c as predictor of all-cause mortality in individuals at high risk of diabetes with normal glucose tolerance, identified by screening: a follow-up study of the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care (ADDITION), Denmark

Association of Glasgow coma scale and endotracheal intubation in predicting mortality among patients admitted to the intensive care unit

BACKGROUND

We assessed predictors of mortality in the intensive care unit (ICU) and investigated if Glasgow coma scale (GCS) is associated with mortality in patients undergoing endotracheal intubation (EI).

METHODS

From February 2020, we performed a 1-year study on 2,055 adult patients admitted to the ICU of two teaching hospitals. The outcome was mortality during ICU stay and the predictors were patients' demographic, clinical, and laboratory features.

RESULTS

EI was associated with a decreased risk for mortality compared with similar patients (adjusted odds ratio [AOR], 0.32; P=0.030). This shows that EI had been performed correctly with proper indications. Increasing age (AOR, 1.04; P<0.001) or blood pressure (AOR, 1.01; P<0.001), respiratory problems (AOR, 3.24; P<0.001), nosocomial infection (AOR, 1.64; P=0.014), diabetes (AOR, 5.69; P<0.001), history of myocardial infarction (AOR, 2.52; P<0.001), chronic obstructive pulmonary disease (AOR, 3.93; P<0.001), immunosuppression (AOR, 3.15; P<0.001), and the use of anesthetics/sedatives/hypnotics for reasons other than EI (AOR, 4.60; P<0.001) were directly; and GCS (AOR, 0.84; P<0.001) was inversely related to mortality. In patients with trauma surgeries (AOR, 0.62; P=0.014) or other surgical categories (AOR, 0.61; P=0.024) undergoing EI, GCS had an inverse relation with mortality (accuracy=82.6%, area under the receiver operator characteristic curve=0.81).

CONCLUSIONS

A variety of features affected the risk for mortality in patients admitted to the ICU. Considering GCS score for EI had the potential of affecting prognosis in subgroups of patients such as those with trauma surgeries or other surgical categories.

Association of HbA1c with carotid artery plaques in patients with coronary heart disease: a retrospective clinical study

BACKGROUND AND AIMS

Haemoglobin A1c (HbA1c) levels have been shown to be related to carotid artery plaques. However, studies on the relationship between HbA1c levels and carotid artery plaques in patients with coronary heart disease (CHD) are limited and inconsistent. Our objective was to examine the correlation between HbA1c levels and carotid artery plaques in patients with CHD.

METHODS

The study comprised 9275 Chinese adults with CHD from January 1, 2014, to September 30, 2020. HbA1c levels were assessed, and colour Doppler ultrasound was used to evaluate the carotid artery, including plaque presence, intima-media thickness, and plaque echo properties, to investigate the association between HbA1c and carotid plaque. A logistic regression model was used to assess the association between carotid artery plaques, carotid plaque echogenicity, and HbA1c.

RESULTS

The HbA1c level of the plaque-present group was higher than that of the plaque-absent group [6.1 (5.6-7.2) vs. 5.8 (5.5-6.5), p < 0.001]. In multiple linear regression analysis, intima-media thickness was associated with HbA1c (p < 0.001). Logistic regression showed that a higher HbA1c level was associated with plaque incidence as well as hyperechoic and heterogeneous plaques (p < 0.001). These associations persist after adjusting for age, sex, blood pressure, lipid profiles, alcohol consumption, and tobacco exposure.

CONCLUSION

HbA1c levels are notably associated with carotid artery plaque incidence, intima-media thickness, and plaque echogenicity in patients with CHD. These findings show that different levels of HbA1c may be an indicator for carotid artery plaques and thus, should be observed in patients with CHD.

Associations between haemoglobin A1c and mortality rate in the KORA S4 and the Heinz Nixdorf Recall population-based cohort studies

BACKGROUND

There is limited knowledge about mortality risk in persons with increased haemoglobin A_1c (HbA_1c ) levels below the diabetes threshold. Moreover, little is known about how associations between increased HbA_1c and mortality depend on the length of follow-up. Therefore, we studied associations between HbA_1c and mortality over long-term follow-up in persons with and without known diabetes.

METHODS

We used data from two German population-based cohort studies: KORA S4 Study (Southern Germany, n = 1458, baseline visits in 1999 to 2001, baseline age 55 to 74 years, mortality follow-up 16.8 years) and Heinz Nixdorf Recall (HNR) Study (Ruhr area, n = 4613, baseline visits in 2000 to 2003, baseline age 45 to 75 years, mortality follow-up 17.8 years). Adjusted log-linear models were fitted to estimate relative risks (RRs) with 95% confidence intervals (CI).

RESULTS

In both cohorts, participants with HbA_1c 39 to 41 mmol/mol (5.7%-5.9%) and HbA_1c 42 to 46 mmol/mol (6.0% to 6.4%) did not have a larger overall mortality risk than participants with HbA_1c  < 39 mmol/mol (5.7%): the corresponding adjusted RRs were 1.00 (95% CI: 0.83-1.21) and 1.01 (0.80-1.27) in KORA and 0.99 (0.82-1.21) and 0.83 (0.65-1.07) in the HNR Study. For the pooled cohorts, the RR for HbA_1c 39 to 46 mmol/mol (5.7%-6.4%) was 0.96 (0.85-1.07). Associations between newly detected diabetes (HbA_1c  ≥ 6.5%) and mortality were weak after 4 and 8 years of follow-up, but were stronger after 12 years of follow-up, whereas associations between previously known diabetes (baseline) and mortality decreased.

CONCLUSIONS

HbA_1c -defined pre-diabetes is not associated with overall mortality. For newly detected and previously known diabetes, mortality risks vary with length of follow-up.

Prospective study of hemoglobin A1c and incident carotid artery plaque in Chinese adults without diabetes

Background

Diabetes has been reported to be associated with carotid artery plaque (CAP). However, it remains unclear whether hemoglobin A1c (HbA1c) level, a marker for long-term glycemic status, is associated with altered CAP risk in individuals with fasting blood glucose (FBG) concentrations below the current cutoff for diabetes.

Methods

Included were 16,863 Chinese adults (aged 18 years or more; 9855 men and 7008 women) with fasting blood glucose < 7.0 mmol/L at baseline (2013). Both HbA1c level and CAP (assessed via ultrasound B-mode imaging) were annually assessed during 2014–2018. All the participants were further classified into three groups based on baseline HbA1c level: ≤ 5.6%, 5.7–6.4%, and ≥ 6.5%. We used Cox proportional-hazards model to evaluate the association between HbA1c level and incident CAP, adjusting for a series of potential confounders.

Results

During 5 years of follow up, 3942 incident CAP cases were identified. Individuals with higher baseline HbA1c had higher future risk of CAP (p-trend < 0.001). In the full-adjusted model, each percent increase of HbA1c was associated with a 56% (HR = 1.56, 95% CI 1.37, 1.78) higher risk of CAP. Excluding participants with chronic inflammation, as assessed by high-sensitivity C-reactive protein and white blood cell, and those with FBG ≥ 5.6 mmol/L at baseline generated similar results.

Conclusions

Elevated HbA1c level was associated with high risk of developing CAP in Chinese adults without FBG defined diabetes.

Effect of metformin treatment in patients with type 2 diabetes with respect to glyoxalase 1 activity in atherosclerotic lesions

BACKGROUND

The enzyme glyoxalase1 (GLO1) is the main opponent in the degradation of the reactive metabolite methylglyoxal (MG), which by glycation of macromolecules is involved in atherogenesis. Reduced GLO1-activity in atherosclerotic tissue is known to be associated with diabetes. It has been shown that treatment of patients with type 2 diabetes with metformin leads to increased GLO1-activity in peripheral-blood-cells. The aim of this study was to evaluate whether metformin treatment increases GLO1-activity in atherosclerotic lesions of patients with type 2 diabetes.

PATIENTS AND METHODS

Patients with type 2 diabetes and carotid artery disease were included into the study prospectively. Type of diabetes-medication was documented upon admission along with demographic and clinical history. Using shock frozen endarterectomy-derived carotid artery plaques, GLO1-activity as well as protein expression was measured by a spectophotometric assay and western-blotting respectively.

RESULTS

33 patients (76 % male, mean age 71 years) were included into the study and were divided according to treatment with metformin or not (15 vs. 18 patients). GLO1-activity was increased by the factor 1.36 when treated with metformin - however, not significantly (0.86 vs. 0.63 U/mg, p = 0.056). Normalisation of GLO1-activity onto GLO1-expression level lead to a significant increase by more than twofold (8.48 vs. 3.85, p = 0.044) while GLO1-protein levels did not differ significantly. GLO1-activity correlated positively with increasing HbA1c, especially under metformin treatment.

CONCLUSIONS

Treatment with metformin in patients with type 2 diabetes is associated with enhanced GLO1-activity in atherosclerotic lesions. Regarding the macro- and microvascular complications in these patients further studies are needed to gain more insight into the effect of metformin on the GLO/MG system.

Significance of prediabetes as a nosological entity

Prediabetes is a glucose metabolism disorder considered as a distinct nosological entity which strongly predicts the development of type 2 diabetes mellitus. This nosological entity itself is a serious condition indicating an increased risk of atherosclerotic and oncological complications. In patients with prediabetes, other components of metabolic syndrome are usually present, such as arterial hypertension, obesity or dyslipidaemia, further increasing an individual's risk of morbidity and mortality. Prediabetes is a long-developing disorder which offers enough time for early diagnosis and intervention; it may even be reversible. This review summarizes current knowledge on the definition, detection, epidemiology, cardiovascular and other consequences of prediabetes. It also gives suggestions for future research, along with recommendations for clinical practice.

Spatholobus suberectus Ameliorates Diabetes-Induced Renal Damage by Suppressing Advanced Glycation End Products in db/db Mice

Spatholobus suberectus (SS) is a medicinal herb commonly used in Asia to treat anemia, menoxenia and rheumatism. However, its effect of diabetes-induced renal damage and mechanisms of action against advanced glycation end-products (AGEs) are unclear. In this study, we evaluated the effects of SS on diabetes-induced renal damage and explored the possible underlying mechanisms using db/db type 2 diabetes mice. db/db mice were administered SS extract (50 mg/kg) orally for 6 weeks. SS-treated group did not change body weight, blood glucose and glycated hemoglobin (HbA1c) levels. However, SS treatment reversed diabetes-induced dyslipidemia and urinary albumin/creatinine ratio in db/db mice. Moreover, SS administration showed significantly increased protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2), which is a transcription factor for antioxidant enzyme. SS significantly upregulated glyoxalase 1 (Glo1) and NADPH quinine oxidoreductase 1 (NQO1) expression but reduced CML accumulation and downregulated receptor for AGEs (RAGE). Furthermore, SS showed significant decrease of periodic acid⁻Schiff (PAS)-positive staining and AGEs accumulation in histological and immunohistochemical analyses of kidney tissues. Taken together, we concluded that SS ameliorated the renal damage by inhibiting diabetes-induced glucotoxicity, dyslipidemia and oxidative stress, through the Nrf2/antioxidant responsive element (ARE) stress-response system.

Elevated Levels of the Reactive Metabolite Methylglyoxal Recapitulate Progression of Type 2 Diabetes

The molecular causes of type 2 diabetes (T2D) are not well understood. Both type 1 diabetes (T1D) and T2D are characterized by impaired insulin signaling and hyperglycemia. From analogy to T1D, insulin resistance and hyperglycemia are thought to also play causal roles in T2D. Recent clinical studies, however, found that T2D patients treated to maintain glycemia below the diabetes definition threshold (HbA_1c < 6.5%) still develop diabetic complications. This suggests additional insulin- and glucose-independent mechanisms could be involved in T2D progression and/or initiation. T2D patients have elevated levels of the metabolite methylglyoxal (MG). We show here, using Drosophila glyoxalase 1 knockouts, that animals with elevated methylglyoxal recapitulate several core aspects of T2D: insulin resistance, obesity, and hyperglycemia. Thus elevated MG could constitute one root cause of T2D, suggesting that the molecular causes of elevated MG warrant further study.

Risk of Cardiovascular Disease and Death in Individuals With Prediabetes Defined by Different Criteria: The Whitehall II Study

OBJECTIVE

We compared the risk of cardiovascular disease (CVD) and all-cause mortality in subgroups of prediabetes defined by fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), or HbA1c.

RESEARCH DESIGN AND METHODS

In the Whitehall II cohort, 5,427 participants aged 50-79 years and without diabetes were followed for a median of 11.5 years. A total of 628 (11.6%) had prediabetes by the World Health Organization (WHO)/International Expert Committee (IEC) criteria (FPG 6.1-6.9 mmol/L and/or HbA1c 6.0-6.4%), and 1,996 (36.8%) by the American Diabetes Association (ADA) criteria (FPG 5.6-6.9 mmol/L and/or HbA1c 5.7-6.4%). In a subset of 4,730 individuals with additional measures of 2hPG, 663 (14.0%) had prediabetes by 2hPG. Incidence rates of a major event (nonfatal/fatal CVD or all-cause mortality) were compared for different definitions of prediabetes, with adjustment for relevant confounders.

RESULTS

Compared with that for normoglycemia, incidence rate in the context of prediabetes was 54% higher with the WHO/IEC definition and 37% higher with the ADA definition (P < 0.001) but declining to 17% and 12% after confounder adjustment (P ≥ 0.111). Prediabetes by HbA1c was associated with a doubling in incidence rate for both the IEC and ADA criteria. However, upon adjustment, excess risk was reduced to 13% and 17% (P ≥ 0.055), respectively. Prediabetes by FPG or 2hPG was not associated with an excess risk in the adjusted analysis.

CONCLUSIONS

Prediabetes defined by HbA1c was associated with a worse prognosis than prediabetes defined by FPG or 2hPG. However, the excess risk among individuals with prediabetes is mainly explained by the clustering of other cardiometabolic risk factors associated with hyperglycemia.

Association between prediabetes and risk of cardiovascular disease and all cause mortality: systematic review and meta-analysis

OBJECTIVES

 To evaluate associations between different definitions of prediabetes and the risk of cardiovascular disease and all cause mortality.

DESIGN

 Meta-analysis of prospective cohort studies.

DATA SOURCES

 Electronic databases (PubMed, Embase, and Google Scholar).

SELECTION CRITERIA

 Prospective cohort studies from general populations were included for meta-analysis if they reported adjusted relative risks with 95% confidence intervals for associations between the risk of composite cardiovascular disease, coronary heart disease, stroke, all cause mortality, and prediabetes.

REVIEW METHODS

 Two authors independently reviewed and selected eligible studies, based on predetermined selection criteria. Prediabetes was defined as impaired fasting glucose according to the criteria of the American Diabetes Association (IFG-ADA; fasting glucose 5.6-6.9 mmol/L), the WHO expert group (IFG-WHO; fasting glucose 6.1-6.9 mmol/L), impaired glucose tolerance (2 hour plasma glucose concentration 7.8-11.0 mmol/L during an oral glucose tolerance test), or raised haemoglobin A1c (HbA1c) of 39-47 mmol/mol : (5.7-6.4%) according to ADA criteria or 42-47 mmol/mol (6.0-6.4%) according to the National Institute for Health and Care Excellence (NICE) guideline. The relative risks of all cause mortality and cardiovascular events were calculated and reported with 95% confidence intervals.

RESULTS

 53 prospective cohort studies with 1 611 339 individuals were included for analysis. The median follow-up duration was 9.5 years. Compared with normoglycaemia, prediabetes (impaired glucose tolerance or impaired fasting glucose according to IFG-ADA or IFG-WHO criteria) was associated with an increased risk of composite cardiovascular disease (relative risk 1.13, 1.26, and 1.30 for IFG-ADA, IFG-WHO, and impaired glucose tolerance, respectively), coronary heart disease (1.10, 1.18, and 1.20, respectively), stroke (1.06, 1.17, and 1.20, respectively), and all cause mortality (1.13, 1.13 and 1.32, respectively). Increases in HBA1c to 39-47 mmol/mol or 42-47 mmol/mol were both associated with an increased risk of composite cardiovascular disease (1.21 and 1.25, respectively) and coronary heart disease (1.15 and 1.28, respectively), but not with an increased risk of stroke and all cause mortality.

CONCLUSIONS

 Prediabetes, defined as impaired glucose tolerance, impaired fasting glucose, or raised HbA1c, was associated with an increased risk of cardiovascular disease. The health risk might be increased in people with a fasting glucose concentration as low as 5.6 mmol/L or HbA1c of 39 mmol/mol.

HbA1c and Risks of All-Cause and Cause-Specific Death in Subjects without Known Diabetes: A Dose-Response Meta-Analysis of Prospective Cohort Studies

Whether HbA_1c levels are associated with mortality in subjects without known diabetes remains controversial. Moreover, the shape of the dose–response relationship on this topic is unclear. Therefore, a dose–response meta-analysis was conducted. PubMed and EMBASE were searched. Summary hazard ratios (HRs) were calculated using a random-effects model. Twelve studies were included. The summary HR per 1% increase in HbA_1c level was 1.03 [95% confidence interval (CI) = 1.01–1.04] for all-cause mortality, 1.05 [95% CI = 1.02–1.07) for cardiovascular disease (CVD) mortality, and 1.02 (95% CI = 0.99–1.07) for cancer mortality. After excluding subjects with undiagnosed diabetes, the aforementioned associations remained significant for CVD mortality only. After further excluding subjects with prediabetes, all aforementioned associations presented non-significance. Evidence of a non-linear association between HbA_1c and mortality from all causes, CVD and cancer was found (all P_{non-linearity} < 0.05). The dose–response curves were relatively flat for HbA_1c less than around 5.7%, and rose steeply thereafter. In conclusion, higher HbA_1c level is associated with increased mortality from all causes and CVD among subjects without known diabetes. However, this association is driven by those with undiagnosed diabetes or prediabetes. The results regarding cancer mortality should be treated with caution due to limited studies.

Abdominal aortic aneurysms--glycaemic status and mortality

AIMS

The prevalence of diabetes mellitus (DM) and mortality with respect to glycaemic status in patients with abdominal aortic aneurysms (AAA) was evaluated. Glycaemic status was assessed by an oral glucose tolerance test (OGTT) and by HbA1c.

METHODS

Sixty-six patients with AAA admitted to the vascular surgery unit for elective surgery between October 2006 and September 2007 were included. Seven patients had previously known DM. OGTT and HbA1c results were available from 58 patients. The patients were categorized as having DM, prediabetes and normoglycaemia according to the WHO's and American Diabetes Association's criteria.

RESULTS

The prevalence of newly diagnosed DM according to the OGTT and HbA1c results were 12% and 14% respectively. Mean follow-up time was 68 months and all-cause mortality 43%. HbA1c was an independent predictor for mortality in the DM category. Hazard ratio of all-cause mortality in the DM category defined by the HbA1c values was 6.35, 95% [CI 1.49-27.1]; p = 0.01.

CONCLUSIONS

DM defined by HbA1c ≥ 6.5% is an important determinant of mortality following surgical treatment for AAA. Half the patients with AAA and DM were unaware of their DM diagnosis. All patients with AAA should be tested for DM using HbA1c. The results should be confirmed in a larger prospective study.

Prediabetes and associated disorders

Prediabetes represents an elevation of plasma glucose above the normal range but below that of clinical diabetes. Prediabetes includes individuals with IFG, IGT, IFG with IGT and elevated HbA1c levels. Insulin resistance and β-cell dysfunction are characteristic of this disorder. The diagnosis of prediabetesis is vital as both IFG and IGT are indeed well-known risk factors for type 2 diabetes with a greater risk in the presence of combined IFG and IGT. Furthermore, as will be illustrated in this review, prediabetes is associated with associated disorders typically only considered in with established diabetes. These include cardiovascular disease, periodontal disease, cognitive dysfunction, microvascular disease, blood pressure abnormalities, obstructive sleep apnea, low testosterone, metabolic syndrome, various biomarkers, fatty liver disease, and cancer. As the vast majority of individuals with prediabetes are unaware of their diagnosis, it is therefore vital that the associated conditions are identified, particularly in the presence of mild hyperglycemia, so they may benefit from early intervention.

daf-16/FOXO and glod-4/glyoxalase-1 are required for the life-prolonging effect of human insulin under high glucose conditions in Caenorhabditis elegans

AIMS/HYPOTHESIS

The aim of this study was to determine the protective effects of human insulin and its analogues, B28Asp human insulin (insulin aspart) and B29Lys(ε-tetradecanoyl),desB30 human insulin (insulin detemir), against glucose-induced lifespan reduction and neuronal damage in the model organism Caenorhabditis elegans and to elucidate the underlying mechanisms.

METHODS

Nematodes were cultivated under high glucose (HG) conditions comparable with the situation in diabetic patients and treated with human insulin and its analogues. Lifespan was assessed and neuronal damage was evaluated with regard to structural and functional impairment. Additionally, the activity of glyoxalase-1 and superoxide dismutase (SOD) and the formation of reactive oxygen species (ROS) and AGEs were determined.

RESULTS

Insulin and its analogues reversed the life-shortening effect of HG conditions and prevented the glucose-induced neuronal impairment. Insulin treatment under HG conditions was associated with reduced concentration of glucose, as well as a reduced formation of ROS and AGEs, and increased SOD activity. These effects were dependent on the Forkhead box O (FOXO) homologue abnormal dauer formation (DAF)-16. Furthermore, glyoxalase-1 activity, which was impaired under HG conditions, was restored by human insulin. This was essential for the insulin-induced lifespan extension under HG conditions, as no change in lifespan was observed following either suppression or overexpression of glyoxalase-1.

CONCLUSIONS/INTERPRETATION

Human insulin and its analogues prevent the reduction in lifespan and neuronal damage caused by HG conditions. The effect of human insulin is mediated by a daf-2/insulin receptor and daf-16/FOXO-dependent pathway and is mediated by upregulation of detoxifying mechanisms.

High tissue glucose alters intersomitic blood vessels in zebrafish via methylglyoxal targeting the VEGF receptor signaling cascade

Hyperglycemia causes micro- and macrovascular complications in diabetic patients. Elevated glucose concentrations lead to increased formation of the highly reactive dicarbonyl methylglyoxal (MG), yet the early consequences of MG for development of vascular complications in vivo are poorly understood. In this study, zebrafish were used as a model organism to analyze early vascular effects and mechanisms of MG in vivo. High tissue glucose increased MG concentrations in tg(fli:EGFP) zebrafish embryos and rapidly induced several additional malformed and uncoordinated blood vessel structures that originated out of existing intersomitic blood vessels (ISVs). However, larger blood vessels, including the dorsal aorta and common cardinal vein, were not affected. Expression silencing of MG-degrading enzyme glyoxalase (glo) 1 elevated MG concentrations and induced a similar vascular hyperbranching phenotype in zebrafish. MG enhanced phosphorylation of vascular endothelial growth factor (VEGF) receptor 2 and its downstream target Akt/protein kinase B (PKB). Pharmacological inhibitors for VEGF receptor 2 and Akt/PKB as well as MG scavenger aminoguanidine and glo1 activation prevented MG-induced hyperbranching of ISVs. Taken together, MG acts on smaller blood vessels in zebrafish via the VEGF receptor signaling cascade, thereby describing a new mechanism that can explain vascular complications under hyperglycemia and elevated MG concentrations.

HbA1c for diagnosis of type 2 diabetes. Is there an optimal cut point to assess high risk of diabetes complications, and how well does the 6.5% cutoff perform?

Glycated hemoglobin (HbA1c) has recently been recommended for the diagnosis of type 2 diabetes mellitus (T2DM) by leading diabetes organizations and by the World Health Organization. The most important reason to define T2DM is to identify subjects with high risk of diabetes complications who may benefit from treatment. This review addresses two questions: 1) to assess from existing studies whether there is an optimal HbA1c threshold to predict diabetes complications and 2) to assess how well the recommended 6.5% cutoff of HbA1c predicts diabetes complications. HbA1c cutoffs derived from predominantly cross-sectional studies on retinopathy differ widely from 5.2%-7.8%, and among other reasons, this is due to the heterogeneity of statistical methods and differences in the definition of retinopathy. From the few studies on other microvascular complications, HbA1c thresholds could not be identified. HbA1c cutoffs make less sense for the prediction of cardiovascular events (CVEs) because CVE risks depend on various strong risk factors (eg, hypertension, smoking); subjects with low HbA1c levels but high values of CVE risk factors were shown to be at higher CVE risk than subjects with high HbA1c levels and low values of CVE risk factors. However, the recommended 6.5% threshold distinguishes well between subjects with and subjects without retinopathy, and this distinction is particularly strong in severe retinopathy. Thus, in existing studies, the prevalence of any retinopathy was 2.5 to 4.5 times as high in persons with HbA1c-defined T2DM as in subjects with HbA1c <6.5%. To conclude, from existing studies, a consistent optimal HbA1c threshold for diabetes complications cannot be derived, and the recommended 6.5% threshold has mainly been brought about by convention rather than by having a consistent empirical basis. Nevertheless, the 6.5% threshold is suitable to detect subjects with prevalent retinopathy, which is the most diabetes specific complication. However, most of the studies on associations between HbA1c and microvascular diabetes complications are cross-sectional, and there is a need for longitudinal studies.

Stress eating and health. Findings from MIDUS, a national study of US adults

The epidemic of obesity and its related chronic diseases has provoked interest in the predictors of eating behavior. Eating in response to stress has been extensively examined, but currently unclear is whether stress eating is associated with obesity and morbidity. We tested whether self-reported stress eating was associated with worse glucose metabolism among nondiabetic adults as well as with increased odds of prediabetes and diabetes. Further, we investigated whether these relationships were mediated by central fat distribution. Participants were 1138 adults (937 without diabetes) in the Midlife in the US study (MIDUS II). Glucose metabolism was characterized by fasting glucose, insulin, insulin resistance (HOMAIR), glycosylated hemoglobin (HbA1c), prediabetes, and diabetes status. Multivariate-adjusted analyses showed that stress eating was associated with significantly higher nondiabetic levels of glucose, insulin, insulin resistance, and HbA1c as well as higher odds of prediabetes or diabetes. Relationships between stress eating and all outcomes were no longer statistically significant once waist circumference was added to the models, suggesting that it mediates such relationships. Findings add to the growing literature on the relationships among psychosocial factors, obesity, and chronic disease by documenting associations between stress eating and objectively measured health outcomes in a national sample of adults. The findings have important implications for interventive targets related to obesity and chronic disease, namely, strategies to modify the tendency to use food as a coping response to stress.

Patients newly diagnosed with clinical type 2 diabetes mellitus but presenting with HbA1c within normal range: 19-year mortality and clinical outcomes

AIMS

To investigate whether long-term mortality or clinical outcomes differed between patients diagnosed with type 2 diabetes mellitus and presenting with HbA1c within or above normal range at time of diagnosis.

METHODS

Data were from a population-based sample of 1136 individuals with newly diagnosed type 2 diabetes mellitus. The diagnosis was confirmed with a single fasting whole blood/plasma glucose ≥7.0/8.0mmol/l. The median time from day of diagnosis until end of follow up was 18.8years. Patients were grouped according to normal HbA1c and elevated HbA1c at diagnosis. The effect of elevated HbA1c on a number of clinical outcomes and all-cause mortality was assessed in Cox regression models.

RESULTS

At diagnosis, 97 patients (8.5%) had an HbA1c level within normal range. Age (mean (SD)) at diagnosis was 64.5 (11.5) years. Both unadjusted and adjusted hazard ratios for the effect of HbA1c on mortality and other outcomes were not statistically significant.

CONCLUSIONS

Patients who are diagnosed with type 2 diabetes mellitus by means of elevated fasting whole blood/plasma glucose but have HbA1c within reference range at diagnosis do not seem to have a relatively benign long-term clinical course. Therefore new diagnostic procedures should preferably be able to identify these individuals.

Current controversies in the use of haemoglobin A1c

Haemoglobin A(1c) (HbA(1c)) has recently been adopted by the World Health Organization into its recommended criteria for diabetes diagnosis. Much debate continues regarding the relative benefits and potential disadvantages surrounding the use of HbA(1c) for this purpose. There is a lack of consensus as to whether this alteration to the definition of diabetes is a step forward or whether it could add further confusion and ambiguity to the debate on the method and criteria for the diagnosis of this globally important disease. This review provides a comprehensive overview of the current issues surrounding how HbA(1c) is measured and reported; and of the evidence for and against its use in diagnosis.

Risk stratification in cardiovascular disease primary prevention - scoring systems, novel markers, and imaging techniques

The aim of this paper is to review and discuss current methods of risk stratification for cardiovascular disease (CVD) prevention, emerging biomarkers, and imaging techniques, and their relative merits and limitations. This report is based on discussions that took place among experts in the area during a special CardioVascular Clinical Trialists workshop organized by the European Society of Cardiology Working Group on Cardiovascular Pharmacology and Drug Therapy in September 2009. Classical risk factors such as blood pressure and low-density lipoprotein cholesterol levels remain the cornerstone of risk estimation in primary prevention but their use as a guide to management is limited by several factors: (i) thresholds for drug treatment vary with the available evidence for cost-effectiveness and benefit-to-risk ratios; (ii) assessment may be imprecise; (iii) residual risk may remain, even with effective control of dyslipidemia and hypertension. Novel measures include C-reactive protein, lipoprotein-associated phospholipase A(2) , genetic markers, and markers of subclinical organ damage, for which there are varying levels of evidence. High-resolution ultrasound and magnetic resonance imaging to assess carotid atherosclerotic lesions have potential but require further validation, standardization, and proof of clinical usefulness in the general population. In conclusion, classical risk scoring systems are available and inexpensive but have a number of limitations. Novel risk markers and imaging techniques may have a place in drug development and clinical trial design. However, their additional value above and beyond classical risk factors has yet to be determined for risk-guided therapy in CVD prevention.

Paper electrocardiograph strips may contain overlooked clinical information in screen-detected type 2 diabetes patients

BACKGROUND

A large number of nondigitized electrocardiograph (ECG) strips are routinely collected in larger cohort studies such as the ADDITION study (Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care). These ECG strips are routinely read manually but may contain overlooked information revealing cardiac autonomic dysfunction. The aim of this study was to investigate whether clinical information may be lost using manual R wave to R wave (RR) interval measurements in the calculation of heart rate variability (HRV) in patients with type 2 diabetes mellitus (T2DM).

METHOD

From the Danish part of the ADDITION study, we randomly selected 120 T2DM patients at baseline of the ADDITION study. Analysis of the ECG strips was performed using two different methods: (1) by experienced technicians using rulers and (2) by experienced technicians using a high-resolution computer-assisted method. Calculation of heart rate and time domain HRV [standard deviation of normal-to-normal RR intervals (SDNN) and root mean square of successive differences (RMSSD)] were performed with the same software.

RESULTS

When comparing results from the two methods, the following values of Pearson's r are obtained: 0.98 for heart rate, 0.76 for SDNN, and 0.68 for RMSSD. These results indicate that heart rate and HRV measurements by the computer-assisted and manually based methods correlate. However, Bland-Altman plots and Pitman's test of difference in variance revealed poor agreements (p < .01) for both HRV measurements (SDNN and RMSSD); only heart rate showed substantiated agreement (p = .54) between the two methods. Low HRV was statistically significantly associated to high heart rate, systolic blood pressure, and diastolic blood pressure in these screen-detected T2DM patients.

CONCLUSIONS

Paper ECG strips may contain overlooked clinical information on the status of autonomic function in patients with T2DM. In our study, manual measurements of RR intervals were inferior to the computer-assisted method. Based on this study, we recommend cautiousness in the clinical use and interpretation of HRV based on manual or low resolution measurements of RR intervals from ECG strips. High resolution measurements of RR intervals reveal significant associations between low HRV and high heart rate, systolic blood pressure, and diastolic blood pressure among patients with screen-detected T2DM. It is feasible to use a computer-assisted method to determine RR intervals in patients with T2DM.

Ageing and associations of fasting plasma glucose and 2 h plasma glucose with HbA(1C) in apparently healthy population. "FIN-D2D" study

OBJECTIVE

In this FIN-D2D cross-sectional survey the relationship of age with HbA(1c) and fasting and 2h glucose in the oral glucose tolerance test (OGTT) was explored in apparently randomly selected healthy population.

PATIENTS AND METHODS

The glycaemic parameters were measured in 1344 men and 1482 women (aged 45-74 years), and among them we excluded all subjects with known diabetes, hypertension or dyslipidaemia. The final analyses for HbA(1c) and the ratios of fasting glucose/HbA(1c) and 2h glucose/HbA(1c) included 649 men and 804 women.

RESULTS

Mean age was 57 years and BMI 26.1kg/m(2) for both genders. HbA(1c) increased in both genders with age (p<0.001). For a particular fasting glucose level HbA(1c) level was higher in older age groups (p<0.001 for linearity). By contrast, a particular 2h plasma glucose value in OGTT implied significantly lower HbA(1c) in the elderly (p<0.001 for linearity).

CONCLUSION

In apparently healthy population, screened with OGTT, in older individuals compared with younger ones a particular HbA(1c) value implies slightly lower fasting glucose, but relatively higher 2h glucose. These results need to be verified in different populations. The effects of age on relation between HbA(1c) and plasma glucose should be taken into account in classifying people into different dysglycaemia categories.

The new puzzle about the treatment of type 2 diabetes after the ACCORD and Da Qing studies

INTRODUCTION

There is a dramatic increase in the worldwide incidence of obesity, diabetes mellitus type 2, and other cardiovascular risk factors, summarized previously under the term "metabolic syndrome". Although preventive lifestyle modifications are effective, they are hard to implement and are therefore associated with a high number needed to treat. In most cases, intervention studies with hard endpoints such as myocardial infarction, stroke, or death are missing.

RESULTS

For example, the Da Qing study proved the efficacy of lifestyle modification with respect to manifestation of diabetes, but failed to show clear benefits regarding cardiovascular mortality. Several studies raised doubt, whether the concept of optimally reducing glucose is the optimal treatment for improving cardiovascular endpoints. Moreover other studies, such as Steno-2, showed an impressive effect of a multimodal therapy on hard endpoints.

CONCLUSIONS

In the future, the focus on new strategies for individualized therapies will increase. Additionally, approaches targeting novel molecular pathways are on the horizon, since plasma levels of posttranslationally modified proteins such as HbA1c are strong cardiovascular risk predictors despite normal glucose levels. For the clinician, it now becomes obvious that epidemiologically proven associations do not necessarily reflect causality. Studies addressing defined clinical endpoints, such as micro- and macrovascular morbidity and mortality are needed, as well as basic research, investigating other pathophysiological mechanisms, e.g., reactive metabolites and the digestive tract. The unexplained reduction in diabetes and its complications by bariatric surgery will give further insight not only into new therapeutic approaches, but also into mechanisms yet to be discovered.