Diabetes mellitus and diabetes-associated vascular disease

Endothelial dysfunction and cardiovascular diseases: The role of human induced pluripotent stem cells and tissue engineering

Cardiovascular disease (CVD) remains to be the leading cause of death globally today and therefore the need for the development of novel therapies has become increasingly important in the cardiovascular field. The mechanism(s) behind the pathophysiology of CVD have been laboriously investigated in both stem cell and bioengineering laboratories. Scientific breakthroughs have paved the way to better mimic cell types of interest in recent years, with the ability to generate any cell type from reprogrammed human pluripotent stem cells. Mimicking the native extracellular matrix using both organic and inorganic biomaterials has allowed full organs to be recapitulated in vitro. In this paper, we will review techniques from both stem cell biology and bioengineering which have been fruitfully combined and have fueled advances in the cardiovascular disease field. We will provide a brief introduction to CVD, reviewing some of the recent studies as related to the role of endothelial cells and endothelial cell dysfunction. Recent advances and the techniques widely used in both bioengineering and stem cell biology will be discussed, providing a broad overview of the collaboration between these two fields and their overall impact on tissue engineering in the cardiovascular devices and implications for treatment of cardiovascular disease.

Gallic acid improves the metformin effects on diabetic kidney disease in mice

OBJECTIVES

Metformin is an antidiabetic agent that is used as the first-line treatment of type 2 diabetes mellitus. Gallic acid is a type of phenolic acid that has been shown to be a potential drug candidate to treat diabetic kidney disease, an important complication of diabetes. We aimed to test whether a combination of gallic acid and metformin can exert synergetic effect on diabetic kidney disease in diabetic mice model.

METHODS

Streptozotocin (65 mg/kg) intraperitoneal injection was used to induce diabetic kidney disease in mice. The diabetic mice were treated with saline (Vehicle), gallic acid (GA) (30 mg/kg), metformin (MET) (200 mg/kg), or the combination of gallic acid (30 mg/kg) and metformin (200 mg/kg) (GA + MET).

RESULTS

Our results demonstrated that compared to the untreated diabetic mice, all three strategies (GA, MET, and GA + MET) exhibited various effects on improving renal morphology and functions, reducing oxidative stress in kidney tissues, and restoring AMP-activated protein kinase (AMPK)/silent mating type information regulation 2 homolog 1 (SIRT1) signaling in kidney tissues of diabetic mice. Notably, the combination strategy (GA + MET) provided the most potent renal protection effects than any single strategies (GA or MET).

CONCLUSION

Our results support the hypothesis that gallic acid might serve as a potential supplement to metformin to enhance the therapeutical effect of metformin.

Mesenchymal Stem Cell-Derived Exosomes: A Novel Approach to Diabetes-Associated Cognitive Impairment

The progression of diabetes frequently results in a myriad of neurological disorders, including ischemic stroke, depression, blood-brain barrier impairment, and cognitive dysfunction. Notably, diabetes-associated cognitive impairment, a prevalent comorbidity during the course of diabetes, progressively affects patients' cognitive abilities and may reciprocally influence diabetes management, thereby severely impacting patients' quality of life. Extracellular vesicles, particularly nanoscale exosomes, have garnered considerable attention in recent years. These exosomes carry and transfer various functional molecules, such as proteins, lipids, and diverse non-coding RNAs, serving as novel regulators and communicators in intercellular interactions. Of particular interest, mesenchymal stem cell-derived exosomes (MSC-Exos) have been reported to traverse the blood-brain barrier and ameliorate intracerebral pathologies. This review elucidates the role of MSC-Exos in diabetes-related cognitive impairment, with a focus on their applications as biomarkers, modulation of neuronal regeneration and synaptic plasticity, anti-inflammatory properties, antioxidative effects, and their involvement in regulating the functionality of β-amyloid proteins during the course of cognitive impairment. The immense therapeutic potential of MSC-Exos in the treatment of diabetes-induced cognitive dysfunction is emphasized.

Endocan in prediabetes, diabetes, and diabetes-related complications: a systematic review and meta-analysis

BACKGROUND

Diabetes is one of the chronic conditions with a high burden all around the world. Macrovascular and microvascular involvement are among the common mechanisms by which diabetes can impact patients' lives. Endocan as an inflammatory endothelial biomarker has been shown to increase in several communicable and non-communicable diseases. Herein, we aim to investigate the role of endocan as a biomarker in diabetes as a systematic review and meta-analysis.

METHODS

International databases, including PubMed, Web of Science, Scopus, and Embase were searched for relevant studies assessing blood endocan in diabetic patients. Estimation of the standardized mean difference (SMD) and 95% confidence interval (CI) for comparison of circulating endocan levels between diabetic patients and non-diabetic controls were conducted through random-effect meta-analysis.

RESULTS

Totally, 24 studies were included, assessing 3354 cases with a mean age of 57.4 ± 8.4 years. Meta-analysis indicated that serum endocan levels were significantly higher in diabetic patients in comparison with healthy controls (SMD 1.00, 95% CI 0.81 to 1.19, p-value < 0.01). Moreover, in the analysis of studies with only type-2 diabetes, the same result showing higher endocan was obtained (SMD 1.01, 95% CI 0.78 to 1.24, p-value < 0.01). Higher endocan levels were also reported in chronic diabetes complications such as diabetic retinopathy, diabetic kidney disease, and peripheral neuropathy.

CONCLUSION

Based on our study's findings, endocan levels are increased in diabetes, however, further studies are needed for assessing this association. In addition, higher endocan levels were detected in chronic complications of diabetes. This can help researchers and clinicians in recognizing disease endothelial dysfunction and potential complications.

The Association Between Diabetes Duration and Domain-Specific Cognitive Impairment: A Population-Based Study

BACKGROUND

Diabetes is a risk factor for cognitive impairment, and disease duration is associated with geriatric decline and functional disabilities.

OBJECTIVE

This study aimed to examine the association of diabetes duration with domain-specific cognitive impairment in elderly.

METHODS

A total of 3,142 participants from the National Health and Nutrition Examination Survey (NHANES) from the period between 2011 and 2014 were included. We assessed cognitive function using the Digit Symbol Substitution Test (DSST), the CERAD Word Learning (CERAD-WL) test, the CERAD Delayed Recall (CERAD-DR) test and animal fluency (AF) test.

RESULTS

After adjusting for age, sex, race/ethnicity, education level, and annual household income, we found that diabetes with a duration longer than 20 years were at 3.32-fold increased risk of DSST impairment (OR = 3.32, 95% CI: 1.95 to 5.67), 1.72-fold increased risk of CERAD-WL impairment (OR = 1.72, 95% CI: 1.13 to 2.62), and 1.76-fold increased risk of AF impairment (OR = 1.76, 95% CI: 1.23 to 2.53), compared with those with no diabetes. Associations were generally stronger in women than in men. Participants with diabetes, who were diagnosed at 50-59 years old were at increased risk of DSST impairment, CERAD-WL impairment, CERAD-DR impairment, and AF impairment per 5 years longer duration of diabetes.

CONCLUSION

Longer diabetes duration was associated with the increased risk of cognitive impairment, especially in processing speed and attention. The presence of chronic kidney disease was associated with the increased risk of DSST impairment.

Links between Metabolic Syndrome and Hypertension: The Relationship with the Current Antidiabetic Drugs

Hypertension poses a significant burden in the general population, being responsible for increasing cardiovascular morbidity and mortality, leading to adverse outcomes. Moreover, the association of hypertension with dyslipidaemia, obesity, and insulin resistance, also known as metabolic syndrome, further increases the overall cardiovascular risk of an individual. The complex pathophysiological overlap between the components of the metabolic syndrome may in part explain how novel antidiabetic drugs express pleiotropic effects. Taking into consideration that a significant proportion of patients do not achieve target blood pressure values or glucose levels, more efforts need to be undertaken to increase awareness among patients and physicians. Novel drugs, such as incretin-based therapies and renal glucose reuptake inhibitors, show promising results in decreasing cardiovascular events in patients with metabolic syndrome. The effects of sodium-glucose co-transporter-2 inhibitors are expressed at different levels, including renoprotection through glucosuria, natriuresis and decreased intraglomerular pressure, metabolic effects such as enhanced insulin sensitivity, cardiac protection through decreased myocardial oxidative stress and, to a lesser extent, decreased blood pressure values. These pleiotropic effects are also observed after treatment with glucagon-like peptide-1 receptor agonists, positively influencing the cardiovascular outcomes of patients with metabolic syndrome. The initial combination of the two classes may be the best choice in patients with type 2 diabetes mellitus and multiple cardiovascular risk factors because of their complementary mechanisms of action. In addition, the novel mineralocorticoid receptor antagonists show significant cardio-renal benefits, as well as anti-inflammatory and anti-fibrotic effects. Overall, the key to better control of hypertension in patients with metabolic syndrome is to consider targeting multiple pathogenic mechanisms, using a combination of the different therapeutic agents, as well as drastic lifestyle changes. This article will briefly summarize the association of hypertension with metabolic syndrome, as well as take into account the influence of antidiabetic drugs on blood pressure control.

Diabetic endothelial microangiopathy and pulmonary dysfunction

Type 2 diabetes mellitus (T2DM) is a widespread metabolic condition with a high global morbidity and mortality rate that affects the whole body. Their primary consequences are mostly caused by the macrovascular and microvascular bed degradation brought on by metabolic, hemodynamic, and inflammatory variables. However, research in recent years has expanded the target organ in T2DM to include the lung. Inflammatory lung diseases also impose a severe financial burden on global healthcare. T2DM has long been recognized as a significant comorbidity that influences the course of various respiratory disorders and their disease progress. The pathogenesis of the glycemic metabolic problem and endothelial microangiopathy of the respiratory disorders have garnered more attention lately, indicating that the two ailments have a shared history. This review aims to outline the connection between T2DM related endothelial cell dysfunction and concomitant respiratory diseases, including Coronavirus disease 2019 (COVID-19), asthma, chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF).

Through-knee versus above-knee amputation for vascular and non-vascular major lower limb amputations

BACKGROUND

Diabetes and vascular disease are the leading causes of lower limb amputation. Currently, 463 million adults are living with diabetes, and 202 million with peripheral vascular disease, worldwide. When a lower limb amputation is considered, preservation of the knee in a below-knee amputation allows for superior functional recovery when compared with amputation at a higher level. When a below-knee amputation is not feasible, the most common alternative performed is an above-knee amputation. Another possible option, which is less commonly performed, is a through-knee amputation which may offer some potential functional benefits over an above-knee amputation.

OBJECTIVES

To assess the effects of through-knee amputation compared to above-knee amputation on clinical and rehabilitation outcomes and complication rates for all patients undergoing vascular and non-vascular major lower limb amputation.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases; the World Health Organization International Clinical Trials Registry Platform; and the ClinicalTrials.gov trials register to 17 February 2021. We undertook reference checking, citation searching, and contact with study authors to identify additional studies.

SELECTION CRITERIA

Published and unpublished randomised controlled trials (RCTs) comparing through-knee amputation and above-knee amputation were eligible for inclusion in this study. Primary outcomes were uncomplicated primary wound healing and prosthetic limb fitting. Secondary outcomes included time taken to achieve independent mobility with a prosthesis, health-related quality of life, walking speed, pain, and 30-day survival.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed all records identified by the search. Data collection and extraction were planned in line with recommendations outlined in the Cochrane Handbook for Systematic Reviews of Interventions. We planned to assess the certainty of evidence using the GRADE approach.

MAIN RESULTS

We did not identify RCTs that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

No RCTs have been conducted to determine comparative clinical or rehabilitation outcomes of through-knee amputation and above-knee amputation, or complication rates. It is unknown whether either of these approaches offers improved outcomes for patients. RCTs are needed to guide practice and to ensure the best outcomes for this patient group.

Prevalence of people at risk of developing type 2 diabetes mellitus and the involvement of community pharmacies in a national screening campaign: a pioneer action in Brazil

BACKGROUND

Brazil is one of top 10 countries with the highest number of people with diabetes mellitus (DM), affecting 16.8 million peoples. It is estimated that 7.7 million people (20-79 years) in the country have not yet been diagnosed, representing an under-diagnosis rate of 46.0%. Herein we aimed to screen people for high blood glucose or risk for developing type 2 DM (T2DM) through community pharmacies in Brazil.

METHODS

A cross-sectional study was carried out in November 2018, involving 977 pharmacists from 345 municipalities in Brazil. The study evaluated people between 20 and 79 years old without a previous diagnosis of DM. Glycemia was considered high when its value was ≥ 100 mg/dL fasting and ≥ 140 mg/dL in a casual feeding state. The FINDRISC (Finnish Diabetes Risk Score) was used to estimate the risk for developing T2DM. The prevalence of high blood glucose was estimated and the associated factors were obtained using Poisson's multivariate analysis with robust variance.

RESULTS

During the national screening campaign, 17,580 people were tested with the majority of the consultations (78.2%) being carried out in private pharmacies. The population was composed mainly of women (59.5%) and people aged between 20 and 45 years (47.9%). The frequency of participants with high blood glucose was 18.4% (95% CI 17.9-19.0). Considering the FINDRISC, 22.7% of people had a high or very high risk for T2DM. The risk factors associated with high blood glucose were: Body Mass Index > 25 kg/m2, abdominal circumference > 94 cm for men and > 80 cm for women; education level below 15 years of study, no daily intake of vegetables and fruits; previous diagnosis of arterial hypertension; history of high blood glucose and family history of DM.

CONCLUSIONS

This is the largest screening study that evaluated the frequency of high blood glucose and its associated factors in a population without a previous diagnosis ever performed in community pharmacies in Brazil. These results may help to improve public health policies and reinforce the role of pharmacists in screening and education actions aimed at this undiagnosed population in a continent-size country such as Brazil.

Endothelial Dysfunction in Diabetes

Diabetes is a worldwide health issue closely associated with cardiovascular events. Given the pandemic of obesity, the identification of the basic underpinnings of vascular disease is strongly needed. Emerging evidence has suggested that endothelial dysfunction is a critical step in the progression of atherosclerosis. However, how diabetes affects the endothelium is poorly understood. Experimental and clinical studies have illuminated the tight link between insulin resistance and endothelial dysfunction. In addition, macrophage polarization from M2 towards M1 contributes to the process of endothelial damage. The possibility that novel classes of anti-hyperglycemic agents exert beneficial effects on the endothelial function and macrophage polarization has been raised. In this review, we discuss the current status of knowledge regarding the pathological significance of insulin signaling in endothelium. Finally, we summarize recent therapeutic strategies against endothelial dysfunction with an emphasis on macrophage polarity.

Inhibition of perivascular mast cell activation is involved in the atheroprotective effect of rosiglitazone in apolipoprotein E-deficient mice

Activation of perivascular mast cells (MCs) and subsequent release of their abundant inflammatory mediators have been well documented to induce excessive inflammation and subsequent rupture of atherosclerotic plaques. Previous studies have suggested that rosiglitazone affects the stability of plaques, although the precise mechanism of action is not clearly understood. In this study, we evaluated the effects of rosiglitazone on MCs in vivo and in vitro. Apolipoprotein E-deficient (ApoE^-/-) mice were fed a high-fat diet (HFD), with or without rosiglitazone supplemented in the drinking water (1.5 mg/kg/day). Compared with the HFD group, rosiglitazone did not affect blood glucose levels, but it attenuated serum levels of tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6), ameliorated plaque lipid accumulation and the expression of matrix metalloproteinases-2 and -9, increased the collagen content of plaques, and inhibited perivascular MC degranulation and chymase expression. The in vitro experiments showed that rosiglitazone treatment repressed the expression of TNFα and IL-6 induced by antigen-challenged RBL-2H3 cells in a peroxisome proliferator-activated receptor γ (PPARγ)-independent manner, which was related to the repression of protein kinase C (PKC)-β1 activation. Combined, these results suggest that the plaque-stabilizing effect of rosiglitazone is attributable to its ability to inhibit the activation of perivascular MCs.

Nuts and Cardio-Metabolic Disease: A Review of Meta-Analyses

OBJECTIVES

Accumulating epidemiological and intervention evidence suggest that nut consumption is associated with reduced incidence of some cardiometabolic diseases. However, to date no review of meta-analyses of epidemiological and intervention studies has evaluated the effects of nut consumption on cardiometabolic disease. Design/Results: Electronic searches for meta-analyses of epidemiological and intervention studies were undertaken in PubMed®/MEDLINE®. Meta-analyses of prospective studies show that nut consumption appears to be associated with reduced all-cause mortality by 19⁻20% (n = 6), cardiovascular disease (CVD) incidence (19%; n = 3) and mortality (25%; n = 3), coronary heart disease (CHD) incidence (20⁻34%; n = 2) and mortality (27⁻30%; n = 2) and stroke incidence (10⁻11%; n = 7) and mortality (18%; n = 2). No association between nut consumption and the risk of type 2 diabetes mellitus (T2DM) was observed in meta-analyses of prospective studies, whereas a decrease in fasting blood glucose ranging from 0.08 to 0.15 mmol/L was observed in 3 meta-analyses of intervention studies. In the interventions, nut consumption also had favorable effects on total cholesterol (0.021 to 0.28 mmol/L reduction from 8 meta-analyses of interventions) and low-density lipoprotein cholesterol (0.017 to 0.26 mmol/L reduction from 8 meta-analyses of interventions) and endothelial function (0.79 to 1.03% increase in flow-mediated dilation from 4 meta-analyses of interventions). Nut consumption did not significantly affect body weight. Nut consumption had no effect on inflammatory markers in intervention studies. The effect on blood pressure was inconsistent. A higher nut consumption was associated with a lower incidence of hypertension in prospective studies, while nut consumption did not improve blood pressure in intervention studies.

CONCLUSIONS

Nut consumption appeared to be associated with lower all-cause mortality and CVD and CHD mortality. There was no association between nut consumption and the incidence of T2DM although fasting blood glucose is decreased in intervention studies. In intervention studies nuts lower total cholesterol and low-density lipoprotein cholesterol (LDL-C).

An evaluation of the impact of antidiabetic medication on treatment satisfaction and quality of life in patients of diabetes mellitus

Aims:

This study aims to measure the quality of life (QOL), treatment satisfaction, and tolerability of antidiabetic drugs in patients suffering from type 2 diabetes mellitus (DM).

Methods:

The prospective, observational study was conducted in consenting patients of type 2 DM attending the outpatient department of a tertiary care hospital in Western India. The QOL instrument for Indian diabetes (QOLID) patients questionnaire and the Diabetes Treatment Satisfaction Questionnaire were administered to all patients at baseline, 3 months, and 6 months of treatment. Tukey–Kramer comparison test was used to analyze the difference in QOLID scores in various domains at baseline, 3 months, and 6 months. WHO-UMC scale, Naranjo's probability scale, Hartwig and Siegel, and Schumock and Thornton modified criteria were used to analyze the adverse drug reactions.

Results:

A male preponderance was observed in 200 patients enrolled in the study. The mean duration of diabetes was 10.96 ± 5.99 years. The patients received metformin alone (40), metformin and glipizide (47), metformin, glipizide and other oral hypoglycemic agents (OHAs) (78), and OHAs and insulin (35). A significant improvement in fasting and postprandial blood sugar was observed at 6 months as compared to the baseline (P < 0.05). A total of 39 (19.5%) patients suffered from adverse effects to metformin and insulin. Physical health and physical endurance improved in patients receiving metformin alone or in combination with glipizide as compared to patients receiving other OHAs and/or insulin. Treatment satisfaction, highest in patients receiving metformin and least in those receiving insulin, was unaltered during the study period.

Conclusions:

While polypharmacy is evident, using lesser medicines offers better treatment satisfaction and QOL in DM. Periodic assessment of QOL and treatment satisfaction are recommended in DM.

Benefits of Nut Consumption on Insulin Resistance and Cardiovascular Risk Factors: Multiple Potential Mechanisms of Actions

Epidemiological and clinical studies have indicated that nut consumption could be a healthy dietary strategy to prevent and treat type 2 diabetes (T2DM) and related cardiovascular disease (CVD). The objective of this review is to examine the potential mechanisms of action of nuts addressing effects on glycemic control, weight management, energy balance, appetite, gut microbiota modification, lipid metabolism, oxidative stress, inflammation, endothelial function and blood pressure with a focus on data from both animal and human studies. The favourable effects of nuts could be explained by the unique nutrient composition and bioactive compounds in nuts. Unsaturated fatty acids (monounsaturated fatty acids and polyunsaturated fatty acids) present in nuts may play a role in glucose control and appetite suppression. Fiber and polyphenols in nuts may also have an anti-diabetic effect by altering gut microbiota. Nuts lower serum cholesterol by reduced cholesterol absorption, inhibition of HMG-CoA reductase and increased bile acid production by stimulation of 7-α hydroxylase. Arginine and magnesium improve inflammation, oxidative stress, endothelial function and blood pressure. In conclusion, nuts contain compounds that favourably influence glucose homeostasis, weight control and vascular health. Further investigations are required to identify the most important mechanisms by which nuts decrease the risk of T2DM and CVD.

Characteristics of children and adolescents at onset of type 2 diabetes in a Tertiary Hospital in Bangladesh

INTRODUCTION

Recent data show that the prevalence of diabetes among children and adolescents is increasing in some ethnic groups. The worldwide epidemic of childhood obesity has been accompanied by an increase in the incidence of type 2 diabetes (T2D) in youth.

METHODS

The aim of this study was to describe the baseline characteristics of children and adolescents diagnosed ≤18 years who had features of T2D and presented at Changing Diabetes in Children, Paediatric Diabetes Clinic at Bangladesh Institute of Research and Rehabilitation of Diabetes, Endocrine, and Metabolic Disorders. All patients who were newly diagnosed and came to the clinic from March 2011 to March 2015 were included.

RESULTS

Among 939 newly registered patients, 77 (8%) had a diagnosis of T2D. The age at diagnosis was 9-10 years in 11 patients (14%), 11-14 years in 46 (60%) and 15-17 years in other 20 patients (26%). Majority of the children had a positive family history of T2D (94%) and 58% were obese. Median fasting insulin (27.9 [17.3-99.3]) was high in 76% patients. Insulin was started initially along with metformin in 40 patients and could be stopped in six patients in 3 months.

CONCLUSION

Our study reflects that T2D is emerging as a problem in children and adolescents in Bangladesh.

(-)-Epicatechin-induced recovery of mitochondria from simulated diabetes: Potential role of endothelial nitric oxide synthase

(-)-Epicatechin increases indicators associated with mitochondrial biogenesis in endothelial cells and myocardium. We investigated endothelial nitric oxide synthase involvement on (-)-epicatechin-induced increases in indicators associated with mitochondrial biogenesis in human coronary artery endothelial cells cultured in normal-glucose and high-glucose media, as well as to restore indicators of cardiac mitochondria from the effects of simulated diabetes. Here, we demonstrate the role of endothelial nitric oxide synthase on (-)-epicatechin-induced increases in mitochondrial proteins, transcription factors and sirtuin 1 under normal-glucose conditions. In simulated diabetes endothelial nitric oxide synthase function, mitochondrial function-associated and biogenesis-associated indicators were adversely impacted by high glucose, effects that were reverted by (-)-epicatechin. As an animal model of type 2 diabetes, 2-month old C57BL/6 mice were fed a high-fat diet for 16 weeks. Fasting and fed blood glucose levels were increased and NO plasma levels decreased. High-fat-diet-fed mice myocardium revealed endothelial nitric oxide synthase dysfunction, reduced mitochondrial activity and markers of mitochondrial biogenesis. The administration of 1 mg/kg (-)-epicatechin for 15 days by oral gavage shifted these endpoints towards control mice values. Results suggest that endothelial nitric oxide synthase mediates (-)-epicatechin-induced increases of indicators associated with mitochondrial biogenesis in endothelial cells. (-)-Epicatechin also counteracts the negative effects that high glucose or simulated type 2 diabetes has on endothelial nitric oxide synthase function.

Indian diabetes risk score and clustering of metabolic syndrome phenotype in a rural community of Asian Indian origin

AIMS

This study was aimed at finding out the efficacy of Indian Diabetes Risk Score (IDRS) in identifying the individuals with increased risk of developing metabolic syndrome (MS) phenotype.

METHODS

A total of 1007 (645 males and 362 females) rural participants aged ≥ 20 years took part in the study. Anthropometric measures and blood pressure were collected using standard techniques. Metabolic profiles and insulin were also estimated and HOMA-IR was calculated accordingly.

RESULTS

There existed significant differences by IDRS categories for waist circumference, waist-hip ratio, waist-height ratio, body mass index, percentage body fat, sum of four skinfolds, total cholesterol, triglycerides, high, low and very low density lipoprotein cholesterol, fasting blood glucose, insulin, insulin resistance, systolic and diastolic blood pressure and mean arterial pressure. Significant (p<0.001) age group differences were also evident for IDRS categories. Remarkably higher prevalence of MS was observed with increasing IDRS.

CONCLUSION

IDRS could be used to identify the individuals with increased risk of developing MS phenotype in this population.

Symptom profiles of subsyndromal depression in disease clusters of diabetes, excess weight, and progressive cerebrovascular conditions: a promising new type of finding from a reliable innovation to estimate exhaustively specified multiple indicators-multiple causes (MIMIC) models

Addressing subsyndromal depression in cerebrovascular conditions, diabetes, and obesity reduces morbidity and risk of major depression. However, depression may be masked because self-reported symptoms may not reveal dysphoric (sad) mood. In this study, the first wave (2,812 elders) from the New Haven Epidemiological Study of the Elderly (EPESE) was used. These population-weighted data combined a stratified, systematic, clustered random sample from independent residences and a census of senior housing. Physical conditions included progressive cerebrovascular disease (CVD; hypertension, silent CVD, stroke, and vascular cognitive impairment [VCI]) and co-occurring excess weight and/or diabetes. These conditions and interactions (clusters) simultaneously predicted 20 depression items and a latent trait of depression in participants with subsyndromal (including subthreshold) depression (11≤ Center for Epidemiologic Studies Depression Scale [CES-D] score ≤27). The option for maximum likelihood estimation with standard errors that are robust to non-normality and non-independence in complex random samples (MLR) in Mplus and an innovation created by the author were used for estimating unbiased effects from latent trait models with exhaustive specification. Symptom profiles reveal masked depression in 1) older males, related to the metabolic syndrome (hypertension-overweight-diabetes; silent CVD-overweight; and silent CVD-diabetes) and 2) older females or the full sample, related to several diabetes and/or overweight clusters that involve stroke or VCI. Several other disease clusters are equivocal regarding masked depression; a couple do emphasize dysphoric mood. Replicating findings could identify subgroups for cost-effective screening of subsyndromal depression.

Impact of protein energy wasting status on survival among Afro-Caribbean hemodialysis patients: a 3-year prospective study

Background

We assessed the prognostic value of protein-energy wasting (PEW) on mortality in Afro-Caribbean MHD patients and analysed how diabetes, cardiovascular disease (CVD) and inflammation modified the predictive power of a severe wasting state.

Method

A 3-year prospective study was conducted in 216 patients from December 2011. We used four criteria from the nomenclature for PEW proposed by the International Society of Renal Nutrition and Metabolism in 2008: serum albumin 38 g/L, body mass index (BMI) ≤23 kg/m², serum creatinine ≤818 µmol/L and protein intake assessed by nPCR ≤0.8 g/kg/day. PEW status was categorized according the number of criteria. Cox regression analyses were used.

Results

Forty deaths (18.5 %) occurred, 97.5 % with a CV cause. Deaths were distributed as follows: 7.4 % in normal nutritional status, 13.2 % in slight wasting (1 PEW criterion), 28 % in moderate wasting (2 criteria) and 50 % in severe wasting (3–4 criteria). Among the PEW markers, low serum albumin (HR 3.18; P = 0.001) and low BMI (HR 1.97; P = 0.034) were the most significant predictors of death. Among the PEW status categories, moderate wasting (HR 3.43; P = 0.021) and severe wasting (HR 6.59; P = 0.001) were significant predictors of death. Diabetes, CVD, and inflammation were all additives in predicting death in association with severe wasting with a strongest HR (7.76; P < 0.001) for diabetic patients.

Conclusions

The nomenclature for PEW predicts mortality in our Afro-Caribbean MHD patients and help to identify patients at risk of severe wasting to provide adequate nutritional support.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-015-1257-3) contains supplementary material, which is available to authorized users.

Chronic Inhibition of PDE5 Limits Pro-Inflammatory Monocyte-Macrophage Polarization in Streptozotocin-Induced Diabetic Mice

Diabetes mellitus is characterized by changes in endothelial cells that alter monocyte recruitment, increase classic (M1-type) tissue macrophage infiltration and lead to self-sustained inflammation. Our and other groups recently showed that chronic inhibition of phosphodiesterase-5 (PDE5i) affects circulating cytokine levels in patients with diabetes; whether PDE5i also affects circulating monocytes and tissue inflammatory cell infiltration remains to be established. Using murine streptozotocin (STZ)-induced diabetes and in human vitro cell-cell adhesion models we show that chronic hyperglycemia induces changes in myeloid and endothelial cells that alter monocyte recruitment and lead to self-sustained inflammation. Continuous PDE5i with sildenafil (SILD) expanded tissue anti-inflammatory TIE2-expressing monocytes (TEMs), which are known to limit inflammation and promote tissue repair. Specifically, SILD: 1) normalizes the frequency of circulating pro-inflammatory monocytes triggered by hyperglycemia (53.7 ± 7.9% of CD11b⁺Gr-1⁺ cells in STZ vs. 30.4 ± 8.3% in STZ+SILD and 27.1 ± 1.6% in CTRL, P<0.01); 2) prevents STZ-induced tissue inflammatory infiltration (4-fold increase in F4/80+ macrophages in diabetic vs. control mice) by increasing renal and heart anti-inflammatory TEMs (30.9 ± 3.6% in STZ+SILD vs. 6.9 ± 2.7% in STZ, P <0.01, and 11.6 ± 2.9% in CTRL mice); 3) reduces vascular inflammatory proteins (iNOS, COX2, VCAM-1) promoting tissue protection; 4) lowers monocyte adhesion to human endothelial cells in vitro through the TIE2 receptor. All these changes occurred independently from changes of glycemic status. In summary, we demonstrate that circulating renal and cardiac TEMs are defective in chronic hyperglycemia and that SILD normalizes their levels by facilitating the shift from classic (M1-like) to alternative (M2-like)/TEM macrophage polarization. Restoration of tissue TEMs with PDE5i could represent an additional pharmacological tool to prevent end-organ diabetic complications.

Diabetes to cardiovascular disease: is depression the potential missing link?

The etiopathological consequences of diabetes and its imperative sequels have been explored extensively in the scientific arena of cardiovascular diabetology. Innumerable risk covariates and confounders have been delineated for the primary and secondary prevention of diabetes and cardiovascular diseases (CVD). However, an intricate interaction of depression on them has been largely overlooked. Depression influences and participates in each and every step that worsens the diabetic state for developing cardiovascular complications. The dilemma is that it coexists, remains silent and generally not considered as relevant clinical parameter amenable to intervention. In this review, it is highlighted that depression has strong association and linkages with both diabetes and CVD and it should be considered and diagnosed at every stage of the diabetes to CVD continuum. Careful attention to the diagnosis and management of these disease states would contribute in lessening the CVD burden of the society.

Structural changes in the myocardium during diabetes-induced cardiomyopathy

Diabetes mellitus (DM) is a major metabolic disorder currently affecting over 250 million people globally. It costs the worldwide health services almost £800 billion annually to diagnose, treat and care for patients with diabetes. DM is predicted to rise to 350 million by 2030. If left unmanaged, DM can lead to numerous long-term complications including micro- and macro-angiopathy and heart failure (HF). Most diabetics usually die as a result of HF resulting from diabetes-induced coronary artery disease and cardiomyopathy. Coronary artery disease and cardiomyopathy are normally preceded by hyperglycaemia (HG). This review examines the structural changes, which occur within the myocardium and cardiomyocytes during exposure of the heart to diabetes-induced HG and HG-induced oxidative stress. HG and the resulting oxidative stress are associated with marked myocardial hypertrophy and fibrosis compared to control heart. At the ultrastructural level, cardiomyocytes subjected to chronic HG and subsequent oxidative stress display swollen mitochondria, reduced mitochondrial number and defective myofibrils and intercalated discs. Evidence from many studies shows that both type 1 and type 2 diabetes-induced HG can cause myocardial fibrosis, mitochondriopathy, myocyte hypertrophy and deranged myofibrils. All of these structural changes may eventually result in HF if left untreated.

Relevance of plasma obestatin and early arteriosclerosis in patients with type 2 diabetes mellitus

We investigated the correlation between obestatin and metabolic parameters and carotid intima-media thickness (IMT) in plasma of patients with type 2 diabetes mellitus (T2DM). We collected 103 patients aged from 60 to 83 years (69.26 ± 5.83 years) form January, 2007 to May, 2009. All patients were divided into normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and T2DM according to the oral glucose tolerance test (OGTT). We found that higher levels of fasting insulin (Fins), fasting blood glucose, 2 h OGTT glucose, homeostasis model assessment of insulin resistance (HOMA-IR), low density lipoprotein cholesterol, glycated haemoglobin, and C-reactive protein (CRP), as well as lower obestatin level and higher intima-media thickness level (IMT), existed in T2DM group compared with NGT group and IGT group (P < 0.01). Also, obestatin level was independently associated with HOMA-IR and CRP, while IMT level was independently associated with HOMA-IR, triglyceride, Fins, and obestatin (P < 0.01), based on stepwise multiple regression analysis. Therefore, we deduced that the low level of plasma obestatin might be related to early arteriosclerosis in patients with T2DM via increasing IMT level, and elevated plasma obestatin levels might protect T2DM patients against carotid atherosclerosis to some extent.

Type 1 diabetes mellitus and celiac disease: endothelial dysfunction

Many reports indicate a hypercoagulative state in diabetes mellitus as result of endothelial damage. Experimental evidence suggests that a metabolic derangement triggers a cascade of biochemical events that lead to vascular dysfunction. The net effect is to convert the endothelium from thromboresistant to thrombogenic surface. In literature, a strong association between type 1 diabetes mellitus (DM1) and celiac disease (CD) has been reported. We do not have information about the hemostatic system in these associated conditions. Our study aims at evaluating whether the presence of CD in a group of DM1 patients is associated with a different expression of some hemostatic factors and with a different manifestation and/or progression of microvascular complications of DM1 in comparison with patients with only diabetes. Ninety-four adult DM1 patients were enrolled in the study and subsequently screened for CD. Anti-endomysial antibodies (EMA) were positive in 13 of 94 DM1 patients (13.8%). CD diagnosis was confirmed by histology and organ culture. The mean age and duration of DM1 of patients also affected by CD were similar to those of only diabetic patients, but the metabolic control and the hemocoagulative parameters were significantly different between the two groups: DM1 patients also affected by CD presented significantly lower concentrations of glycosylated hemoglobin (HbA1c) (P < 0.05), cholesterol (P < 0.001), triglycerides (P < 0.001), factor VII antigen (FVII:ag) (P < 0.005), factor VII coagulant activity (FVII:c) (P < 0.05), and prothrombin degradation fragments (F1+2) (P < 0.001), as well as higher values of activated C protein (APC) (<0.001). No retinal abnormalities and no signs of renal damage were observed in DM1 patients also affected by CD. Our results suggest a potential protective role of CD in the prothrombotic state of DM1.

Rosiglitazone enhances neovascularization in diabetic rat ischemic hindlimb model

BACKGROUND

There is increasing evidence that peroxisome proliferator-activated receptors (PPARs) may be involved in the regulation of angiogenesis. In this study, we examined whether rosiglitazone, a PPARγ agonist, can restore angiogenesis in a rat hindlimb ischemia model of diabetes.

METHODS

Male wistar rats were divided into four groups (n=6 each): control, diabetic and control and diabetic rats who received rosiglitazone (8 mg/kg/day). Diabetes was induced by streptozotocin (55 mg/kg; ip). After 21 days, serum concentrations of nitric oxide (NO), vascular endothelial growth factor (VEGF) and soluble VEGF receptor-2 (VEGFR-2) were measured and neovascularization in ischemic legs was evaluated by immunohistochemistry.

RESULTS

Capillary density and capillary/fiber ratio in hindlimb ischemia of diabetic animals were significantly lower than the control group (P<0.05). Rosiglitazone significantly restored neovascularization in diabetic animals (P<0.05).

CONCLUSIONS

rosiglitazone enhances neovascularization in diabetic ischemic skeletal muscle and could be considered for treatment of peripheral artery disease in diabetic subjects.

Use of Metformin in Patients with Kidney and Cardiovascular Diseases

Metformin is an insulin-sensitizing agent with anti-hyperglycemic properties that is widely used for the treatment of type-2 diabetes. The efficacy of metformin in reducing hyperglycemia is well established, and there is emerging evidence that its chronic use is associated with cancer and cardiovascular disease (CVD) risk reduction. While the hypoglycemic properties of metformin are largely attributed to suppression of hepatic glucose production and increases in peripheral tissue insulin sensitivity, the precise mechanism of the hypoglycemic action of metformin remains unclear. There is evidence that metformin use interrupts mitochondrial oxidative stress in the liver and corrects abnormalities of intracellular calcium metabolism in insulin-sensitive tissues (liver, skeletal muscle, and adipocytes) and cardiovascular tissue. However, the use of metformin in patients with kidney disease, a high-risk CVD state, is confounded by confusion regarding appropriate concerns about the development of lactic acidosis in this population. Thus, we will review current evidence on metformin use for improving CVD outcomes and its therapeutic use in kidney disease.

Inflammation determines the pro-adhesive properties of high extracellular d-glucose in human endothelial cells in vitro and rat microvessels in vivo

Background

Hyperglycemia is acknowledged as an independent risk factor for developing diabetes-associated atherosclerosis. At present, most therapeutic approaches are targeted at a tight glycemic control in diabetic patients, although this fails to prevent macrovascular complications of the disease. Indeed, it remains highly controversial whether or not the mere elevation of extracellular D-glucose can directly promote vascular inflammation, which favors early pro-atherosclerotic events.

Methods and Findings

In the present work, increasing extracellular D-glucose from 5.5 to 22 mmol/L was neither sufficient to induce intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression, analyzed by flow cytometry, nor to promote leukocyte adhesion to human umbilical vein endothelial cells (HUVEC) in vitro, measured by flow chamber assays. Interestingly, the elevation of D-glucose levels potentiated ICAM-1 and VCAM-1 expression and leukocyte adhesion induced by a pro-inflammatory stimulus, such as interleukin (IL)-1β (5 ng/mL). In HUVEC, high D-glucose augmented the activation of extracellular signal-regulated kinase 1/2 (ERK 1/2) and nuclear transcription factor-κB (NF-κB) elicited by IL-1β, measured by Western blot and electromobility shift assay (EMSA), respectively, but had no effect by itself. Both ERK 1/2 and NF-κB were necessary for VCAM-1 expression, but not for ICAM-1 expression. In vivo, leukocyte trafficking was evaluated in the rat mesenteric microcirculation by intravital microscopy. In accordance with the in vitro data, the acute intraperitoneal injection of D-glucose increased leukocyte rolling flux, adhesion and migration, but only when IL-1β was co-administered.

Conclusions

These results indicate that the elevation of extracellular D-glucose levels is not sufficient to promote vascular inflammation, and they highlight the pivotal role of a pro-inflammatory environment in diabetes, as a critical factor conditioning the early pro-atherosclerotic actions of hyperglycemia.

Prehypertension is associated with atherosclerosis in Type 2 diabetes

BACKGROUND

Prehypertension is a risk factor for hypertension, diabetes, and cardiovascular diseases. However, the association between prehypertension and atherosclerosis in Type 2 diabetes mellitus (T2DM) has not been evaluated. In the present study, we investigated the impact of prehypertension on atherosclerosis in T2DM.

METHODS

Patients (n=930) with T2DM were recruited for the present study from the outpatient clinic of Shanghai Ruijin Hospital. The intima-media thickness (IMT) of the common carotid artery (CCA) was determined using ultrasound and brachial-ankle pulse wave velocity (baPWV) was determined by volume plethysmography to assess atherosclerosis.

RESULTS

Of the 930 patients with T2DM (mean age of 59 years), 167 were categorized as normotensive, 213 were prehypertensive, and 550 were hypertensive. Diabetic subjects with prehypertension had significantly higher CCA-IMT and baPWV than those with normal blood pressure after adjustment for age and gender. Multiple logistic regression analysis revealed that, compared with normotension, prehypertension was a significant independent determinant of atherosclerosis (for maximum IMT ≥1.1 mm, odds ratio (OR) 2.10 and 95% confidence interval (CI) 1.28-3.44; for baPWV ≥1400 cm/s, OR 3.09 and 95% CI 1.78-5.36).

CONCLUSION

Prehypertension is associated with atherosclerosis independent of conventional cardiovascular risk factors in T2DM patients. We speculate that maintenance of systolic blood pressure <120 mmHg and diastolic blood pressure <80 mmHg may reduce the risk of atherosclerosis in T2DM.

Effect of rosiglitazone on progression of atherosclerosis: insights using 3D carotid cardiovascular magnetic resonance

BACKGROUND

There is recent evidence suggesting that rosiglitazone increases death from cardiovascular causes. We investigated the direct effect of this drug on atheroma using 3D carotid cardiovascular magnetic resonance.

RESULTS

A randomized, placebo-controlled, double-blind study was performed to evaluate the effect of rosiglitazone treatment on carotid atherosclerosis in subjects with type 2 diabetes and coexisting vascular disease or hypertension. The primary endpoint of the study was the change from baseline to 52 weeks of carotid arterial wall volume, reflecting plaque burden, as measured by carotid cardiovascular magnetic resonance. Rosiglitazone or placebo was allocated to 28 and 29 patients respectively. Patients were managed to have equivalent glycemic control over the study period, but in fact the rosiglitazone group lowered their HbA1c by 0.88% relative to placebo (P < 0.001). Most patients received a statin or fibrate as lipid control medication (rosiglitazone 78%, controls 83%). Data are presented as mean +/- SD. At baseline, the carotid arterial wall volume in the placebo group was 1146 +/- 550 mm3 and in the rosiglitazone group was 1354 +/- 532 mm3. After 52 weeks, the respective volumes were 1134 +/- 523 mm3 and 1348 +/- 531 mm3. These changes (-12.1 mm3 and -5.7 mm3 in the placebo and rosiglitazone groups, respectively) were not statistically significant between groups (P = 0.57).

CONCLUSION

Treatment with rosiglitazone over 1 year had no effect on progression of carotid atheroma in patients with type 2 diabetes mellitus compared to placebo.

Activation of prostaglandin E2 EP1 receptor increases arteriolar tone and blood pressure in mice with type 2 diabetes

AIMS

Type 2 diabetes mellitus is frequently associated with hypertension, but the underlying mechanisms are not completely understood. We tested the hypothesis that activation of type 1 prostaglandin E(2) (PGE(2)) receptor (EP1) increases skeletal muscle arteriolar tone and blood pressure in mice with type 2 diabetes.

METHODS AND RESULTS

In 12-week-old, male db/db mice (with homozygote mutation in leptin receptor), systolic blood pressure was significantly elevated, compared with control heterozygotes. Isolated, pressurized gracilis muscle arterioles ( approximately 90 microm) of db/db mice exhibited an enhanced pressure- and angiotensin II (0.1-10 nM)-induced tone, which was reduced by the selective EP1 receptor antagonist, AH6809 (10 microM), to the level observed in arterioles of control mice. Exogenous application of PGE(2) (10 pM-100 nM) or the selective agonist of the EP1 receptor, 17-phenyl-trinor-PGE(2) (10 pM-100 nM), elicited arteriolar constrictions that were significantly enhanced in db/db mice (max: 31 +/- 4 and 29 +/- 5%), compared with controls (max: 20 +/- 2 and 14 +/- 3%, respectively). In the aorta of db/db mice, an increased protein expression of EP1, but not EP4, receptor was also detected by western immunoblotting. Moreover, we found that oral administration of the EP1 receptor antagonist, AH6809 (10 mg/kg/day, for 4 days), significantly reduced the systolic blood pressure in db/db, but not in control mice.

CONCLUSION

Activation of EP1 receptors increases arteriolar tone, which could contribute to the development of hypertension in the db/db mice.

Glucose-induced de novo synthesis of fatty acyls causes proportional increases in INS-1E cellular lipids

Raised concentrations of glucose for extended periods of time have detrimental effects on the insulin-producing beta-cell. As de novo synthesis of lipids has been observed under such conditions, it was hypothesized that newly formed lipids may preferentially contain saturated fatty acids, which in particular have been associated with impaired beta-cell function. Glucose-induced de novo synthesis of fatty acids in INS-1E cells cultured in 5.5, 11, 20 or 27 mM glucose for 5 days was assessed by high-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy and gas chromatography-mass spectrometry (GC-MS). The glucose origin of the increase in fatty acyls was verified by replacing glucose with [1-13C]glucose during culture followed by analysis with two-dimensional 1H-13C NMR spectroscopy. The composition of the fatty acyls was determined by GC-MS. Fatty acyls determined by HR-MAS (1)H NMR spectroscopy were increased fivefold in INS-1E cells cultured in 20 or 27 mM glucose compared with cells cultured in 5.5 mM glucose. The five most abundant fatty acids with their relative percentages in INS-1E cells cultured in 5.5 mM glucose were oleate (33%), palmitate (25%), stearate (19%), octadecenoate (13%) and palmitoleate (4.4%). These proportions were not affected by glucose- induced de novo synthesis in INS-1E cells cultured in 11, 20 or 27 mM glucose. It is concluded that glucose-induced de novo lipid synthesis results in accumulation of both saturated and unsaturated fatty acids in specific proportions that are identical with those present under control conditions.

Evaluation of antidiabetic, antioxidant and vasoprotective effects of Posidonia oceanica extract

The aim of this study is to evaluate antidiabetic, antioxidant and vasoprotective effects of Posidonia oceanica extract (POE) in alloxan diabetic rats. Posidonia oceanica (L) Delile (Posidoniaceae), is a widely allocated phanerogam in Mediterranean and Aegean Sea. Up to date, no published data relevant to use of the plant in traditional medicine are available. However, decoction of the leaves has been quoted to be used as a remedy for diabetes mellitus and hypertension by villagers living by the sea coast of Western Anatolia. Oral administration of extract for 15 days (50, 150, and 250 mg/kg b.wt.) resulted in a dose-dependent decrease in blood glucose. Relaxant responses to acetylcholine (ACh) in diabetic thoracic aorta were restored by POE treatment (50, 150, and 250 mg/kg b.wt.). POE also attenuated the augmented phenylephrine (PE) and serotonin (5-HT) contractions. At concentration levels of 150 and 250 mg/kg b.wt., POE exerted a protective effect on the significantly decreased levels of antioxidants namely, glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase and nitric oxide (NO). POE (50mg/kg b.wt.) produced no effect on alloxan-induced alterations in the antioxidant status while possessing glucose lowering and vasoprotective activities. Furthermore, liver and kidney function markers, leucocyte counts, body weight and liver glycogen content remained unchanged at dose level of 50mg/kg b.wt., when compared with diabetic control group. These results suggest that antidiabetic and vasoprotective effects of POE may be unrelated to its antioxidant properties.

Epidemiologic perspectives of risk for developing diabetes and diabetes complications

The incidence and prevalence of diabetes is increasing worldwide. National recommendations for screening and diagnosis of diabetes, hypertension, and dyslipidemia provide a basis for early detection, treatment, and intervention that may potentially decrease related complications, and personal and economic costs of the disease. Most important is that knowledge exists about who is at risk for diabetes by weight, family history of diabetes, ethnicity, and history of gestational diabetes that allows for the development and implementation of diabetes primary prevention programs. Multiple national health care providers, systems of care, and communities that can be used to guide such prevention, early screening, and disease detection and intervention programs aimed at decreasing the burden of diabetes.

Vascular effects of TZDs: New implications

The incidence of diabetes, now affecting more than 170 million individuals is growing rapidly. Type 2 diabetes, which accounts for 90% of all diabetes cases, is associated with increased cardiovascular morbidity and mortality. Thiazolidinediones (TZDs), used for the treatment of patients with type 2 diabetes improve insulin sensitivity and endothelial dysfunction and exert beneficial effects on the lipid profile by activating the peroxisome proliferator-activated receptor gamma (PPAR-gamma). Moreover, a large body of evidence indicates that TZDs exhibit antiatherogenic effects independent of their antidiabetic and lipid-lowering properties by modulating inflammatory processes. This review will focus on the role of PPAR-gamma agonists in the vessel wall and summarize their effects on C-reactive protein (CRP), plasminogen activator inhibitor type-1 (PAI-1), matrix metalloproteinase-9 (MMP-9), adiponectin and ATP-binding cassette transporter A1 (ABCA1) and their implications for treatment of advanced stages of atherosclerosis, particularly in a setting of type 2 diabetes.

Enhanced sympathetic reactivity associates with insulin resistance in the young Zucker rat

Somatosympathetic reflexes were studied in young hyperinsulinemic, insulin-resistant (Zucker fatty) rats (ZFR) and a related control (Zucker lean) strain (ZLR). Glucose metabolism was characterized by minimal model analysis of intravenous glucose tolerance test data. Seven-week-old ZFR (n=18) and ZLR (n=17) were studied under pentobarbital anesthesia. Mean body weight and plasma glucose and insulin concentration were significantly greater (P<0.05) in ZFR than in ZLR, whereas basal values of mean arterial pressure (MAP) and heart rate (HR) were not significantly different. Increments of MAP (DeltaMAP) and HR (DeltaHR) elicited by electrical stimulation of the sciatic nerve (5-s trains of 100 pulses, 0.5-ms pulse duration, 100- to 400-microA pulse intensity) were significantly higher (ANOVA, P<0.05) in ZFR at each level of stimulus intensity. Regression analysis showed a linear increase in DeltaMAP and DeltaHR with increasing sciatic nerve stimulus intensity. Pressor responses to phenylephrine after ganglionic blockade demonstrated that vascular reactivity to adrenergic stimulation is not increased in ZFR compared with ZLR. Thus this factor does not contribute to enhancement of somatosympathetic reflexes observed in this strain. Insulin sensitivity in ZFR was one-fourth (P<0.05) that in ZLR. These results suggest that stronger sympathetic nervous reactivity in ZFR is associated with a severe insulin-resistant state before the onset of hypertension and support the hypothesis that insulin-mediated stimulation of the sympathetic nervous system is involved in the development of cardiovascular diseases related to alterations of glucose metabolism.

Management of type 2 diabetes in youth (part 2)

Type 2 diabetes is increasing at an alarming rate in minority youth in the United States. Early diagnosis is important so that a treatment plan including diabetes self-management education, medical nutrition therapy, exercise, and behavioral modification can be developed to optimize blood glucose level. Prevention and treatment of hypertension and dyslipidemia may decrease cardiovascular disease later in life. Management of type 2 diabetes requires a team approach that is patient and family centered with the health care provider, a registered dietitian, an exercise physiologist, a social worker, and a psychologist available.

Treating insulin resistance in type 2 diabetes with metformin and thiazolidinediones

Insulin resistance underlies the pathogenesis of hyperglycaemia and cardiovascular disease in most people with type 2 diabetes. Metformin and thiazolidinediones (pioglitazone and rosiglitazone) counter insulin resistance by different cellular mechanisms and with complementary effects, making them suited for use in combination. Metformin exerts a stronger suppression of hepatic glucose output, while thiazolidinediones produce a greater increase in peripheral glucose uptake, enabling metformin-thiazolidinedione combinations to improve glycaemic control in type 2 diabetes with additive efficacy. Basal insulin concentrations are not raised by metformin or thiazolidinediones, so there is minimal risk of hypoglycaemia, and metformin can reduce the weight gain associated with thiazolidinediones. There are overlapping effects of metformin and thiazolidinediones against a range of athero-thrombotic factors and markers. These include decreased plasminogen activator inhibitor-1, reduced platelet aggregation, reductions of several vascular adhesion molecules, and reduced markers of low-grade inflammation such as C-reactive protein. Additionally, thiazolidinediones increase adiponectin and slightly reduce blood pressure. Both metformin and thiazolidinediones can improve components of the lipid profile: thiazolidinediones consistently reduce free fatty acid concentrations and decrease the proportion of small dense low-density-lipoprotein, and pioglitazone also decreases triglycerides. During co-administration, metformin and thiazolidinediones do not interfere with each other's pharmacokinetics, and lower doses of the two agents together can achieve efficacy with fewer side effects. Metformin-thiazolidinedione combinations require attention to the precautions for both agents, especially renal, cardiac and hepatic status. Thus, metformin and thiazolidinediones can be used in combination to address the hyperglycaemia and vascular risk in type 2 diabetes.