Effects of Incretin-Based Therapies on Diabetic Microvascular Complications

The morbidity and mortality associated with diabetic complications impose a huge socioeconomic burden worldwide. Therefore, the ultimate goal of managing diabetes mellitus (DM) is to lower the risk of macrovascular complications and highly morbid microvascular complications such as diabetic nephropathy (DN) and diabetic retinopathy (DR). Potential benefits of incretin-based therapies such as glucagon-like peptide 1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors on the diabetic macrovascular complications have been recently suggested, owing to their pleiotropic effects on multiple organ systems. However, studies primarily investigating the role of these therapies in diabetic microvascular complications are rare. Nevertheless, preclinical and limited clinical data suggest the potential protective effect of incretin-based agents against DN and DR via their anti-inflammatory, antioxidative, and antiapoptotic properties. Evidence also suggests that these incretin-dependent and independent beneficial effects are not necessarily associated with the glucose-lowering properties of GLP-1 RAs and DPP-4 inhibitors. Hence, in this review, we revisit the preclinical and clinical evidence of incretin-based therapy for DR and DN, the two most common, morbid complications in individuals with DM. In addition, the review discusses a few recent studies raising concerns of aggravating DR with the use of incretin-based therapies.

Cardiovascular Diseases and Life Expectancy in Adults With Type 2 Diabetes: A Korean National Sample Cohort Study

OBJECTIVE

Although type 2 diabetes is a strong risk factor for cardiovascular disease and mortality, information on its association with mortality and life expectancy according to cardiovascular comorbidities is limited, especially in Asia. Thus, this study assessed mortality and reductions in life expectancy associated with cardiometabolic multimorbidity.

DESIGN AND METHODS

A total of 569,831 participants older than 30 years from Korean National Health Insurance Service-National Sample Cohort were enrolled between 2002 and 2006 and followed for a median of 12.0 years. They were categorized into five mutually exclusive groups according to baseline disease status, as follows: none (reference group); diabetes only; diabetes and stroke; diabetes and myocardial infarction (MI); and diabetes, stroke, and MI. Mortality rates and hazard ratios (HRs), reductions of life expectancy, and age-specific contributions to life expectancy were calculated by constructing life tables.

RESULTS

The mortality rates per 1000 person-years were 6.85, 19.86, 67.17, 66.34, and 115.52 in the reference, diabetes only; diabetes and stroke; diabetes and MI; and diabetes, stroke, and MI groups, respectively. The corresponding HRs for all-cause mortality were 1.70 [95% confidence interval (CI), 1.66 to 1.75], 3.66 (95% CI, 3.32 to 4.03), 3.56 (95% CI, 3.06 to 4.14), and 4.79 (95% CI, 3.05 to 7.50) compared with the reference group. The estimated reductions in life expectancy were greater at younger ages and markedly increased with more cardiometabolic comorbidities.

CONCLUSION

Young Asians with type 2 diabetes, especially those with cardiovascular comorbidity, did not live as long than their nondiabetic equivalents. Thus, these individuals require special attention to prevent further reductions in life expectancy.

Factors associated with greater benefit of a national reimbursement policy for blood glucose test strips in adult patients with type 1 diabetes: A prospective cohort study

AIMS/INTRODUCTION

We aimed to identify factors independently associated with greater benefit of a national reimbursement policy for blood glucose test strips in adult patients with type 1 diabetes, in terms of glycemic control and the rate of severe hypoglycemia.

MATERIALS AND METHODS

This was a prospective cohort study of 466 adult patients with type 1 diabetes from five tertiary referral hospitals who registered for a national reimbursement program for blood glucose strips and were then followed-up for 12 months. Factors associated with a > 5% reduction in glycated hemoglobin (HbA1c) and decreased rate of severe hypoglycemia (SH) at 12 months from baseline were evaluated.

RESULTS

At the end of the 12 months of follow up, 158 of 466 patients (33.9%) achieved >5% reduction in HbA1c, and 47 of 111 patients (42.3%) had a decreased rate of SH relative to baseline. Higher HbA1c (P < 0.001), lower total daily insulin dose at baseline (P = 0.048) and an increase in self-monitoring of blood glucose (SMBG) frequency during follow up (P = 0.001) were independently associated with >5% reduction in HbA1c. A higher SMBG frequency (P < 0.001), higher rate of SH at baseline (P = 0.029) and lack of hypoglycemic unawareness (P = 0.044) were independently associated with an increase in the frequency of SMBG during follow up. Higher SMBG frequency at baseline (P < 0.001) was independently associated with a decreased rate of SH.

CONCLUSIONS

Several factors, including higher SMBG frequency at baseline, were independently associated with reduced HbA1c and a decreased rate of severe hypoglycemia, showing that patients with these characteristics derive the most benefit from reimbursement of blood glucose test strips.

Metabolically healthy obesity: a friend or foe?

Obesity is associated with a reduced life expectancy, largely because obese individuals are at an increased risk of type 2 diabetes, cardiovascular disease, and several types of cancer. Much interest has recently focused on the concept of "all obesity is not created equally." Obese individuals without the metabolic abnormalities that commonly accompany excess adiposity, a condition known as metabolically healthy obesity (MHO), account for a substantial proportion of the obese adult population. Numerous possible mechanisms underlying MHO have been suggested, including adipose tissue distribution and inflammation. However, the prognostic value of MHO is controversial and considerably challenging. The lack of a standard definition for metabolic health and obesity as well as the dynamic properties of MHO may have contributed to these inconsistent results. This review aimed to present several current issues regarding MHO including its definition, epidemiology, natural course, suggested mechanisms, and clinical implications in the context of patient prognosis.

Impact of diabetes duration and degree of carotid artery stenosis on major adverse cardiovascular events: a single-center, retrospective, observational cohort study

BACKGROUND

We aimed to investigate the impact of diabetes duration and carotid artery stenosis (CAS) on the occurrence of major adverse cardiovascular events (MACE) in patients with type 2 diabetes mellitus (T2DM) without clinical cardiovascular disease.

METHODS

A total of 2006 patients with T2DM, without clinical cardiovascular disease, aged >50 years, and who underwent baseline carotid Doppler ultrasound screening with regular follow-ups at the outpatient clinic of our diabetes center, were stratified into four subgroups according to diabetes duration and CAS degree. The primary outcomes included the occurrence of MACE, defined as fatal or nonfatal stroke and myocardial infarction, and all-cause mortality.

RESULTS

The difference in the MACE incidence was significantly greater in patients with a longer diabetes duration (≥10 years) and significant CAS (50-69% luminal narrowing) (p < 0.001). Analysis of individual MACE components indicated a trend towards an increased incidence of stroke (p < 0.001), parallel to a longer diabetes duration and significant CAS. In contrast, the risk of myocardial infarction was significantly higher in patients with a diabetes duration <10 years and significant CAS (p = 0.039). Multivariate regression analysis showed that patients with both a longer diabetes duration and significant CAS demonstrated additive and very high risks of MACE (hazard ratio [HR], 2.07; 95% confidence interval [CI] 1.17-3.66; p = 0.012) and stroke (HR, 3.38; 95% CI 1.54-7.44; p = 0.002).

CONCLUSIONS

The risk of MACE is significantly greater in patients with T2DM, without clinical cardiovascular disease, who have both a longer diabetes duration and significant CAS, compared with those who have a shorter duration and/or nonsignificant CAS.

Fatty liver disease determines the progression of coronary artery calcification in a metabolically healthy obese population

OBJECTIVES

Metabolically healthy obese (MHO) phenotype describes an obese state with a favorable metabolic profile. However, the prognosis of this subpopulation remains controversial. We aimed to examine whether MHO phenotype is associated with progression of atherosclerotic activity, reflected as the changes in coronary artery calcification (CAC) over time. If so, we sought to determine the role of fatty liver disease (FLD), the hallmark of hepatic steatosis, in this progression.

METHODS

We enrolled 1,240 asymptomatic subjects who underwent repeated CAC score measurement during routine health examinations. CAC score progression was defined as either incident CAC in a population free of CAC at baseline, or an increase by ≥2.5 units between the baseline and final square root of CAC scores in participants with detectable CAC at baseline. Subjects were stratified by body mass index (cut-off, 25.0 kg/m2) and metabolic health state using Adult Treatment Panel-III criteria. FLD was assessed via ultrasonography.

RESULTS

Over 2.9 years of follow-up, 25.2% of total subjects exhibited CAC score progression. The MHO phenotype was not significantly associated with CAC score progression (multivariate adjusted-odds ratio [OR], 1.45; 95% confidence interval [CI], 0.93-2.25), as compared to the metabolically healthy non-obese (MHNO) phenotype. However, subgroup analysis indicated that the MHO/FLD phenotype was significantly associated with CAC score progression (multivariate adjusted-OR, 2.37; 95% CI, 1.34-4.16), as compared to the MHNO/no FLD phenotype, whereas the MHO/no FLD phenotype was not (multivariate adjusted OR, 1.25; 95% CI, 0.71-2.24).

CONCLUSIONS

Obese individuals with FLD have an increased risk of atherosclerosis progression, despite their healthy metabolic profile. Preventive interventions targeting cardiometabolic risk factors should be considered in such individuals, regardless of the weight status.

Improved trends in cardiovascular complications among subjects with type 2 diabetes in Korea: a nationwide study (2006-2013)

Background

Representative data on the secular trends in cardiovascular disease (CVD) are limited in Asian populations with diabetes. We aimed to estimate the temporal trends in cardiovascular complications using Korean nationwide whole population-based claims data in subjects with and without diabetes.

Methods

Type 2 diabetes was defined as a current medication history of anti-diabetic drugs and the presence of International Classification of Diseases (ICD)-10 codes (E11–E14) as diagnosis. We compared the 8-year rates of six cardiovascular complications [i.e., ischemic heart disease, acute myocardial infarction (AMI), ischemic stroke, hemorrhagic stroke, percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG)] in Korean adults aged 30 years and older using data from four consecutive nationwide databases (2006–2007, 2008–2009, 2010–2011, and 2012–2013) of Korean national health insurance service.

Results

A total of 1,645,348, 1,971,559, 2,291,247, and 2,562,612 subjects with type 2 diabetes were found in the year of 2006–2007, 2008–2009, 2010–2011, and 2012–2013, respectively. Age and gender standardized rates of the six predefined cardiovascular complications decreased in Korean adults with type 2 diabetes during the study period. The greatest relative reductions were observed for hospitalization due to AMI (−37.28%), followed by hospitalizations due to ischemic stroke (−36.98%). In the overall population without type 2 diabetes, the greatest relative reductions were observed for hospitalization for hemorrhagic stroke (−29.47%), followed by hospitalization due to ischemic stroke (−28.92%). Relative decreases in all six predefined cardiovascular complications were generally more profound in adults with diabetes than in those without diabetes, which led to significant decrease in the relative risks of all six cardiovascular complications in subjects with diabetes over the past 8 years. However, people with diabetes still had a two- to sixfold higher risk of hospitalization for major CVD events and interventions than people without diabetes.

Conclusions

Our findings suggest a significant reduction in the rate of people affected by CVD within the diabetic population. However, as the number of people with diabetes rises, the absolute burden of CVD will still be high in Korea.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0482-6) contains supplementary material, which is available to authorized users.

Differential association of body mass index on glycemic control in type 1 diabetes

BACKGROUND

In contrast to type 2 diabetes, the association of body mass index (BMI) with glycemic control in type 1 diabetes (T1D) remains unclear. We investigated the relationship between BMI and average HbA_1c levels in subjects with T1D.

METHOD

In this multi-centre observational study, we analysed 719 subjects with T1D aged ≥18 years. Average HbA_1c levels over 18 months and other clinical and laboratory parameters were evaluated.

RESULTS

The mean age and duration of diabetes at baseline were 41.5 ± 13.9 and 11.3 ± 8.7 years, respectively. A U-shaped correlation between BMI and 18-month average HbA_1c levels was documented by a spline curve. Based on this finding, subjects were divided into three groups according to BMI (group I, <21; group II, 21-23; and group III, ≥23 kg/m² ). In group I, the BMI negatively correlated with average HbA_1c (r = -0.172, p = 0.011), while a positive relationship was observed (r = 0.162, p = 0.012) in group III. Average HbA_1c levels were lower and the proportion of individuals with well-controlled glycemia (HbA_1c <7%) were increased in the higher BMI tertile group among subjects with group I as well as in the lower BMI tertile group among subjects with group III BMI. After adjustment with additional covariates in the multiple regression model, these associations between BMI and HbA_1c levels according to the different BMI ranges remained significant.

CONCLUSIONS

In Korean subjects with T1D, an inverse relationship of BMI with HbA_1c levels was observed in the low BMI group, while a positive correlation was shown in the high BMI group. Copyright © 2016 John Wiley & Sons, Ltd.

Mortality and causes of death in a national sample of type 2 diabetic patients in Korea from 2002 to 2013

BACKGROUND

We aimed to investigate the mortality rate (MR), causes of death and standardized mortality ratio (SMR) in Korean type 2 diabetic patients from 2002 to 2013 using data from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC).

METHODS

From this NHIS-NSC, we identified 29,807 type 2 diabetic subjects from 2002 to 2004. Type 2 diabetes was defined as a current medication history of anti-diabetic drugs and the presence of International Classification of Diseases (ICD)-10 codes (E11-E14) as diagnosis. Specific causes of death were recorded according to ICD-10 codes as the following: diabetes, malignant neoplasm, disease of the circulatory system, and other causes.

RESULTS

A total of 7103 (23.8 %) deaths were recorded. The MR tended to increase with age. In particular, the ratio of MR for men versus women was the highest in their 40s-50s. The overall SMR was 2.32 and the SMRs attenuated with increasing age. The causes of death ascribed to diabetes, malignant neoplasm, ischemic heart disease, cerebrovascular disease, and other causes were 22.0, 24.8, 6.2, 11.2 and 31.3 %, respectively. The SMRs according to each cause of death were 9.73, 1.76, 2.60, 2.04 and 1.89, respectively.

CONCLUSIONS

The MRs among type 2 diabetic subjects increased with age, and diabetic men exhibited a higher mortality risk than diabetic women in Korea. Subjects with type 2 diabetes exhibited an excess mortality when compared with the general population. Approximately 78.0 % of the diabetes-related deaths was not ascribed to diabetes, and malignant neoplasm was the most common cause of death among those not recorded as diabetes.

Association of prediabetes, defined by fasting glucose, HbA1c only, or combined criteria, with the risk of cardiovascular disease in Koreans

BACKGROUND

The aim of the present study was to compare the association between cardiovascular diseases (CVD) and prediabetes defined by either fasting plasma glucose (FPG), HbA1c, or their combination in a Korean population.

METHODS

In all, 76 434 South Koreans who voluntarily underwent a general health examination in the Health Screening & Promotion Center (Asan Medical Center) were analyzed after excluding patients with a previous history of CVD. Cardiovascular events and death due to CVD during a median follow-up period of 3.1 years (interquartile range 1.9-4.3 years) were identified from the Nationwide Health Insurance Claims Database and death certificates using ICD-10 codes.

RESULTS

Age- and sex-adjusted hazard ratios (HRs) for overall CVD events were significantly greater for subjects with prediabetes defined by FPG only (HR 1.19; 95% confidence interval [CI] 1.08-1.31), HbA1c only (HR 1.28; 95% CI 1.16-1.42), and combined criteria (HR 1.20; 95% CI 1.09-1.32) compared with the normoglycemic group. After adjusting for multiple conventional risk factors (e.g. hypertension, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, smoking status, family history of CVD, and BMI), the HRs for overall CVD were significantly increased only for participants with prediabetes defined by HbA1c. Age- and sex-adjusted HRs for major ischemic heart disease events were significantly increased for subjects with prediabetes defined either by HbA1c or combined criteria. Similarly, age- and sex-adjusted HRs for percutaneous coronary intervention were significantly higher for subjects with prediabetes defined by HbA1c only. For diabetes, the multivariate-adjusted HRs for all outcomes were significantly increased by all three criteria.

CONCLUSIONS

Adding an HbA1c criterion when defining prediabetes in Koreans can help identify individuals with an increased risk of CVD.

2013 ACC/AHA Cholesterol Guideline Versus 2004 NCEP ATP III Guideline in the Prediction of Coronary Artery Calcification Progression in a Korean Population

BACKGROUND

Since the release of the 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines, significant controversy has surrounded the applicability of the new cholesterol guidelines and the Pooled Cohort Equations. In this present study, we investigated whether eligibility for statin therapy determined by the 2013 ACC/AHA guidelines on the management of blood cholesterol is better aligned with the progression of coronary artery calcification (CAC) detected by coronary computed tomography angiography (CCTA) than the previously recommended 2004 National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III guidelines.

METHODS AND RESULTS

We enrolled 1246 asymptomatic participants who underwent repeated CAC score measurement during routine health examinations. The CAC score progression was defined as either incident CAC in a population free of CAC at baseline or increase ≥2.5 units between the baseline and final square root of CAC scores participants who had detectable CAC at baseline examination. Application of the ACC/AHA guidelines to the study population increased the proportion of statin-eligible subjects from 20.5% (according to ATP III) to 54.7%. Statin-eligible subjects, as defined by ACC/AHA guidelines, showed a higher odds ratio for CAC score progression than those considered statin eligible according to ATP III guidelines (2.73 [95% CI, 2.07-3.61] vs 2.00 [95% CI, 1.49-2.68]).

CONCLUSIONS

Compared with the ATP III guidelines, the new ACC/AHA guidelines result in better discrimination of subjects with cardiovascular risk detected by CAC score progression in an Asian population.

The association of incident hypertension with metabolic health and obesity status: definition of metabolic health does not matter

OBJECTIVE

Metabolically healthy obese (MHO) phenotype refers to obese individuals with a favourable metabolic profile. Its prognostic value remains controversial and may partly depend on differences in how the phenotype is defined. We aimed to investigate whether the MHO phenotype is associated with future development of incident hypertension in a Korean population according to various definitions of metabolic health.

SUBJECTS AND METHODS

The study population comprised 31 033 Koreans without hypertension. Participants were stratified into metabolically healthy nonobese (MHNO), metabolically unhealthy nonobese (MUNO), metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) by body mass index (cut-off value, 25·0 kg/m(2) ) and metabolic health state, using four different definitions: Adult Treatment Panel (ATP)-III, Wildman, Karelis and the homoeostasis model assessment (HOMA) criteria.

RESULTS

Over the median follow-up period of 35·0 months (range, 4·5-81·4 months), 4589 of the 31 033 individuals (14·8%) developed incident hypertension. Compared with the MHNO group, the MHO group showed increased association with incident hypertension with multivariate-adjusted odds ratios of 1·56 (95% confidence interval [CI], 1·41-1·72), 1·58 (95% CI 1·42-1·75), 1·52 (95% CI 1·35-1·71) and 1·46 (95% CI 1·33-1·61), when defined by ATP-III, Wildman, Karelis and HOMA criteria, respectively.

CONCLUSION

MUO individuals showed the highest association with the incident hypertension (adjusted odds ratios up to 2·00). MHO subjects showed an approximately 1·5-fold higher association with incident hypertension than their nonobese counterpart regardless of the definition of metabolic health used. Thus, considering both metabolic health and obesity is important for the assessment of potential cardiovascular outcomes.

An Internet-based health gateway device for interactive communication and automatic data uploading: Clinical efficacy for type 2 diabetes in a multi-centre trial

Introduction The aim of this study was to improve the quality of diabetes control and evaluate the efficacy of an Internet-based integrated healthcare system for diabetes management and safety. Methods We conducted a large-scale, multi-centre, randomized clinical trial involving 484 patients. Patients in the intervention group ( n = 244) were treated with the Internet-based system for six months, while the control group ( n = 240) received the usual outpatient management over the same period. HbA1c, blood chemistries, anthropometric parameters, and adverse events were assessed at the beginning of the study, after three months, and the end of the study. Results There were no initial significant differences between the groups with respect to demographics and clinical parameters. Upon six-month follow-up, HbA1c levels were significantly decreased from 7.86 ± 0.69% to 7.55 ± 0.86% within the intervention group ( p < 0.001) compared to 7.81 ± 0.66% to 7.70 ± 0.88% within the control group. Postprandial glucose reduction was predominant. A subgroup with baseline HbA1c higher than 8% and good compliance achieved a reduction of HbA1c by 0.8 ± 1.05%. Glucose control and waist circumference reduction were more effective in females and subjects older than 40 years of age. There were no adverse events associated with the intervention. Discussion This e-healthcare system was effective for glucose control and body composition improvement without associated adverse events in a multi-centre trial. This system may be effective in improving diabetes control in the general population.

Trends of antidiabetic drug use in adult type 2 diabetes in Korea in 2002-2013: Nationwide population-based cohort study

This study investigated trends in the prescription of antidiabetic medications for patients with type 2 diabetes, focusing on changing patterns of prescriptions and the cost of drugs during the last 10 years. Retrospective data on patients with type 2 diabetes aged 30 years or older were analyzed using information from the National Health Information Database collected by the National Health Insurance Service in Korea from January 2002 to December 2013. We identified patients with type 2 diabetes who had at least one service claim in each year during the study period. The prescribing information was collected and fixed-dose combination tablets were counted as each of their constituent classes. The total number of adults with type 2 diabetes who were treated using antidiabetic agents increased from 0.87 million in 2002 to 2.72 million in 2013 in Korea. Among antidiabetic medications in 2002, sulfonylurea (SU) was the most commonly used agent (87.2%), and metformin was the second (52.9%). However, in 2013, the use of metformin increased to 80.4% of the total antidiabetic prescriptions. The use of dipeptidyl peptidase-4 (DPP-4) inhibitor increased remarkably after release in late 2008 and composed one-third of the market share with 1 million prescriptions (38.4%) in 2013. Among the prescriptions for monotherapy, only 13.0% were metformin in 2002, but the amount increased to 53.2% by 2013. In contrast, the use of SU declined dramatically from 75.2% in 2002 to 30.6% in 2013. Dual and triple combinations steadily increased from 35.0% and 6.6% in 2002 to 44.9% and 15.5% in 2013, respectively. In 2013, SU with metformin (41.7%) and metformin with DPP-4 inhibitor (32.5%) combination were most frequently prescribed. The total antidiabetic medication cost increased explosively from U.S. $70 million (82.5 billion won) in 2002 to U.S. $4 billion (480 billion won) in 2013.The use of antidiabetic agents and their costs have been increasing steadily. Metformin is the most commonly used drug recently. The use of DPP-4 inhibitor increased significantly over the past decade, whereas the use of SU decreased. However, SUs still remain the most commonly prescribed second-line agents with metformin in 2013.

Cardiovascular Effects of Glucagon-Like Peptide-1 Receptor Agonists

Glucagon-like peptide-1 (GLP-1) is a member of the proglucagon incretin family, and GLP-1 receptor agonists (RAs) have been introduced as a new class of antidiabetic medications in the past decade. The benefits of GLP-1 RAs are derived from their pleiotropic effects, which include glucose-dependent insulin secretion, suppressed glucagon secretion, and reduced appetite. Moreover, GLP-1 RAs also exert beneficial roles on multiple organ systems in which the GLP-1 receptors exist, including the cardiovascular system. Cardiovascular effects of GLP-1 RAs have been of great interest since the burden from cardiovascular diseases (CVD) has been unbearably increasing in a diabetic population worldwide, despite strict glycemic control and advanced therapeutic techniques to treat CVD. Preclinical studies have already demonstrated the beneficial effects of GLP-1 on myocardium and vascular endothelium, and many clinical studies evaluating changes in surrogate markers of CVD have suggested potential benefits from the use of GLP-1 RAs. Data from numerous clinical trials primarily evaluating the antihyperglycemic effects of multiple GLP-1 RAs have also revealed that changes in most CVD risk markers reported as secondary outcomes have been in favor of GLP-1 RAs treatment. However, to date, there is only one randomized clinical trial of GLP-1 RAs (the ELIXA study) evaluating major cardiovascular events as their primary outcomes, and in this study, a neutral cardiovascular effect of lixisenatide was observed in high-risk diabetic subjects. Therefore, the results of ongoing CVD outcome trials with the use of GLP-1 RAs should be awaited to elucidate the translation of benefits previously seen in CVD risk marker studies into large clinical trials with primary cardiovascular outcomes.

A novel imaging platform for non-invasive screening of abnormal glucose tolerance

Optical measurement of skin auto-fluorescence (SAF), most likely emanating from accumulated advanced glycation end-products (AGEs), has been proposed for the noninvasive diagnosis of glucose intolerance in clinical settings. Here, we developed a novel imaging system with transmission geometry for SAF measurement and compared its diagnostic performance in a Korean population.

Fatty liver index is a risk determinant of incident type 2 diabetes in a metabolically healthy population with obesity

OBJECTIVE

This study investigated the effect of fatty liver disease (FLD) on the risk of incident type 2 diabetes in a population with metabolically healthy obesity (MHO).

METHODS

The study population comprised 34,258 Koreans without type 2 diabetes. Participants were stratified by BMI (cutoff value, 25.0 kg/m(2) ) and metabolic health state (using Wildman criteria). FLD was defined by the fatty liver index (FLI), a predictive algorithm to detect FLD. Subjects were classified into low and high FLI groups based on tertile.

RESULTS

At baseline, there were significant differences in FLI between four study groups. During a median follow-up of 36.5 months, 1.7% individuals developed type 2 diabetes. The risk of incident type 2 diabetes varied for the MHO group according to the level of FLI. The risk of type 2 diabetes in the MHO with low FLI was not significantly elevated compared with the metabolically healthy individuals without obesity (MHNO) with low FLI (multivariate-adjusted HR, 1.19 [95% CI 0.66-2.14]). However, the MHO with high FLI had an elevated risk of incident type 2 diabetes (multivariate-adjusted HR, 1.99 [95% CI 1.36-2.92]).

CONCLUSIONS

MHO subjects have a substantially higher risk of incident type 2 diabetes than MHNO subjects. The presence of FLD assessed by FLI partially explains this increased risk.

Effects of Dipeptidyl Peptidase-4 Inhibitors on Hyperglycemia and Blood Cyclosporine Levels in Renal Transplant Patients with Diabetes: A Pilot Study

BACKGROUND

The use of dipeptidyl peptidase-4 (DPP-4) inhibitors is increasing among renal transplant patients with diabetes. However, the glucose-lowering efficacies of various DPP-4 inhibitors and their effects on blood cyclosporine levels have not been fully investigated. We compared the glucose-lowering efficacies of DPP 4 inhibitors and evaluate their effects on the blood levels of cyclosporine in renal transplant recipients with diabetes.

METHODS

Sixty-five renal allograft recipients who received treatment with DPP-4 inhibitors (vildagliptin, sitagliptin, or linagliptin) following kidney transplant were enrolled. The glucose-lowering efficacies of the DPP-4 inhibitors were compared according to the changes in the hemoglobin A1c (HbA1c) levels after 3 months of treatment. Changes in the trough levels of the cyclosporine were also assessed 2 months after treatment with each DPP-4 inhibitor.

RESULTS

HbA1c significantly decreased in the linagliptin group in comparison with other DPP-4 inhibitors (vildagliptin -0.38%±1.03%, sitagliptin -0.53%±0.95%, and linagliptin -1.40±1.34; P=0.016). Cyclosporine trough levels were significantly increased in the sitagliptin group compared with vildagliptin group (30.62±81.70 ng/mL vs. -24.22±53.54 ng/mL, P=0.036). Cyclosporine trough levels were minimally changed in patients with linagliptin.

CONCLUSION

Linagliptin demonstrates superior glucose-lowering efficacy and minimal effect on cyclosporine trough levels in comparison with other DPP-4 inhibitors in kidney transplant patients with diabetes.

Effect of Pitavastatin Treatment on ApoB-48 and Lp-PLA₂ in Patients with Metabolic Syndrome: Substudy of PROspective Comparative Clinical Study Evaluating the Efficacy and Safety of PITavastatin in Patients with Metabolic Syndrome

BACKGROUND

Apolipoprotein (Apo) B-48 is an intestinally derived lipoprotein that is expected to be a marker for cardiovascular disease (CVD). Lipoprotein-associated phospholipase A₂ (Lp-PLA₂) is a vascular-specific inflammatory marker and important risk predictor of CVD. The aim of this study was to explore the effect of pitavastatin treatment and life style modification (LSM) on ApoB-48 and Lp-PLA₂ levels in metabolic syndrome (MS) patients at relatively low risk for CVD, as a sub-analysis of a previous multi-center prospective study.

METHODS

We enrolled 75 patients with MS from the PROPIT study and randomized them into two treatment groups: 2 mg pitavastatin daily+intensive LSM or intensive LSM only. We measured the change of lipid profiles, ApoB-48 and Lp-PLA₂ for 48 weeks.

RESULTS

Total cholesterol, low density lipoprotein cholesterol, non-high density lipoprotein cholesterol, and ApoB-100/A1 ratio were significantly improved in the pitavastatin+LSM group compared to the LSM only group (P≤0.001). Pitavastatin+LSM did not change the level of ApoB-48 in subjects overall, but the level of ApoB-48 was significantly lower in the higher mean baseline value group of ApoB-48. The change in Lp-PLA₂ was not significant after intervention in either group after treatment with pitavastatin for 1 year.

CONCLUSION

Pitavastatin treatment and LSM significantly improved lipid profiles, ApoB-100/A1 ratio, and reduced ApoB-48 levels in the higher mean baseline value group of ApoB-48, but did not significantly alter the Lp-PLA₂ levels.

C1q/TNF-related protein-9 inhibits cytokine-induced vascular inflammation and leukocyte adhesiveness via AMP-activated protein kinase activation in endothelial cells

Although recent studies have reported cardioprotective effects of C1q/TNF-related protein 9 (CTRP9), the closet adiponectin paralog, its role on cytokine-induced endothelial inflammation is unknown. We investigated whether CTRP9 prevented inflammatory cytokine-induced nuclear factor-kappa B (NF-κB) activation and inhibited the expression of adhesion molecules and a chemokine in the vascular endothelial cell. We used human aortic endothelial cells (HAECs) to examine the effects of CTRP9 on NF-κB activation and the expression of NF-κB-mediated genes, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and monocyte chemoattractant protein-1 (MCP-1). Tumor necrosis factor alpha (TNFα) was used as a representative proinflammatory cytokine. In an adhesion assay using THP-1 cells, CTRP9 reduced TNFα-induced adhesion of monocytes to HAECs. Treatment with CTRP9 significantly decreased TNFα-induced activation of NF-κB, as well as the expression of ICAM-1, VCAM-1, and MCP-1. In addition, treatment with CTRP9 significantly increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC), the downstream target of AMPK. The inhibitory effect of CTRP9 on the expression of ICAM-1, VCAM-1, and MCP-1 and monocyte adhesion to HAECs was abolished after transfection with an AMPKα1-specific siRNA. Our study is the first to demonstrate that CTRP9 attenuates cytokine-induced vascular inflammation in endothelial cells mediated by AMPK activation.

Serum Total Bilirubin Levels Provide Additive Risk Information over the Framingham Risk Score for Identifying Asymptomatic Diabetic Patients at Higher Risk for Coronary Artery Stenosis

BACKGROUND

The diagnosis of coronary artery disease (CAD) is often delayed in patients with type 2 diabetes. Serum total bilirubin levels are inversely associated with CAD. However, no studies have examined whether this can be used as a biochemical marker for identifying asymptomatic diabetic patients at higher risk for having obstructive CAD.

METHODS

We performed a cross-sectional study of 460 consecutive asymptomatic patients with type 2 diabetes. All patients underwent coronary computed tomographic angiography, and their serum total bilirubin levels were measured. Obstructive CAD was defined as ≥50% diameter stenosis in at least one coronary artery.

RESULTS

Serum total bilirubin tertiles showed an inverse association with the prevalence of obstructive CAD. In multivariate logistic regression analysis, the odds ratio for the highest versus the lowest tertile of total bilirubin was 0.227 (95% confidence interval [CI], 0.130 to 0.398), and an increment of 1 µmol/L in serum total bilirubin level was associated with a 14.6% decrease in obstructive CAD after adjustment for confounding variables. Receiver operating characteristic curve analysis showed that the area under the curve for the Framingham Risk Score (FRS) plus serum total bilirubin level was 0.712 (95% CI, 0.668 to 0.753), which is significantly greater than that of the FRS alone (P=0.0028).

CONCLUSION

Serum total bilirubin level is inversely associated with obstructive CAD and provides additive risk information over the FRS. Serum total bilirubin may be helpful for identifying asymptomatic patients with type 2 diabetes who are at higher risk for obstructive CAD.

Association between serum gamma-glutamyltransferase and the progression of coronary artery calcification

BACKGROUND

Elevated serum gamma-glutamyltransferase (GGT) has been demonstrated to be associated with coronary artery calcification (CAC). CAC progression is an important marker of atherosclerosis and correlates with future cardiovascular risk. However, there is a lack of research that directly examines the association between serum GGT and CAC progression. The aim of this study was to elucidate the association between serum GGT activity and CAC progression.

METHODS

We enrolled 1246 asymptomatic participants who underwent repeated CAC score measurement during routine health examinations. To eliminate the dependence of the inter scan variability on the baseline CAC scores, square root-transformed CAC scores were used to analyze CAC progression. In addition, the annualized rate of change in CAC scores was computed.

RESULTS

Serum GGT activities were significantly higher in "progressors" than "nonprogressors". The prevalence of progression increased with the GGT tertile (11.9%, 20.1% and 27.9% in the 1st, 2nd, and 3rd GGT tertiles, respectively; p < 0.001). In the multivariate logistic regression analysis, the odds ratio (95% confidence interval) for CAC score progression was 1.85 (1.14-3.00) in the highest GGT tertile group. By multivariate linear regression analysis, baseline serum GGT activity demonstrated a positive association with the annualized change in CAC score (β = 0.002; p = 0.006) after adjusting for cardiovascular risk factors.

CONCLUSION

Elevated serum GGT levels are independently associated with CAC progression. Serum GGT levels may be a potential biomarker of future coronary atherosclerosis and prognosis.