Postchallenge hyperglycemia and mortality in a national sample of U.S. adults

Assessment of postprandial glucose excursions throughout the day in newly diagnosed type 2 diabetes

BACKGROUND

A growing body of evidence suggests that postprandial glucose (PPG) is independently linked to multiple complications and that testing of PPG should be added to hemoglobin A1c (HbA1c) and fasting glucose measurements in the evaluation of glycemic control of type 2 diabetes patients. An ongoing debate is questioning how to assess PPG. This observational study looks further into this question in a cohort of newly diagnosed type 2 diabetes patients.

SUBJECTS AND METHODS

PPG characteristics and intra-/intersubject variations post-breakfast, -lunch, and -dinner, obtained from continuous glucose monitoring (CGM), were retrospectively analyzed in 86 newly diagnosed non-insulin-treated type 2 diabetes patients.

RESULTS

In total, 462 recorded meals were analyzed. The area under the curve 1-4 h postmeal was significantly larger after breakfast compared with both lunch and dinner (P<0.001). Time to peak was approximately 90 min and did not differ significantly between meals. However, the distribution of the blood glucose peaks was only normally distributed among breakfasts, and time to peak had a day-to-day correlation coefficient of 0.60, compared with a nonsignificant result for lunch and dinner. Breakfast PPG peaks were highly correlated to HbA1c (P<0.05, r=0.64) and had a day-to-day correlation coefficient of 0.86 compared with 0.44 for lunch and 0.74 for dinner.

CONCLUSIONS

Self-monitoring of blood PPG should be evaluated with care. From our data, monitoring of PPG patterns in newly diagnosed type 2 diabetes patients should preferably be obtained following breakfast for a more consistent assessment, reducing day-to-day variations.

Proteomic analysis of retinopathy-related plasma biomarkers in diabetic patients

Diabetic retinopathy occurs in approximately 25% of patients with type 1 or type 2 diabetes; the disease can cause poor vision and even blindness because high glucose levels weaken retinal capillaries, causing leakage of blood into surrounding areas. We adopted a proteomics-based approach using 2D-DIGE and MALDI-TOF/TOF MS to compare the differential plasma proteome between diabetic retinopathy with significant retinopathy occurrence within 5years after diagnosis of diabetes, and diabetic non-retinopathy without diagnosed retinopathy for more than 10years after diagnosis of diabetes. We identified 77 plasma proteins, which represent 28 unique gene products. These proteins mainly have inflammatory response and coagulation roles. Our approach identified several potential diabetic retinopathy biomarkers including afamin and the protein arginine N-methyltransferase 5, which may be associated with the progression and development of diabetes. In conclusion, we report a comprehensive patient-based plasma proteomic approach to the identification of potential plasma biomarkers for diabetic retinopathy screening and detection.

Ethnopharmacological survey of plants used against diabetes in Kisangani City (DR Congo)

ETHNOPHARMACOLOGICAL RELEVANCE

An ethnopharmacological survey was conducted in Kisangani City (Democratic Republic of Congo) in order to make an inventory of plant species used in folk medicine for the management of diabetes and their different modes of preparation.

MATERIALS AND METHODS

Fifty-five traditional practitioners from different ethnic groups were interviewed about the plants they use against diabetes in folk medicine in Kisangani. All cited plants were collected and identified at the herbarium of the Faculty of Sciences, University of Kisangani.

RESULTS

Thirty-one plant species were collected out of which phanerophytes predominate (18 species). Eighty-three percent of herbal remedies are prepared by aqueous decoction. Ninety-seven percents of recipes are administered to patients by oral route. All plant parts are used fresh with water as the sole solvent. Leaves are the most used parts and the treatment lasts one to two weeks.

CONCLUSION

Herbal remedies used against diabetes in Kisangani City, DR Congo are widely administered as aqueous decoctions. Chemical and pharmacological studies of these preparations are in progress and might lead to interesting antidiabetic remedies.

High glucose-induced proteome alterations in retinal pigmented epithelium cells and its possible relevance to diabetic retinopathy

Diabetic retinopathy can cause poor vision and blindness. Previous research has shown that high blood glucose weakens retinal capillaries and induces glycoxidation. However, the detailed molecular mechanisms underlying the effects of high blood glucose on development of diabetic retinopathy have yet to be elucidated. In this study, we cultured a retinal pigmented epithelium cell line (ARPE-19) in mannitol-balanced 5.5 mM, 25 mM, and 100 mM d-glucose media, and evaluated protein expression and redox-regulation. We identified 56 proteins that showed significant changes in protein expression, and 33 proteins showing significant changes in thiol reactivity, in response to high glucose concentration. Several proteins that are involved in signal transduction, gene regulation, and transport showed significant changes in expression, whereas proteins involved in metabolism, transport, and cell survival displayed changes in thiol reactivity. Further analyses of clinical plasma specimens confirmed that the proteins lamin B2, PUMA, WTAP, ASGR1, and prohibitin 2 showed type 2 diabetic retinopathy-dependent alterations. In summary, in this study, we used a comprehensive retinal cell-based proteomic approach for the identification of changes in protein expression and redox-associated retinal markers induced by high glucose concentration. Some of the identified proteins have been validated with clinical samples and provide potential targets for the prognosis and diagnosis of diabetic retinopathy.

Impact of postprandial glycaemia on health and prevention of disease

Postprandial glucose, together with related hyperinsulinemia and lipidaemia, has been implicated in the development of chronic metabolic diseases like obesity, type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). In this review, available evidence is discussed on postprandial glucose in relation to body weight control, the development of oxidative stress, T2DM, and CVD and in maintaining optimal exercise and cognitive performance. There is mechanistic evidence linking postprandial glycaemia or glycaemic variability to the development of these conditions or in the impairment in cognitive and exercise performance. Nevertheless, postprandial glycaemia is interrelated with many other (risk) factors as well as to fasting glucose. In many studies, meal-related glycaemic response is not sufficiently characterized, or the methodology with respect to the description of food or meal composition, or the duration of the measurement of postprandial glycaemia is limited. It is evident that more randomized controlled dietary intervention trials using effective low vs. high glucose response diets are necessary in order to draw more definite conclusions on the role of postprandial glycaemia in relation to health and disease. Also of importance is the evaluation of the potential role of the time course of postprandial glycaemia.

Glycemic control and cardiovascular disease: what's a doctor to do?

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in individuals with diabetes mellitus. Moreover, rates of CVD mortality are two to four times higher in diabetes than in those without diabetes. It was conventional thinking that achieving near-normoglycemia would help reduce CVD risk and overall mortality in type 2 diabetes mellitus. Several recent large trials attempted to answer this question using a randomized control trial design with a conventional therapy and an intensive control arm. Surprisingly, these trials did not demonstrate neither mortality nor a CVD advantage with intensive glycemic control. Moreover, some studies (e.g., the ACCORD [Action to Control Cardiovascular Risk in Diabetes] study) showed increased mortality in the intensive control arm. In this review, our goal is to summarize the findings of the major trials in this field and to explore the potential reasons for why these trials had largely negative results. We conclude with some lessons that may be applied to the clinical management of patients with diabetes.

Lowering physical activity impairs glycemic control in healthy volunteers

INTRODUCTION

Postprandial glucose (PPG) is an independent predictor of cardiovascular events and death, regardless of diabetes status. Whereas changes in physical activity produce changes in insulin sensitivity, it is not clear whether changes in daily physical activity directly affect PPG in healthy free-living persons.

METHODS

We used continuous glucose monitors to measure PPG and PPG excursions (ΔPPG, postmeal - premeal blood glucose) at 30-min increments after meals in healthy habitually active volunteers (n = 12, age = 29 ± 1 yr, body mass index = 23.6 ± 0.9 kg·m(-2), VO2max = 53.6 ± 3.0 mL·kg(-1)·min(-1)) during 3 d of habitual (≥10,000 steps per day) and reduced (<5000 steps per day) physical activity. Diets were standardized across monitoring periods, and fasting-state oral glucose tolerance tests (OGTT) were performed on the fourth day of each monitoring period.

RESULTS

During 3 d of reduced physical activity (12,956 ± 769 to 4319 ± 256 steps per day), PPG increased at 30 and 60 min after a meal (6.31 ± 0.19 to 6.68 ± 0.23 mmol·L(-1) and 5.75 ± 0.16 to 6.26 ± 0.28 mmol·L(-1), P < 0.05 relative to corresponding active time point), and ΔPPG increased by 42%, 97%, and 33% at 30, 60, and 90 min after a meal, respectively (P < 0.05). Insulin and C-peptide responses to the OGTT increased after 3 d of reduced activity (P < 0.05), and the glucose response to the OGTT did not change significantly.

CONCLUSIONS

Thus, despite evidence of compensatory increases in plasma insulin during an OGTT, ΔPPG assessed by continuous glucose monitoring systems increased markedly during 3 d of reduced physical activity in otherwise healthy free-living individuals. These data indicate that daily physical activity is an important mediator of glycemic control, even among healthy individuals, and reinforce the utility of physical activity in preventing pathologies associated with elevated PPG.

Glycaemic control is improved by 7 days of aerobic exercise training in patients with type 2 diabetes

AIMS/HYPOTHESIS

Cardiovascular events and death are better predicted by postprandial glucose (PPG) than by fasting blood glucose or HbA(1c). While chronic exercise reduces HbA(1c) in patients with type 2 diabetes, short-term exercise improves measures of insulin sensitivity but does not consistently alter responses to the OGTT. The purpose of this study was to determine whether short-term exercise training improves PPG and glycaemic control in free-living patients with type 2 diabetes, independently of the changes in fitness, adiposity and energy balance often associated with chronic exercise training.

METHODS

Using continuous glucose monitors, PPG was quantified in previously sedentary patients with type 2 diabetes not using exogenous insulin (n = 13, age 53 ± 2 years, HbA(1c) 6.6 ± 0.2% (49.1 ± 1.9 mmol/mol)) during 3 days of habitual activity and during the final 3 days of a 7 day aerobic exercise training programme (7D-EX) which does not elicit measurable changes in cardiorespiratory fitness or body composition. Diet was standardised across monitoring periods, with modifications during 7D-EX to offset increases in energy expenditure. OGTTs were performed on the morning following each monitoring period.

RESULTS

7D-EX attenuated PPG (p < 0.05) as well as the frequency, magnitude and duration of glycaemic excursions (p < 0.05). Conversely, average 24 h blood glucose did not change, nor did glucose, insulin or C-peptide responses to the OGTT.

CONCLUSIONS/INTERPRETATION

7D-EX attenuated glycaemic variability and PPG in free-living patients with type 2 diabetes but did not significantly alter responses to the laboratory-based OGTT. These effects appeared to be independent of changes in fitness, body composition or energy balance. ClinicalTrials.gov numbers: NCT00954109 and NCT00972452.

FUNDING

This project was funded by the University of Missouri Institute for Clinical and Translational Sciences (CRM), NIH grant T32 AR-048523 (CRM), Diabetes Action Research and Education Foundation (JPT). Medtronic supplied CGMS sensors at a discounted rate.

Fasting and post-challenge glucose as quantitative cardiovascular risk factors: a meta-analysis

AIM

The post-challenge glucose (PCG) level has been suggested to be superior to the fasting blood glucose (FG) level for predicting the risk of future cardiovascular disease (CVD); however, the extent of its superiority has not been consistently shown among previous cohort studies. Therefore, we conducted a meta-analysis to summarize the quantitative association of FG and PCG with CVD risk and compared the strengths of the two associations.

METHOD

Electronic literature searches using MEDLINE and EMBASE with an additional manual search were conducted for prospective observational studies of the association of FG and PCG with CVD risk. Studies were included if they were prospective studies in which the relative risk (RR) of CVD per 1 standard deviation increase in both FG and PCG could be estimated. Pooled relative risks for the incremental increase were calculated as RR(FG) and RR(PCG) using a bivariate random-effects model.

RESULT

Data were obtained from 14 eligible studies that included 70,889 participants and 2,927 cases. The pooled RR(FG) and RR(PCG) (95% confidence interval) were, respectively, 1.15 (1.06 to 1.26) and 1.24 (1.12 to 1.36); the difference was significant (P =0.001). The association of PCG with CVD risk was stronger in studies that targeted participants with a baseline mean FG < 100 mg/dl (P < 0.001) or mean age ≥ 55 years (P =0.004).

CONCLUSIONS

Overall, the association of PCG with CVD risk was stronger than that of FG by approximately 50% on a log scale. Measuring PCG is especially important in populations with relatively low FG levels or in the elderly, although it is often burdensome in routine clinical practice.

Hypoglycemia assessed by continuous glucose monitoring is associated with preclinical atherosclerosis in individuals with impaired glucose tolerance

Hypoglycemia is associated with increased risk of cardiovascular adverse clinical outcomes. There is evidence that impaired glucose tolerance (IGT) is associated with cardiovascular morbidity and mortality. Whether IGT individuals have asymptomatic hypoglycemia under real-life conditions that are related to early atherosclerosis is unknown. To this aim, we measured episodes of hypoglycemia during continuous interstitial glucose monitoring (CGM) and evaluated their relationship with early manifestation of vascular atherosclerosis in glucose tolerant and intolerant individuals. An oral glucose tolerance test (OGTT) was performed in 79 non-diabetic subjects. Each individual underwent continuous glucose monitoring for 72 h. Cardiovascular risk factors and ultrasound measurement of carotid intima-media thickness (IMT) were evaluated. IGT individuals had a worse cardiovascular risk profile, including higher IMT, and spent significantly more time in hypoglycemia than glucose-tolerant individuals. IMT was significantly correlated with systolic (r = 0.22; P = 0.05) and diastolic blood pressure (r = 0.28; P = 0.01), total (r = 0.26; P = 0.02) and LDL cholesterol (r = 0.27; P = 0.01), 2-h glucose (r = 0.39; P<0.0001), insulin sensitivity (r = -0.26; P = 0.03), and minutes spent in hypoglycemia (r = 0.45; P<0.0001). In univariate analyses adjusted for gender, minutes spent in hypoglycemia were significantly correlated with age (r = 0.26; P = 0.01), waist circumference (r = 0.33; P = 0.003), 2-h glucose (r = 0.58; P<0.0001), and 2-h insulin (r = 0.27; P = 0.02). In a stepwise multivariate regression analysis, the variables significantly associated with IMT were minutes spent in hypoglycemia (r(2) = 0.252; P<0.0001), and ISI index (r(2) = 0.089; P = 0.004), accounting for 34.1% of the variation. Episodes of hypoglycemia may be considered as a new potential cardiovascular risk factor for IGT individuals.

Blood glucose and subsequent cardiovascular disease: update of a meta-analysis

BACKGROUND/PURPOSE

A 1999 meta-analysis described the relationship between blood glucose and subsequent cardiovascular events (MI, stroke, cardiovascular mortality). More studies have been published; therefore, we updated and refined estimates of this relationship in people without diabetes. ACCEPTABILITY CRITERIA: We accepted prospective studies that reported screening results for blood glucose levels (either fasting, 2-hour postprandial, 1-hour postprandial, or casual) divided into ≥3 quantiles. Required data within each quantile were numbers exposed plus study duration or person-years at risk, and numbers of cardiovascular outcomes (myocardial infarction, stroke, death). No restrictions were placed on language or publication date.

DATA SOURCES

Two reviewers searched Medline, Embase, Scopus, and Cochrane databases from inception until December 2009. Consensus settled discrepancies.

DATA SYNTHESIS

Poisson regression quantified the relationship between glucose quantile and outcomes. Beta values were combined with inverse variance weightings using a random effects meta-analytic model.

RESULTS

We found 36 articles with 141 datasets examining the relationship between blood glucose (32 fasting, 52 2-hour postprandial, 37 1-hour postprandial, 20 casual) in 191,249 patients without diabetes (73% male) for 3 million person-years. There were 12,537 (6.6%) cardiovascular deaths, 14,445 (7.6%) cardiovascular events, 6862 (3.6%) cardiac and 3412 (1.7%) stroke deaths. Relative risks/unit increase in blood glucose were all significant for total cardiovascular events (RRs ranged from 1.09-1.51, all p-values < 0.005) and cardiovascular deaths (RR = 1.05-1.24, p < 0.007), and all for cardiac deaths (p < 0.05) except casual glucose; stroke mortality was less clear. The two strongest relationships were found between fasting levels and all events (RR = 1.51, CI: 1.20-1.89) and with cardiovascular mortality (RR = 1.40, CI: 1.18-1.60). With 2-hour postprandial levels, the respective RRs were 1.22 (1.17-1.28) and 1.24 (1.19-1.30). A limitation is the assumption of a continuous relationship between variables.

CONCLUSIONS

We have provided refined estimates confirming the association between elevated blood glucose and subsequent cardiovascular events.

Prediabetes: to treat or not to treat?

The incidence of diabetes is continuously increasing worldwide. Pre-diabetes (defined as impaired glucose tolerance, impaired fasting glucose or both) represents an intermediate state, which often progresses to overt diabetes within a few years. In addition, pre-diabetes may be associated with increased risk of microvascular and macrovascular complications. Thus, reverting a pre-diabetic state as well as preventing the development of diabetes represents enormous challenge for the clinician. Lifestyle modification in pre-diabetic individuals was found particularly effective in the prevention of diabetes. However, compliance to lifestyle modification measures can be a crucial problem in the everyday clinical practice, especially in developing countries. During the last decade many studies support the use of anti-diabetic treatment schemes in pre-diabetic subjects to be advantageous. The American Diabetes Prevention Program (DPP) as well as other minor studies and meta-analyses has convincingly demonstrated the efficacy of metformin in this patient group. In addition, results of the 10 year DPP follow up have recently been published, demonstrating the long term safety and sustainability of metformin treatment benefits in this population. In contrast to metformin, the evidence from the use of other anti-diabetic agents (thiazolidinediones, a-glucosidase inhibitors, incretin mimetics) in pre-diabetic individuals is rather inadequate and prospective data is further needed. Furthermore, large scale studies with hard clinical endpoints are needed to delineate the effect of pre-diabetes treatment on macro- and microvascular complications. In conclusion, several strategies of patient management, mainly lifestyle modification and pharmacological interventions can prevent diabetes development in subjects diagnosed with pre-diabetes or even revert pre-diabetic state. However, whether this biochemical improvement can be translated into actual clinical benefit remains to be established.

Cardiac arrhythmia prevalence in postmenopausal women

Aim.To study the prevalence and features of cardiac arrhythmias (CA) in postmenopausal women, as well as to investigate the CA association with carbohydrate metabolism disturbances.Material and methods.This cross-sectional study included 210 postmenopausal women (median age 57 years; age range 54,0-61,0 years). Median menopause duration was 7,9 years (3,0-12,0 years). The examination included Holter ECG monitoring, clinical evaluation, measurement of blood pressure, body mass index, waist and hips circumference the levels of glucose, insulin, lipids, Mg, Ca, uric acid, brain natriuretic peptide, and thyrotropin.Results.CA were registered in 99,5% of the participants, including ischemia (17,1%), supraventricular extrasystolia (88,1%), ventricular extrasystolia (VE; 53,8%), high-grade VE (HGVE; 21,5%), SV tachycardia paroxysms (19%), atrial fibrillation (2,3%), V tachycardia paroxysms (1,4%), asystolic periods (0,9%), sino-atrial and atrioventricular blocks (9,1%), bundle branch blocks (3,3%), sinus tachycardia (50,9%), and sinus bradycardia (23,8%). In postmenopausal women with disturbed carbohydrate metabolism, CA prevalence was higher for VE (1,9 times), HGVE (2,4 times), and polytopic VE (2,5 times). VE prevalence was higher in women with abdominal obesity and chronic pancreatitis. In addition, CA odds were higher in postmenopausal women with coronary heart disease (CHD; 2,75 times), chronic heart failure (CHF; 2,6 times), and acute cardiovascular events such as myocardial infarction or stroke (3,3 times).Conclusion.CA and ischemia prevalence was high in postmenopausal women, 21,5% of whom had high potential risk of sudden death. Increased odds of ventricular arrhythmias among postmenopausal women were associated with carbohydrate metabolism disturbances, CHD, CHF.

Glucose levels are associated with cardiovascular disease and death in an international cohort of normal glycaemic and dysglycaemic men and women: the EpiDREAM cohort study

Aims: In an international prospective cohort study we assessed the relationship between glucose levels and incident cardiovascular events and death.

Methods and results: 18,990 men and women were screened for entry into the DREAM clinical trial from 21 different countries. All had clinical and biochemical information collected at baseline, including an oral glucose tolerance test (OGTT), and were prospectively followed over a median (IQR) of 3.5 (3.0–4.0) years for incident cardiovascular (CV) events including coronary artery disease (CAD), stroke, congestive heart failure (CHF) requiring hospitalization, and death. After OGTT screening, 8000 subjects were classified as normoglycaemic, 8427 had impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), and 2563 subjects had newly diagnosed type 2 diabetes mellitus (DM). There were incident events in 491 individuals: 282 CAD, 54 strokes, 19 CHF, and 164 died. The annualized CV or death event rate was 0.79/100 person-years in the overall cohort, 0.51/100 person-years in normoglycaemics, 0.92/100 person-years among subjects with IFG and/or IGT at baseline, and 1.27/100 person-years among those with DM ( p for trend <0.0001). Among all subjects, a 1 mmol/l increase in fasting plasma glucose (FPG) or a 2.52 mmol/l increase in the 2-h post-OGTT glucose was associated with a hazard ratio increase in the risk of CV events or death of 1.17 (95% CI 1.13–1.22).

Conclusions: In this large multiethnic cohort, the risk of CV events or death increased progressively among individuals who were normoglycaemic, IFG or IGT, and newly diagnosed diabetics. A 1 mmol/l increase in FPG was associated with a 17% increase in the risk of future CV events or death. Therapeutic or behavioural interventions designed to either prevent glucose levels from rising, or lower glucose among individuals with dysglycaemia should be evaluated.

γ-Tocopherol abolishes postprandial increases in plasma methylglyoxal following an oral dose of glucose in healthy, college-aged men

Postprandial hyperglycemia contributes to the risk of cardiovascular disease in part by increasing concentrations of the reactive dicarbonyl methylglyoxal (MGO), a byproduct of glucose metabolism. Oxidative stress increases MGO formation from glucose in vitro and decreases its glutathione-dependent detoxification to lactate. We hypothesized that the antioxidant γ-tocopherol, a form of vitamin E, would decrease hyperglycemia-mediated postprandial increases in plasma MGO in healthy, normoglycemic, college-aged men. Participants (n=12 men; 22.3±1.0 years; 29.3±2.4 kg/m(2)) received an oral dose of glucose (75 g) in the fasted state prior to and following 5-day ingestion of a vitamin E supplement enriched in γ-tocopherol (500 mg/day). γ-Tocopherol supplementation increased (P<.0001) plasma γ-tocopherol from 2.22±0.32 to 7.06±0.71 μmol/l. Baseline MGO concentrations and postprandial hyperglycemic responses were unaffected by γ-tocopherol supplementation (P>.05). Postprandial MGO concentrations increased in the absence of supplemental γ-tocopherol (P<.05), but not following γ-tocopherol supplementation (P>.05). Area under the curve for plasma MGO was significantly (P<.05) smaller with the supplementation of γ-tocopherol than without (area under the curve (0-180 min), -778±1010 vs. 2277±705). Plasma concentrations of γ-carboxyethyl-hydroxychroman, reduced glutathione and markers of total antioxidant capacity increased after supplementation, and these markers and plasma γ-tocopherol were inversely correlated with plasma MGO (r=-0.48 to -0.67, P<.05). These data suggest that short-term supplementation of γ-tocopherol abolishes the oral glucose-mediated increases in postprandial MGO through its direct and indirect antioxidant properties and may reduce hyperglycemia-mediated cardiovascular disease risk.

Postprandial hyperglycemia and glycemic variability: should we care?

The aim of this article is to evaluate the pros and cons of a specific impact of postprandial hyperglycemia and glycemic variability on the--mainly cardiovascular (CV)--complications of diabetes, above and beyond the average blood glucose (BG) as measured by HbA(1c) or fasting plasma glucose (FPG). The strongest arguments in favor of this hypothesis come from impressive pathophysiological studies, also in the human situation. Measures of oxidative stress and endothelial dysfunction seem to be especially closely related to glucose peaks and even more so to fluctuating high and low glucose concentrations and can be restored to normal by preventing those glucose peaks or wide glucose excursions. The epidemiological evidence, which is more or less confined to postprandial hyperglycemia and postglucose load glycemia, is also rather compelling in favor of the hypothesis, although certainly not fully conclusive as there are also a number of conflicting results. The strongest cons are seen in the missing evidence as derived from randomized prospective intervention studies targeting postprandial hyperglycemia longer term, i.e., over several years, and seeking to reduce hard CV end points. In fact, several such intervention studies in men have recently failed to produce the intended beneficial outcome results. As this evidence by intervention is, however, key for the ultimate approval of a treatment concept in patients with diabetes, the current net balance of attained evidence is not in favor of the hypothesis here under debate, i.e., that we should care about postprandial hyperglycemia and glycemic variability. The absence of a uniformly accepted standard of how to estimate these parameters adds a further challenge to this whole debate.

The prediabetic period: review of clinical aspects

Hyperglycemia that does not satisfy the diagnostic criteria for diabetes mellitus (DM) is generally called prediabetes (preDM). The global prevalence of preDM has been increasing progressively in the past few decades, and it has been established that preDM status is a strong risk factor for DM and cardiovascular disease. Currently, preDM status is classified into two subtypes: impaired fasting glucose and impaired glucose tolerance. Currently, preDM is not regarded as an independent clinical entity, but only as a risk factor for others. In this article, we review various clinical aspects of preDM in terms of the working definition, changes in criteria over the years, epidemiology, and pathophysiological characteristics, and its clinical significance in current medicine.

Mechanisms of vascular complications in prediabetes

Although the state of prediabetes is defined by its role as a diabetes risk factor, it also carries a significant risk of cardiovascular disease, independent of progression to diabetes. Typical diabetic microvascular complications also occur, albeit at low rates, in prediabetes. There is evidence that both glucose-related and glucose-independent mechanisms contribute to these vascular complications. Effective preventive strategies will likely require control of glycemia, as well as other metabolic risk factors. This article reviews some of the proposed mechanisms for the vascular complications of the prediabetic state.

dGlucose is linked to renal function changes in diabetes

AIMS

This study examines if dglucose, two-hour postprandial (2 hPP) minus fasting glucose (F), predicts glycemic control better than F or 2 hPPglucose.

METHODS

F and 2 hPPglucose, and renal function variables; BUN, serum creatinine (Scr), and estimated GFR (eGFR), were obtained from 56 insulin treated diabetic adults. 2 hPP-F(d) was calculated. Variables were compared when 2 hPPglucose was <200 (n=23) or >200 mg/dL (n=33). Correlation coefficients were calculated for F, 2 hPP or 2 hPP-F(d) renal function variables versus those for glucose.

RESULTS

Variables differed significantly between F and 2 hPP (t-test, p<0.05) for all patients and when 2 hPPglucose was < or >200 mg/dL, except dBUN at <200 mg/dL. When F, 2 hPP or 2 hPP-F(d) variables between 2 hPPglucose< and >200 mg/dL were compared, dScr was significant (p=0.0327). Correlation coefficients between dglucose and dScr or deGFR, were significant for all patients (r=0.420, p=0.0013, and r=-0.434, p=0.0008, respectively) and for 2 hPPglucose >200 mg/dL (r=0.523, p=0.0018 and r=-0.513, p=0.0023, respectively) but not 2 hPPglucose <200 mg/dL. When dglucose increased by 100 mg/dL, dScr increased by 0.08 and 0.11 mg/dL, and deGFR decreased by 2.73 and 3.73 mL/min for all patients and >200 mg/dL, respectively.

CONCLUSIONS

dGlucose better predicts renal function changes than F or 2 hPPglucose. Postprandial hyperglycemia (<200 mg/dL) control is crucial for renal protection in diabetes.

Comparison of effects of insulin aspart three times a day versus insulin detemir once a day on oxidative stress in patients with type 2 diabetes

The main purpose of this study was to investigate whether treatment with long-acting insulin once a day or short-acting insulin three times before each meal daily has a stronger antioxidative effect in patients with type 2 diabetes. These patients had not been treated previously with insulin and were hospitalized for initiation of glycemic control by insulin injection. The patients (n=43) were assigned consecutively and alternately to a group treated with insulin aspart injection three times daily just before each meal and a group treated with insulin detemir injection once daily before bedtime. The results showed that insulin aspart three times a day produced a greater improvement in plasma glucose, and particularly in mean postprandial plasma glucose, compared with insulin detemir once a day (p = 0.0006 for comparison of changes between the two insulin treatments). The amount of insulin needed to approach the target levels of plasma glucose was larger in the insulin aspart group (26.0 ± 10.7 U/day vs. 13.7 ± 4.9 U/day; p < 0.0001). However, only insulin detemir significantly decreased oxidative stress evaluated based on the level of urinary 8-iso-prostaglandin F2α (p = 0.0079), although the mechanisms are not fully evident.

Marginal differences in health-related quality of life of diabetic patients with and without macrovascular comorbid conditions in the United States

PURPOSE

To examine and quantify, at the US national level, the marginal differences in health-related quality of life (HRQoL) of diabetic patients with and without macrovascular comorbid conditions (MaVCC).

METHODS

Using the pooled Medical Expenditure Panel Survey (MEPS) 2001 and 2003 data, a nationally representative community-dwelling adult sample (age ≥ 18) was included in the study. HRQoL measures included the preference-based EQ-5D index, Euroqol visual analogue scale (EQ-VAS), SF-12 physical component summary (PCS), and SF-12 mental component summary (MCS). Given the censored distribution of the data, a two-part model was used to identify the relationship between MaVCC and the EQ-5D index after controlling for age, sex, race, ethnicity, education, income, employment status, health insurance, smoking status, diabetes severity, and comorbidities. Censored least absolute deviation and ordinary least square models were employed to analyze EQ-VAS and SF-12 PCS/MCS, respectively.

RESULTS

Compared to diabetic patients without MaVCC (N = 2431), those with MaVCC (N = 747) had significantly lower EQ-5D index (-0.062), EQ-VAS (-9.2), SF-12 PCS (-5.0), and MCS (-2.1) after controlling for differences in sociodemographics, smoking status, diabetes severity, and comorbidities (all P < 0.001).

CONCLUSIONS

MaVCC is consistently associated with lower HRQoL for patients with diabetes in the United States. Results of this study are valuable for future comparative-effectiveness and cost-effectiveness analyses in diabetes.

Oxidative stress and diabetic complications

Oxidative stress plays a pivotal role in the development of diabetes complications, both microvascular and cardiovascular. The metabolic abnormalities of diabetes cause mitochondrial superoxide overproduction in endothelial cells of both large and small vessels, as well as in the myocardium. This increased superoxide production causes the activation of 5 major pathways involved in the pathogenesis of complications: polyol pathway flux, increased formation of AGEs (advanced glycation end products), increased expression of the receptor for AGEs and its activating ligands, activation of protein kinase C isoforms, and overactivity of the hexosamine pathway. It also directly inactivates 2 critical antiatherosclerotic enzymes, endothelial nitric oxide synthase and prostacyclin synthase. Through these pathways, increased intracellular reactive oxygen species (ROS) cause defective angiogenesis in response to ischemia, activate a number of proinflammatory pathways, and cause long-lasting epigenetic changes that drive persistent expression of proinflammatory genes after glycemia is normalized ("hyperglycemic memory"). Atherosclerosis and cardiomyopathy in type 2 diabetes are caused in part by pathway-selective insulin resistance, which increases mitochondrial ROS production from free fatty acids and by inactivation of antiatherosclerosis enzymes by ROS. Overexpression of superoxide dismutase in transgenic diabetic mice prevents diabetic retinopathy, nephropathy, and cardiomyopathy. The aim of this review is to highlight advances in understanding the role of metabolite-generated ROS in the development of diabetic complications.

Prevalence, diagnosis, and treatment of impaired fasting glucose and impaired glucose tolerance in nondiabetic U.S. adults

OBJECTIVE

To estimate the rates of prevalence, diagnosis, and treatment of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS

A representative sample of the U.S. population (the National Health and Nutrition Examination Survey [NHANES]) from 2005-2006 including 1,547 nondiabetic adults (>18 years of age) without a history of myocardial infarction was assessed to determine the proportion of adults who met the criteria for IFG/IGT, and the proportion of IFG/IGT subjects who: 1) reported receiving a diagnosis from their physicians; 2) were prescribed lifestyle modification or an antihyperglycemic agent; and 3) were currently on therapy. We used multivariable regression analysis to identify predictors of diagnosis and treatment.

RESULTS

Of the 1,547 subjects, 34.6% (CI 30.3-38.9%) had pre-diabetes; 19.4% had IFG only; 5.4% had IGT only, and 9.8% had both IFG and IGT. Only 4.8% of those with pre-diabetes reported having received a formal diagnosis from their physicians. No subjects with pre-diabetes received oral antihyperglycemics, and the rates of recommendation for exercise or diet were 31.7% and 33.5%, respectively. Among the 47.7% pre-diabetic subjects who exercised, 49.4% reported exercising for at least 30 min daily.

CONCLUSIONS

Three years after a major clinical trial demonstrated that interventions could greatly reduce progression from IFG/IGT to type 2 diabetes, the majority of the U.S. population with IFG/IGT was undiagnosed and untreated with interventions. Whether this is due to physicians being unaware of the evidence, unconvinced by the evidence, or clinical inertia is unclear.

[Pathomechanism of diabetic neuropathy: background of the pathogenesis-oriented therapy]

The pathomechanism of diabetic neuropathy remains still poorly understood, however, a broad spectrum of novel findings associated with therapeutic consequences emerged during the last decades. Both disturbed function of primary hemostasis and increased activity of coagulation system contribute to the reduced endoneurial blood flow. Increased superoxide anion production induced by hyperglycemia leads to decreased activity of glycerinaldehid-3-phosphate dehydrogenase and to consequential increased activity of alternative pathways, including the polyol-, hexosamine-, diacilglycerol protein kinase-C- and advanced glycation pathways. Advanced glycation endproducts increase the activity of the nuclear-factor kappa-B, as well as the production of vasoactive factors and cytokines (interleukin-1, -6, tumor necrosis factor alpha). The aim of pathogenetic oriented treatment is to slow down, stop or reverse the progression of neuropathy. Components of pathogenetic oriented treatment are glycaemic control, management of risk factors, benfotiamine and alpha-lipoic acid. On one hand, transketolase-activator benfotiamine inhibits alternative pathways induced by hyperglycemia (the polyol-, hexosamine-, diacilglycerol protein kinase-C-, and advanced glycation pathways), while, on the other hand, it increases the activity of the pentose-phosphate-shunt. The clinical effectiveness of benfotiamine has been shown in many international and Hungarian trials. Alpha-lipoic acid as a powerful antioxidant decreases oxidative stress and this way increases the activity of glycerinaldehid-3-phosphate dehydrogenase. Alpha-lipoic acid administered in infusion or oral treatment decreases both symptoms of neuropathy and neuropathic deficit. In conclusion, the case of diabetic neuropathy illustrates well, how widening of our knowledge on pathogenesis might contribute to successful therapy.

The changes in early phase insulin secretion in newly diagnosed, drug naive korean prediabetes subjects

Background

There have been no systematic observations regarding changes in early phase insulin secretion among Korean prediabetes and early stage type 2 diabetes mellitus (T2DM) patients.

Methods

We conducted 75-g oral glucose tolerance tests (OGTT) in 873 subjects with suspected abnormal glucose tolerance. All subjects were diagnosed as having normal glucose tolerance (NGT), prediabetes (preDM), or T2DM according to the OGTT results and the insulin secretory and insulin resistance indices of each subject were calculated. Additionally, we analyzed the changes in early phase insulin secretion according to changes in fasting (Glc₀), post-prandial (Glc₁₂₀) glucose and HbA1c (A1c) levels.

Results

As compared to subjects with NGT, the insulin secretory indices of the preDM and T2DM subjects progressively declined, and the insulin resistance indices were progressively aggravated. Early phase insulin secretion decreased rapidly according to the increments of Glc₀, Glc₁₂₀ and A1c, and these changes were most prominent in the NGT stage. Compared to the control group, the early phase insulin secretion levels of the preDM or T2DM subjects were less than 50% when Glc₀ was over 100 mg/dL, Glc₁₂₀ was over 145 mg/dL, and A1c was over 5.8%.

Conclusion

This study suggests that progressive beta cell dysfunction in Koreans may be initiated and rapidly aggravated during the period generally designated as 'normal.'

The relationship between glycaemic control and mortality in patients with type 2 diabetes in general practice (ZODIAC-11)

BACKGROUND

The relationship between the degree of glycaemic control and mortality remains an important topic of discussion.

AIM

This study aimed to investigate this relationship.

DESIGN OF STUDY

Prospective cohort study.

SETTING

Primary care.

METHOD

A total of 1145 patients with type 2 diabetes were enrolled in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) in 1998. Their survival status was recorded in September 2004. Mortality ratios were calculated using standardised mortality ratios (SMRs). Associations between haemoglobin A(1c) (HbA(1c)) levels and mortality were studied with a Cox proportional hazard model. HbA(1c) levels were studied as continuous and as categorical variables.

RESULTS

A total of 335 patients died after a median follow-up period of 5.8 years. The SMR (95% confidence interval [CI]) for total mortality was 1.86 (95% CI = 1.66 to 2.06) and 2.24 (95% CI = 1.91 to 2.61) for cardiovascular mortality. For each 1% increase in HbA(1c) there was a 21% increase in the hazard ratio for total mortality. When compared with the target HbA(1c) group (HbA(1c) 6.5-7%), the group with very poor glycaemic control (HbA1c >9%) had a hazard ratio of 2.21 (95% CI = 1.42 to 3.42) for total mortality. The group with normal glycaemic control (HbA(1c) <6.5%) had a hazard ratio of 1.00 (95% CI = 0.46 to 2.19) for total mortality.

CONCLUSION

HbA(1c) level was associated with mortality and this effect seemed largely attributable to patients who were in really poor glycaemic control. The absence of differences in mortality in the groups with lower HbA(1c) levels supports the position that there is no basis for continually decreasing the therapeutic target HbA(1c) level in patients with type 2 diabetes mellitus.

Diabetes, cardiovascular risk and nephropathy

Diabetic patients with chronic kidney disease are at high risk for cardiovascular disease (CVD). All aspects of risk reduction should be rigorously applied to such patients. Statins should be used with reduction of low-density lipoprotein cholesterol levels, and blood pressure management is important. Glycemic control remains important for reduction in the development and progression of retinopathy, neuropathy, and even nephropathy itself. Reduction of other risk factors, such as smoking cessation and weight reduction, should also be implemented. Multiple risk factor reduction can have a large effect on reduction of CVD outcomes.

Markers of dysglycaemia and risk of coronary heart disease in people without diabetes: Reykjavik prospective study and systematic review

BACKGROUND

Associations between circulating markers of dysglycaemia and coronary heart disease (CHD) risk in people without diabetes have not been reliably characterised. We report new data from a prospective study and a systematic review to help quantify these associations.

METHODS AND FINDINGS

Fasting and post-load glucose levels were measured in 18,569 participants in the population-based Reykjavik study, yielding 4,664 incident CHD outcomes during 23.5 y of mean follow-up. In people with no known history of diabetes at the baseline survey, the hazard ratio (HR) for CHD, adjusted for several conventional risk factors, was 2.37 (95% CI 1.79-3.14) in individuals with fasting glucose > or = 7.0 mmol/l compared to those < 7 mmol/l. At fasting glucose values below 7 mmol/l, adjusted HRs were 0.95 (0.89-1.01) per 1 mmol/l higher fasting glucose and 1.03 (1.01-1.05) per 1 mmol/l higher post-load glucose. HRs for CHD risk were generally modest and nonsignificant across tenths of glucose values below 7 mmol/l. We did a meta-analysis of 26 additional relevant prospective studies identified in a systematic review of Western cohort studies that recorded fasting glucose, post-load glucose, or glycated haemoglobin (HbA(1c)) levels. In this combined analysis, in which participants with a self-reported history of diabetes and/or fasting blood glucose > or = 7 mmol/l at baseline were excluded, relative risks for CHD, adjusted for several conventional risk factors, were: 1.06 (1.00-1.12) per 1 mmol/l higher fasting glucose (23 cohorts, 10,808 cases, 255,171 participants); 1.05 (1.03-1.07) per 1 mmol/l higher post-load glucose (15 cohorts, 12,652 cases, 102,382 participants); and 1.20 (1.10-1.31) per 1% higher HbA(1c) (9 cohorts, 1639 cases, 49,099 participants).

CONCLUSIONS

In the Reykjavik Study and a meta-analysis of other Western prospective studies, fasting and post-load glucose levels were modestly associated with CHD risk in people without diabetes. The meta-analysis suggested a somewhat stronger association between HbA(1c) levels and CHD risk.

Pre-existing cardiovascular diseases and glycemic control in patients with type 2 diabetes mellitus in Europe: a matched cohort study

Background

Although there is a growing body of evidence showing that patients with type 2 diabetes mellitus (T2DM) have poor glycemic control in general, it is not clear whether T2DM patients with pre-existing cardiovascular diseases (CVD) are more or less likely to have good glycemic control than patients without pre-existing CVD. Our aim was to examine the degree of glycemic control among T2DM patients in Europe with and without pre-existing CVD.

Methods

This is a matched cohort study based on a multi-center, observational study with retrospective medical chart reviews of T2DM patients in Spain, France, United Kingdom, Norway, Finland, Germany, and Poland. Included patients were aged >= 30 years at time of diagnosis of T2DM, had added a SU or a PPARγ agonist to failing metformin monotherapy (index date) and had pre-existing CVD (cases). A control cohort with T2DM without pre-existing CVD was identified using 1:1 propensity score matching. With difference-in-difference approach, logistic and linear regression analyses were applied to identify differences in glycemic control by CVD during the follow up period, after controlling for baseline demographics, clinical information, and concurrent anti-hyperglycemic medication use.

Results

The percentage of case patients with adequate glycemic control relative to control patients during the 1st, 2nd, 3rd, and 4th years after the index date was 19.9 vs. 26.5, 16.8 vs. 26.5, 18.8 vs. 28.3, and 16.8 vs. 23.5 respectively. Cases were significantly less likely to have adequate glycemic control (odds ratio: 0.62; 95% confidence interval: 0.46-0.82) than controls after adjusting for baseline differences, secular trend, and other potential confounding covariates.

Conclusions

T2DM patients with pre-existing CVD tended to have poorer glycemic control than those without pre-existing CVD, all other factors being equal. It suggests that clinicians may need to pay more attention to glycemic control among T2DM patients with CVD.

Pre-diabetes and the risk for cardiovascular disease: a systematic review of the evidence

OBJECTIVES

Our objective was to estimate the magnitude of the relative risk (RR) for cardiovascular disease associated with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) from published prospective observational studies.

BACKGROUND

Hyperglycemia is a known risk factor for cardiovascular disease. However, the magnitude of the RR for cardiovascular disease associated with IFG and IGT is unclear.

METHODS

We searched PubMed from 1997 through 2008 for relevant publications and performed a meta-analysis.

RESULTS

In 18 publications with information about IFG (110 to 125 mg/dl) (IFG 110), estimates of RR ranged from 0.65 to 2.50. The fixed-effects summary estimate of RR was 1.20 (95% confidence interval [CI]: 1.12 to 1.28). In 8 publications with information about IFG (100 to 125 mg/dl) (IFG 100), estimates of RR ranged from 0.87 to 1.40. The fixed-effects summary estimate of RR was 1.18 (95% CI: 1.09 to 1.28). In 8 publications with information about IGT, estimates of RR ranged from 0.83 to 1.34. The fixed-effects summary estimate of RR was 1.20 (95% CI: 1.07 to 1.34). Five studies combined IFG and IGT, yielding a fixed-effects summary estimate of RR of 1.10 (95% CI: 0.99 to 1.23). No significant difference between the summary estimates for men and women were detected (IFG 110: men: 1.17 [95% CI: 1.05 to 1.31], women: 1.30 [95% CI: 1.10 to 1.54]; IFG 100: men: 1.23 [95% CI: 1.06 to 1.42], women: 1.16 [95% CI: 0.99 to 1.36]).

CONCLUSIONS

Impaired fasting glucose and IGT are associated with modest increases in the risk for cardiovascular disease.

Health care and productivity costs associated with diabetic patients with macrovascular comorbid conditions

OBJECTIVE

To examine and quantify from the societal perspective the impact of macrovascular comorbid conditions (MVCCs) on health care and productivity costs in diabetic patients in the U.S.

RESEARCH DESIGN AND METHODS

With use of the pooled Medical Expenditure Panel Survey (MEPS) 2004 and 2006 data, a nationally representative adult sample (aged >or=18 years) was included in the study. Health care cost was measured by the annual health care expenditure. Productivity cost was calculated from the lost productivity from missed work days and additional bed days due to illness/injury based on the 2006 average national hourly wage. Both 2004 and 2006 cost data were adjusted to 2006 dollars. Given the heavily right-skewed distribution of the cost data, the generalized linear model with log-link function and gamma variance was used to identify the relationship between MVCCs and costs after controlling for age, sex, race, ethnicity, education, income, employment status, smoking status, health insurance, diabetes severity, and comorbidities. Negative binomial models were applied to analyze the outcomes of missed work days and bed days. All statistics were adjusted using the proper sampling weight from MEPS.

RESULTS

Compared with diabetic patients without MVCCs (n = 3,320), those with MVCCs (n = 913) had statistically significant higher annual health care costs (5,120 USD, P < 0.001), more missed work days (13.03 days, P < 0.001), and more bed days (7.60 days, P = 0.025) per patient after controlling for differences in sociodemographics, smoking, diabetes severity, and comorbidities. The marginal lost productivity cost was 2,388 USD annually per patient.

CONCLUSIONS

From the U.S. societal perspective, MVCCs in diabetic patients are associated with increased health care and lost productivity costs.

Impact of glucose tolerance status on development of ischemic stroke and coronary heart disease in a general Japanese population: the Hisayama study

BACKGROUND AND PURPOSE

Few studies have shown the association between glucose tolerance status defined by a 75-g oral glucose tolerance test and the development of different types of cardiovascular disease.

METHODS

A total of 2421 community-dwelling Japanese subjects aged 40 to 79 years who underwent the oral glucose tolerance test were followed up for 14 years.

RESULTS

In multivariable analysis, the risks of ischemic stroke in both sexes and coronary heart disease (CHD) in women were significantly higher in subjects with diabetes determined by the World Health Organization criteria than in those with normal glucose tolerance even after adjustment for other confounding factors, but such association was not seen for CHD in men (ischemic stroke: adjusted hazard ratio [HR]=2.54, P=0.002 in men; adjusted HR=2.02, P=0.03 in women; CHD: adjusted HR=1.26, P=0.47 in men; adjusted HR=3.46, P=0.002 in women). Similar associations were observed for fasting plasma glucose levels of >or=7.0 mmol/L (ischemic stroke: adjusted HR=2.15, P=0.03 in men; adjusted HR=2.10, P=0.045 in women; CHD: adjusted HR=1.29, P=0.47 in men; adjusted HR=3.83, P=0.003 in women) and for 2-hour postload glucose levels of >or=11.1 mmol/L (ischemic stroke: adjusted HR=2.71, P=0.003 in men; adjusted HR=2.19, P=0.03 in women; CHD: adjusted HR=1.58, P=0.16 in men; adjusted HR=4.44, P<0.001 in women). The age-adjusted incidences of ischemic stroke and CHD did not significantly increase in subjects with impaired fasting glycemia or impaired glucose tolerance in either sex.

CONCLUSIONS

Our findings suggest that diabetes is an independent risk factor for ischemic stroke in both sexes and CHD in women in the Japanese population.

Initiating insulin therapy in elderly patients with Type 2 diabetes: efficacy and safety of lispro mix 25 vs. basal insulin combined with oral glucose-lowering agents

AIMS

To compare starter insulins in the elderly subgroup of the DURABLE trial 24-week initiation phase.

METHODS

In a post-hoc analysis of the > or = 65 years subgroup enrolled in the DURABLE trial, we compared the safety and efficacy of lispro mix 25 (LM25: lispro 25%/insulin lispro protamine suspension 75%), n = 258, vs. glargine, n = 222, added to oral glucose-lowering agents.

RESULTS

Baseline glycated hemoglobin (HbA(1c)) was similar (LM25 8.7 +/- 1.2, glargine 8.8 +/- 1.1%, P = 0.612). At 24-weeks, LM25 patients had lower HbA(1c) (7.0 +/- 0.9 vs. 7.3 +/- 0.9%, P < 0.001), greater HbA(1c) reduction (-1.7 +/- 1.2 vs. -1.5 +/- 1.1%, P < 0.001), and more patients reaching HbA(1c) < 7.0% (55.6 vs. 41.0%, P = 0.005). LM25 patients were on more insulin (0.40 +/- 0.19 vs. 0.33 +/- 0.19 u/kg/day, P < 0.001) and experienced more weight gain (3.6 +/- 3.6 vs. 1.8 +/- 3.2 kg, P < 0.001). Additionally, LM25-treated patients reported a higher mean overall hypoglycaemia rate than glargine patients (40.8 +/- 47.6 vs. 31.1 +/- 48.5 episodes/patient/year, P = 0.037), while nocturnal hypoglycaemia rates were similar. Over 24 weeks, incidence of severe hypoglycaemia was higher for LM25 (4.3% vs. 0.9%, P = 0.018); however, by 24-week endpoint incidence was similar (0.8% vs. 0.0%P = 0.125).

CONCLUSIONS

In this elderly subgroup post-hoc analysis, LM25 demonstrated a lower endpoint HbA(1c) and a higher % of patients reaching HbA(1c) target of < 7.0%, but with more weight gain and higher rates of hypoglycaemia compared to glargine.

The assessment of glycemic variability and its impact on diabetes-related complications: an overview

There is a growing body of evidence that the sole use of hemoglobin A1c is insufficient to adequately reflect the metabolic situation of patients with diabetes mellitus. The risk of developing diabetes-related complications apparently not only depends on the long-term stability of glucose values, but also on the presence or occurrence of short-term glycemic peaks and nadirs lasting for minutes or hours during a day. This leads to the phenomenon of glycemic variability. This article reviews the existing evidence for the clinical relevance of short-term glucose variations and the currently available different means of measuring glycemic variability.

Integrating glycaemic variability in the glycaemic disorders of type 2 diabetes: a move towards a unified glucose tetrad concept

The high incidence of atherosclerosis and cardiovascular disease (CVD) is the leading cause of morbidity and mortality among patients with diabetes. Evidence is accumulating that postprandial hyperglycaemia is an independent risk factor for diabetes-associated complications and mortality, and that worsening diabetes control is characterized by postprandial glucose (PPG) deterioration preceding an impairment in fasting glucose levels. Postprandial and general glucose fluctuations play a major role in activating oxidative stress, leading to the endothelial dysfunction, one of the mechanisms responsible for vascular complications. Therefore, the management of PPG is key for any strategy used in the monitoring and treatment of diabetes. We recommend that any strategy aimed at controlling the glycaemic disorders associated with type 2 diabetes, and limiting the risk of complications, should target the 'glucose tetrad', which comprises the following components: HbA(1c), fasting and postprandial plasma glucose, and markers of glycaemic variability, such as the mean amplitude of glycaemic excursions (MAGE) index. This brings together, in a simple, unified concept, the conventional markers (HbA(1c) and fasting glucose) and the more recently recognized markers of glycaemic control (PPG excursions and acute glycaemic variability).

Pathophysiology of prediabetes

The term prediabetes refers to subjects with impaired fasting glucose and/or impaired glucose tolerance who are at increased risk for type 2 diabetes mellitus. Although both types of patients are at increased risk for developing type 2 diabetes mellitus and cardiovascular disease, they manifest distinct metabolic abnormalities. In this article, we summarize the metabolic abnormalities that characterize each state and the contribution of these metabolic abnormalities to the increased risk of diabetes and cardiovascular disease.

Optimum control of blood glucose for prevention and treatment of ischemic and hemorrhagic stroke

Stroke is the most common cause of disability and a major cause of mortality. Each year, more than 500,000 Americans sustain a stroke. Reperfusion and antithrombotic therapies are still of limited benefit, hence increasing interest has been focused on therapeutic approaches that prevent and/or modulate infarct evolution. Hyperglycemia in acute stroke has a poor prognosis and is associated with significant morbidity and mortality. However, it remains unclear whether intensive lowering of blood glucose levels in the hyperacute and acute phases of stroke improves clinical outcomes. Experimental data suggest that elevated blood glucose may contribute to infarct expansion directly through a number of maladaptive metabolic pathways and that treatment with insulin may attenuate these adverse effects. Despite some controversy surrounding the optimal level of blood glucose control, much of the evidence to date supports rigorous blood glucose control and comprehensive cardiovascular risk factor management to prevent stroke in patients with diabetes. The current recommendation is to aim for strict control of blood pressure, glucose, and lipids along with lifestyle modification to improve cardiovascular health. However, there remains a distinct paucity of information concerning secondary stroke prevention. To date, the overwhelming evidence suggests that aggressive glucose management should be the standard of care in all patients with stroke and hyperglycemia. This article presents an overview of the recommendations for the optimum control of blood glucose for prevention and treatment of ischemic and hemorrhagic stroke.

Post-challenge hyperglycemia in older adults is associated with increased cardiovascular risk profile

CONTEXT

Post-challenge hyperglycemia (PCH) is common in older adults and is associated with increased cardiovascular disease (CVD) risk and total mortality. However, PCH is rarely recognized in clinical settings, and the glycemic exposure and CVD risk profile of elderly individuals with PCH has not been defined.

OBJECTIVE

The aim of the study was to characterize metabolic and CVD risk profile of elderly subjects with PCH and to determine the effect of acute postprandial metabolic changes on vascular biomarkers.

DESIGN

We conducted a cross-sectional study with a standard meal challenge protocol.

PARTICIPANTS

Older adults with normal glucose tolerance (n = 30) or PCH (fasting glucose <126 mg/dl and 2-h glucose >or=170 mg/dl; n = 28) participated in the study.

MAIN OUTCOME MEASURES

We assessed fasting and postprandial levels of glucose, insulin, lipids, high sensitivity C-reactive protein, plasminogen activator inhibitor-1, and adiponectin and endothelial function using reactive hyperemia peripheral arterial tonometry.

RESULTS

Normal glucose tolerance and PCH subjects were matched for age, sex, body mass index, and ethnicity. Fasting glucose (102 +/- 3 vs. 93 +/- 2 mg/dl; P < 0.001) and glycosylated hemoglobin (5.7 vs. 5.4%; P = 0.01) were modestly higher in the PCH group, which was also more insulin resistant (homeostasis model assessment for insulin resistance, 7.0 +/- 1.3 vs. 4.1 +/- 0.6; P = 0.03). Fasting high sensitivity C-reactive protein was higher (2.6 +/- 0.5 vs. 1.3 +/- 0.2 mg/dl; P = 0.05), and adiponectin was lower (11.6 +/- 1.6 vs. 14.0 +/- 1.3 microg/ml; P = 0.03) in subjects with PCH. Peak and 6-h postprandial area under the curve glucose, insulin, and lipids were higher in PCH subjects, who also had higher fasting and postprandial levels of plasminogen activator inhibitor-1. Reactive hyperemia peripheral arterial tonometry declined postprandially only in PCH.

CONCLUSIONS

Older adults with PCH experience significant fasting and postprandial metabolic dysregulation, which is accompanied by a proatherosclerotic and prothrombotic vascular profile.

Excess glycaemic excursions after an oral glucose tolerance test compared with a mixed meal challenge and self-measured home glucose profiles: is the OGTT a valid predictor of postprandial hyperglycaemia and vice versa?

INTRODUCTION

Postprandial hyperglycaemia is often assumed in individuals with high glucose excursions during an oral glucose tolerance test (OGTT), but the relationship between glucose levels during the OGTT and after a mixed meal is yet unclear. We addressed whether (i) glucose concentrations after an oral glucose load are similar to those after a test meal or under daily life conditions and (ii) impaired glucose tolerance (IGT) predicts postprandial hyperglycaemia.

PATIENTS AND METHODS

A total of 60 subjects with normal (NGT), IGT or diabetic (DM) glucose tolerance were examined with an OGTT, a mixed meal challenge (3433 kJ) and a self-determined 10-point home glucose profile.

RESULTS

There was a significant correlation between the 120-min OGTT glucose levels and the glycaemic excursions after the test meal and during everyday conditions. However, glucose excursions during the OGTT exceeded those after the test meal and during everyday conditions by approximately 20 and approximately 30% respectively. Likewise, insulin and C-peptide levels rose to higher levels after oral glucose compared with mixed meal ingestion. The mean self-determined diurnal glucose levels were already 10% higher in subjects with IGT compared with NGT subjects (p < 0.0001).

CONCLUSIONS

Glucose levels reached after an oral glucose challenge and during real life are correlated to some extent, but the absolute levels of glycaemia greatly differ between both conditions. Therefore, 'postchallenge' glucose levels measured during an OGTT might be used as a predictor of 'postprandial hyperglycaemia', but caution should be taken when both terms are used synonymously. Furthermore, subjects with IGT during an OGTT already exhibit increased postprandial glucose levels under real-life conditions. This suggests that IGT should already be considered an overt disease condition rather than merely a high-risk situation.

Fasting plasma glucose cutoff for diagnosis of diabetes in a Japanese population

OBJECTIVE

We examined the relationship between fasting plasma glucose (FPG) and 2-h post-load glucose (PG) levels, and the optimal FPG cutoff level to correspond to a 2-h PG of 11.1 mmol/liter, the gold standard diagnostic criterion, in a general Japanese population.

DESIGN

Cross-sectional study populations of 2421 subjects in 1988 and 2698 subjects in 2002, aged 40-79 yr and without antidiabetic medication, were tested with an oral glucose tolerance test. The relationship between FPG and 2-h PG was investigated by various regression models and a receiver operating characteristic curve.

RESULTS

The best-fit model for the relationship between FPG and 2-h PG was a quadratic regression model. The FPG cutoff levels corresponding to the 2-h PG of 11.1 mmol/liter by this model were 6.2 mmol/liter in 1988 and 6.3 mmol/liter in 2002. In the combined populations, the FPG cutoff point was 6.3 mmol/liter; the sensitivity and specificity of this cutoff point for detecting a 2-h PG of 11.1 mmol/liter were 75.2 and 88.6%, respectively. The receiver operating characteristic curve analysis confirmed that the corresponding FPG point was 6.2 mmol/liter in both the 1988 and 2002 populations. In a stratified analysis, the FPG cutoff level increased with increasing body mass index levels; however, even in subjects with body mass index more than or equal to 30 kg/m2, the FPG cutoff level was lower than 7.0 mmol/liter.

CONCLUSIONS

Our findings suggest that the FPG cutoff level corresponding to the 2-h PG of 11.1 mmol/liter in the general Japanese population is lower than the current diagnostic criterion.

[Cardiovascular disease in diabetes mellitus: classical and non-classical risk factors]

Cardiovascular disease, which includes coronary heart disease (CHD), cerebrovascular disease (CVD), and peripheral vascular disease (PVD), is the leading cause of mortality in populations, particularly in the diabetic one. Individuals with diabetes have at least a two-fold to four-fold increased risk of having cardiovascular events and a double risk of death compared with age-matched subjects without diabetes. A decline in mortality from CVD has been shown, but decline due to CHD is consistently lower in individuals with diabetes when compared with non-diabetics. The presence of several factors in diabetes leads to high occurrence of CVD such as hyperglycemia, insulin resistance, and classical and non-classical risk factors (systemic hypertension, dyslipidemia, obesity, proinflammatory condition and others). It is possible that the atherogenic role of obesity may be at least in part due to increased adipocyte production of cytokines. Considering the marked association of diabetes and CVD and unfavorable prognosis following an event, it is important to identify who is at high risk and how to screen. The American Heart Association and American Diabetes Association recommend risk stratification using diagnostic tests. However, the challenge is to accurately identify patients without a prior history of an event and those without symptoms strongly suggesting CVD, in whom additional testing would be indicated in order to achieve the most effective prevention. The benefits of glycemic control and the other risk factors have already been shown and justify optimization of the management of this high-risk population, aiming to reduce cardiovascular mortality disease and improve quality of life.

Diabetes, fasting glucose levels, and risk of ischemic stroke and vascular events: findings from the Northern Manhattan Study (NOMAS)

OBJECTIVE

There is insufficient randomized trial data to support evidence-based recommendations for tight control of fasting blood glucose (FBG) among diabetic subjects in primary stroke prevention. We explored the relationship between FBG among diabetic subjects and risk of ischemic stroke in a multiethnic prospective cohort.

RESEARCH DESIGN AND METHODS

Medical and social data and FBG values were collected for 3,298 stroke-free community residents: mean age +/- SD was 69 +/-10 years; 63% were women, 21% were white, 24% were black, and 53% were Hispanic; and follow-up was 6.5 years. Baseline FBG levels were categorized: 1) elevated FBG: history of diabetes and FBG >or=126 mg/dl (7.0 mmol/l); 2) target FBG: history of diabetes and FBG <126 mg/dl (7.0 mmol/l); or 3) no diabetes/reference group. Cox models were used to calculate hazard ratios (HRs) and 95% CI for ischemic stroke and vascular events.

RESULTS

In the Northern Manhattan Study, 572 participants reported a history of diabetes and 59% (n = 338) had elevated FBG. Elevated FBG among diabetic subjects was associated with female sex (P < 0.04), Medicaid (P = 0.01), or no insurance (P = 0.03). We detected 190 ischemic strokes and 585 vascular events. Diabetic subjects with elevated FBG (HR 2.7 [95% CI 2.0-3.8]) were at increased risk of stroke, but those with target FBG levels (1.2 [0.7-2.1]) were not, even after adjustment. A similar relationship existed for vascular events: elevated FBG (2.0 [1.6-2.5]) and target FBG (1.3 [0.9-1.8].

CONCLUSIONS

This prospective cohort study provides evidence for the benefits of tighter glucose control for primary stroke prevention.

Primary prevention of cardiovascular disease in people with dysglycemia

Cardiovascular disease accounts for a great majority of deaths in patients with type 2 diabetes. According to the World Health Organization, the prevalence of cardiovascular disease in diabetic patients ranges from 26 to 36%. Fatality rate after myocardial infarction is greater in diabetic patients, and overall prognosis after coronary heart disease is worse. Based on these observations, it has been proposed that diabetes should be considered as a coronary heart disease risk equivalent. If that is the case, prevention of diabetes and early intervention should be pursued. This view is supported by the notion that cardiovascular risk is already increased in people with impaired glucose tolerance. Moreover, higher-than-optimum blood glucose is a major cause of cardiovascular mortality in most world regions of the world. Whether dysglycemia is a marker for a more complex metabolic condition or may directly contribute to excess cardiovascular risk is still a matter of debate. However, experimental work has shown how increased glucose level can trigger multiple mechanisms of susceptibility to atherosclerosis, and diabetes prevention trials have indicated that along with reduction of the rate of conversion toward diabetes, significant improvement in cardiovascular risk factors occurs. Moreover, in the STOP-NIDDM trial, targeting postprandial glucose was associated with reduction in new cases of hypertension, myocardial infarction, and any cardiovascular events. In conclusion, dysglycemia should be included in the list of established cardiovascular risk factors and early treatment introduced in the attempt to improve cardiovascular morbidity and mortality.

The relationship between post-prandial plasma glucose and post-challenge plasma glucose in Japanese population

The relationship between post-prandial plasma glucose (PPG) and post-challenge plasma glucose (PCG) within individuals was investigated in Japanese population. The oral glucose tolerance test (OGTT) and measurements of PPG 2h after ingestion of a standardized rice-based meal (PPG2h), were performed in 4471 middle-aged Japanese subjects (2774 men and 1697 women, 50.7+/-8.5 years). There was a loose correlation between PPG2h and PCG2h (r=0.327, p<0.001). The diabetes group (n=170) showed the highest PPG2h, followed by the IGT group (n=786) and the NGT group (n=3414) (p<0.05). At the cutoff point of 140 mg/dl (7.8 mmol/l) for PPG2h, specificities were 94.9% for IGT plus diabetes and 92.9% for diabetes, but sensitivities were as low as 23.2% for IGT plus diabetes and 44.7% for diabetes. The correlation of PPG2h with PCG2h was stronger in the obese group (BMI>or=25 kg/m2) than in the lean group (BMI<20 kg/m2). We conclude that the correlation between PPG2h and PCG2h was significant but not very tight. In evaluating PPG2h, if the cutoff point of 140 mg/dl (7.8 mmol/l) for PCG2h is extrapolated, the majority of subjects with dysglycemia could be overlooked.

Contribution of nonesterified fatty acids to insulin resistance in the elderly with normal fasting but diabetic 2-hour postchallenge plasma glucose levels: the Baltimore Longitudinal Study of Aging

Isolated postchallenge hyperglycemia (IPH) with normal fasting plasma glucose <100 mg/dL and plasma glucose with diabetic 2-hour plasma glucose >or=200 mg/dL after an oral glucose tolerance test (OGTT) is a common occurrence in the elderly. We sought to understand what unique characteristics this population might have that puts it at risk for this particular metabolic finding. We therefore conducted a longitudinal study of volunteers in the Baltimore Longitudinal Study of Aging (BLSA). All volunteers had an OGTT performed (75 g) on 2 or more occasions. We measured plasma levels of glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), ghrelin, leptin, adiponectin, resistin, C-reactive protein, cytokines, and their soluble receptors, as well as nonesterified free fatty acids (NEFAs). We determined that 22 subjects in BLSA had IPH, accounting for 2.1% of the BLSA population. All 22 were older than 65 years. They were then matched by age, sex, and body mass index to 12 subjects who had isolated impaired glucose tolerance (IGT) and 15 subjects with normal glucose tolerance (NGT). All subjects had normal fasting glucose levels <100 mg/dL in accordance with the American Diabetes Association Expert Committee on the Classification and Diagnosis of Diabetes Mellitus criteria (2003). We found that subjects with IPH had similar plasma insulin levels to the other 2 groups, except at the 2-hour time when their insulin levels were higher than NGT (P < .05). Although there was a clear trend for differences in the insulinogenic index, the areas under the curves for insulin, systolic blood pressure, adiponectin, and C-reactive protein across the glucose tolerance categories revealed no statistical significance. Cytokines and their soluble receptors, gut hormones, and adipokines were similar in all 3 groups. The NEFA levels were significantly elevated in the fasting state (P < .05) in the IPH compared with NGT, with IGT intermediate between the other 2 groups. The rate of clearance of NEFAs after the OGTT decreased progressively from the NGT to the IPH group (in micromoles per liter per minute: NGT, 11.9 vs IGT, 7.6 vs IPH, 3.0). We conclude that the rate of suppression of lipolysis in the elderly determines the sensitivity of glucose uptake to insulin after OGTT.