Epidemiology of risk factors for cardiovascular disease in diabetes and impaired glucose tolerance

8-Prenylgenistein Isoflavone in Cheonggukjang Acts as a Novel AMPK Activator Attenuating Hepatic Steatosis by Enhancing the SIRT1-Mediated Pathway

8-Prenylgenistein (8PG), a genistein derivative, is present in fermented soybeans (Glycine max), including cheonggukjang (CGJ), and exhibits osteoprotective, osteogenic, and antiadipogenic properties. However, the hepatoprotective effects of 8PG and its underlying molecular mechanisms remain largely unexplored. Here, we identified the high binding affinity of 8PG with AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1), which acts as a potent AMPK activator that counteracts hepatic steatosis. Notably, 8PG exhibited better pharmacokinetics with greater absorption and higher plasma binding than the positive controls for the target proteins. Moreover, 8PG exerted non-carcinogenic activity in rats and significantly increased AMPK phosphorylation. Compound C, an AMPK inhibitor, did not antagonize 8PG-activated AMPK in HepG2 cells. 8PG significantly attenuated palmitate-induced lipid accumulation and enhanced phosphorylated AMPK and its downstream target, acetyl-CoA carboxylase. Further, 8PG activated nuclear SIRT1 at the protein level, which promoted fatty acid oxidation in palmitate-treated HepG2 cells. Overall, 8PG acts as a potent AMPK activator, further attenuating hepatic steatosis via the SIRT1-mediated pathway and providing new avenues for dietary interventions to treat metabolic dysfunction-associated steatotic liver disease (MASLD).

Uncovering the link between diabetes and cardiovascular diseases: insights from adipose-derived stem cells

Cardiovascular diseases (CVDs) are the leading causes of morbidity and mortality worldwide. The escalating global occurrence of obesity and diabetes mellitus (DM) has led to a significant upsurge in individuals afflicted with CVDs. As the prevalence of CVDs continues to rise, it is becoming increasingly important to identify the underlying cellular and molecular mechanisms that contribute to their development and progression, which will help discover novel therapeutic avenues. Adipose tissue (AT) is a connective tissue that plays a crucial role in maintaining lipid and glucose homeostasis. However, when AT is exposed to diseased conditions, such as DM, this tissue will alter its phenotype to become dysfunctional. AT is now recognized as a critical contributor to CVDs, especially in patients with DM. AT is comprised of a heterogeneous cellular population, which includes adipose-derived stem cells (ADSCs). ADSCs resident in AT are believed to regulate physiological cardiac function and have potential cardioprotective roles. However, recent studies have also shown that ADSCs from various adipose tissue depots become pro-apoptotic, pro-inflammatory, less angiogenic, and lose their ability to differentiate into various cell lineages upon exposure to diabetic conditions. This review aims to summarize the current understanding of the physiological roles of ADSCs, the impact of DM on ADSC phenotypic changes, and how these alterations may contribute to the pathogenesis of CVDs.

Platelet-derived lipids promote insulin secretion of pancreatic β cells

Hyperreactive platelets are commonly observed in diabetic patients indicating a potential link between glucose homeostasis and platelet reactivity. This raises the possibility that platelets may play a role in the regulation of metabolism. Pancreatic β cells are the central regulators of systemic glucose homeostasis. Here, we show that factor(s) derived from β cells stimulate platelet activity and platelets selectively localize to the vascular endothelium of pancreatic islets. Both depletion of platelets and ablation of major platelet adhesion or activation pathways consistently resulted in impaired glucose tolerance and decreased circulating insulin levels. Furthermore, we found platelet-derived lipid classes to promote insulin secretion and identified 20-Hydroxyeicosatetraenoic acid (20-HETE) as the main factor promoting β cells function. Finally, we demonstrate that the levels of platelet-derived 20-HETE decline with age and that this parallels with reduced impact of platelets on β cell function. Our findings identify an unexpected function of platelets in the regulation of insulin secretion and glucose metabolism, which promotes metabolic fitness in young individuals.

CGMap: Characterizing continuous glucose monitor data in thousands of non-diabetic individuals

Despite its rising prevalence, diabetes diagnosis still relies on measures from blood tests. Technological advances in continuous glucose monitoring (CGM) devices introduce a potential tool to expand our understanding of glucose control and variability in people with and without diabetes. Yet CGM data have not been characterized in large-scale healthy cohorts, creating a lack of reference for CGM data research. Here we present CGMap, a characterization of CGM data collected from over 7,000 non-diabetic individuals, aged 40-70 years, between 2019 and 2022. We provide reference values of key CGM-derived clinical measures that can serve as a tool for future CGM research. We further explored the relationship between CGM-derived measures and diabetes-related clinical parameters, uncovering several significant relationships, including associations of mean blood glucose with measures from fundus imaging and sleep monitoring. These findings offer novel research directions for understanding the influence of glucose levels on various aspects of human health.

Intensified Multifactorial Intervention in Patients with Type 2 Diabetes Mellitus

In the management of diabetes mellitus, one of the most important goals is to prevent its micro- and macrovascular complications, and to that end, multifactorial intervention is widely recommended. Intensified multifactorial intervention with pharmacotherapy for associated risk factors, alongside lifestyle modification, was first shown to be efficacious in patients with microalbuminuria (Steno-2 study), then in those with less advanced microvascular complications (the Anglo-Danish-Dutch Study of Intensive Treatment In People with Screen Detected Diabetes in Primary Care [ADDITION]-Europe and the Japan Diabetes Optimal Treatment study for 3 major risk factors of cardiovascular diseases [J-DOIT3]), and in those with advanced microvascular complications (the Nephropathy In Diabetes-Type 2 [NID-2] study and Diabetic Nephropathy Remission and Regression Team Trial in Japan [DNETT-Japan]). Thus far, multifactorial intervention led to a reduction in cardiovascular and renal events, albeit not necessarily significant. It should be noted that not only baseline characteristics but also the control status of the risk factors and event rates during intervention among the patients widely varied from one trial to the next. Further evidence is needed for the efficacy of multifactorial intervention in a longer duration and in younger or elderly patients. Moreover, now that new classes of antidiabetic drugs are available, it should be addressed whether strict and safe glycemic control, alongside control of other risk factors, could lead to further risk reductions in micro- and macrovascular complications, thereby decreasing all-cause mortality in patients with type 2 diabetes mellitus.

Flow cytometry based platelet activation markers and state of inflammation among subjects with type 2 diabetes with and without depression

Type 2 Diabetes Mellitus (T2DM) and Major Depressive Disorder (MDD) are highly disabling disorders associated with a multitude of vascular complications. Platelets are known to play a role in the pathogenesis of vascular complications in both T2DM and MDD. These complications could increase in patients with comorbid diabetes and depression. To quantify and compare flow cytometry based platelet activation markers and the inflammatory state between individuals of diabetes with depression, individuals of diabetes without depression and healthy controls. Out of 114 participants, each study group contained 38 participants in diabetic group, diabetics with depression group and matched control group. Diabetes was diagnosed with the American Diabetes Association (ADA) criteria. Screening of MDD was done with Patient Health Questionnaire 2 (PHQ2) and severity of depression assessed with Hamilton Depression Rating (HAM-D) scale. Platelet markers CD41, CD42b, CD62P and CD63 were assayed using flow cytometer. Platelet count, surface expression of platelet activation markers CD62P and CD63, hs-CRP, insulin and HOMA-IR score differed significantly between the groups. Post hoc analysis showed significantly high CD63 expression in patients with comorbid diabetes and depression compared to those having diabetes without depression. Patients with comorbid diabetes and depression have enhanced platelet hyperactivation and a pro inflammatory state which increases susceptibility to vascular complications.

Inflammatory cardiovascular risk markers and silent myocardial ischemia in type 2 diabetic patients

Background/Aim. A special feature of coronary heart disease (CHD) in patients with type 2 diabetes mellitus (T2DM) is that it is often a symptomatic and occurs as a consequence of cardiovascular autonomic neuropathy. Dysregulation of the autonomic nervous system is associated with elevated values of inflammatory markers such as high-sensitivity C-reactive protein (hs-CRP) and interleukin- 6 (IL-6), which accelerate atherosclerosis and the occurrence of cardiovascular complications in patients with T2DM. The aim of the study was to evaluate the importance of determining inflammatory cardiovascular risk markers IL-6 and hs-CRP in screening for the presence of CHD in asymptomatic patients with T2DM. Methods. The study included 169 patients with T2DM without any symptoms and signs of CHD. Ergometric testing proved or ruled out the presence of silent CHD. The levels of hs- CRP and IL-6 were determined by ELISA. Results. IL-6 values were significantly higher in patients with a positive ergometric test (6.83 ? 1.99 pg/mL) compared to patients with a negative ergometric test (3.04 ? 1.39 pg/mL) (p < 0.001). We also found that hs-CRP values in patients with a positive ergometric test were significantly higher compared to patients with a negative ergometric test (6.37 ? 2.25 vs 1.67 ? 1.41 mg/L; p < 0.001). Combinations of IL-6 and hs-CRP with age, HbA1c values, and duration of diabetes, presented through three binary logistic regression models, are significant predictors of silent CHD proven by ergometric testing, ie, with their increase, the probability of a positive ergometric test also increases (p < 0.01). The sensitivity of the associated finding of elevated IL-6 and hs-CRP values in the detection of silent CHD by ergometric testing was 90%, and the specificity was 86%. Conclusion. Hs-CRP and IL-6 are significant predictors of silent CHD, and their determination could be recommended for improving cardiovascular risk stratification in asymptomatic patients with T2DM.

Hydroxysafflor yellow A, a natural compound from Carthamus tinctorius L with good effect of alleviating atherosclerosis

BACKGROUND

Atherosclerosis is a chronic vascular inflammatory disease with complex pathogenesis. Its serious consequence is insufficient blood supply to heart and brain, which eventually leads to myocardial ischemia, infarction and stroke. Hydroxysafflor yellow A (HSYA), a single chalcone glycoside compound with a variety of pharmacological effects, which has shown a potential biological activity for prevention and treatment of atherosclerosis.

PURPOSE

The main purpose of this review is to comprehensively elucidate the mechanism of HSYA on atherosclerosis and its risk factors (hyperlipidemia, hypertension and diabetes mellitus).

METHOD

The literatures on HSYA in the treatment of atherosclerosis and its risk factors were searched in PubMed, Google Scholar, China National Knowledge Infrastructure, including in vitro (cell), in vivo (animal) and clinical (human) studies, and summarized reasonably.

RESULTS

HSYA is a promising natural product for treating atherosclerosis. It can suppress foam cell formation, vascular endothelial cell dysfunction, vascular smooth muscle cell proliferation and migration, and platelet activation. The mechanisms are achieved by regulating the reverse cholesterol transport process, fatty acid synthesis, oxidative stress, PI3K/Akt/mTOR, NLRP3 inflammasome, TNFR1/NF-κB, NO-cGMP, Bax/Bcl-2, MAPKs, CDK/CyclinD and TLR4/Rac1/Akt signaling pathways. Besides, HSYA is devoted to lowering blood lipids, regulating ion channels, reducing vascular inflammation, and protecting pancreatic beta cells, which is conducive to reducing the harm of independent risk factors of atherosclerosis.

CONCLUSIONS

HSYA exhibits the preventive and therapeutic effects on atherosclerosis and its risk factors in vivo and in vitro, which is relevant to multiple mechanisms. The clinical trials of HSYA need to be further investigated to provide a solid foundation for its clinical application.

Characteristics of atheromatosis in the prediabetes stage: a cross-sectional investigation of the ILERVAS project

Background

Prediabetes has recently been associated with subclinical atheromatous disease in the middle-aged population. Our aim was to characterize atheromatous plaque burden by the number of affected territories and the total plaque area in the prediabetes stage.

Methods

Atheromatous plaque burden (quantity of plaques and total plaque area) was assessed in 12 territories from the carotid and femoral regions using ultrasonography in 6688 non-diabetic middle-aged subjects without cardiovascular disease. Prediabetes was defined by glycosylated hemoglobin (HbA1c) between 5.7 and 6.4% according to the American Diabetes Association guidelines.

Results

Prediabetes was diagnosed in 33.9% (n = 2269) of the ILERVAS participants. Subjects with prediabetes presented a higher prevalence of subclinical atheromatous disease than participants with HbA1c < 5.7% (70.4 vs. 67.5%, p = 0.017). In the population with prediabetes this was observed at the level of the carotid territory (p < 0.001), but not in the femoral arteries. Participants in the prediabetes stage also presented a significantly higher number of affected territories (2 [1;3] vs. 1 [0;3], p = 0.002), with a positive correlation between HbA1c levels and the number of affected territories (r = 0.068, p < 0.001). However, atheromatosis was only significantly (p = 0.016) magnified by prediabetes in those subjects with 3 or more cardiovascular risk factors. The multivariable logistic regression model showed that the well-established cardiovascular risk factors together with HbA1c were independently associated with the presence of atheromatous disease in participants with prediabetes. When males and females were analyzed separately, we found that only men with prediabetes presented both carotid and femoral atherosclerosis, as well as an increase of total plaque area in comparison with non-prediabetic subjects.

Conclusions

The prediabetes stage is accompanied by an increased subclinical atheromatous disease only in the presence of other cardiovascular risk factors. Prediabetes modulates the atherogenic effect of cardiovascular risk factors in terms of distribution and total plaque area in a sex-dependent manner.

Trial registration NCT03228459 (clinicaltrials.gov)

Lifestyle characteristics as moderators of the effectiveness of weight control interventions among semiconductor workers

BACKGROUND

Workers in high technology industry are experiencing stressful environment and have been ranked as a high risk group for adverse health effects. The effectiveness of worksite health promotion is important for occupational health. This study is to investigate the effect of health interventions on body measurement changes while examining the role of their lifestyle factors.

METHODS

A total of 904 participants aged over 30 years were recruited from 14 semiconductor worksites in Taiwan from 2011 to 2015. A multi-settings, quasi-experimental study was conducted that assigned participants into two intervention programs, including exercise program and diet-plus-exercise program. The outcomes include the changes of body weight, waist circumference, body mass index (BMI), and biophysiological indicators. Lifestyle variables include alcohol consumption, cigarette smoking, and regular exercise. Multiple linear regression analyses were performed to test the association.

RESULTS

The findings have demonstrated that one kilogram body weight reduction is associated with a decrease of 0.58 mmHg SBP (p < 0.001), 0.29 mmHg DBP (p < 0.001), 3.33 mg/dL triglyceride (p < 0.001), 0.96 mg/dL total cholesterol (p < 0.001), and 0.68 mg/dL LDL (p < 0.001). The diet-plus-exercise group had more significant effect on both weight changes and biophysiological changes than exercise-only group (p < 0.001). Lifestyle factors, including cigarette smoking, alcohol consumption, and regular exercise, were significant moderators of the effectiveness of health interventions.

CONCLUSIONS

Both exercise and diet interventions are important to the effectiveness of health promotion in occupational sectors. Lifestyle modifications are vital for weight control programs in improving body shape changes and biophysiological indicators.

Endothelial dysfunction and platelet hyperactivity in type 2 diabetes mellitus: molecular insights and therapeutic strategies

The incidence and prevalence of diabetes mellitus is rapidly increasing worldwide at an alarming rate. Type 2 diabetes mellitus (T2DM) is the most prevalent form of diabetes, accounting for approximately 90-95% of the total diabetes cases worldwide. Besides affecting the ability of body to use glucose, it is associated with micro-vascular and macro-vascular complications. Augmented atherosclerosis is documented to be the key factor leading to vascular complications in T2DM patients. The metabolic milieu of T2DM, including insulin resistance, hyperglycemia and release of excess free fatty acids, along with other metabolic abnormalities affects vascular wall by a series of events including endothelial dysfunction, platelet hyperactivity, oxidative stress and low-grade inflammation. Activation of these events further enhances vasoconstriction and promotes thrombus formation, ultimately resulting in the development of atherosclerosis. All these evidences are supported by the clinical trials reporting the importance of endothelial dysfunction and platelet hyperactivity in the pathogenesis of atherosclerotic vascular complications. In this review, an attempt has been made to comprehensively compile updated information available in context of endothelial and platelet dysfunction in T2DM.

Association between skeletal muscle mass to visceral fat area ratio and arterial stiffness in Chinese patients with type 2 diabetes mellitus

BACKGROUND

The skeletal muscle mass-to-visceral fat area ratio (SVR) has been linked to arterial stiffness in non-diabetic adults. We examined the association between the SVR and arterial stiffness in patients with type 2 diabetes mellitus (T2DM).

METHODS

Patients with type 2 diabetes mellitus (252 men and 171 women) aged 40-75 years were enrolled and divided into three groups according to SVR tertiles. Arterial stiffness was measured as brachial-ankle pulse wave velocity (baPWV), with baPWV> 1800 mm/s defined as high. Spearman's partial correlation was used to adjust confounding factors. The odds ratio for high baPWV was determined by multiple logistic regression analyses, and receiver-operating characteristic analysis was conducted.

RESULTS

SVR was associated with baPWV in Chinese patients with T2DM (Spearman's partial correlation = - 0.129, P < 0.01). SVR was found to be significantly associated with baPWV on multiple logistic regression analysis. Patients in the lower SVR tertiles had a higher OR than did those in the higher SVR tertiles, after adjusting for multiple covariates (Q1: OR = 4.33 in men and 4.66 in women; Q3: OR = 1). The area under the curve for SVR was significantly greater than that for appendicular skeletal muscle (ASM), ASM/height², and visceral fat area (VAF) for identifying high baPWV (0.747 in men and 0.710 in women). The optimal cutoffs values of SVR for detecting high baPWV were 191.7 g/cm² for men and 157.3 g/cm² for women.

CONCLUSIONS

SVR has an independent, negative association with arterial stiffness, and is a better risk-assessment tool than ASM, ASM/height², and VFA in clinical practice to identify patients with type 2 diabetes at high cardiovascular risk.

Regression of Nonalcoholic Fatty Liver Disease with Zinc and Selenium Co-supplementation after Disease Progression in Rats

BACKGROUND

Studies have shown that zinc and selenium deficiency is common in nonalcoholic fatty liver disease (NAFLD). However, the effects of zinc and selenium co-supplementation before and/or after disease progression on NAFLD are not clear enough. The aim of this study was to compare the effects of zinc and selenium co-supplementation before and/or after disease progression on NAFLD prognosis.

MATERIALS AND METHODS

Forty male Sprague-Dawley rats (197±4 g) were randomly assigned to 4 dietary groups: normal-fat diet (NFD; receiving 9% of calories as fat), high-fat diet (HFD; receiving 82% of calories as fat), supplementation before disease progression (S+HFD), and supplementation after disease progression (HFD+S). The diets were implemented over a 20-week period in all the groups. Biochemical and histologic parameters were compared between the 4 groups, and between-group comparisons were also carried out.

RESULTS

There were significant differences in the average food dietary intake (P<0.001), weight (P<0.001), fasting blood sugar (P=0.005), triglyceride (P<0.001), total cholesterol (P<0.001), low-density lipoprotein cholesterol (P=0.002), high-density lipoprotein cholesterol (P=0.001), alanine aminotransferase (P<0.001), and aspartate aminotransferase (P<0.001) between the 4 dietary groups. Serum triglyceride and total cholesterol were significantly lower in the HFD+S Group than in the S+HFD Group (P<0.001 and P=0.003, respectively). Fat accumulation was significantly reduced in the HFD+S Group (P<0.001).

CONCLUSION

Zinc and selenium co-supplementation after disease progression improved biochemical and histologic parameters in an experimental model of NAFLD.

Significance of vascular dipeptidyl peptidase-4 inhibition on vascular protection in Zucker diabetic fatty rats

To clarify the role of dipeptidyl peptidase-4 (DPP-4) inhibition in vascular tissues, we compared the effects of the poorly tissue-penetrative DPP-4 inhibitor sitagliptin to the highly tissue-penetrative DPP-4 inhibitor linagliptin in Zucker diabetic fatty (ZDF) rats. Six-week-old ZDF rats were orally treated with placebo, sitagliptin (10 mg/kg), or linagliptin (3 mg/kg) for 4 weeks. Sitagliptin and linagliptin produced equivalent decreases in blood glucose concentrations and increased plasma insulin concentrations during oral glucose tolerance tests after the first and the last treatments. In isolated arteries, acetylcholine-induced vascular relaxation was significantly augmented by sitagliptin and linagliptin, with significantly stronger relaxation observed with linagliptin compared to sitagliptin. Vascular DPP-4 activity was attenuated by these drugs, with linagliptin producing significant greater attenuation than sitagliptin. Vascular malondialdehide levels were significantly lower with linagliptin compared to sitagliptin. Significantly greater attenuation of vascular gene expressions of p22(phox) and monocyte chemoattractant protein-1 by linagliptin, compared with sitagliptin, was also observed. In conclusion, the superior vascular protection by linagliptin compared with sitagliptin was unrelated to the regulation of circulating glucose and insulin levels, and the stronger vascular DPP-4 inhibition by linagliptin may contribute to the mechanism of vascular protection.

Abdominal obesity and low-grade systemic inflammation as markers of subclinical organ damage in type 2 diabetes

AIM

This study aimed to explore the associations between abdominal obesity, inflammatory markers and subclinical organ damage in 740 middle-aged patients with type 2 diabetes.

METHODS

Waist circumference (WC) and sagittal abdominal diameter (SAD) were measured, and blood samples were analyzed for C-reactive protein (CRP) and IL-6. Carotid intima-media thickness (IMT) was evaluated by ultrasonography, and aortic pulse wave velocity (PWV) measured with applanation tonometry.

RESULTS

Abdominal obesity as determined by SAD and WC was significantly correlated with IL-6 (WC: r=0.27, P<0.001; SAD: r=031, P<0.001), CRP (WC: r=0.29, P<0.001; SAD: r=0.29, P<0.001), IMT (WC: r=0.09, P=0.013; SAD: r=0.11, P=0.003) and PWV (WC: r=0.18, P<0.001; SAD: r=0.21, P<0.001). In multiple linear regressions with IMT and PWV as dependent variables, and age, gender, statin use, systolic blood pressure (SBP), body mass index (BMI), CRP and HbA1c as independent variables, both SAD and WC remained associated with IMT and PWV. On stepwise linear regression and entering both SAD and WC, the association between SAD and PWV was stronger than the association between WC and PWV.

CONCLUSION

Both SAD and WC are feasible measures of obesity, and both provide information on inflammation, atherosclerosis and arterial stiffness in type 2 diabetes, while SAD appears to be slightly more robustly associated with subclinical organ damage than WC.

Predictors of stroke in patients with impaired glucose tolerance: results from the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research trial

BACKGROUND AND PURPOSE

Risk factors for stroke are well-established in general populations but sparsely studied in individuals with impaired glucose tolerance.

METHODS

We identified predictors of stroke among participants with impaired glucose tolerance in the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial. Cox proportional-hazard regression models were constructed using baseline variables, including the 2 medications studied, valsartan and nateglinide.

RESULTS

Among 9306 participants, 237 experienced a stroke over 6.4 years. Predictors of stroke included classical risk factors such as existing cerebrovascular and coronary heart disease, higher pulse pressure, higher low-density lipoprotein cholesterol, older age, and atrial fibrillation. Other factors, including previous venous thromboembolism, higher waist circumference, lower estimated glomerular filtration rate, lower heart rate, and lower body mass index, provided additional important predictive information, yielding a C-index of 0.72. Glycemic measures were not predictive of stroke. Variables associated with stroke were similar in participants with no prior history of cerebrovascular disease at baseline.

CONCLUSIONS

The most powerful predictors of stroke in patients with impaired glucose tolerance included a combination of established risk factors and novel variables, such as previous venous thromboembolism and elevated waist circumference, allowing moderately effective identification of high-risk individuals.

Dual renin-angiotensin system inhibition for prevention of renal and cardiovascular events: do the latest trials challenge existing evidence?

Circulatory and tissue renin-angiotensin systems (RAS) play a central role in cardiovascular (CV) and renal pathophysiology, making RAS inhibition a logical therapeutic approach in the prevention of CV and renal disease in patients with hypertension. The cardio- and renoprotective effects observed with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) monotherapy, together with the availability of a direct renin inhibitor (DRI), led to the investigation of the potential benefits of dual RAS inhibition. In small studies, ARB and ACE inhibitor combinations were shown to be beneficial in patients with CV or renal disease, with improvement in surrogate markers. However, in larger outcome trials, involving combinations of ACE inhibitors, ARBs or DRIs, dual RAS inhibition did not show reduction in mortality in patients with diabetes, heart failure, coronary heart disease or after myocardial infarction, and was in fact, associated with increased harm. A recent meta-analysis of all major trials conducted over the past 22 years involving dual RAS inhibition has clearly shown that the risk-benefit ratio argues against the use of dual RAS inhibition. Hence, the recent evidence clearly advocates against the use of dual RAS inhibition, and single RAS inhibition appears to be the most suitable approach to controlling blood pressure and improving patient outcomes.

Sagittal abdominal diameter is a more independent measure compared with waist circumference to predict arterial stiffness in subjects with type 2 diabetes--a prospective observational cohort study

Background

Anthropometric measurements are useful in clinical practice since they are non-invasive and cheap. Previous studies suggest that sagittal abdominal diameter (SAD) may be a better measure of visceral fat depots. The aim of this study was to prospectively explore and compare how laboratory and anthropometric risk markers predicted subclinical organ damage in 255 patients, with type 2 diabetes, after four years.

Methods

Baseline investigations were performed in 2006 and were repeated at follow-up in 2010. Carotid intima-media thickness (IMT) was evaluated by ultrasonography and aortic pulse wave velocity (PWV) was measured with applanation tonometry over the carotid and femoral arteries at baseline and at follow-up in a cohort of subjects with type 2 diabetes aged 55–65 years old.

Results

There were significant correlations between apolipoprotein B (apoB) (r = 0.144, p = 0.03), C - reactive protein (CRP) (r = 0.172, p = 0.009) at baseline and IMT measured at follow-up. After adjustment for sex, age, treatment with statins and Hba1c, the associations remained statistically significant. HbA1c, total cholesterol or LDL-cholesterol did not correlate to IMT at follow-up. Baseline body mass index (BMI) (r = 0.130, p = 0.049), waist circumference (WC) (r = 0.147, p = 0.027) and sagittal Abdominal Diameter (SAD) (r = 0.184, p = 0.007) correlated to PWV at follow-up. Challenged with sex, SBP and HbA1c, the association between SAD, not WC nor BMI, and PWV remained statistically significant (p = 0.036). In a stepwise linear regression, entering both SAD and WC, the association between SAD and PWV was stronger than the association between WC and PWV.

Conclusions

We conclude that apoB and CRP, but not LDL-cholesterol predicted subclinical atherosclerosis. Furthermore, SAD was more independent in predicting arterial stiffness over time, compared with WC, in middle-aged men and women with type 2 diabetes.

Cardiovascular disease and diabetes

Some biochemical mechanisms are discussed which may explain the increased incidence of cardiovascular disease in diabetics compared to nondiabetic humans. Absence of insulin or insensitivity of tissues to insulin leads to hyperglycaemia and elevated plasma fatty acid concentration. Hyperglycaemia can lead to modification of protein functions which can contribute to accelerated atherosclerosis. The latter is the pathological condition which underlies most cardiovascular disease. Elevated plasma fatty acid concentration impairs insulin signalling in skeletal muscle and reduce nitric oxide production in muscle. If elevated plasma fatty acid concentrations reduce endothelial nitric oxide synthase in the artery wall then this also could contribute to the increased atherosclerosis in diabetes. Also treatment of diabetes is discussed briefly in relation to cardiovascular disease.

Reduction of oxidative stress and inflammation by blunting daily acute glucose fluctuations in patients with type 2 diabetes: role of dipeptidyl peptidase-IV inhibition

OBJECTIVE

Evaluate the effects of two dipeptidyl peptidase-IV (DPP-4) inhibitors, sitagliptin and vildagliptin, known to have different efficacy on mean amplitude of glycemic excursions (MAGE), on oxidative stress, and on systemic inflammatory markers in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A prospective, randomized, open-label PROBE design (parallel group with a blinded end point) study was performed in 90 patients with type 2 diabetes inadequately controlled by metformin. The study assigned 45 patients to receive sitagliptin (100 mg once daily; sitagliptin group) and 45 patients to receive vildagliptin (50 mg twice daily; vildagliptin group) for 12 weeks. MAGE, evaluated during 48 h of continuous subcutaneous glucose monitoring, allowed an assessment of daily glucose fluctuations at baseline and after 12 weeks in all patients. Assessment of oxidative stress (nitrotyrosine) and systemic levels of inflammatory markers interleukin (IL)-6 and IL-18 was performed at baseline and after 12 weeks in all patients.

RESULTS

HbA(1c), fasting and postprandial glucose, MAGE, and inflammatory and oxidative stress markers were similar between the groups at baseline. After 12 weeks, MAGE (P < 0.01) was lower in the vildagliptin group than in the sitagliptin group. After treatment, HbA(1c) and postprandial glucose evidenced similar changes between the groups (P = NS). Vildagliptin treatment was associated with a stronger decrease in nitrotyrosine (P < 0.01), IL-6 (P < 0.05), and IL-18 (P < 0.05) than sitagliptin treatment. Nitrotyrosine and IL-6 changes significantly correlated with changes in MAGE but not in fasting glucose and HbA(1c).

CONCLUSIONS

MAGE reduction is associated with reduction of oxidative stress and markers of systemic inflammation in type 2 diabetic patients. These effects were greater in the vildagliptin group than in the sitagliptin group.

Sitagliptin: anti-platelet effect in diabetes and healthy volunteers

Sitagliptin, a selective dipeptidyl peptidase-4 inhibitor drug is used to treat type-2 diabetes (T2DM). We investigated the anti-platelet activity of sitagliptin in patients with T2DM and in in vitro samples obtained from healthy humans. Patients with T2DM (27 male + 23 female) were selected and followed up before (control) and after treatment with sitagliptin for up to 3 months. Platelets were isolated from the blood of sitagliptin treated patients and controls. Patients with T2DM treated with sitagliptin for 1and 3 months, showed 10 ± 2% and 30 ± 5% inhibition of platelet aggregation, respectively. For the in vitro study, platelets from 10 normal humans (n = 10) were isolated. Platelet aggregation, intracellular free calcium and tyrosine phosphorylation of multiple proteins were measured by aggregometer, spectrofluorometer and western blotting, respectively. Platelets pre-treated with 5 and 10 µg/ml of sitagliptin, showed 25 ± 4% and 40 ± 6% inhibition of thrombin-induced platelet aggregation, respectively. Sitagliptin decreased intracellular free calcium (2.5-fold) and tyrosine phosphorylation of multiple proteins in thrombin-induced platelet activation. Sitagliptin inhibited platelet aggregation in T2DM as well as in healthy humans. Sitagliptin has significant concentration-dependent anti-platelet activity. This activity was due to its inhibitory effect on intracellular free calcium and tyrosine phosphorylation.

Generation and characterization of a mouse model of the metabolic syndrome: apolipoprotein E and aromatase double knockout mice

The aim of this study was to create a comprehensive mouse model of the metabolic syndrome by crossing aromatase-deficient (ArKO) mice with apolipoprotein E-deficient (ApoE(-/-)) mice. Successive crossbreeding of ArKO with ApoE(-/-)-deficient mice generated double knockout, MetS-Tg mice. The phenotypic characteristics of the MetS-Tg mice were assessed at 3, 6, and 12 mo of age and compared with age- and sex-matched wild-type (WT) controls. Blood pressure and heart rate were recorded by a noninvasive, computerized tail-cuff system. Oral glucose and intraperitoneal insulin tolerance tests were performed. Serum cholesterol levels were measured by a combined quantitative colorimetric assay. Plasma adiponectin, C-reactive protein (CRP), insulin, interleukin-6 (IL-6), leptin, resistin, and tumor necrosis factor-α (TNF-α) were measured by multiplexed ELISA. MetS-Tg mice displayed significantly increased body weight, central obesity, and elevated blood pressure at all three ages compared with WT mice. Elevated serum cholesterol was associated with higher triglycerides and LDL/VLDL cholesterol particles and was accompanied by a decrease in HDL and histological evidence of fatty liver. MetS-Tg mice of all ages showed impaired glucose tolerance. At 12 mo, MetS-Tg mice had elevated plasma levels of CRP, IL-6, leptin, and TNF-α, but resistin levels were largely unchanged. We now report that this combination of gene knockouts produces a novel strain of mice that display the diverse clinical features of the metabolic syndrome, including central obesity, progressive hypertension, an adverse serum lipid profile, fatty liver, glucose intolerance, insulin resistance, and evidence of an inflammatory state.

Type 2 diabetes and cardiovascular diseases: do they share a common soil? The Asian Indian experience

In India, diabetes and cardiovascular disease (CVD) are growing health problems. CVD accounts for much of the increased morbidity and premature mortality associated with type 2 diabetes. Moreover, CVD also occurs 2-3 decades earlier among diabetic subjects and runs a more aggressive course and has a worse prognosis. The pathophysiology of the link between diabetes and CVD is complex and multifactorial and understanding the mechanisms of the disease can help identify and treat CVD in patients with diabetes and vice versa. The current article reviews the common antecedents between type 2 diabetes and CVD including non-modifiable and modifiable risk factors and suggests that future research on diabetes and CVD should focus on searching for risk factors for CVD that may be more specific to diabetes, such as hypoglycaemia or medication related comorbidities. Also, the authors recommend research on common genetic variants which might have stronger effects and hence have a potential role in diabetes and CVD risk prediction. Finally, primary prevention trials trying to prevent both diabetes and CVD are the urgent need of the hour!

Tissue Factor, Tissue Factor Pathway Inhibitor and Factor VII Activity in Cardiovascular Complicated Type 2 Diabetes Mellitus

OBJECTIVES

Tissue factor (TF) is the main initiator of the extrinsic coagulation pathway through factor VII (FVII) activation, which is physiologically inhibited by tissue factor pathway inhibitor (TFPI). Alteration of this pathway has been described in Type 2 diabetes mellitus (T2DM). The aim of this study is to assess TF and TFPI plasma levels and FVII coagulant activity (FVIIa) in T2DM in relation to cardiothrombotic disease and their correlation to metabolic and clinical behavior of the patients.

METHODS

The study was conducted on 80 T2DM patients divided to accordingly; groupI: 40 patients without a history or clinically detected heart disease, and groupII: 40 patients with a history of myocardial infarction compared to 30 controls. The patients were recruited from Ain Shams University diabetes clinic from September 2007 to February 2009 after informed consent was obtained. Peripheral blood samples were taken for measurement of plasma TF and TFPI levels using ELISA technique and quantitative FVIIa using FVII deficient plasma.

RESULTS

Plasma levels of TF, TFPI and FVIIa were significantly higher in T2DM patients compared to the controls (p<0.001). TF (236.50±79.23)and TFPI (242.33±85.84)were significantly higher in group II, compared to group I (150.33±81.16), (152.8± 82.46), (p<0.001). TF and TFPI were significantly correlated to body mass index and glycemic control. Also, TF and TFPI were significantly higher in hypertensives (p=0.001) and dyslipidemics (p=0.006) but not in smokers (p=0.64), (p=0.11) respectively.

CONCLUSION

There was a correlation between high TF, TFPI plasma levels, FVIIa activity and cardiothrombotic complications in T2DM especially in the presence of high risk factors such as poor glycemic control, dyslipidemia and obesity. Future target therapy against TF may be beneficial for T2DM patients.

Platelet function in patients with diabetes mellitus: from a theoretical to a practical perspective

Patients with diabetes mellitus have an increased prevalence of vascular disease. Pathologic thrombosis associated with atherosclerotic plaque rupture is a major cause of morbidity and mortality. Platelets are intimately involved in the initiation and propagation of thrombosis. Evidence suggests that platelets from patients with type 2 diabetes have increased reactivity and baseline activation compared to healthy controls. We review the pathophysiology of platelet hyperreactivity in DM patients and its implications in clinical practice, with particular focus on acute coronary syndromes, percutaneous coronary intervention, and novel antiplatelet agents.

Improvement of cardio-ankle vascular index by glimepiride in type 2 diabetic patients

AIMS

Glimepiride, a third generation sulfonylurea (SU), is known to have extrapancreatic effects, but its vascular effect is unclear. We investigated the efficacy of glimepiride in improving arterial stiffness assessed by cardio-ankle vascular index (CAVI) in type 2 diabetic patients, compared with glibenclamide, a conventional SU.

METHODS

Forty type 2 diabetic patients were randomly assigned to two groups. One group was administered glimepiride 1.5 mg/day, and the other group was administered glibenclamide 1.25 mg/day for 6 months.

RESULTS

No significant difference in hypoglycaemic effect was observed between two groups. CAVI significantly decreased only in glimepiride group (9.4 ± 1.4→8.9 ± 0.8, p < 0.05). Decrease in CAVI was greater in glimepiride group than in glibenclamide group (-0.50 ± 0.98 vs. -0.04 ± 0.57, p = 0.048). Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) decreased in glimepiride group and increased in glibenclamide group, and the changes were significantly different between groups (-1.5 ± 3.5 vs. + 1.8 ± 3.6, p = 0.009); whereas serum lipoprotein lipase mass increased in glibenclamide group and decreased in glibenclamide group, and the changes tended to be different between groups (+ 2.1 ± 19.1 vs. -7.4 ± 19.2, p = 0.096). Change in urinary 8-OHdG was a significant independent predictor for change in CAVI in all subjects.

CONCLUSIONS

These results suggest that glimepiride improves CAVI compared with glibenclamide. Reduced oxidative stress and improved insulin resistance may contribute to the improvement of CAVI by glimerpiride.

Peripheral Arterial Disease in Community-based Patients with Diabetes in Singapore: Results from a Primary Healthcare Study

Introduction: Peripheral arterial disease (PAD) is an important complication of diabetes mellitus (DM), significantly associated with increased morbidity and mortality secondary to amputations, strokes and coronary artery disease. Information on DM patients with PAD is limited in our ethnically diverse population in Singapore. We aimed to determine the prevalence, risk factors and co-morbidities of PAD in patients managed for DM in the primary care setting. Materials and Methods: A cross-sectional study was conducted among 521 diabetics in 9 of the 18 government-aided clinics in the community. Data including demographics, presence of co-morbidities and vascular risk factors were collected using an interviewer-administered questionnaire, and Ankle-Brachial Index (ABI) was calculated from systolic ankle and brachial pressure measurements. Results: The prevalence of PAD, defined as resting ABI of <0.9 on either leg and/or a history of gangrene or non-traumatic amputation was 15.2% [95% confidence interval (CI), 12.3-18.5]. This prevalence of PAD was higher in patients with pre-existing microvascular and other macrovascular complications. In multivariate analysis, prevalence of PAD was positively associated with increasing age (OR, 1.08; 95% CI, 1.05-1.12), Malay versus Chinese ethnicity (OR, 2.27; 95% CI, 1.09-4.70), low HDL-cholesterol (OR, 1.87; 95% CI, 1.04-3.37), and insulin treatment (OR, 2.98; 95%CI, 1.39-6.36). Conclusion: PAD is an important cause of concern among patients with diabetes, with a high prevalence which further increases with increasing age and duration of DM, and exhibits ethnic variation. Risk factors identified in this study may improve early identification of PAD, allowing for prompt interventions, with a potential to reduce long-term morbidity and mortality. Key words: Ethnic variation, Macrovascular complications, Risk factors

Glutathione S-transferase T1- and M1-null genotypes and coronary artery disease risk in patients with Type 2 diabetes mellitus Cardiovasc

Introduction: Since long-term exposure to oxidative stress is strongly implicated in the pathogenesis of diabetic complications, polymorphic genes of detoxifying enzymes must be involved in the development of coronary artery disease (CAD). We assessed the potential glutathione S-transferase (GST) gene–gene (GSTM1null–GSTT1null) and gene–smoking interactions on the development of CAD in patients with Type 2 diabetes. Materials & methods: In a case-only design, we enrolled 231 patients with Type 2 diabetes (147 male, 66.1 ± 9.7 years) referred to our institute for coronary angiography investigation. CAD was diagnosed if there was over 50% obstruction of one or more major vessels. Results: Coronary angiography revealed significant CAD in 184 patients (80%). Male gender (p < 0.001), smoking habits (p = 0.003) and GSTT1null genotype (p = 0.003) were significantly correlated with the increasing extent of the coronary atherosclerosis. Case-only analysis revealed that patients with both Mnull–Tnull genotypes had the highest risk for 3-vessel CAD compared with patients who express both GST genes (odds ratio: 3.1; 95% confidence interval: 1.0–10.3, p = 0.04). A nearly threefold interaction existed between cigarette smoking and Mnull–Tnull genotypes (odds ratio: 2.9, 95% confidence interval: 1.7–7.8, p = 0.03). A significant interaction between Mnull–Tnull genotypes and smoking was also observed on the increasing number of coronary vessels that were diseased (χ2 = 14.0; p = 0.03). Conclusion: These data suggest that polymorphisms in GSTM1 and GSTT1 genes are risk factors for CAD in Type 2 diabetic patients, especially among smokers. These genetic markers may permit the targeting of preventive and early intervention on high-risk patients to reduce their cardiovascular risk.

Evaluation of peripheral and autonomic neuropathy among patients with newly diagnosed impaired glucose tolerance

BACKGROUND

We have aimed to investigate the presence of peripheral and autonomic neuropathy in individuals who had been diagnosed with impaired glucose tolerance (IGT) on the basis of an oral glucose tolerance test, by comparing with age-matched healthy subjects with an oral glucose tolerance test (OGTT) in normoglycemic ranges.

MATERIAL AND METHODS

Conventional nerve conduction studies, heart rate variation variability, heart rate response to deep breathing, heart rate response to valsalva maneuvre, blood pressure response to standing up quickly, hand grip test and sympathetic skin response tests were used to evaluate the IGT and the control subjects.

RESULTS

No obvious statistical difference indicating peripheral neuropathy and/or cardiac autonomic neuropathy was detected between patient group and controls. Amplitudes of sympathetic skin response of two limbs (right upper and lower extremities) were lower in the IGT patient group when compared to healthy controls (p < 0.05) indicating the presence of sudomotor autonomic neuropathy.

CONCLUSION

Complaints and neurological examinations of patients with IGT were thought to be consistent with small-fiber neuropathy in the early phase of glucose intolerance. Not detecting any neuropathic findings in conventional electroneurography should be attributed to insufficient time allowed for settling down of large-fiber neuropathy. Obtaining no response in some of the patients in addition to general decrease in the amplitudes of sympathetic skin responses indicates that sudomotor fibers tend to be affected earlier in autonomic neuropathy in the group with IGT when compared with healthy controls. Newly diagnosed IGT patients take receive priority in primary protection since the time for settling down of cardiac autonomic neuropathy was short.

Monocyte chemoattractant protein-1 secreted by adipose tissue induces direct lipid accumulation in hepatocytes

For many years, adipose tissue has been mainly considered as an inert reservoir for storing triglycerides. Since the discovery that adipocytes may secrete a variety of bioactive molecules (hormones, chemokines, and cytokines), an endocrine and paracrine role for white adipose tissue (WAT) in the regulation of energy balance and other physiological processes has been established, particularly with regard to brain and muscle. In contrast, little is known about the interactions of WAT with liver. Hence, we examined the effect of the secretory products of WAT on hepatocytes. Conditioned medium of human WAT explants induced significant steatosis in hepatocyte cell lines. Factor(s) responsible for the conditioned medium-induced steatosis were screened by a battery of blocking antibodies against different cytokines/chemokines shown to be secreted by WAT. In contrast to interleukin-8 and interleukin-6, the monocyte chemoattractant protein-1 was capable of inducing steatosis in hepatocytes in a time-dependent manner at concentrations similar to those found in conditioned medium. Incubation of conditioned medium with antimonocyte chemoattractant protein-1 antibodies prevented triglyceride accumulation. Investigation of the mechanism leading to the triglyceride accumulation showed that both a diminution of apolipoprotein B secretion and an increase in phosphoenolpyruvate carboxykinase messenger RNA may be involved.

CONCLUSION

The monocyte chemoattractant protein-1 secreted by adipose tissue may induce steatosis not only recruiting macrophages but also acting directly on hepatocytes.

Early diagnosis and prevention of diabetes in developing countries

Type 2 diabetes has an insidious onset with a long latent period of dysglycaemia. By the time the diagnosis of diabetes is made, diabetes-related tissue damage occurs in nearly half of the patients. Even after diagnosis, the glycaemic control is suboptimal in more than 50%, leading to the vascular complications. Evidences suggest that early detection of diabetes by appropriate screening methods, especially in subjects with high risk for diabetes will help to prevent or delay the vascular complications and thus reduce the clinical, social and economic burden of the disease. There are also evidences to show that intervention at the prediabetic stage is superior to diagnosis of diabetes.

Improvement of cardiovascular risk factors in patients with type 2 diabetes after long-term continuous subcutaneous insulin infusion

BACKGROUND

The effects of long-term continuous subcutaneous insulin infusion (CSII) on cardiovascular risk factors such as hyperglycaemia, dyslipidaemia, and proinflammatory cytokine levels have not been assessed so far in type 2 diabetes.

METHODS

We analysed the levels of HbA(1c), serum lipids, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) at 0, 2, and 30 weeks after CSII in 15 patients with type 2 diabetes (mean age, 53.3+/-10.1 years; disease duration, 9.4+/-5.3 years) without previous history of major cardiovascular events.

RESULTS

At week 30, CSII significantly lowered HbA(1c) by 5.0+/-0.9% compared to baseline (7.9+/-1.9%, p<0.001) and improved high-density lipoprotein cholesterol (HDLc; 1.09+/-0.16 at baseline vs 1.25+/-0.15 mmol/L at week 30; p<0.05) and low-density lipoprotein cholesterol (LDLc)/HDLc ratios (2.8+/-1.4 at baseline vs 2.2+/-0.9 at week 30; p<0.05). CSII also decreased the proportion of patients with dyslipidaemia at week 30. At baseline, TNF-alpha and IL-6 levels were up-regulated (2.65+/-4.04 and 2.82+/-1.81 pg/mL, respectively) compared to the normal control (p<0.01 and p<0.05, respectively); however, cytokine levels decreased significantly at week 30 (1.44+/-2.25 and 1.99+/-1.05 pg/mL, respectively; p=NS vs control).

CONCLUSIONS

Long-term CSII alone decreased cardiovascular risk factors in poorly controlled type 2 diabetes, suggesting that the synchronization of sufficient insulin peaks with meal ingestion and continuous pulsatile infusion of basal insulin corrects metabolic derangements.

Effects of atorvastatin and pravastatin on glucose tolerance, adipokine levels and inflammatory markers in hypercholesterolaemic patients

Several randomized clinical trials have suggested that atorvastatin and pravastatin may differ in terms of their pleiotropic effects. To verify this, we compared the effects of both statins on glucose tolerance, adipokine concentrations and inflammatory markers. A total of 36 hypercholesterolaemic patients without known coronary heart disease (CHD) were enrolled in an open-label, randomized, crossover study. The patients received pravastatin or atorvastatin (10 mg/day) for 4 months and then switched to the other statin for an additional 4 months. At the end of both treatment periods, atorvastatin significantly reduced the concentration of serum lipids (total and low-density lipoprotein-cholesterol and triglycerides) and inflammatory markers (high-sensitivity C-reactive protein and tumour necrosis factor-a) and increased serum adiponectin levels compared with pravastatin treatment. Although these effects would be expected to improve insulin sensitivity, atorvastatin did not affect glucose tolerance, which was assessed by fasting glucose and insulin concentrations, the homeostasis model assessment index and glycosylated haemoglobin (HbA(1c)) levels. Only obese patients showed increased HbA(1c) levels after atorvastatin treatment. Our results suggest that atorvastatin has both advantages and disadvantages compared with pravastatin treatment. Further studies are required to compare the relative clinical value of atorvastatin and pravastatin, especially in obese patients without CHD.

The importance of treating cardiometabolic risk factors in patients with type 2 diabetes

Cardiometabolic risk factors are the combined vascular and metabolic components of risk that may lead to a cardiovascular event. There are numerous such factors. Underlying the concept of cardiometabolic risk is an association with excess visceral fat, leading to the dysregulation of the adipokines, the signalling proteins derived from adipose tissue. Changes in the levels of the adipokines - tumour necrosis factor-alpha, cholesteryl ester transfer protein and adiponectin, for example - can lead to alterations in insulin sensitivity and high-density lipoprotein cholesterol metabolism. At present, specific cardiometabolic risk factors are commonly managed on an individual basis. We are now moving from the era of single risk factor intervention, however, to multiple risk factor intervention in people at high cardiovascular risk, with the additional possibility of using new drug classes to target the underlying cardiometabolic problems more effectively.

Beneficial effects of strategies for primary prevention of diabetes on cardiovascular risk factors: results of the Indian Diabetes Prevention Programme

In subjects with impaired glucose tolerance (IGT) who participated in the Indian Diabetes Prevention Programme (IDPP), abnormalities related to body mass index, waist circumference (WC), blood pressure (BP), lipid profile and electrocardiography were analysed (at baseline and third-year follow-up) in control, lifestyle modification (LSM), metformin (MET) and LSM + MET groups. At baseline, elevated levels of low-density lipoprotein cholesterol (LDL-C) showed the highest (78.6%) and total cholesterol (TC) showed the lowest (42%) prevalence. At follow-up, prevalence of hypertension (BP > or = 130/> or = 85 mmHg) had increased significantly in all groups. Cardiovascular abnormalities were lower in intervention groups, with the lowest rates in the MET group (p=0.013 vs. control); the LDL-C level decreased in intervention groups. In this programme, Asian Indian IGT subjects were observed to have a high prevalence of cardiovascular risk factors. LSM and MET had beneficial effects on the atherogenic phenotype of lipids but had no influence on blood pressure.

Diazoxide prevents abdominal adiposity and fatty liver in obese OLETF rats at prediabetic stage

Epidemiological studies in both humans and experimental animals have shown an association between visceral obesity and cardiovascular risk factors such as dyslipidemia, hyperinsulinemia, and type 2 diabetes mellitus. The objective of this study was to evaluate the effects of diazoxide, an inhibitor of glucose-stimulated insulin secretion, on the prevention of fat deposition in the liver and in the abdominal cavity of prediabetic rats. Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which are a well-established animal model of human obesity, were used. Diazoxide (25 mg/kg/day) was administered from 8 to 30 weeks of age. Various fat distribution parameters, including computerized tomography imaging, histopathological examination, lipid metabolism, and insulin resistance, were determined in prediabetic OLETF rats. Occurrences of abdominal adiposity and fatty liver were markedly reduced by diazoxide treatment. Diazoxide significantly lowered hyperinsulinemia, triglycerides, free fatty acid levels, insulin resistance, weight gain, and food intake. In addition, it inhibited the development of diabetes in these animals. Linear regression assay demonstrated a close correlation between decreasing hyperinsulinemia and the protective effects of diazoxide. The present study demonstrates that diazoxide treatment in obese OLETF rats at prediabetic stage prevents abdominal obesity and fat deposition in the liver. These metabolic changes may occur through a direct effect on beta-cells through reduction of their workload and suppression of insulin secretion.

Metabolic syndrome and incident end-stage peripheral vascular disease: a 14-year follow-up study in elderly Finns

OBJECTIVE

We investigated the relationship of the metabolic syndrome and its single components, defined by four different criteria, with peripheral vascular disease (PVD) in a prospective population-based study.

RESEARCH DESIGN AND METHODS

The metabolic syndrome was defined according to the World Health Organization (WHO), the National Cholesterol Education Program (NCEP), the International Diabetes Federation (IDF), and the American Heart Association (updated NCEP) criteria. We investigated the relationship of the metabolic syndrome defined by the aforementioned four criteria with PVD (revacularization and amputation) by Cox regression analyses in a Finnish population of 1,212 subjects, aged 65-74 years, with and without diabetes during a 14-year follow-up.

RESULTS

The metabolic syndrome defined by the WHO, NCEP, and updated NCEP criteria was associated with a statistically significant risk for incident PVD (n = 57) with adjustment for all confounding variables except for prevalent diabetes (hazard ratios [HRs] from 1.91 to 2.62). After adjustment for prevalent diabetes or after the exclusion of subjects with prevalent diabetes, there was no association between the metabolic syndrome by any criteria and incident PVD. Of the single components of the metabolic syndrome, elevated fasting glucose by the WHO and NCEP criteria (HR 2.35) and microalbuminuria by the WHO definition (2.56) predicted PVD in multivariable models (prevalent diabetes included).

CONCLUSIONS

The metabolic syndrome defined by the WHO, NCEP, and updated NCEP criteria predicted incident end-stage PVD in elderly Finns but only when not adjusted for diabetes status. Two of the single components of the metabolic syndrome, elevated fasting plasma glucose and microalbuminuria, predicted PVD. We conclude that the metabolic syndrome predicts PVD but not above and beyond the risk associated with diabetes and microalbuminuria.

Postprandial lipemia: an under-recognized atherogenic factor in patients with diabetes mellitus

Atherosclerotic disease is the leading cause of both morbidity and mortality in patients with type 2 diabetes. In these patients, postprandial dyslipidemia include not only quantitative but also qualitative abnormalities of lipoproteins which are potentially atherogenic and seems to be a significant risk factor for cardiovascular disease since there is evidence that it results in endothelial dysfunction and enhanced oxidative stress. The most common pattern of postprandial dyslipidemia in diabetes consists of high concentrations of triglycerides, higher VLDLs production by the liver and a decrease in their clearance, a predominance of small dense LDL particles, and reduced levels of HDL. The cause of this postprandial dyslipidemia in diabetes is complex and involves a variety of factors including hyperinsulinemia, insulin resistance, hyperglycemia and disturbed fatty acid metabolism. Numerous clinical studies have shown that postprandial dyslipidemia is associated with endothelial dysfunction in type 2 diabetes and with alterations in other surrogate markers in the cascade of atherosclerosis. Current published guidelines indicate that in diabetics the primary lipid target is LDL<100 mg/dL (70 mg/dL in very high-risk patients) and the most appropriate class of drugs are statins although the issue of postprandial dyslipidemia has not been specifically addressed so far. Moreover, several other classes of medications (fibrates, niacin and antidiabetic drugs) as well as non-pharmacological interventions (i.e. diet, smoking cessation and exercise) can be used to treat lipid and lipoprotein abnormalities associated with insulin resistance and type 2 diabetes. These type of interventions may be more appropriate to ameliorate postprandial dyslipidemia. However, this remains to be confirmed on clinical grounds.

The effect of pioglitazone on recurrent myocardial infarction in 2,445 patients with type 2 diabetes and previous myocardial infarction: results from the PROactive (PROactive 05) Study

OBJECTIVES

This analysis from the PROactive (PROspective pioglitAzone Clinical Trial In macroVascular Events) study assesses the effects of pioglitazone on mortality and macrovascular morbidity in patients with type 2 diabetes and a previous myocardial infarction (MI).

BACKGROUND

People with type 2 diabetes have an increased incidence of MI compared with the general population. Those with diabetes and MI have a worse prognosis than nondiabetic patients with cardiovascular disease.

METHODS

The PROactive study was a prospective, multicenter, double-blind, placebo-controlled trial of 5,238 patients with type 2 diabetes and macrovascular disease. Patients were randomized to either pioglitazone or placebo in addition to their other glucose-lowering and cardiovascular medication. Treatment of diabetes, dyslipidemia, and hypertension was encouraged according to the International Diabetes Federation guidelines. Patients were followed for a mean of 2.85 years. The primary end point was the time to first occurrence of macrovascular events or death. Of the total cohort, the subgroup of patients who had a previous MI (n = 2,445 [46.7%]; n = 1,230 in the pioglitazone group and n = 1,215 in the placebo group) was evaluated using prespecified and post-hoc analyses.

RESULTS

Pioglitazone had a statistically significant beneficial effect on the prespecified end point of fatal and nonfatal MI (28% risk reduction [RR]; p = 0.045) and acute coronary syndrome (ACS) (37% RR; p = 0.035). There was a 19% RR in the cardiac composite end point of nonfatal MI (excluding silent MI), coronary revascularization, ACS, and cardiac death (p = 0.033). The difference in the primary end point defined in the main PROactive study did not reach significance in the MI population (12% RR; p = 0.135). The rates of heart failure requiring hospitalization were 7.5% (92 of 1,230) with pioglitazone and 5.2% (63 of 1,215) with placebo. Fatal heart failure rates were similar (1.4% [17 of the 92] with pioglitazone versus 0.9% [11 of the 63] with placebo).

CONCLUSIONS

In high-risk patients with type 2 diabetes and previous MI, pioglitazone significantly reduced the occurrence of fatal and nonfatal MI and ACS. (PROspective pioglitAzone Clinical Trial In macroVascular Events; http://www.clinicaltrials.gov/ct/show/NCT00174993?order = 1; ISRCTN NCT00174993).

Lipid transfer protein activities in subjects with impaired glucose tolerance

BACKGROUND

Impaired glucose tolerance (IGT) is associated with an increased risk of atherosclerosis that may be due in part to dyslipidemia. The purpose of this study was to assess the regulatory role of lipid transfer proteins in the development of this dyslipidemia.

METHODS

Activities of cholesterol ester transfer protein (CETP) and phospholipid transfer protein (PLTP), as well as lipid and protein components of the major lipoprotein fractions, were evaluated in probands with IGT and were compared with those in subjects with normal glucose tolerance. The effect of a fat-rich meal on these variables was also investigated.

RESULTS

IGT probands had a higher triglyceride content in subfractions of low- (LDL) and high-density lipoprotein (HDL). IGT patients had higher fasting CETP activity. The latter was positively correlated with HDL2 triglycerides and negatively with HDL3 total cholesterol. PLTP activity and mass were not higher in IGT patients. However, PLTP activity correlated with components of VLDL and LDL and was influenced by the type of obesity. Neither CETP and PLTP activities nor PLTP mass were altered by a fat-rich meal. PLTP and CETP activities correlated in both fasting and postprandial conditions.

CONCLUSIONS

Increased fasting CETP activity may contribute to increased risk of atherosclerosis in subjects with IGT.

Effects of melatonin and zinc on lipid profile and renal function in type 2 diabetic patients poorly controlled with metformin

Glycemic control and prevention of secondary complications are the most important goals of using pharmacologic treatment of diabetes mellitus (DM). The inadequate responses to oral hypoglycemic agents may be attributed to inadequate postreceptor events even when insulin levels are quite sufficient, and associated with oxidative stress induced by long-term hyperglycemia. The administration of antioxidants such as melatonin and zinc may improve tissue responses to insulin and increase the efficacy of drugs, e.g. metformin, which act through this pathway. This project was designed to evaluate the effects of melatonin and zinc on the lipid profile and renal function in type 2 DM patients poorly controlled with metformin. A placebo-controlled, double-blind clinical trial was performed in which 46 type 2 diabetic patients were selected and allocated into three groups. These groups were treated with single daily oral doses of both 10 mg of melatonin and 50 mg of zinc acetate alone: 10 mg of melatonin and 50 mg of zinc acetate in addition to the regularly used metformin or placebo, given at bedtime for 90 days. Fasting lipid profiles and microalbuminuria (MAU) were measured before initiating the treatments (zero time) and after 30 and 90 days of treatment. Daily administration of melatonin and zinc improved the impaired lipid profile and decreased the level of MAU; the addition of this treatment regimen in combination with metformin improved the tissue responses to this oral hypoglycemic agent. In conclusion, the combination of melatonin and zinc acetate, when used alone or in combination with metformin, improves DM-related complications such as the impaired lipid profile and MAU in type 2 DM patients.