Subclinical states of glucose intolerance and risk of death in the U.S

Non-linear relationship between TyG index and the risk of prediabetes in young people: a 5-year retrospective cohort study in Chinese young adults

Objective

Given the limited evidence on the relationship between the triglyceride-glucose (TyG) index and the risk of prediabetes among young adults, our study aimed to investigate the potential impact of the TyG index on the future development of prediabetes in young individuals.

Methods

This retrospective cohort study included 125,327 healthy adults aged 20 to 45 years. We utilized Cox proportional hazards regression models, combined with cubic spline functions and smooth curve fitting, to assess the relationship between baseline TyG index and the risk of prediabetes among young adults, exploring its non-linear association. A series of sensitivity analyses and subgroup analyses were conducted to ensure the robustness of our findings.

Results

After adjusting for covariates, the study found a positive correlation between the TyG index and the risk of prediabetes (HR=1.81, 95%CI: 1.54-2.13, p<0.0001). The risk of prediabetes increased progressively across quartiles of the TyG index (Q1 to Q4), with Q4 showing a significantly higher risk compared to Q1 (adjusted HR=2.33, 95% CI=1.72-3.16). Moreover, a non-linear relationship was identified between the TyG index and the risk of prediabetes, with an inflection point at 9.39. To the left of the inflection point, the HR was 2.04 (95% CI: 1.69 to 2.46), while to the right, the HR was 0.89 (95% CI: 0.48 to 1.65).

Conclusion

Our study reveals a non-linear relationship and a saturation effect between the TyG index and the development of prediabetes among young individuals in China, with an inflection point at 9.39. Understanding this non-linear relationship can assist clinicians in identifying young individuals at high risk and implementing targeted interventions to reduce their risk of progressing to diabetes.

Common carotid artery intima media thickness (CIMT) in patients with prediabetes and newly diagnosed type 2 diabetes mellitus

AIM

To evaluate the relationship between common carotid artery intima media thickness (CIMT) in patients with prediabetes and new-onset diabetes mellitus without proven cardiovascular disease and some classic cardio-metabolic risk factors.

PATIENTS AND METHODS

The study included 461 obese patients with an average age of 53.2 ± 10.7 years, divided into three groups - group 1 without carbohydrate disturbances (n = 182), group 2 with prediabetes (n = 193) and group 3 with newly diagnosed diabetes mellitus (n = 86).

RESULTS

The patients with new-onset diabetes had significantly higher mean CIMT values compared to those with prediabetes or without carbohydrate disturbances and a higher frequency of abnormal IMT values. CIMT correlated significantly with age, systolic BP, diastolic BP and fasting blood glucose and showed a high predictive value for the presence of diabetic neuropathy and sudomotor dysfunction. Patients with abnormal CIMT values had a higher incidence of arterial hypertension, dyslipidemia, metabolic syndrome, peripheral neuropathy, and sudomotor dysfunction. Patients who developed type 2 diabetes during follow-up had a significantly higher initial mean CIMT, which showed the highest predictive value for the risk of new-onset diabetes, with CIMT≥0.7 mm having 53 % sensitivity and 83 % specificity for the risk of progression to diabetes mellitus.

CONCLUSION

Patients with new-onset diabetes mellitus had significantly greater intima media thickness of the common carotid artery and a greater frequency of abnormal CIMT values compared to those with normoglycemia and prediabetes. CIMT has a high predictive value for the presence of diabetic neuropathy, sudomotor dysfunction and the risk of new onset diabetes.

Diagnosis and Management of Prediabetes: A Review

Importance

Prediabetes, an intermediate stage between normal glucose regulation and diabetes, affects 1 in 3 adults in the US and approximately 720 million individuals worldwide.

Observations

Prediabetes is defined by a fasting glucose level of 100 to 125 mg/dL, a glucose level of 140 to 199 mg/dL measured 2 hours after a 75-g oral glucose load, or glycated hemoglobin level (HbA1C) of 5.7% to 6.4% or 6.0% to 6.4%. In the US, approximately 10% of people with prediabetes progress to having diabetes each year. A meta-analysis found that prediabetes at baseline was associated with increased mortality and increased cardiovascular event rates (excess absolute risk, 7.36 per 10 000 person-years for mortality and 8.75 per 10 000 person-years for cardiovascular disease during 6.6 years). Intensive lifestyle modification, consisting of calorie restriction, increased physical activity (≥150 min/wk), self-monitoring, and motivational support, decreased the incidence of diabetes by 6.2 cases per 100 person-years during a 3-year period. Metformin decreased the risk of diabetes among individuals with prediabetes by 3.2 cases per 100 person-years during 3 years. Metformin is most effective for women with prior gestational diabetes and for individuals younger than 60 years with body mass index of 35 or greater, fasting plasma glucose level of 110 mg/dL or higher, or HbA1c level of 6.0% or higher.

Conclusions and Relevance

Prediabetes is associated with increased risk of diabetes, cardiovascular events, and mortality. First-line therapy for prediabetes is lifestyle modification that includes weight loss and exercise or metformin. Lifestyle modification is associated with a larger benefit than metformin.

Are HOMA-IR and HOMA-B good predictors for diabetes and pre-diabetes subtypes?

BACKGROUND

To investigate the association between the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Homeostasis Model Assessment of Beta-cell function (HOMA-B) with the incidence of diabetes and pre-diabetes subtypes.

METHODS

A total of 3101 normoglycemic people aged 20-70 years were included in the 6-year follow-up study. Multinomial logistic regression was used to calculate the incidence possibility of isolated Impaired Fasting Glucose (iIFG), isolated Impaired Glucose Tolerance (iIGT), Combined impaired fasting glucose & impaired glucose tolerance (CGI), and Diabetes Mellitus (DM) per standard deviation (SD) increment in HOMA-IR and HOMA-B in the crude and multivariable model.

RESULTS

In the multivariate model, an increase in one SD change in HOMA-IR was associated with a 43, 42, 75, and 92% increased risk of iIFG, iIGT, CGI, and DM, respectively. There was a positive correlation between the increase in HOMA-B and the incidence of iIGT; however, after adjusting the results for metabolic syndrome components, it was inversely correlated with the incidence of iIFG [Odds Ratio = 0.86(0.75-0.99)].

CONCLUSIONS

HOMA-IR is positively correlated with diabetes and pre-diabetes subtypes' incidence, and HOMA-B is inversely correlated with the incidence of iIFG but positively correlated with iIGT incidence. However, none of these alone is a good criterion for predicting diabetes and pre-diabetes.

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

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

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

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

Prediabetes and What It Means: The Epidemiological Evidence

Prediabetes is an intermediate stage between normal glycemia and diabetes and is highly prevalent, especially in older age groups and obese individuals. Five different definitions of prediabetes are used in current practice, which are based on different cut points of HbA_1C, fasting glucose, and 2-h glucose. A major challenge for the field is a lack of guidance on when one definition might be preferred over another. Risks of major complications in persons with prediabetes, including diabetes, cardiovascular disease, kidney disease, and death, also vary depending on the prediabetes definition used. Randomized clinical trials have demonstrated that lifestyle and pharmacologic interventions can be cost-effective, prevent diabetes, and improve cardiovascular risk factors in adults with prediabetes. However, the practical implementation of lifestyle modification or the use of metformin for treating prediabetes is inadequate and complicated by a lack of agreement on how to define the condition. Establishing consensus definitions for prediabetes should be a priority and will help inform expansion of insurance coverage for lifestyle modification and improve current screening and diagnostic practices.

Associations of impaired glucose tolerance and sleep disorders with mortality among the US general population

INTRODUCTION

Sleep disorders and short sleep duration are common symptoms among people with diabetes. However, the evidence is limited about the associations of post-challenge hyperglycemia and sleep quality or quantity with all-cause mortality in the US general population.

RESEARCH DESIGN AND METHODS

Our study included 8795 adults from the National Health and Nutrition Examination Survey 2005-2014. Mortality data were ascertained through 2015. Multivariable Cox proportional-hazards models were used to estimate adjusted HRs (aHRs) for all-cause mortality according to 2-hour plasma glucose levels during the 75 g oral glucose tolerance test-normal glucose tolerance (NGT), <140 mg/dL; impaired glucose tolerance (IGT), 140-199 mg/dL; and diabetes, ≥200 mg/dL. We then examined the associations of glucose tolerance status and self-reported physician-diagnosed sleep disorders (yes vs no) or sleep duration (<7 vs ≥7 hours) with all-cause mortality.

RESULTS

During follow-up (median, 5.6 years), the diabetes group had a higher risk of all-cause mortality compared with the NGT group (aHR (95% CI)=1.93 (1.41 to 2.64)), but not the IGT group (aHR (95% CI)=1.19 (0.90 to 1.59)). When we categorized participants according to glucose tolerance status and sleep disorders, the IGT group with sleep disorders had a higher risk of all-cause mortality (aHR (95% CI)=2.03 (1.24 to 3.34)) compared with the NGT group without sleep disorders. Both diabetes groups with and without sleep disorders also showed high mortality risks. The results were consistent when we used sleep duration instead of sleep disorders.

CONCLUSIONS

Using the most updated US national data, we found a high risk of all-cause mortality among individuals with IGT having sleep disorders or short sleep duration as well as those with diabetes. Future investigations are needed to identify whether and what kind of sleep management is beneficial for people with impaired glucose metabolism to prevent early death.

Novel Approaches to Air Pollution Exposure and Clinical Outcomes Assessment in Environmental Health Studies

An accurate assessment of pollutants’ exposure and precise evaluation of the clinical outcomes pose two major challenges to the contemporary environmental health research. The common methods for exposure assessment are based on residential addresses and are prone to many biases. Pollution levels are defined based on monitoring stations that are sparsely distributed and frequently distanced far from residential addresses. In addition, the degree of an association between outdoor and indoor air pollution levels is not fully elucidated, making the exposure assessment all the more inaccurate. Clinical outcomes’ assessment, on the other hand, mostly relies on the access to medical records from hospital admissions and outpatients’ visits in clinics. This method differentiates by health care seeking behavior and is therefore, problematic in evaluation of an onset, duration, and severity of an outcome. In the current paper, we review a number of novel solutions aimed to mitigate the aforementioned biases. First, a hybrid satellite-based modeling approach provides daily continuous spatiotemporal estimations with improved spatial resolution of 1 × 1 km2 and 200 × 200 m2 grid, and thus allows a more accurate exposure assessment. Utilizing low-cost air pollution sensors allowing a direct measurement of indoor air pollution levels can further validate these models. Furthermore, the real temporal-spatial activity can be assessed by GPS tracking devices within the individuals’ smartphones. A widespread use of smart devices can help with obtaining objective measurements of some of the clinical outcomes such as vital signs and glucose levels. Finally, human biomonitoring can be efficiently done at a population level, providing accurate estimates of in-vivo absorbed pollutants and allowing for the evaluation of body responses, by biomarkers examination. We suggest that the adoption of these novel methods will change the research paradigm heavily relying on ecological methodology and support development of the new clinical practices preventing adverse environmental effects on human health.

Risk factors in the illness-death model: Simulation study and the partial differential equation about incidence and prevalence

Recently, we developed a partial differential equation (PDE) that relates the age-specific prevalence of a chronic disease with the age-specific incidence and mortality rates in the illness-death model (IDM). With a view to planning population-wide interventions, the question arises how prevalence can be calculated if the distribution of a risk-factor in the population shifts. To study the impact of such possible interventions, it is important to deal with the resulting changes of risk-factors that affect the rates in the IDM. The aim of this work is to show how the PDE can be used to study such effects on the age-specific prevalence of a chronic disease, to demonstrate its applicability and to compare the results to a discrete event simulation (DES), a frequently used simulation technique. This is done for the first time based on the PDE which only needs data on population-wide epidemiological indices and is related to the von Foerster equation. In a simulation study, we analyse the effect of a hypothetical intervention against type 2 diabetes. We compare the age-specific prevalence obtained from a DES with the results predicted from modifying the rates in the PDE. The DES is based on 10000 subjects and estimates the effect of changes in the distributions of risk-factors. With respect to the PDE, the change of the distribution of risk factors is synthesized to an effective rate that can be used directly in the PDE. Both methods, DES and effective rate method (ERM) are capable of predicting the impact of the hypothetical intervention. The age-specific prevalences resulting from the DES and the ERM are consistent. Although DES is common in simulating effects of hypothetical interventions, the ERM is a suitable alternative. ERM fits well into the analytical theory of the IDM and the related PDE and comes with less computational effort.

Regression to Normal Glucose Regulation in American Indians and Alaska Natives of a Diabetes Prevention Program

OBJECTIVE

This study evaluated whether regression from impaired glucose regulation (IGR) to normal glucose regulation (NGR) after 1 year of a lifestyle intervention reduces diabetes risk in American Indians and Alaska Natives (AI/ANs). In addition, we sought to identify predictors for regression to NGR and understand possible mechanisms for the association between NGR and future diabetes risk.

RESEARCH DESIGN AND METHODS

Data from participants enrolled from 2006 to 2009 in the Special Diabetes Program for Indians Diabetes Prevention Program with IGR at baseline and an oral glucose tolerance test at year 1 were analyzed (N = 1,443). Cox regression models were used to estimate the subsequent diabetes risk (year 1 to year 3) by year 1 glucose status. Mediation analysis was used to estimate the proportions of the association between year 1 glycemic status and diabetes risk explained by specific factors.

RESULTS

Those who reverted to NGR at year 1 (38%) had lower diabetes risk than those with sustained IGR (adjusted hazard ratio 0.28, 95% CI 0.12-0.67). The lower risk associated with regression to NGR was explained by both baseline risk factors and differences in weight loss. Metformin use, weight loss, and an increase in exercise were modifiable risk factors associated with higher odds of regression to NGR.

CONCLUSIONS

Patients with prediabetes who reverted to NGR had a reduced risk of developing type 2 diabetes over the next 2 years. Both baseline and modifiable risk factors explained the risk reduction associated with NGR.

Mortality risk in adults according to categories of impaired glucose metabolism after 18 years of follow-up in the North of Spain: The Asturias Study

People who develop type 2 diabetes (T2D) are known to have a higher mortality risk. We estimated all-cause, cardiovascular, and cancer mortality-risks in our patient cohort according to categories of impaired glucose metabolism. This 18-year retrospective analysis included a region-wide, representative sample of a population aged 30-75 years. Age- and sex-stratified hazard ratios (HRs) were calculated for 48 participants with diagnosed T2D, 83 with undiagnosed T2D (HbA1c ≥6.5%, fasting glycemia ≥126 mg/dL, or glycemia after 75 g glucose load ≥200 mg/dL); 296 with prediabetes (HbA1c 5.7%-6.4%, fasting glycemia 100-125 mg/dL, or glycemia after 75 g glucose load 140-199 mg/dL), and 607 with normoglycemia. Over 18,612 person-years, 32 individuals with undiagnosed T2D, 30 with diagnosed T2D, 62 with prediabetes, and 80 with normoglycemia died. Total sample crude mortality rate (MR) was 10.96 deaths per 1,000 person-years of follow-up. MR of the diagnosed T2D group was more than 3-times higher and that of newly diagnosed T2D was 2-times higher (34.72 and 21.42, respectively) than total sample MR. Adjusted HR for all-cause mortality was 2.02 (95% confidence interval 1.29-3.16) and 1.57 (95% CI 1.00-2.28) in the diagnosed T2D group and the newly diagnosed T2D group, respectively. Adjusted HR for cardiovascular mortality in the T2D group was 2.79 (95% CI 1.35-5.75); this risk was greatly increased in women with T2D: 6.72 (95% CI 2.50-18.07). In Asturias, age- and sex-standardized all-cause mortality is more than 2-times higher for adults with T2D than for adults without T2D. The HR for cardiovascular mortality is considerably higher in T2D women than in normoglycemic women.

The Timing of Activity after Eating Affects the Glycaemic Response of Healthy Adults: A Randomised Controlled Trial

There is scant information on how a time lag between the cessation of eating and commencement of physical activity affects postprandial glycaemia. Starting at baseline (t = 0), participants ingested white bread containing 50 g of available carbohydrates within 10 min. Using two crossover conditions, we tested the effect over 2 h on postprandial glycaemia of participants undertaking light activity at 15 or 45 min following baseline and compared it with a sedentary control condition. The activity involved cycling on a stationary ergometer for 10 min at 40 revolutions per min with zero resistance. Seventy-eight healthy adults were randomized to the 15 or 45 min activity arm and then randomised to the order in which they undertook the active and sedentary conditions. Cycling 45 min after baseline changed the course of the blood glucose response (likelihood ratio chi square = 31.47, p < 0.01) and reduced mean blood glucose by 0.44 mmol/L (95% confidence interval 0.14 to 0.74) at 60 min when compared with the sedentary control. No differences in postprandial blood glucose response were observed when cycling started 15 min after baseline compared with the sedentary control. Undertaking activity after waiting for 30 min following eating might be optimal in modifying the glycaemic response.

Insulin resistance and cardiovascular disease

Insulin resistance is characterised by a decreased rate of insulin-mediated glucose uptake and is associated with adverse changes in cardiovascular risk factors, such as high triglyceride levels, low levels of high-density lipoprotein cholesterol, raised blood pressure, obesity and increased levels of plasminogen activator inhibitor 1. The term `insulin resistance syndrome' (IRS) is used to describe the complex of factors associated with insulin resistance that is found in patients both with and without type 2 diabetes. Although the presence of insulin resistance syndrome is generally considered to be a risk factor for cardiovascular disease, there is a lack of definitive evidence for a causal link. Recently, however, a statistical method known as factor analysis has been applied to the cluster of cardiovascular risk factors associated with IRS. This has been able to show that the `insulin resistance factor' (high plasma insulin and glucose levels, body mass index, waist-to-hip ratio and triglyceride levels) predicted coronary heart disease events in elderly non-diabetic men as well as in patients with type 2 diabetes. Therefore, treatment of insulin resistance whether by pharmacological (eg. thiazolidinediones) or nonpharmacological means has the potential to offer both improvements in glycaemic control and in cardiovascular events.

Norepinephrine transporter expression is inversely associated with glycaemic indices: a pilot study in metabolically diverse persons with overweight and obesity

Objective

The objective of this study was to examine the cross‐sectional relationship between the expression of norepinephrine transporter (NET), the protein responsible for neuronal uptake‐1, and indices of glycaemia and hyperinsulinaemia, in overweight and obese individuals.

Methods

Thirteen non‐medicated, non‐smoking subjects, aged 58 ± 1 years (mean ± standard error of the mean), body mass index (BMI) 31.4 ± 1.0 kg m⁻², with wide‐ranging plasma glucose and haemoglobin A1c (HbA1c, range 5.1% to 6.5%) participated. They underwent forearm vein biopsy to access sympathetic nerves for the quantification of NET by Western blot, oral glucose tolerance test (OGTT), euglycaemic hyperinsulinaemic clamp, echocardiography and assessments of whole‐body norepinephrine kinetics and muscle sympathetic nerve activity.

Results

Norepinephrine transporter expression was inversely associated with fasting plasma glucose (r = −0.62, P = 0.02), glucose area under the curve during OGTT (AUC_0–120, r = −0.65, P = 0.02) and HbA1c (r = −0.67, P = 0.01), and positively associated with steady‐state glucose utilization during euglycaemic clamp (r = 0.58, P = 0.04). Moreover, NET expression was inversely related to left ventricular posterior wall dimensions (r = −0.64, P = 0.02) and heart rate (r = −0.55, P = 0.05). Indices of hyperinsulinaemia were not associated with NET expression. In stepwise linear regression analysis adjusted for age, body mass index and blood pressure, HbA1c was an independent inverse predictor of NET expression, explaining 45% of its variance.

Conclusions

Hyperglycaemia is associated with reduced peripheral NET expression. Further studies are required to identify the direction of causality.

Glycated albumin is associated with body mass index in euglycemic adults but is not predictive of postprandial blood glucose response

BACKGROUND

The level of glycated albumin in circulation is an indicator of blood glucose control over the preceding 2 weeks. It is not known if the level of glycated albumin in circulation relates to an individual's postprandial blood glucose response.

METHODS

Eighty-four euglycemic young adults (21.1 [3.9] years, BMI 23.9 [4.0] kg/m² ) primarily of European descent underwent a fasted meal test of 50 g carbohydrate from white bread. Capillary blood was then sampled at regular intervals over 2 hours. Correlations were sought between glycated albumin, fasted and 2-hour post-load blood glucose measurements, incremental area under the blood glucose curve, glycemic range, body mass index (BMI), and C-reactive protein (CRP).

RESULTS

When adjusted for age and sex, glycated albumin was inversely correlated with BMI (r=-.25, P=.027). No significant correlations existed for glycated albumin and postprandial markers of blood glucose control. BMI and CRP values correlate in this population (r=.30, P=.009).

CONCLUSIONS

Glycated albumin in circulation is not related to postprandial blood glucose response in young euglycemic adults. Glycated albumin is lower in euglycemic adults with higher BMI values. Contrary to research with older adults or those with impaired glucose control, glycated albumin did not correlate to CRP.

Severity of coronary artery disease and retinal microvascular signs in patients with diagnosed versus undiagnosed diabetes: cross-sectional study

BACKGROUND

There is increasing evidence that a considerable proportion of patients with diabetes remain undiagnosed and untreated, however, it is unclear whether this is associated with more severe coronary artery disease (CAD) and microvasculature changes compared with diagnosed patients. We assessed CAD extent and severity, along with changes to the retinal microvascular structure in participants with undiagnosed versus diagnosed type 2 diabetes.

METHODS

Participants of the Australian Heart Eye Study were stratified into participants with previously diagnosed diabetes (n=489), undiagnosed diabetes (n=76) and no diabetes (n=1,112). Retinal vessel caliber was measured from digital retinal images. Extent and severity of CAD was assessed using Extent and Gensini scores from angiography findings, respectively.

RESULTS

Participants with undiagnosed and diagnosed diabetes versus those with no diabetes (reference group) had increased odds of being in the highest quartile of Gensini scores, multivariate adjusted odds ratios (OR) =7.02 [95% confidence interval (CI), 2.04-24.1] and OR =2.76 (95% CI, 1.67-4.55), respectively. Participants with undiagnosed and diagnosed diabetes versus those with no diabetes also had increased odds of being in the highest quartile of Extent scores, multivariate adjusted OR =7.63 (95% CI, 2.15-27.10) and OR =3.72 (95% CI, 2.22-6.27), respectively. No significant differences were observed in retinal vessel caliber between participants with undiagnosed versus diagnosed diabetes.

CONCLUSIONS

The present study demonstrated that participants with undiagnosed diabetes compared to those with previously diagnosed diabetes, had a stronger likelihood of having more severe and extensive CAD. However, retinal microvascular signs did not differ by diabetes status.

Obstructive Sleep Apnoea, Glucose Tolerance and Liver Steatosis in Obese Women

In this study of obstructive sleep apnoea (OSA), glucose tolerance and liver steatosis in females from an obesity unit, 45 patients (mean age 46.8 years, mean body mass index 39.4 kg/m2, all non-diabetic and alcohol abstainers) underwent nocturnal polysomnography, a 2 h oral glucose tolerance test and abdominal ultrasonography. OSA, defined as an apnoea–hypopnoea index (AHI) of ≤ 10 events/h, was present in 20 patients (44%). Impaired glucose tolerance (IGT) was found in eight patients (40%) with OSA and three patients (12%) without OSA; there was a positive linear relationship between AHI and post-load glucose levels. On multivariate logistic regression analysis, IGT was predicted by OSA independently of age, waist circumference, systolic blood pressure and current smoking. Liver steatosis was present in 37 women (82.2%), of whom six had grade III steatosis. Of the variables tested, IGT was the only predictor of grade III steatosis. In conclusion, OSA is an independent predictor of IGT which, in turn, is associated with severe liver steatosis in an obesity unit-based sample of women.

Association of Inflammation prior to Kidney Transplantation with Post-Transplant Diabetes Mellitus

BACKGROUND/OBJECTIVE

Post-transplant diabetes mellitus (PTDM) is both common and associated with poor outcomes after kidney transplantation. Our objective was to examine relationships of uremia-associated inflammation and adiponectin with PTDM.

METHODS

Nondiabetic kidney transplant patients were enrolled with donor controls. Inflammatory cytokines and adiponectin were measured before and after transplantation. Adipose tissue was obtained for gene expression analysis. Glucose transport was quantified in vitro in C2C12 cells following cytokine exposure. The patients were monitored up to 12 months for PTDM.

RESULTS

We studied 36 controls and 32 transplant patients, of whom 11 (35%) developed PTDM. Compared to controls, plasma TNFα, IL-6, MCP-1, and CRP levels were higher in transplant patients (p < 0.01). In multivariable analysis, TNFα plasma levels before transplantation were associated with development of PTDM (OR = 2.03, p = 0.04). Visceral adipose tissue TNFα mRNA expression was higher in transplant patients than controls (fold change 1.33; p < 0.05). TNFα mRNA expression was also higher in patients who developed PTDM than in those who did not (fold change 1.42; p = 0.05), and adiponectin mRNA expression was lower (fold change 0.48; p < 0.05). The studies on the C2C12 cells demonstrated an increase in glucose uptake following exposure to adiponectin and no significant change after exposure to TNFα alone. Concomitant TNFα and adiponectin exposure blunted adiponectin-induced glucose uptake (11% reduction; p < 0.001).

CONCLUSION

Our in vitro and clinical observations suggest that TNFα could contribute to PTDM through an effect on adiponectin. Our study proposes that inflammation is involved in glucose regulation after kidney transplantation.

Overweight and abdominal obesity as determinants of undiagnosed diabetes and pre-diabetes in Bangladesh

BACKGROUND

Type 2 diabetes and pre-diabetes are an increasing pandemic globally and often remain undiagnosed long after onset in low-income settings. The objective of this study is to assess the determinants and prevalence of undiagnosed diabetes and pre-diabetes among adults in Bangladesh.

METHODS

In an exploratory study, we performed oral glucose tolerance test on 1243 adults ≥20 years of age from urban Mirpur, Dhaka (n = 518) and rural Matlab, Chandpur (n = 725) who had never been diagnosed with diabetes or pre-diabetes. We collected data on socioeconomic, demographic, past medical history, physical activity, and measured weight, height, waist and hip circumferences, and blood pressure. Risk factors associated with undiagnosed diabetes and pre-diabetes were examined using a multiple logistic regression model.

RESULTS

Overall prevalence of diabetes and pre-diabetes was 6.6 % (95 % CI 5.3, 8.1) and 16.6 % (14.5, 18.7) respectively, with both being significantly higher in urban than rural populations (diabetes 12.2 % vs 2.6 % respectively, p < 0.000; pre-diabetes 21.2 % vs 13.2 %, p < 0.001). After adjustment the variables, urban residence (OR 2.5 [95 % CI 1.02, 5.9]), age group 40-59 y (2.9 [1.7-5.2]), ≥60 y (8.1 [2.8-23.8]), overweight (2.2 [1.3-3.9]), abdominal obesity (3.3 [1.8-6.0]) and high WHR 5.6 (2.7-11.9) were all significant predictors of diabetes. Significant predictors of pre-diabetes included age group 40-59 (1.6 [1.1-2.2]), female sex (1.5 [1.0-2.2]), abdominal obesity (1.7 [1.2-2.4]) and high WHR (1.6 [1.2-2.3]).

CONCLUSION

Both overweight and abdominal obesity contribute to the hidden public health threat of undiagnosed diabetes and pre-diabetes. Awareness raising and screening of high risk groups combined with a tailored approach are essential for halting the epidemic of diabetes and pre-diabetes in Bangladesh.

Potential Anti-Atherosclerotic Properties of Astaxanthin

Astaxanthin is a naturally occurring red carotenoid pigment classified as a xanthophyll, found in microalgae and seafood such as salmon, trout, and shrimp. This review focuses on astaxanthin as a bioactive compound and outlines the evidence associated with its potential role in the prevention of atherosclerosis. Astaxanthin has a unique molecular structure that is responsible for its powerful antioxidant activities by quenching singlet oxygen and scavenging free radicals. Astaxanthin has been reported to inhibit low-density lipoprotein (LDL) oxidation and to increase high-density lipoprotein (HDL)-cholesterol and adiponectin levels in clinical studies. Accumulating evidence suggests that astaxanthin could exert preventive actions against atherosclerotic cardiovascular disease (CVD) via its potential to improve oxidative stress, inflammation, lipid metabolism, and glucose metabolism. In addition to identifying mechanisms of astaxanthin bioactivity by basic research, much more epidemiological and clinical evidence linking reduced CVD risk with dietary astaxanthin intake is needed.

Therapeutic Challenges in Diabetes Prevention: We Have Not Found the "Exercise Pill"

Type 2 diabetes has become an enormous public health burden, making diabetes prevention a pressing issue. While lifestyle modification is the most effective preventive strategy, it is resource-intensive and not universally sustainable. We review the evidence on pharmacological options for diabetes prevention, in search of a medication that is efficacious, easy to adhere to, well tolerated, and cost-effective. With the exception of metformin, most other drugs have either limited efficacy or costly side effects.

Approaching pre-diabetes

As the global epidemic of type 2 diabetes continues to rise, the time has come to revisit our approach to pre-diabetes. Recently, much ado has been made about screening, diagnosis, pathophysiology and clinical interventions in pre-diabetes, and all for good reason as the key to reversing the diabetes epidemic likely lies therein. The somewhat controversial term "pre-diabetes" represents collective dysglycemic states intermediate between normal glucose regulation (NGR) and diabetes. Not all people with pre-diabetes will develop diabetes, but the majority will. In fact, up to 70% of those with pre-diabetes may acquire the disease over their lifetime. Furthermore, even when overt diabetes is delayed or prevented, both micro- and macrovascular disease appears more prevalent in those with pre-diabetes compared to their normoglycemic peers. Hence, there is growing consensus that NGR should be the goal for people with pre-diabetes. Nevertheless, there is much to consider in that pursuit. Herein, we provide an update on the global burden of pre-diabetes, its underlying pathophysiology and discuss clinical considerations in these individuals at high risk of developing diabetes.

Three 15-min bouts of moderate postmeal walking significantly improves 24-h glycemic control in older people at risk for impaired glucose tolerance

OBJECTIVE

The purpose of this study was to compare the effectiveness of three 15-min bouts of postmeal walking with 45 min of sustained walking on 24-h glycemic control in older persons at risk for glucose intolerance.

RESEARCH DESIGN AND METHODS

Inactive older (≥60 years of age) participants (N=10) were recruited from the community and were nonsmoking, with a BMI<35 kg/m2 and a fasting blood glucose concentration between 105 and 125 mg dL(-1). Participants completed three randomly ordered exercise protocols spaced 4 weeks apart. Each protocol comprised a 48-h stay in a whole-room calorimeter, with the first day serving as the control day. On the second day, participants engaged in either 1) postmeal walking for 15 min or 45 min of sustained walking performed at 2) 10:30 a.m. or 3) 4:30 p.m. All walking was on a treadmill at an absolute intensity of 3 METs. Interstitial glucose concentrations were determined over 48 h with a continuous glucose monitor. Substrate utilization was measured continuously by respiratory exchange (VCO2/VO2).

RESULTS

Both sustained morning walking (127±23 vs. 118±14 mg dL(-1)) and postmeal walking (129±24 vs. 116±13 mg dL(-1)) significantly improved 24-h glycemic control relative to the control day (P<0.05). Moreover, postmeal walking was significantly (P<0.01) more effective than 45 min of sustained morning or afternoon walking in lowering 3-h postdinner glucose between the control and experimental day.

CONCLUSIONS

Short, intermittent bouts of postmeal walking appear to be an effective way to control postprandial hyperglycemia in older people.

Modeling the impact of prevention policies on future diabetes prevalence in the United States: 2010-2030

BACKGROUND

Although diabetes is one of the most costly and rapidly increasing serious chronic diseases worldwide, the optimal mix of strategies to reduce diabetes prevalence has not been determined.

METHODS

Using a dynamic model that incorporates national data on diabetes prevalence and incidence, migration, mortality rates, and intervention effectiveness, we project the effect of five hypothetical prevention policies on future US diabetes rates through 2030: 1) no diabetes prevention strategy; 2) a "high-risk" strategy, wherein adults with both impaired fasting glucose (IFG) (fasting plasma glucose of 100-124 mg/dl) and impaired glucose tolerance (IGT) (2-hour post-load glucose of 141-199 mg/dl) receive structured lifestyle intervention; 3) a "moderate-risk" strategy, wherein only adults with IFG are offered structured lifestyle intervention; 4) a "population-wide" strategy, in which the entire population is exposed to broad risk reduction policies; and 5) a "combined" strategy, involving both the moderate-risk and population-wide strategies. We assumed that the moderate- and high-risk strategies reduce the annual diabetes incidence rate in the targeted subpopulations by 12.5% through 2030 and that the population-wide approach would reduce the projected annual diabetes incidence rate by 2% in the entire US population.

RESULTS

We project that by the year 2030, the combined strategy would prevent 4.6 million incident cases and 3.6 million prevalent cases, attenuating the increase in diabetes prevalence by 14%. The moderate-risk approach is projected to prevent 4.0 million incident cases, 3.1 million prevalent cases, attenuating the increase in prevalence by 12%. The high-risk and population approaches attenuate the projected prevalence increases by 5% and 3%, respectively. Even if the most effective strategy is implemented (the combined strategy), our projections indicate that the diabetes prevalence rate would increase by about 65% over the 23 years (i.e., from 12.9% in 2010 to 21.3% in 2030).

CONCLUSIONS

While implementation of appropriate diabetes prevention strategies may slow the rate of increase of the prevalence of diabetes among US adults through 2030, the US diabetes prevalence rate is likely to increase dramatically over the next 20 years. Demand for health care services for people with diabetes complications and diabetes-related disability will continue to grow, and these services will need to be strengthened along with primary diabetes prevention efforts.

Isolated post-challenge hyperglycaemia and risk of cardiovascular events: Tehran Lipid and Glucose Study

OBJECTIVE

To evaluate the risk of cardiovascular events in diabetes defined by isolated post-challenge hyperglycaemia (IPH).

METHODS

We followed 3794 subjects aged ≥40 years without known history of diabetes or cardiovascular disease (CVD) at baseline for CVD events. Participants were categorized as subjects without diabetes [fasting plasma glucose (FPG) < 126 mg/dL and 2-h post-challenge plasma glucose (2-hPG) < 200 mg/dL], IPH (FPG < 126 mg/dL and 2-h PG ≥ 200 mg/dL) and fasting hyperglycaemia (fasting blood glucose (FBS) ≥ 126 mg/dL). Hazard ratios (HRs) were calculated with the use of Cox proportional-hazards regression models to evaluate the risk of CVD events.

RESULTS

At baseline, of 486 subjects with newly diagnosed diabetes, 190 (39%) had IPH. Over the next 8 years, age and sex-adjusted HR for incident CVD was 1.77 (95% confidence interval (CI): 1.19-2.64; p = 0.005) in subjects with IPH compared with subjects without diabetes. After further adjustment for potential confounders, the HR for CVD was not significant [1.32 (95% CI: 0.88-1.99; p = 0.2)].

CONCLUSIONS

IPH in middle-aged adults adds nothing for identifying CVD risks when other risk factors are taken into account. Associated metabolic risk factors seem to be more important than hyperglycaemia per se.

Vildagliptin and pioglitazone in patients with impaired glucose tolerance after kidney transplantation: a randomized, placebo-controlled clinical trial

BACKGROUND

New-onset diabetes after transplantation (NODAT) is a serious complication after kidney transplantation affecting graft and patient survival. Currently, no guidelines exist for the management of renal transplant patients with impaired glucose tolerance (IGT), a risk factor for the development of NODAT and an independent predictor of death.

METHODS

In a population of 48 stable renal transplant recipients at least 6 months from time of transplantation with newly diagnosed IGT, we tested the dipeptidylpeptidase-4 inhibitor vildagliptin, the thiazolidinedione pioglitazone, or placebo for 3 months in addition to lifestyle counseling. Outcome measures were difference in change in oral glucose tolerance test between the groups and between baseline and end of study as well as change in HbA1c, serum lipids, and renal and hepatic function.

RESULTS

In both treatment groups, 2-hr plasma glucose at 3 months was significantly reduced compared with baseline (vildagliptin: -20±24 mg/dL; P=0.002 and pioglitazone: -23±29 mg/dL; P=0.004), and pioglitazone also significantly improved fasting plasma glucose (-11±14 mg/dL; P=0.003), although the primary outcome (difference in change in 2-hr plasma glucose among the three groups) did not reach statistical significance. Furthermore, HbA1c was decreased in both treatment arms (vildagliptin: -0.1%±0.3%; P=0.046 and pioglitazone: -0.2%±0.3%; P=0.029). In the placebo group, no significant changes in these parameters were observed. Only mild adverse events occurred and at a similar rate in all three groups.

CONCLUSIONS

These data demonstrate that both vildagliptin and pioglitazone are of potential benefit in patients with IGT after renal transplantation in addition to lifestyle modification.

Satisfaction with glucose-lowering treatment and well-being in patients with type 2 diabetes and myocardial infarction: a DIGAMI2 QoL sub-study

The second Diabetes Glucose and Myocardial Infarction (DIGAMI 2) study randomised patients with diabetes and myocardial infarction to insulin or oral-based treatment. To determine the effects of insulin-based treatment, the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and the Psychological General Well-Being (PGWB) Index were administered at baseline and 12 months. Insulin-treated patients (n = 197) had a worse risk profile and more co-morbidity at baseline than patients on oral glucose-lowering agents (n = 127). The treatment satisfaction and psychological well-being was similar between insulin and oral groups at baseline [DTSQ: median (first-third quartile) 30 (24-34) vs 31 (27-34), NS; PGWB: 77 (73-82) vs 79 (76-82), NS] and at 12 months [DTSQ: 32 (28-35) vs 34 (30-36), NS; PGWB: 81 (78-84) vs 82 (78-84), NS]. Improvement was significant in both groups. Insulin-based therapy was well accepted and did not decrease treatment satisfaction or psychological well-being compared to oral glucose-lowering treatment in patients with type 2 diabetes and myocardial infarction.

Should we still screen for type 2 diabetes after ADDITION-Cambridge? A low-income world perspective

The worldwide growing epidemic of diabetes is driven by the increase in type 2 diabetes. The very insidious natural history of type 2 diabetes and the availability of simple means to detect it as well as its preceding silent stages make type 2 diabetes and ideal disease for screening. Although public policies for type 2 diabetes screening do exist in many developed countries, issues related to its benefits on disease outcomes and its cost-effectiveness have been a concern. Recent results from the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care (ADDITION)-Cambridge show that screening for type 2 diabetes is not associated with a reduction in mortality, either all-cause, cardiovascular or diabetes-related, after 10 years of follow-up. It seems crucial to raise the awareness of the medical community on the high risk of misinterpretation of these results as the death knell of type 2 diabetes screening. To that end, we discuss here some potential explanations of the lack of benefit, and we suggest a cautious uptake of the results, especially in low-income countries where type 2 diabetes screening is by far more likely to yield substantial health benefits.

Risk scores for diabetes and impaired glycaemia in the Middle East and North Africa

AIMS

To develop risk scores for diabetes and diabetes or impaired glycaemia for individuals living in the Middle East and North Africa region. In addition, to derive national risk scores for Algeria, Saudi Arabia and the United Arab Emirates and to compare the performance of the regional risk scores with the national risk scores.

METHODS

An opportunistic sample of 6588 individuals aged 30-75 years was screened. Screening consisted of a questionnaire and a clinical examination including measurement of HbA(1c). Two regional risk scores and national risk scores for each of the three countries were derived separately by stepwise backwards multiple logistic regression with diabetes [HbA(1c) ≥ 48 mmol/mol (≥ 6.5%)] and diabetes or impaired glycaemia [HbA(1c) ≥ 42 mmol/mol (≥ 6.0%)] as outcome. The performance of the regional and national risk scores was compared in data from each country by receiver operating characteristic analysis.

RESULTS

The eight risk scores all included age and BMI, while additional variables differed between the scores. The areas under the receiver operating characteristic curves were between 0.67 and 0.70, and for sensitivities approximately 75%; specificities varied between 50% and 57%. The regional and the national risk scores performed equally well in the three national samples.

CONCLUSIONS

Two regional risk scores for diabetes and diabetes or impaired glycaemia applicable to the Middle East and North Africa region were identified. The regional risk scores performed as well as the national risk scores derived in the same manner.

Pioglitazone ameliorates endothelial dysfunction in those with impaired glucose regulation among the first-degree relatives of type 2 diabetes mellitus patients

OBJECTIVE

To study the effects of pioglitazone on endothelial dysfunction of subjects with impaired glucose regulation (IGR) among the first-degree relatives of patients with type 2 diabetes mellitus (T2DM).

SUBJECTS AND METHODS

The first-degree relatives of T2DM patients were screened with oral glucose test and IGR was diagnosed. IGR subjects whose blood glucose was still above the level after 1-month exercise were randomized to receive pioglitazone (15 mg/day) or vehicle for 12 weeks. Endothelial function was assessed as endothelium-dependent and -independent vasodilation. Blood nitric oxide (NO), blood pressure, body mass index, insulin and serum lipids were also measured. Area under the curve of glucose (AUC(glu)) and insulin (AUC(INS)), homeostasis model assessment of insulin resistance (HOMA-IR), HOMA of β-cell function (HOMA-β) and early insulin secretion index (ΔI(30)/ΔG(30)) were calculated.

RESULTS

After pioglitazone treatment, fasting plasma, 2-hour plasma glucose, triglyceride (TG), fasting insulin, AUC(glu), HOMA-β and HOMA-IR, 2-hour insulin, AUC(INS) and ΔI(30)/ΔG(30) decreased. Endothelium-dependent vasodilation and NO were significantly improved in the treatment group. Furthermore, the changes of endothelium-dependent vasodilation were negatively correlated with changes in AUC(INS) but positively with NO and HOMA-β. Stepwise multivariate regression analysis showed that changes in NO and HOMA-β were both independent parameters for improvement of endothelial dysfunction.

CONCLUSION

Pioglitazone decreased blood glucose and TG, increased insulin sensitivity, and ameliorated endothelial dysfunction of IGR subjects among the first-degree relatives of T2DM patients. Increased NO production may be associated with the improvement of endothelial dysfunction.

Screening for hyperglycemia in the developing world: rationale, challenges and opportunities

BACKGROUND

The prevalence of diabetes and prediabetes are increasingly high in developing countries, where detection rates remain very low. This manuscript discusses the rationale, challenges and opportunities for early detection of diabetes and prediabetes in developing countries.

METHODS

PubMed was searched up to March 2012 for studies addressing screening for hyperglycemia in developing countries. Relevant studies were summarized through key questions derived from the Wilson and Junger criteria.

RESULTS

In developing countries, diabetes predominantly affects working-age persons, has high rates of complications and devastating economic impacts. These countries are ill-equipped to handle advanced stages of the disease. There are acceptable and relatively simple tools that can aid screening in these countries. Interventions shown to be cost-effective in preventing diabetes and its complications in developed countries can be used in screen-detected people of developing countries. However, effective implementation of these interventions remains a challenge, and the costs and benefits of diabetes screening in these settings are less well-known. Implementing screening policies in developing countries will require health systems strengthening, through creative funding and staff training.

CONCLUSIONS

For many compelling reasons, screening for hyperglycemia preferably targeted, should be a policy priority in developing countries. This will help reorient health systems toward cost-saving prevention.

Cost and clinical implications of diabetes prevention in an Australian setting: a long-term modeling analysis

AIMS/HYPOTHESIS

Metformin and intensive lifestyle changes (ILC) reduced the incidence of type 2 diabetes (T2D) versus standard care (control) in overweight or obese subjects with impaired glucose tolerance (IGT) in the Diabetes Prevention Program (DPP) trial and Diabetes Prevention Program Outcomes Study (DPPOS). We projected lifetime clinical and economic outcomes based on the results from the DPP+DPPOS, from a 3rd-party payer perspective in Australia.

METHODS

A semi-Markov, 2nd-order Monte Carlo model was developed with four health states: "normal glucose regulation" (NGR); IGT; T2D and 'dead'. Outcomes were discounted at 5% annually. Univariate and probabilistic sensitivity analyses were performed. Incremental cost-effectiveness ratios (ICERs) were calculated.

RESULTS

Cumulative incidence (standard deviation) of T2D was 89.7% (0.2), 83.8% (0.2) and 73.4% (0.3%) for control, metformin and ILC respectively. Lifetime incremental direct costs were $1217 (4411) per subject for metformin versus control, with cost savings of $289 (4296) for ILC versus control. ILC therefore dominated control, with improvements in clinical outcomes and overall cost savings. Incremental costs per QALY-gained for metformin versus control were $10,142. Probability of cost-effectiveness at willingness-to-pay threshold of $50,000 was 78% and 100% for metformin or ILC respectively. Results were most sensitive to probabilities of developing T2D and costs of implementing the interventions.

CONCLUSIONS/INTERPRETATION

Substantial improvements in lifetime clinical outcomes could be expected in high risk subjects treated with metformin or ILC. Prevention of T2D in this group of subjects is good value for money, and may even lead to long term cost savings.

A globally applicable screening model for detecting individuals with undiagnosed diabetes

AIMS

Current risk scores for undiagnosed diabetes are additive in structure. We sought to derive a globally applicable screening model based on established non-invasive risk factors for diabetes but with a more flexible structure.

METHODS

Data from the DETECT-2 study were used, including 102,058 participants from 38 studies covering 8 geographical regions worldwide. A global screening model for undiagnosed diabetes was identified through tree-structured regression analysis. The performance of the global screening model was evaluated in each of the geographical regions by receiver operating characteristic (ROC) analysis.

RESULTS

The global screening model included age, height, body mass index, waist circumference and systolic- and diastolic blood pressure. Area under the ROC curve ranged between 0.64 in North America and 0.76 in Australia and New Zealand. Overall, to identify 75% of the undiagnosed diabetes cases, 49% required further diagnostic testing.

CONCLUSIONS

We identified a globally applicable screening model to detect individuals at high risk of undiagnosed diabetes. The model performed well in most geographical regions, is simple and requires no calculations. This global screening model may be particularly helpful in developing countries with no population based data with which to develop own screening models.

Plasma kinetics of an LDL-like nanoemulsion and lipid transfer to HDL in subjects with glucose intolerance

OBJECTIVE

Glucose intolerance is frequently associated with an altered plasma lipid profile and increased cardiovascular disease risk. Nonetheless, lipid metabolism is scarcely studied in normolipidemic glucose-intolerant patients. The aim of this study was to investigate whether important lipid metabolic parameters, such as the kinetics of LDL free and esterified cholesterol and the transfer of lipids to HDL, are altered in glucose-intolerant patients with normal plasma lipids.

METHODS

Fourteen glucose-intolerant patients and 15 control patients were studied; none of the patients had cardiovascular disease manifestations, and they were paired for age, sex, race and co-morbidities. A nanoemulsion resembling a LDL lipid composition (LDE) labeled with 14C-cholesteryl ester and ³H-free cholesterol was intravenously injected, and blood samples were collected over a 24-h period to determine the fractional clearance rate of the labels by compartmental analysis. The transfer of free and esterified cholesterol, triglycerides and phospholipids from the LDE to HDL was measured by the incubation of the LDE with plasma and radioactivity counting of the supernatant after chemical precipitation of non-HDL fractions.

RESULTS

The levels of LDL, non-HDL and HDL cholesterol, triglycerides, apo A1 and apo B were equal in both groups. The 14C-esterified cholesterol fractional clearance rate was not different between glucose-intolerant and control patients, but the ³H-free-cholesterol fractional clearance rate was greater in glucose-intolerant patients than in control patients. The lipid transfer to HDL was equal in both groups.

CONCLUSION

In these glucose-intolerant patients with normal plasma lipids, a faster removal of LDE free cholesterol was the only lipid metabolic alteration detected in our study. This finding suggests that the dissociation of free cholesterol from lipoprotein particles occurs in normolipidemic glucose intolerance and may participate in atherogenic signaling.

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.

Myocardial function may improve equally in diabetic patients following both multivessel percutaneous coronary intervention and coronary artery bypass grafting: results from a CARDia trial substudy

AIMS

The CARDia (Coronary Artery Revascularization in Diabetes) trial compared coronary artery bypass grafting (CABG) and optimal percutaneous coronary intervention (PCI) in diabetic patients with multivessel coronary disease. Patients enrolled had symptoms of myocardial ischaemia. As symptom assessment is flawed in diabetic patients, a substudy was undertaken to compare the extent to which these revascularization strategies alter reversible ischaemia.

METHODS AND RESULTS

Seventy-one patients underwent stress echo at baseline and at 6 months. A 17-segment echocardiographic wall motion score index (WMSI) was assigned at baseline [WMSI(pre)] and at 6 months [WMSI(post)]. An overall score defined the difference: WMSI(∂) = WMSI(pre)--WMSI(post). Of 71 patients recruited, 42 underwent PCI and 29 CABG. Mean WMSI(pre) in the PCI group was 1.63 and mean WMSI(post) was 1.32. Mean WMSI(pre) in the CABG group was 1.69 and mean WMSI(post) was 1.46. The PCI WMSI(∂) was 0.31 and CABG WMSI(∂) was 0.23 (P = 0.8). Of 42 PCI patients, 39 demonstrated ischaemia at baseline. At 6 months 31 had improvements in ischaemia (79%), 5 showed no improvement, and 3 ischaemia worsened. Of 29 CABG patients, 23 demonstrated ischaemia at baseline. At 6 months, 20 had improvements in ischaemia (87%), 2 had no improvement, and in 1 ischaemia worsened. No difference was seen in the number of patients with improvements in reversible ischaemia between PCI and CABG [79 vs. 87%, (P = 0.9)].

CONCLUSION

Optimal revascularization in diabetic patients with multivessel disease remains controversial. This subset analysis of the CARDia trial suggests both PCI and CABG achieve similar improvement in reversible ischaemia.

Categories of glucose tolerance and continuous glycemic measures and mortality

We investigated the association of undiagnosed diabetes, previously known diabetes and prediabetes (WHO 1999 classification) with all-cause and cause-specific mortality in an older German population. Previous study results for mortality in patients with very low levels of HbA1c, fasting plasma glucose (FPG), and 2-h plasma glucose (2hPG) are still inconclusive. Thus we have extended the analyses to continuous measures of glycemia. A total of 1,466 subjects aged 55-74 years from the population-based KORA survey S4 (conducted from 1999 to 2001) were included in our observational mortality study (152 subjects with previously known diabetes, and 1,314 further subjects who underwent oral glucose tolerance tests). Mortality was followed up for a maximum of 10.0 years (median follow-up 8.8 years). A total of 180 (12.3%) of the 1,466 subjects have died during the follow-up period. The age- and sex-adjusted hazard ratios for all-cause mortality were 2.6 (95%CI, 1.7-3.8) for known diabetes, 2.8 (95%CI, 1.7-4.4) for undiagnosed diabetes, and 1.1 (95%CI, 0.8-1.7) for prediabetes [reference: normal glucose tolerance (NGT)]. After multivariable adjustment, undiagnosed diabetes was associated with 3.0-fold increased cancer mortality, 1.1-fold increased cardiovascular mortality, and 4.7-fold increased non-cancer, non-cardiovascular mortality compared with NGT. For HbA1c, FPG, and 2hPG, J-shaped associations with all-cause mortality were observed. Undiagnosed diabetes is associated with increased all-cause, cancer, and non-cancer non-cardiovascular mortality, but not with cardiovascular mortality in this older population. All-cause mortality in undiagnosed diabetes is similar to that in previously known diabetes but much higher than mortality in prediabetes and NGT.

Combined effects of glycated hemoglobin A1c and blood pressure on carotid artery atherosclerosis in nondiabetic patients

BACKGROUND

The relationship between HbA(1c), blood pressure, and carotid atherosclerosis in nondiabetic patients is not clear.

HYPOTHESIS

HbA(1c) and blood pressure can affect carotid-artery atherosclerosis in nondiabetic patients.

METHODS

This retrospective cross-sectional study included 216 patients without diabetes mellitus. A positive carotid ultrasonographic result was defined as intima-media thickness of the common carotid artery ≥ 0.9 mm, or presence of carotid plaque.

RESULTS

Compared with patients without carotid atherosclerosis, patients with carotid atherosclerosis had significantly higher levels of HbA(1c) and systolic blood pressure (SBP). Higher levels of HbA(1c) and SBP were found to be associated with increased carotid atherosclerosis. Given similar SBP levels, higher HbA(1c) (>5.6%) was also related to increased carotid atherosclerosis. In multiple logistic regression analysis, HbA(1c) (odds ratio: 4.1, P = 0.009) emerged as the only statistically significant modifiable factor that was associated with carotid atherosclerosis, independent of smoking, body mass index, fasting plasma glucose, 2-hour plasma glucose, SBP, diastolic blood pressure, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol.

CONCLUSIONS

Our study shows that a slight increase of HbA(1c) may associate with carotid atherosclerosis in nondiabetic patients. Moreover, the coexistence of an elevated SBP level and a slightly increased HbA(1c) level may have a more significant effect on carotid atherosclerosis.

Screening for type 2 diabetes and dysglycemia

Type 2 diabetes mellitus (T2DM) and dysglycemia (impaired glucose tolerance and/or impaired fasting glucose) are increasingly contributing to the global burden of diseases. The authors reviewed the published literature to critically evaluate the evidence on screening for both conditions and to identify the gaps in current understanding. Acceptable, relatively simple, and accurate tools can be used to screen for both T2DM and dysglycemia. Lifestyle modification and/or medication (e.g., metformin) are cost-effective in reducing the incidence of T2DM. However, their application is not yet routine practice. It is unclear whether diabetes-prevention strategies, which influence cardiovascular risk favorably, will also prevent diabetic vascular complications. Cardioprotective therapies, which are cost-effective in preventing complications in conventionally diagnosed T2DM, can be used in screen-detected diabetes, but the magnitude of their effects is unknown. Economic modeling suggests that screening for both T2DM and dysglycemia may be cost-effective, although empirical data on tangible benefits in preventing complications or death are lacking. Screening for T2DM is psychologically unharmful, but the specific impact of attributing the label of dysglycemia remains uncertain. Addressing these gaps will inform the development of a screening policy for T2DM and dysglycemia within a holistic diabetes prevention and control framework combining secondary and high-risk primary prevention strategies.

Evaluation of the Finnish Diabetes Risk Score as a screening tool for impaired fasting glucose, impaired glucose tolerance and undetected diabetes

AIM

To evaluate the performance of FINDRISC as a screening tool for prediabetes - impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) and undetected diabetes (UDD) in subjects at risk of developing diabetes.

SUBJECTS AND METHODS

2169 subjects with at least one risk factor for diabetes completed the FINDRISC questionnaire and underwent an oral glucose tolerance test. FINDRISC performance was assessed using the area under the receiver operating characteristic curve (AUC-ROC).

RESULTS

56.6% of subjects demonstrated normal glucose tolerance (NGT), 14.5% - IFG, 11.4% - IGT and 17.5% - UDD. NGT group demonstrated mean FINDRISC 10.1±3.4, IFG group - 13.8±4.3 (p<0.0001 vs. NGT), IGT group - 14.4±5.4 (p<0.0001 vs. NGT) and UDD group - 15.5±4.8 (p<0.0001 vs. NGT and IFG, p<0.01 vs. IGT). The AUC-ROC was 0.70 (95% CI 0.67-0.73) for UDD and 0.71 (95% CI 0.69-0.73) for undetected prediabetes and diabetes. The FINDRISC cut-off value of 10 to identify both prediabetes and diabetes had sensitivity of 84% and specificity of 61%.

CONCLUSIONS

FINDRISC is a feasible, non-invasive and useful tool for identifying subjects at risk for undetected diabetes and prediabetes. Laboratory screening should be performed in subjects with FINDRISC higher than 10.

Projection of the year 2050 burden of diabetes in the US adult population: dynamic modeling of incidence, mortality, and prediabetes prevalence

BACKGROUND

People with diabetes can suffer from diverse complications that seriously erode quality of life. Diabetes, costing the United States more than $174 billion per year in 2007, is expected to take an increasingly large financial toll in subsequent years. Accurate projections of diabetes burden are essential to policymakers planning for future health care needs and costs.

METHODS

Using data on prediabetes and diabetes prevalence in the United States, forecasted incidence, and current US Census projections of mortality and migration, the authors constructed a series of dynamic models employing systems of difference equations to project the future burden of diabetes among US adults. A three-state model partitions the US population into no diabetes, undiagnosed diabetes, and diagnosed diabetes. A four-state model divides the state of "no diabetes" into high-risk (prediabetes) and low-risk (normal glucose) states. A five-state model incorporates an intervention designed to prevent or delay diabetes in adults at high risk.

RESULTS

The authors project that annual diagnosed diabetes incidence (new cases) will increase from about 8 cases per 1,000 in 2008 to about 15 in 2050. Assuming low incidence and relatively high diabetes mortality, total diabetes prevalence (diagnosed and undiagnosed cases) is projected to increase from 14% in 2010 to 21% of the US adult population by 2050. However, if recent increases in diabetes incidence continue and diabetes mortality is relatively low, prevalence will increase to 33% by 2050. A middle-ground scenario projects a prevalence of 25% to 28% by 2050. Intervention can reduce, but not eliminate, increases in diabetes prevalence.

CONCLUSIONS

These projected increases are largely attributable to the aging of the US population, increasing numbers of members of higher-risk minority groups in the population, and people with diabetes living longer. Effective strategies will need to be undertaken to moderate the impact of these factors on national diabetes burden. Our analysis suggests that widespread implementation of reasonably effective preventive interventions focused on high-risk subgroups of the population can considerably reduce, but not eliminate, future increases in diabetes prevalence.

Projection of the year 2050 burden of diabetes in the US adult population: dynamic modeling of incidence, mortality, and prediabetes prevalence

Background

People with diabetes can suffer from diverse complications that seriously erode quality of life. Diabetes, costing the United States more than $174 billion per year in 2007, is expected to take an increasingly large financial toll in subsequent years. Accurate projections of diabetes burden are essential to policymakers planning for future health care needs and costs.

Methods

Using data on prediabetes and diabetes prevalence in the United States, forecasted incidence, and current US Census projections of mortality and migration, the authors constructed a series of dynamic models employing systems of difference equations to project the future burden of diabetes among US adults. A three-state model partitions the US population into no diabetes, undiagnosed diabetes, and diagnosed diabetes. A four-state model divides the state of "no diabetes" into high-risk (prediabetes) and low-risk (normal glucose) states. A five-state model incorporates an intervention designed to prevent or delay diabetes in adults at high risk.

Results

The authors project that annual diagnosed diabetes incidence (new cases) will increase from about 8 cases per 1,000 in 2008 to about 15 in 2050. Assuming low incidence and relatively high diabetes mortality, total diabetes prevalence (diagnosed and undiagnosed cases) is projected to increase from 14% in 2010 to 21% of the US adult population by 2050. However, if recent increases in diabetes incidence continue and diabetes mortality is relatively low, prevalence will increase to 33% by 2050. A middle-ground scenario projects a prevalence of 25% to 28% by 2050. Intervention can reduce, but not eliminate, increases in diabetes prevalence.

Conclusions

These projected increases are largely attributable to the aging of the US population, increasing numbers of members of higher-risk minority groups in the population, and people with diabetes living longer. Effective strategies will need to be undertaken to moderate the impact of these factors on national diabetes burden. Our analysis suggests that widespread implementation of reasonably effective preventive interventions focused on high-risk subgroups of the population can considerably reduce, but not eliminate, future increases in diabetes prevalence.