Cardiovascular disease and arterial calcification in insulin-dependent diabetes mellitus: interrelations and risk factor profiles. Pittsburgh Epidemiology of Diabetes Complications Study-V

Synergistic Effect of Naringin and Glimepiride in Streptozotocin-induced Diabetic Rats

OBJECTIVE

Evaluation of the synergistic effect of Naringin and Glimepiride in streptozotocin (STZ)-induced diabetic rats.

METHODS

Wistar rats were chosen and divided into five groups (n=6). STZ was used for the induction of diabetes. The combination of naringin and glimepiride was administered to diabetic rats. The changes in fasting blood sugar, body weight, Hb, HbA1c, and creatinine were evaluated, and urine was collected and the volume was observed. The lipid profiles like TC, HDL, LDL, and TG were measured. The biochemical parameters SGOT, SGPT, and ALP were analysed. Besides, endogenous antioxidant parameters like SOD, GSH, and catalase were also assessed. Lastly, the histopathological study of the beta cells in islets of the pancreas, glomerulus, and tubules of kidney and liver cells was conducted in all groups.

RESULTS

The result shows significant reduction (p<0.001) of blood sugar in the naringin and glimepiride-treated group when compared with the control group (diabetes). Additionally, the combination of Naringin (100 mg/kg) and Glimepiride (0.1 mg/kg) significantly restores the creatinine levels and urine volumes, SGOT, SGPT, and ALP when compared to a single dose of administration. Further, the abnormal lipid profile levels (TC, LDL, TG, and HDL), and endogenous antioxidant enzymes (SOD, GSH, catalase) in diabetic control rats were restored to normal levels in a significant manner. The histopathological result reveals significant alterations, including hypertrophy of islets and mild degeneration, renal necrosis, and inflammation of hepatocytes.

CONCLUSION

A synergistic effect of Naringin and glimepiride was observed during the estimation of various biochemical parameters like body weight, fasting blood sugar, creatinine, urine level, TG, total cholesterol, SGOT, SGPT, ALP, Insulin, HbA1c, antioxidant parameters like SOD, GSH, and catalase in STZ-induced diabetic rats. Further, the combination of therapy improves the protective effect of the pancreas, kidney, and liver, suggesting a potential antidiabetic effect.

Mönckeberg's medial calcific sclerosis in diabetic and non-diabetic foot infections

The aim of this study was to evaluate the prevalence and extent of lower extremity Mönckeberg's Medial Calcific Sclerosis (MMCS) in patients with and without diabetes in patients admitted to the hospital for foot infections. This study retrospectively reviewed 446 patients admitted to the hospital with a moderate or severe foot infection. We defined diabetes based on ADA criteria and reviewed electronic medical records for demographics, medical history and physical examination data. Anterior-posterior and lateral foot radiographs were examined to identify the presence and extent of vascular calcification. We categorised MMCS based on anatomical location: ankle joint to the navicular-cuneiform joint, Lis Franc joint to metatarsophalangeal joints and distal to the metatarsophalangeal joints. The prevalence of MMCS was 40.6%. The anatomic extent of MMCS was 19.3% in the toes, 34.3% in the metatarsals and 40.6% in the hindfoot/ankle. Calcification was not common solely in the dorsalis pedis artery (DP) (3.8%) or solely in the posterior tibial artery (PT) (7.0%). Usually, both DP and PT arteries were affected by MMCS (29.8%). The prevalence of MMCS was higher in people with diabetes (in hindfoot and ankle [50.1% vs. 9.9%, p ≤ 0.01]; metatarsals [42.6% vs. 5.9%, p ≤ 0.01]; and toes [23.8% vs. 4.0%, p ≤ 0.01]). People with diabetes were 8.9 (CI: 4.5-17.8) times more likely to have MMCS than those without diabetes. This is a group that often has poor perfusion and needs vascular assessment. The high prevalence of MMCS raises questions about the reliability of the conventional segmental arterial Doppler studies to diagnose PAD.

Better TIR, HbA1c, and less hypoglycemia in closed-loop insulin system in patients with type 1 diabetes: a meta-analysis

The study aimed to evaluate the effectiveness and safety of long-term use of closed-loop insulin system (CLS) in non-pregnant patients with type 1 diabetes mellitus (T1DM) using systematic review and meta-analysis. A literature search was performed using MEDLINE, EMBASE, and the Cochrane Library. Randomized controlled trials (RCTs) on long-term use (not less than 8 weeks) of CLS in patients with T1DM were selected. Meta-analysis was performed with RevMan V.5.3.5 to compare CLS with controls (continuous subcutaneous insulin infusion with blinded continuous glucose monitoring or unblinded sensor-augmented pump therapy or multiple daily injections or predictive low-glucose suspend system) in adults and children with type 1 diabetes. Research quality evaluation was conducted using the Cochrane risk of bias tool. Eleven RCTs (817 patients) that satisfied the eligibility criteria were included in the meta-analysis. Compared with controls, the CLS group had a favorable effect on the proportion of time with sensor glucose level in 3.9-10 mmol/L (10.32%, 8.70% to 11.95%), above 10 mmol/L (-8.89%, -10.57% to -7.22%), or below 3.9 mmol/L (-1.09%, -1.54% to -0.64%) over 24 hours. The CLS group also had lower glycated hemoglobin levels (-0.30%, -0.41% to -0.19%), and glucose variability, coefficient of variation of glucose, and SD were lower by 1.41 (-2.38 to -0.44, p=0.004) and 6.37 mg/dL (-9.19 mg/dL to -3.55 mg/dL, p<0.00001). There were no significant differences between the CLS and the control group in terms of daily insulin dose, quality of life assessment, and satisfaction with diabetes treatment. CLS is a better solution than control treatment in optimizing blood glucose management in patients with T1DM. CLS could become a common means of treating T1DM in clinical practice.

Pulmonary surfactant protein B carried by HDL predicts incident CVD in patients with type 1 diabetes

Atherosclerotic CVD is the major cause of death in patients with type 1 diabetes mellitus (T1DM). Alterations in the HDL proteome have been shown to associate with prevalent CVD in T1DM. We therefore sought to determine which proteins carried by HDL might predict incident CVD in patients with T1DM. Using targeted MS/MS, we quantified 50 proteins in HDL from 181 T1DM subjects enrolled in the prospective Coronary Artery Calcification in Type 1 Diabetes study. We used Cox proportional regression analysis and a case-cohort design to test associations of HDL proteins with incident CVD (myocardial infarction, coronary artery bypass grafting, angioplasty, or death from coronary heart disease). We found that only one HDL protein-SFTPB (pulmonary surfactant protein B)-predicted incident CVD in all the models tested. In a fully adjusted model that controlled for lipids and other risk factors, the hazard ratio was 2.17 per SD increase of SFTPB (95% confidence interval, 1.12-4.21, P = 0.022). In addition, plasma fractionation demonstrated that SFTPB is nearly entirely bound to HDL. Although previous studies have shown that high plasma levels of SFTPB associate with prevalent atherosclerosis only in smokers, we found that SFTPB predicted incident CVD in T1DM independently of smoking status and a wide range of confounding factors, including HDL-C, LDL-C, and triglyceride levels. Because SFTPB is almost entirely bound to plasma HDL, our observations support the proposal that SFTPB carried by HDL is a marker-and perhaps mediator-of CVD risk in patients with T1DM.

Symptoms of depression and anxiety in adults with type 1 diabetes: Associations with self-care behaviour, glycaemia and incident complications over four years - Results from diabetes MILES-Australia

OBJECTIVE

To examine whether symptoms of depression or anxiety predict glycaemia and incident diabetes complications four years later, and whether diabetes self-care behaviours mediate these associations, in adults with type 1 diabetes (T1DM).

METHODS

Data of 205 adults with T1DM from the 2011 and 2015 Diabetes MILES-Australia surveys were analysed. Variables of interest were: baseline depression and anxiety (PHQ-8 and GAD-7, respectively) symptoms; HbA_1c and incident complications at four-year follow-up; and self-care behaviours at both time points. Longitudinal associations were analysed using structural equation modelling.

RESULTS

Forty-two participants (20.6%) reported incident complications. Baseline depressive symptoms predicted higher HbA_1c at follow-up indirectly via less optimal self-care at follow-up (β = 0.19, P = 0.011). Baseline anxiety was not independently associated with HbA_1c or self-care at follow-up (P ≥ 0.64). Neither depressive nor anxiety symptoms predicted incident complications, although depressive symptoms were associated with less optimal self-care at baseline (β = -0.67, P < 0.001), and this predicted microvascular complications (β = -0.38, P = 0.044); however, the indirect association via self-care was not significant (β = 0.25, P = 0.067).

LIMITATIONS

Participants were self-selected; all study variables were assessed using self-report measures; and adjusting for baseline HbA_1c was not possible.

CONCLUSIONS

Depressive symptoms predicted suboptimal self-care behaviour and glycaemic outcome four years later, while anxiety symptoms did not. The findings suggest that tailored diabetes care should take the potential impact of comorbid depression into consideration to help people improve their diabetes self-care and achieve best possible health outcomes.

Predictive value of lower extremity color doppler ultrasonography before knee arthroplasty on a postoperative cardiovascular event

BACKGROUND

The study intended to determine the presence of lower limb arterial calcification (LLAC) in lower extremity color Doppler ultrasonography (CDUS) before primary total knee arthroplasty (TKA) and its relation with cardiovascular events (CVE) during knee arthroplasty and the postoperative period, as well as to investigate its effect on surgical risk estimation.

METHODS

We designed this study as a retrospective cohort study. The study comprised 467 patients who met the inclusion criteria and had surgery for a primary gonarthrosis diagnosis between January 2005 and December 2015 were included. In the study group, patients with arterial calcification in the lower extremity CDUS were included; however, those reported not to have it were included in the control group. The research data were obtained from preoperative anesthesia records and patient medical records.

RESULTS

72% of the sample had preoperative cardiovascular comorbidity. There was no difference between the groups in terms of comorbidities, except for congestive heart failure (CHF) and peripheral artery disease (PAD). The groups did not differ in terms of ASA scores, either. Both pre- and post-operative CVEs, i.e., ischemic heart disease, dysrhythmia, and CHF, were statistically high in the study group. In terms of postoperative mortality, there was no statistical difference between the groups.

CONCLUSION

The study demonstrates that the presence of LLAC in CDUS is associated with increased risk of perioperative cardiovascular events (CVEs). Ultrasonographic detection of LLAC may give some idea the surgeon about the requirement for additional preoperative cardiac examinations.

Evaluation of Electrocardiographic Ventricular Depolarization and Repolarization Variables in Type 1 Diabetes Mellitus

Background

The risk of cardiovascular events and sudden death increases with type 1 diabetes mellitus (T1DM).

Objective

To evaluate electrocardiographic markers of arrhythmias in T1DM patients.

Methods

Electrocardiographic parameters reflecting ventricular depolarization and repolarization, namely, QT, QTc, QTd, QTdc, Tp-e, JT, and JTc intervals and Tp-e/QT and Tp-e/QTc ratios, of 46 patients diagnosed with T1DM were retrospectively analyzed and compared with 46 healthy age-, sex-, and body mass-matched controls. Correlations between T1DM duration, hemoglobin A1c (HbA1c), and ventricular repolarization variables were analyzed. P values lower than 0.05 were considered statistically significant.

Results

Diabetes duration was 16.6 ± 7.1 years, and HbA1c was 10.81% ± 3.27% in the T1DM group. In comparison with the control group, heart rate, QTc, QTd, QTdc, Tp-e and JTc intervals, Tp-e/QT ratio (p < 0.001), and Tp-e/QTc ratio (p = 0.007) were significantly higher in T1DM patients. T1DM duration and HbA1c levels were significantly correlated with QTc, QTd, QTdc, Tp-e, and JTc intervals and Tp-e/QT and Tp-e/QTc ratios.

Conclusions

In T1DM patients, potential electrocardiographic repolarization predictors were significantly increased in correlation with disease duration and HbA1c levels. These findings may contribute to the understanding of sudden cardiac death in patients with T1DM.

Electrical Analysis Of Normal And Diabetic Blood For Evaluation Of Aggregation And Coagulation Under Different Rheological Conditions

Introduction

Erythrocyte aggregation and blood coagulation are of great interest and are still under investigation by many researchers. Erythrocytes have a direct effect on hemorheological properties. Real-time in vitro studies on blood coagulation and aggregation provide a chance to understand their mechanisms in normal and pathological conditions. Additionally, this method offers control over the physical and chemical conditions during the study.

Objective

The present study introduced a simple in vitro technique to study blood aggregation and coagulation under controlled conditions.

Methods

The technique used in this study is based on the measurement of the electrical properties of blood. A simple flow chamber was made from two cylinders with a gap between them. The outer cylinder remains stationary, and the inner cylinder rotates about its axis. The inner cylinder velocity is controlled by a stepper motor. Blood samples are introduced in the gap between the two cylinders. Capacitance and impedance of blood samples were recorded by two electrodes attached to the outer cylinders and in direct contact with blood.

Results

Quantitative parameters were extracted from the capacitance and impedance time courses. These parameters were used to describe the aggregation and coagulation processes under different shear rates. Strong correlations between the aggregation index and shear rate were found for normal and diabetic blood samples. Additionally, strong negative correlations of coagulation time were found for normal and diabetic blood samples. In conclusion, the electrical analysis of blood reflects well the interactions between internal blood contents.

Conclusion

The parameters extracted from this technique can be used in the quantitative description of hemorheological processes under different physical conditions.

Potential Diagnostic Hemorheological Indexes for Chronic Kidney Disease in Patients With Type 2 Diabetes

Many studies have demonstrated that an alteration in hemorheological properties is closely correlated with diabetic microcirculatory diseases. However, most of these studies have been limited to animal studies or used a small number of clinical samples, due to a lack of effective point-of-care (POC) devices to measure such properties within clinical environments. Owing to recent developments in microfluidic technology, several hemorheological POC devices have been designed that allow for the possibility of conducting extensive clinical studies using hemorheological measurements. Here, we reviewed recent clinical studies of diabetic kidney disease (DKD) associated with hemorheological parameters. We found that RBC deformability alone did not show a significant difference according to the degree of DKD, whereas critical shear stress (CSS) was found to be closely related to the ratio of albumin to creatinine and glomerular filtration rate. We also reviewed studies that alteration of hemorheological properties are associated with the development of DKD, which showed that CSS could be considered as a potential index to diagnose other diabetic complications as well as DKD.

Vascular disease in the lower limb in type 1 diabetes

This review considers peripheral arterial disease (PAD) in the diabetic ischaemic lower limb including both macrovascular and microvascular aspects. The presentation of PAD is probably not significantly different in type 1 compared with type 2 diabetes. PAD in diabetic patients is diffuse and located distally being most severe in the crural and also the foot arteries. It is associated with arterial calcification and occlusion of the arteries rather than stenosis. Compared with the nondiabetic patient, PAD develops at a younger age, and women are equally affected as men. It is not known whether the presentation of ischaemic lower limb disease in diabetes can be explained by one disease, namely, atherosclerosis, which has particular features peculiar to diabetes such as distal arterial involvement, or by the occurrence of two separate diseases: first, classical atherosclerosis and, second, a diabetic macroangiopathy, a term for nonatherosclerotic arterial disease in diabetes that is characterized by medial arterial calcification. Furthermore, there is controversy with regard to the significance of structural changes in the microcirculation of the diabetic foot.

The use of ankle brachial pressure indices in a cohort of black African diabetic patients

BACKGROUND

Peripheral arterial disease is very common in patients with diabetes, but it remains grossly under-recognized in this type of patients. Ankle brachial index (ABI) is a simple, non-invasive and reproducible method for detection and improving risk stratification. However, the sensitivity appears to be lower in diabetic patients and, false 'high' readings occur because of the arterial calcification of the vessel media which render the vessels incompressible.

MATERIALS AND METHODS

The study evaluated the prevalence of a low ABI <0.9 in diabetic patients in a hospital-based cross sectional observational study. The study has been registered.

RESULTS

The prevalence of peripheral arterial disease in diabetics with ABI< 0.9 was 18%. The majority (77%) of responders were asymptomatic with mild PAD (ABI 0.7-0.9). Age >60 years, hypertension (systolic BP > 140 mmHg) and presence of foot ulcer were identified as independent risk factors. 22 participants (4.4%) of the 500 had ABI greater than 1.3 but were excluded in the analysis.

CONCLUSION

The prevalence of PAD in diabetics measured by the ABI index was low and the majority in our setting had mild PAD and were asymptomatic. ABI could be used in patients with diabetes, but values should be interpreted with precision, according to the clinical situation as higher values are common.

Incidence of diabetes-related complications in Chinese patients with type 1 diabetes: a population-based longitudinal cohort study in Taiwan

OBJECTIVE

To estimate the incidence densities and cumulative incidence of diabetes-related complications in patients with type 1 diabetes for a maximum of 15-year follow-up. The estimations were further stratified by gender and age at diagnosis (ie, early onset: 0-12 years, late onset:≥13 years).

DESIGN

A population-based retrospective longitudinal cohort study.

SETTING

Taiwan's National Health Insurance medical claims.

PARTICIPANTS

4007 patients newly diagnosed with type 1 diabetes were identified during 1999-2012.

OUTCOME MEASURES

Acute complications included diabetic ketoacidosis (DKA) and hypoglycaemia. Chronic complications were cardiovascular diseases (CVD), retinopathy, neuropathy and nephropathy.

RESULTS

The incidence density of retinopathy was greatest (97.74 per 1000 person-years), followed by those of nephropathy (31.36), neuropathy (23.93) and CVD (4.39). Among acute complications, the incidence density of DKA was greatest (121.11 per 1000 person-years). The cumulative incidences of acute complications after 12 years following diagnosis were estimated to be 52.1%, 36.1% and 4.1% for DKA, outpatient hypoglycaemia and hospitalised hypoglycaemia, respectively. For chronic complications, the cumulative incidence of retinopathy after 12 years following diagnosis was greatest (65.2%), followed by those of nephropathy (30.2%), neuropathy (23.7%) and CVD (4.1%). Females with late-onset diabetes were greatly affected by advanced retinopathy (ie, sight-threatening diabetic retinopathy) and hospitalised hypoglycaemia, whereas those with early-onset diabetes were more vulnerable to DKA. Chronic complications were more commonly seen in late-onset diabetes, whereas early-onset diabetes were most affected by acute complications.

CONCLUSIONS

Ethnic Chinese patients with type 1 diabetes were greatly affected by DKA and retinopathy. The incidence of diabetes-related complications differed by age at diagnosis and sex.

Arterial Calcification in Diabetes Mellitus: Preclinical Models and Translational Implications

Diabetes mellitus increasingly afflicts our aging and dysmetabolic population. Type 2 diabetes mellitus and the antecedent metabolic syndrome represent the vast majority of the disease burden-increasingly prevalent in children and older adults. However, type 1 diabetes mellitus is also advancing in preadolescent children. As such, a crushing wave of cardiometabolic disease burden now faces our society. Arteriosclerotic calcification is increased in metabolic syndrome, type 2 diabetes mellitus, and type 1 diabetes mellitus-impairing conduit vessel compliance and function, thereby increasing the risk for dementia, stroke, heart attack, limb ischemia, renal insufficiency, and lower extremity amputation. Preclinical models of these dysmetabolic settings have provided insights into the pathobiology of arterial calcification. Osteochondrogenic morphogens in the BMP-Wnt signaling relay and transcriptional regulatory programs driven by Msx and Runx gene families are entrained to innate immune responses-responses activated by the dysmetabolic state-to direct arterial matrix deposition and mineralization. Recent studies implicate the endothelial-mesenchymal transition in contributing to the phenotypic drift of mineralizing vascular progenitors. In this brief overview, we discuss preclinical disease models that provide mechanistic insights-and point to challenges and opportunities to translate these insights into new therapeutic strategies for our patients afflicted with diabetes mellitus and its arteriosclerotic complications.

The Humanistic Burden of Type 1 Diabetes Mellitus in Europe: Examining Health Outcomes and the Role of Complications

Aims

Diagnoses of Type 1 Diabetes Mellitus (T1DM) in Europe appear to be on the rise. Therefore it is imperative that researchers understand the potential impact that increases in prevalence could have on the affected individuals as well as on society as a whole. Accordingly this study examined the humanistic and economic burden of T1DM in patients relative to those without the condition across a number of health outcomes including health status, work productivity loss, activity impairment, and healthcare resource use.

Methods

Survey data from a large, representative sample of EU adults (The EU National Health and Wellness Survey) were examined.

Results

Results suggest that overall burden is higher for those diagnosed with T1DM than respondents without diabetes and that burden increases as complications associated with T1DM increase.

Conclusions

Taken together, these results suggest that treatment strategies for T1DM should balance clinical, humanistic, and economic burden and patients should be educated on the role of complications in disease outcomes.

Ultrastructural Changes in the Venous Wall Induced by Experimental Diabetes: Preliminary Findings

Objective:

To study whether experimental streptozotocin (STZ) induced diabetes results in structural alterations to the venous wall of the femoral vein in adult rats, in order to develop further studies using this model.

Design:

A prospective study of femoral veins obtained from controls and STZ-induced diabetes rats.

Setting:

Department of Morphology, Universidad de Las Palmas de Gran Canaria, Spain.

Interventions:

Experimental diabetes induced by intraperitoneal injection of streptozotocin.

Main outcome measures:

The samples were studied at 6 and 12 weeks post-injection using light and transmission electron microscopy.

Results:

The results show that the venous wall is affected by an increase in the deposition of extracellular tissue. In addition the endothelial, muscular and adventitial cells show morphological changes.

Conclusions:

Our results demonstrate significant alterations in the venous wall due to hyperglycaemia in the STZ-animal model.

Nuclear magnetic resonance-determined lipoprotein subclasses and carotid intima-media thickness in type 1 diabetes

BACKGROUND

Dyslipidemia has been linked to vascular complications of Type 1 diabetes (T1DM). We investigated the prospective associations of nuclear magnetic resonance-determined lipoprotein subclass profiles (NMR-LSP) and conventional lipid profiles with carotid intima-media thickness (IMT) in T1DM.

METHODS

NMR-LSP and conventional lipids were measured in a subset of Diabetes Control and Complications Trial (DCCT) participants (n = 455) at study entry ('baseline', 1983-89), and were related to carotid IMT determined by ultrasonography during the observational follow-up of the DCCT, the Epidemiology of Diabetes Interventions and Complications (EDIC) study, at EDIC Year 12 (2004-2006). Associations were defined using multiple linear regression stratified by gender, and following adjustment for HbA1c, diabetes duration, body mass index, albuminuria, DCCT randomization group, smoking status, statin use, and ultrasound devices.

RESULTS

In men, significant positive associations were observed between some baseline NMR-subclasses of LDL (total IDL/LDL and large LDL) and common and/or internal carotid IMT, and between conventional total- and LDL-cholesterol and non-HDL-cholesterol and common carotid IMT, at EDIC Year 12; these persisted in adjusted analyses (p < 0.05). Large LDL particles and conventional triglycerides were positively associated with common carotid IMT changes over 12 years (p < 0.05). Inverse associations of mean HDL diameter and large HDL concentrations, and positive associations of small LDL with common and/or internal carotid IMT (all p < 0.05) were found, but did not persist in adjusted analyses. No significant associations were observed in women.

CONCLUSION

NMR-LSP-derived LDL particles, in addition to conventional lipid profiles, may help in identifying men with T1DM at highest risk for vascular disease.

Investigation of hypoglycemic, hypolipidemic and antioxidant activities of aqueous extract of Terminalia paniculata bark in diabetic rats

OBJECTIVE

To investigate the hypoglycemic, hypolipidemic and antioxidant activities of aqueous extract of Terminalia paniculata bark (AETPB) in streptozotocin (STZ)-induced diabetic rats.

METHODS

Acute toxicity was studied in rats after the oral administration of AETPB to determine the dose to assess hypoglycemic activity. In rats, diabetes was induced by injection of STZ (60 mg/kg, i.p.) and diabetes was confirmed 72 h after induction, and then allowed for 14 days to stabilize blood glucose level. In diabetic rats, AETPB was orally given for 28 days and its effect on blood glucose and body weight was determined on a weekly basis. At the end of the experimental day, fasting blood sample was collected to estimate the haemoglobin (Hb), glycosylated haemoglobin (HbA1c), serum creatinine, urea, serum glutamate-pyruvate transaminase (SGPT), serum glutamate-oxaloacetate transaminase (SGOT) and insulin levels. The liver and kidney were collected to determine antioxidants levels in diabetic rats.

RESULTS

Oral administration of AETPB did not exhibit toxicity and death at a dose of 2 000 mg/kg. AETPB treated diabetic rats significantly (P<0.001, P<0.01 and P<0.05) reduced elevated blood glucose, HbA1c, creatinine, urea, SGPT and SGOT levels when compared with diabetic control rats. The body weight, Hb, insulin and total protein levels were significantly (P<0.001, P<0.01 and P<0.05) increased in diabetic rats treated with AETPB compared to diabetic control rats. In diabetic rats, AETPB treatment significantly reversed abnormal status of antioxidants and lipid profile levels towards near normal levels compared to diabetic control rats.

CONCLUSIONS

Present study results confirm that AETPB possesses significant hypoglycemic, hypolipidemic and antioxidant activities in diabetic condition.

[Peripheral arterial disease of the lower limbs in African diabetic patients: ultrasonography and determining factors]

INTRODUCTION

Diabetic peripheral arterial disease (PAD) of the lower limbs is underdiagnosed.

METHODOLOGY

This was a prospective study conducted over a six-month period from November 2012 to April 2013. A total of 308 diabetic patients were included from three diabetes centers in Abidjan (Ivory Coast).

AIM

To screen for PAD of the lower limbs in a diabetic population and to identify the determining factors.

RESULTS

Among the 308 patients, the ankle-brachial index (ABI) was<0.9 in 68 (22.07%) patients considered to have PAD; the ABI was>1.3 in 56 (18.2%) patients who had suspected mediacalcosis. The average age of the PAD patients was 60.2 years. Female gender predominated (55.9%). The mean duration of diabetes was 9.6 years: 97.1% type 2 diabetes. The other cardiovascular risk factors in this population were hypertension (58.8%) and dyslipidemia (40.9%). Smoking was present in 29.4% of patients and obesity in 23.9%. PAD of the lower limbs was mild in 46 patients (67.6%), moderate in 16 (23.5%) and severe in 6 (8.8%). Duplex Doppler commonly showed lesions of the tibial arteries. Determining factors of diabetic PAD of the lower limbs were hypertension (58.8% vs 36.6%; OR=2.46; 95% CI: 1.13-5.36; P=0.034) and dyslipidemia (40.9% vs 8.3%; OR=7.6; 95% CI: 2.31-25.08; P=0.0009). For mediacalcosis, male gender (71.5% vs 39.7; OR=0.26 95% CI/0.10-0.64. P=0.004) was the only factor identified.

CONCLUSION

Hypertension and dyslipidemia were predictive factors for diabetic PAD of the lower limbs in our African population.

Interaction between diabetes and a high ankle-brachial index on mortality risk

OBJECTIVE

Low ankle-brachial index (ABI) is a predictor of increased mortality. The impact of a high ABI on mortality is less studied. Moreover, diabetes is frequently associated with high ABI and, because of specific mechanisms in diabetic vascular diseases, the relationship with prognosis may be unique. Therefore, our aim was to compare mortality in individuals with and without diabetes according to abnormally low and high ABI.

DESIGN AND METHODS

We studied the association between ABI and all-cause and cardiovascular mortality in 6986 participants from the REACH registry, a cohort of 45 years and older stable outpatients at high cardiovascular risk (2875 (41.1%) with diabetes) followed for 4 years.

RESULTS

ABI was normal (0.91-1.29) in 49.5%, low (≤0.9) in 47.5%, and high (≥1.3) in 2.9% of participants. During follow up, 9.9% of participants died (6.5% from cardiovascular causes). A low ABI was associated with cardiovascular mortality (adjusted hazard ratio, HR, 1.98, 95% CI 1.62-2.41) and all-cause mortality (HR 2.01, 95% CI 1.72-2.36), without heterogeneity according to diabetes. In contrast, high ABI was associated with higher risk of all-cause mortality in individuals with diabetes (HR 2.11, 95% CI 1.16-3.84), but not without diabetes (HR 0.82, 95% CI 0.36-1.85; p-value for interaction 0.07). The trend was similar for cardiovascular mortality (HR 2.13, 95% CI 1.03-4.44 and HR 1.05, 95% CI 0.43-2.59 with and without diabetes, respectively; p-value for interaction 0.24).

CONCLUSIONS

In the REACH registry, low ABI was associated with mortality, similarly in individuals without and with diabetes, whereas the association with high ABI was only observed in patients with diabetes.

Type 1 diabetes

Over the past decade, knowledge of the pathogenesis and natural history of type 1 diabetes has grown substantially, particularly with regard to disease prediction and heterogeneity, pancreatic pathology, and epidemiology. Technological improvements in insulin pumps and continuous glucose monitors help patients with type 1 diabetes manage the challenge of lifelong insulin administration. Agents that show promise for averting debilitating disease-associated complications have also been identified. However, despite broad organisational, intellectual, and fiscal investments, no means for preventing or curing type 1 diabetes exists, and, globally, the quality of diabetes management remains uneven. This Seminar discusses current progress in epidemiology, pathology, diagnosis, and treatment of type 1 diabetes, and prospects for an improved future for individuals with this disease.

Changing impact of modifiable risk factors on the incidence of major outcomes of type 1 diabetes: the Pittsburgh Epidemiology of Diabetes Complications Study

OBJECTIVE

The incidence of type 1 diabetes complications appears to be decreasing, but relative contributions of risk factors are unclear. We thus estimated the effect of modifiable risk factors on the incidence of a composite end point, major outcomes of diabetes (MOD).

RESEARCH DESIGN AND METHODS

The Pittsburgh Epidemiology of Diabetes Complications (EDC) Study was used to derive two cohorts based on diabetes diagnosis year (1960-1969 and 1970-1980). Baseline exam data in the current analysis for the 1960s group were collected in 1986-1988 and for the 1970s in 1996-1998. Each group was followed for 8 years for MOD incidence (diabetes-related death, myocardial infarction, revascularization procedure/blockage ≥50%, stroke, end-stage renal disease, blindness, and amputation). Assessed risk factors include the following: HbA1c, hypertension, microalbuminuria, BMI, hypercholesterolemia, and smoking. Accelerated failure time models were used to estimate the acceleration factor.

RESULTS

MOD incidence decreased in the 1970s cohort (15.8% [95% CI 11.6-21.4]) compared with the 1960s (22.6% [17.0-29.1]) over the 8-year follow-up (P = 0.06). Hypertension and microalbuminuria were associated with significantly accelerated MOD incidence in both cohorts (P < 0.01 for both). High HbA1c (P = 0.0005), hypercholesterolemia (P = 0.01), and current smoking (P = 0.003) significantly accelerated the incidence of MOD in the 1960s but not 1970s cohort. BMI was not associated with MOD in either cohort.

CONCLUSIONS

These results suggest that hypertension and microalbuminuria remain important predictors of complications that are not being adequately addressed.

Antidiabetic, antihyperlipidemic and antioxidant potential of methanol extract of Tectona grandis flowers in streptozotocin induced diabetic rats

OBJECTIVE

To investigate antidiabetic, antihyperlipidemic and antioxidant activity of methanol extract of Tectona grandis (T. grandis) flowers (METGF) in streptozotocin (STZ) induced diabetic rats to supports its traditional use.

METHODS

Acute toxicity study of METGF was carried out in rat to determine its dose for the antidiabetic study. Oral glucose tolerance test (OGTT) was performed to evaluate METGF effect on elevated blood glucose level. Diabetes was induced in rats by administration of STZ (60 mg/kg, ip.) and it was confirmed 72 h after induction. METGF was orally given to the diabetic rats up to 28 days and blood glucose level were estimated each week. On 28 day of the experiment, diabetic rats were sacrificed after the blood collection for the biochemical parameters analysis and liver, kidney was collected to determine antioxidants levels.

RESULTS

In acute toxicity, METGF did not show toxicity and death up to a dose 2 000 mg/kg in rats. Administration of METGF 100 and 200 mg/kg significantly (P<0.001) reduced blood glucose levels in OGTT and STZ-induced diabetic rats. Both doses of METGF treatment significantly (P<0.001, P<0.01 and P<0.05) increased body weight, serum insulin, haemoglobin (Hb) and total protein levels in diabetic rats. Also, MEGTF treatment reduced elevated glycosylated haemoglobin (HbA1c) and other biochemical parameters levels significantly (P<0.001) in diabetic rats. Altered lipid profiles and antioxidants levels were reversed to near normal in diabetic rats treated with METGF.

CONCLUSIONS

These results concluded that METGF possesses antidiabetic, antihyperglycemic and antioxidant activity which supports its traditional use.

The prevalence of peripheral arterial disease in korean patients with type 2 diabetes mellitus attending a university hospital

BACKGROUND

Peripheral arterial disease (PAD) is a common manifestation of systemic atherosclerosis and is associated with significant morbidity and mortality. Diabetes is known to increase the risk of PAD two- to four-fold. The prevalence of PAD in Korean diabetic patients has not been established. In this study, we investigated the prevalence of PAD in Korean patients with type 2 diabetes attending a large university hospital and analyzed the factors associated with PAD.

METHODS

A total of 2,002 patients with type 2 diabetes who underwent ankle-brachial index (ABI) measurement in an outpatient clinic were enrolled. PAD was defined as an ABI ≤0.9. Clinical characteristics of 64 patients with PAD were compared with those of 192 age- and sex-matched control patients without PAD.

RESULTS

Of the 2,002 type 2 diabetic patients, 64 (3.2%) were diagnosed as having PAD. PAD was associated with higher prevalences of retinopathy, nephropathy, neuropathy, cerebrovascular and coronary artery disease. Patients with PAD had higher systolic blood pressure and serum triglyceride level and reported higher pack-years of smoking. Multivariate analysis showed that the presence of micro- and macrovascular complications and high systolic blood pressure are factors independently associated with PAD.

CONCLUSION

The prevalence of PAD in diabetic patients was 3.2%, suggesting that the prevalence in Korean diabetic patients is lower than that of patients in Western countries.

Carotid intima-media thickness as a surrogate marker of cardiovascular disease in diabetes

BACKGROUND

Diabetes mellitus is associated with a high risk of cardiovascular disease. Carotid intima-media thickness (CIMT) is increasingly used as a surrogate marker for atherosclerosis. Its use relies on its ability to predict future clinical cardiovascular end points.

METHODS

This review examines the evidence linking CIMT as a surrogate marker of vascular complications in people with type 1 and type 2 diabetes. We have also reviewed the various treatment strategies which have been shown to influence CIMT.

CONCLUSIONS

CIMT measurement is an effective, noninvasive tool which can assist in identifying people with diabetes who are at higher risk of developing microvascular and macrovascular complications. It may also help to evaluate the effectiveness of various treatment strategies used to treat people with diabetes.

Use and utility of ankle brachial index in patients with diabetes

Ankle brachial index (ABI) is a simple method to screen peripheral arterial disease (PAD) and to evaluate cardiovascular (CV) prognosis in the general population. Measuring it requires a hand-held Doppler probe but it can be done also with an automatic device. ABI is an effective tool for clinical practice or clinical studies. However, in diabetic patients, it has some specific caveats. Sensitivity of the standard threshold of 0.9 appears to be lower in diabetic patients with complications. Moreover, highly frequent arterial medial calcifications in diabetes increase ABI. It has been demonstrated that measurements >1.3 are well correlated with both an increased prevalence of PAD and CV risk. Therefore, ABI thresholds of less than 0.9 and more than 1.3 are highly suspicious for PAD and high CV risk in diabetic patients. However, when there is concomitant clinical peripheral neuropathy or high risk of arterial calcification, the efficiency of ABI seems to be limited. In this case, other methods should be applied, toe pressure, in particular. Thus, the ABI could be used in patients with diabetes, but values should be interpreted with precision, according to the clinical situation.

Pulse wave analysis and prevalent cardiovascular disease in type 1 diabetes

OBJECTIVE

Type 1 diabetes (T1D) is associated with a high risk for and mortality from premature coronary artery disease (CAD), including coronary artery calcification (CAC), a subclinical marker, and lower extremity arterial disease (LEAD). Pulse wave analysis (PWA) arterial stiffness indices have been associated with cardiovascular disease (CVD) risk factors and outcomes in various populations, but little is known regarding these relationships in T1D.

METHODS

PWA was performed using the SphygmoCor Px device on 144 participants in the Pittsburgh EDC Study of childhood-onset T1D. The cross-sectional associations between arterial stiffness indices, augmentation index (AIx) and augmentation pressure (AP), and subendocardial viability ratio (SEVR), an estimate of myocardial perfusion, with prevalent CAD, electron beam computed tomography-measured CAC and low (<0.90) ankle-brachial index (ABI) were examined.

RESULTS

Higher AP (but not AIx) and lower SEVR were univariately associated with prevalent CAD, high CAC score, and low ABI. AP and SEVR's association with CAD and CAC did not, however, remain significant after adjustment for age. In individuals not using nitrates, which profoundly affect PWA measures, AP was significantly higher in those with CAD events and explained more of the variance than either age or brachial blood pressure measures. SEVR was associated with low ABI in multivariable models.

CONCLUSIONS

Greater augmentation pressure is independently associated with prevalent CAD and estimated myocardial perfusion with low ABI in type 1 diabetes. These measures may thus help to better characterize CVD risk in type 1 diabetes and need to be examined prospectively.

Ankle brachial index screening for occult vascular disease is not useful in HIV-positive patients

Metabolic complications common to the HIV-positive population may increase the risk for cardiovascular disease. Asymptomatic peripheral arterial disease (PAD) is associated with increased cardiovascular risk. The ankle-brachial pressure index (ABI) is a screening tool commonly used for the detection of asymptomatic PAD. The prevalence of asymptomatic PAD based on ABI in HIV-positive patients is unknown. This study was cross-sectional in design and assessed PAD by measuring the systolic ABI as determined by a handheld 8-MHz Doppler probe with the patient at rest in a supine position. A brief medical history including pertinent risk factors was obtained. One hundred and sixty-seven HIV-positive patients were evaluated (97.6% male; mean age 52.0 years; 31.2% current smokers, 29.4% former smokers, 26.3% diabetes mellitus). Asymptomatic PAD (ABI < or = 0.9) was found in four patients (2.4%, 95% CI: 0.3-4.5%). Smoking was a significant predictor of PAD. Patients with a positive test for PAD had at least two major risk factors for the disease including smoking, a history of disease in another vascular bed, dyslipidemia, diabetes, and hypertension. All patients with a positive test for PAD had a high risk (>20%) for cardiovascular disease according to the Framingham risk score. Three of the four patients with positive tests had previously diagnosed vascular disease (CAD, stroke). Three patients presenting with PAD were evaluated and all had a positive ABI. The prevalence of PAD compared to previous studies on PAD in HIV was low and identified only those patients with high cardiovascular risk based on other features. ABI was not useful in detecting occult vascular disease in HIV-positive patients and offers no additional information to that derived from cardiovascular risk stratification.

Intracellular Ca2+ regulating proteins in vascular smooth muscle cells are altered with type 1 diabetes due to the direct effects of hyperglycemia

Background

Diminished calcium (Ca²⁺) transients in response to physiological agonists have been reported in vascular smooth muscle cells (VSMCs) from diabetic animals. However, the mechanism responsible was unclear.

Methodology/Principal Findings

VSMCs from autoimmune type 1 Diabetes Resistant Bio-Breeding (DR-BB) rats and streptozotocin-induced rats were examined for levels and distribution of inositol trisphosphate receptors (IP₃R) and the SR Ca²⁺ pumps (SERCA 2 and 3). Generally, a decrease in IP₃R levels and dramatic increase in ryanodine receptor (RyR) levels were noted in the aortic samples from diabetic animals. Redistribution of the specific IP₃R subtypes was dependent on the rat model. SERCA 2 was redistributed to a peri-nuclear pattern that was more prominent in the DR-BB diabetic rat aorta than the STZ diabetic rat. The free intracellular Ca²⁺ in freshly dispersed VSMCs from control and diabetic animals was monitored using ratiometric Ca²⁺ sensitive fluorophores viewed by confocal microscopy. In control VSMCs, basal fluorescence levels were significantly higher in the nucleus relative to the cytoplasm, while in diabetic VSMCs they were essentially the same. Vasopressin induced a predictable increase in free intracellular Ca²⁺ in the VSMCs from control rats with a prolonged and significantly blunted response in the diabetic VSMCs. A slow rise in free intracellular Ca²⁺ in response to thapsigargin, a specific blocker of SERCA was seen in the control VSMCs but was significantly delayed and prolonged in cells from diabetic rats. To determine whether the changes were due to the direct effects of hyperglycemica, experiments were repeated using cultured rat aortic smooth muscle cells (A7r5) grown in hyperglycemic and control conditions. In general, they demonstrated the same changes in protein levels and distribution as well as the blunted Ca²⁺ responses to vasopressin and thapsigargin as noted in the cells from diabetic animals.

Conclusions/Significance

This work demonstrates that the previously-reported reduced Ca²⁺ signaling in VSMCs from diabetic animals is related to decreases and/or redistribution in the IP₃R Ca²⁺ channels and SERCA proteins. These changes can be duplicated in culture with high glucose levels.

Hemorheological disorders in diabetes mellitus

The objective of the present study is to review hemorheological disorders in diabetes mellitus. Several key hemorheological parameters, such as whole blood viscosity, erythrocyte deformability, and aggregation, are examined in the context of elevated blood glucose level in diabetes. The erythrocyte deformability is reduced, whereas its aggregation increases, both of which make whole blood more viscous compared to healthy individuals. The present paper explains how the increased blood viscosity adversely affects the microcirculation in diabetes, leading to microangiopathy.

The association between elevated ankle systolic pressures and peripheral occlusive arterial disease in diabetic and nondiabetic subjects

OBJECTIVE

The presence of a high ankle-brachial index (ABI) is related to stiff ankle arteries due to medial calcification. Recently, this condition has attracted new interest after reports of a worse cardiovascular prognosis, similar to a low ABI. We sought to compare risk factors contributing to a low (< or =0.90) and high (> or =1.40) ABI. Additionally, we hypothesized that in instances of high ABI, occlusive PAD may coexist.

METHOD

This cross-sectional study was conducted at vascular laboratories in a university medical center. The subjects were 510 ambulatory patients (37% had diabetes) previously examined at our vascular laboratories and who responded positively to our invitation. We collected data on smoking, diabetes, hypertension, dyslipidemia, and cardiovascular disease history. The noninvasive assessment of lower limb arteries consisted of the measurement of ABI, toe-brachial index (TBI), and posterior tibial artery peak flow velocity (Pk-PT). A TBI >0.7 and a Pk-PT >10 cm/s were considered normal.

RESULTS

High- and low-ABI were detected, respectively, in 2.1% and 57.8% of limbs. For a low ABI, age (odds ratio [OR], 1.29/10 y), pack-years (OR, 1.08/10 units), and hypertension (OR, 1.90) were independent significant (P < .001) factors. A strong association was found between diabetes and high ABI (OR, 16.0; P < .001). When ABI ranges were compared with TBI and Pk-PT results, those with ABI < or =0.90 and ABI > or =1.40 presented similar patterns of abnormalities. Pk-PT or TBI, or both, was abnormal in more than 80% of cases in both ABI < or =0.90 and > or =1.40 groups. The ABI vs TBI relationship appeared linear in nondiabetic patients, but had an inverted J-shape in diabetic patients, suggesting high ABI masked leg ischemia.

CONCLUSIONS

Diabetes is the dominant risk factor for a high (> or =1.40) ABI. Occlusive PAD is highly prevalent in subjects with high ABI, and these subjects should be considered as PAD-equivalent.

The immune response is involved in atherosclerotic plaque calcification: could the RANKL/RANK/OPG system be a marker of plaque instability?

Atherogenesis is characterized by an intense inflammatory process, involving immune and vascular cells. These cells play a crucial role in all phases of atherosclerotic plaque formation and complication through cytokine, protease, and prothrombotic factor secretion. The accumulation of inflammatory cells and thus high amounts of soluble mediators are responsible for the evolution of some plaques to instable phenotype which may lead to rupture. One condition strongly associated with plaque rupture is calcification, a physiopathological process orchestrated by several soluble factors, including the receptor activator of nuclear factor (NF)κB ligand (RANKL)/receptor activator of nuclear factor (NF)κB (RANK)/osteoprotegerin (OPG) system. Although some studies showed some interesting correlations with acute ischemic events, at present, more evidences are needed to evaluate the predictive and diagnostic value of serum sRANKL and OPG levels for clinical use. The major limitation is probably the poor specificity of these factors for cardiovascular disease. The identification of tissue-specific isoforms could increase the importance of sRANKL and OPG in predicting calcified plaque rupture and the dramatic ischemic consequences in the brain and the heart.

Non-traditional cardiovascular risk factors contribute to peripheral arterial disease in patients with type 2 diabetes

OBJECTIVE

This study evaluated the prevalence of peripheral arterial disease (PAD) in type 2 diabetes and its association with traditional and non-traditional cardiovascular (CV) risk factors.

SUBJECTS AND METHODS

In 1610 type 2 diabetics PAD was defined as ankle-brachial pressure index (ABPI)<0.9.

RESULTS

PAD prevalence was 17%, increased with age, diabetes duration, HbA 1c levels, previous CV events. There were no significant differences in the prevalence of traditional CV risk factors between patients with and without PAD. PAD patients had higher levels of fibrinogen (10.88+/-2.32 versus 10.2+/-2.23micromol/L; p<0.0001), uric acid (327.1+/-89.2 versus 315.2+/-83.3micromol/L, p<0.01), pulse pressure (70+/-18 versus 60+/-16mm Hg, p<0.0001), higher rate of microalbuminuria (21.3% versus 13.7%; p<0.05) and lower glomerular filtration rate (GFR, 80.7+/-24 versus 89.9+/-22 ml/min/1.73 m2; p<0.001) than those without. In age-gender-adjusted analysis, smoking (OR 1.5; CI: 1.07-2.2), HbA 1c (OR 1.45; CI: 1.07-2.08), high pulse pressure (OR 2.81; CI: 1.63-4.82), reduced GFR (OR 2.16; CI: 1.4-3.3), microalbuminuria (OR 1.62; CI: 1.11-2.36), high fibrinogen levels (OR 2.03; CI: 1.34-3.07) were associated with PAD. In multivariate analysis age, male sex, smoking, high pulse pressure, low GFR, high fibrinogen levels, previous CV events were independent risk factors for PAD.

CONCLUSIONS

PAD prevalence is high in Type 2 diabetic patients. Non-traditional cardiovascular risk factors may be involved in the development of this complication.

Hyperhomocysteinemia and elevated ox-LDL in Tunisian type 2 diabetic patients: Role of genetic and dietary factors

INTRODUCTION

Total plasma homocysteine (tHcy) is an emerging risk factor for the development of atherosclerosis. However, its relationship with diabetes is still unclear.

OBJECTIVES

We evaluated the association between tHcy levels and methylenetetrahydrofolate reductase (MTHFR) 677C-->T genotype in a type 2 diabetes mellitus (DM) population and their relationship with oxidized LDL (ox-LDL) according to dietary habits and vascular complications.

DESIGN AND METHODS

Eighty-six DM patients were compared to 120 healthy volunteers.

RESULTS

Associated higher tHcy levels and significantly higher ox-LDL levels (p<0.001) were found in DM patients compared to healthy subjects. Homozygosity for the T allele of MTHFR was more frequent in diabetics than in healthy subjects (12.8% vs. 7.2%) and it was associated with higher tHcy levels. Moreover, this elevated level was associated with significantly higher ox-LDL levels in DM patients with hypertension (p<0.05). Improving folate and vitamin C intakes could have beneficial effects on lowering the tHcy and ox-LDL levels.

CONCLUSIONS

The interplay of genetic and dietary factors modulates the effect of homocysteine on cardiovascular risk factors.

Lower-extremity arterial calcification as a correlate of coronary artery calcification

Coronary artery calcification (CAC) has been used as a testing modality for coronary atherosclerosis burden. In diabetes, arterial calcification in the tunica media is common and predicts renal and cardiovascular mortality. It is unknown whether the 2 calcification processes are related. We identified risk factors associated with lower-extremity arterial calcification (LEAC) and determined its relationship to the presence of CAC 6 years later and the incidence of complications in type 1 diabetes mellitus. A random sample of 190 participants from the Pittsburgh Epidemiology of Diabetes Complications Study, a prospective cohort of childhood-onset type 1 diabetes mellitus, received radiographs of their ankles and feet at the 4-year follow-up examination (1990-1992) and was followed up for approximately 6 years. At the 10-year examination, 121 of these individuals received an electron beam tomography scan. Male sex (odds ratio [OR] = 12.72, P < .0001), diabetes duration (OR = 4.53, P < .0001), and autonomic neuropathy (AN; OR = 5.92, P = .007) independently increased the odds of LEAC. Controlling for other known risk factors (duration and high-density lipoprotein cholesterol), we found that LEAC correlated with the presence of CAC 6 years later (OR = 1.12, P = .03), although adjusting for neuropathy attenuated this relationship (P = .08). LEAC also independently predicted AN but not the onset of other diabetes complications. Although arterial calcification in the lower extremities and the heart share many of the same risk factors, LEAC is an independent correlate of the later presence of CAC and AN. Thus, factors related to the calcification process in addition to vascular risk factors may play a role in determining the extent of CAC.

The Relationship Between Plasma Osteoprotegerin Levels and Coronary Artery Calcification in Uncomplicated Type 2 Diabetic Subjects

OBJECTIVES

This study sought to prospectively evaluate the relationship between plasma osteoprotegerin (OPG), inflammatory biomarkers (high-sensitivity C-reactive protein [hs-CRP], interleukin-6 [IL-6], coronary artery calcification (CAC), and cardiovascular events in patients with type 2 diabetes.

BACKGROUND

Arterial calcification is a prominent feature of atherosclerosis and is associated with an increased risk of cardiovascular events. Osteoprotegerin is a cytokine that has recently been implicated in the regulation of vascular calcification.

METHODS

A total of 510 type 2 diabetic patients (53 +/- 8 years; 61% male) free of symptoms of cardiovascular disease were evaluated by CAC imaging. Risk factors, hs-CRP, IL-6, and OPG levels were measured. Patients were followed up for cardiovascular events (cardiac death, myocardial infarction, acute coronary syndrome, late revascularization, and nonhemorrhagic stroke).

RESULTS

Significant CAC (>10 Agatston units) was seen in 236 patients (46.3%); OPG was significantly elevated in patients with increased CAC. In multivariable analyses, OPG retained a strong association with elevated CAC scores after adjustment for age, gender, and other risk factors (odds ratio = 2.84, 95% confidence interval 2.2 to 3.67; p < 0.01). Sixteen cardiovascular events occurred during a mean follow-up of 18 +/- 5 months. The waist-to-hip ratio, United Kingdom Prospective Diabetes Study (UKPDS) risk score, OPG level, and CAC score were significant predictors of time to cardiovascular events in a univariate Cox proportional hazards model. In the multivariate model, the CAC score was the only independent predictor of adverse events. Levels of hs-CRP and IL-6 were related to neither the extent of CAC nor short-term events.

CONCLUSIONS

A high proportion of asymptomatic diabetic patients have significant subclinical atherosclerosis. Of the biomarkers studied, only OPG predicted both subclinical disease and near-term cardiovascular events. Therefore, measurement of OPG merits further investigation as a simple test for identifying high-risk type 2 diabetic patients.

Risk factors for peripheral arterial disease incidence in persons with diabetes: the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Some risk factors for peripheral arterial disease (PAD) have been identified, but little information is available on PAD risk factors in individuals with diabetes.

METHODS

Using data from the Atherosclerosis Risk in Communities (ARIC) Study, we assessed the relation of traditional and non-traditional risk factors with the risk of PAD in 1651 participants with diabetes, but not PAD, at baseline. Incident PAD was defined as an ankle-brachial index (ABI)<0.9 assessed at regular examinations; hospital discharge codes for PAD, amputation, or leg revascularization; or claudication assessed by annual questionnaire.

RESULTS

Over a mean of 10.3 years of follow-up, 238 persons developed incident PAD identified, yielding a PAD event rate of 13.9 per 1000 person years. Adjusted for sex, age, race, and center, the risk of developing PAD was increased 1.87-fold (95% confidence interval (95% CI): 1.36-2.57) in persons who were current smokers versus non-smokers, 2.27-fold (95% CI: 1.57-3.26) for baseline coronary heart disease (CHD) versus no baseline CHD, and 1.75-fold (95% CI: 1.18-2.60) for the highest quartile versus lowest quartile of triglycerides. We found no evidence of an association with other blood lipids or hypertension. Compared with the lowest quartiles, comparably-adjusted relative risks for the highest quartiles were 1.60 (95% CI: 1.10-2.33) for waist-to-hip ratio, 2.52 (95% CI: 1.70-3.73) for fibrinogen, 1.70 (95% CI: 1.17-2.47) for factor VIII, 1.73 (95% CI: 1.18-2.54) for von Willebrand factor, 2.15 (95% CI: 1.43-3.24) for white blood cell count, 1.81 (95% CI: 1.19-2.74) for serum creatinine, 0.55 (95% CI: 0.37-0.83) for serum albumin, and 2.73 (95% CI: 1.77-4.22) for carotid intima-media thickness. Persons who had a prior history of diabetes and were taking insulin had a relative risk of 1.97 (95% CI: 1.35-2.87) for future PAD events, compared with those with newly identified diabetes at baseline. In our final multivariable model, current smoking, prevalent CHD, elevated fibrinogen and carotid IMT, and a prior history of diabetes with insulin treatment were independently associated with greater PAD incidence.

CONCLUSION

These markers might be useful to identify individuals with diabetes at particular risk for PAD.

Effect of glucocorticoids on the arteries in rheumatoid arthritis

OBJECTIVE

Glucocorticoids are suspected to cause atherosclerosis. Because of the possibility that their antiinflammatory effect may be antiatherogenic, this study investigated the effect of glucocorticoids on the arteries of patients with rheumatoid arthritis (RA).

METHODS

We assessed the arteries of 647 patients with RA. Central atherosclerosis was measured using high-resolution carotid ultrasound for the presence of plaque and for the extent of carotid artery intima-media thickness (CaIMT). Peripheral atherosclerosis was assessed using the systolic pressures of the dorsal pedal, posterior tibial, and brachial arteries to obtain the ankle-brachial index (ABI). Cumulative glucocorticoid dose was determined using pharmacy records, supplemented by self-report. Cardiovascular (CV) risk factors and RA clinical manifestations were ascertained using clinical and laboratory methods.

RESULTS

Among the RA patients studied, 427 (66%) had received glucocorticoids. Of those who had never received glucocorticoids, 100 (47%) of 215 had carotid plaque and 17 (8%) of 219 had > or =1 incompressible lower-limb artery (ABI >1.3). Among patients in the highest tertile of lifetime glucocorticoid exposure (>16.24 gm prednisone), the frequency of carotid plaque increased to 85 (62%) of 138 (P = 0.006) and that of lower-limb arterial incompressibility increased to 24 (17%) of 140 (P = 0.008), with differences remaining significant after adjustment for age at onset, disease duration, sex, CV risk factors, and RA clinical manifestations (tender, swollen, and deformed joint counts, subcutaneous nodules, rheumatoid factor seropositivity, and erythrocyte sedimentation rate). The CaIMT also displayed an increase with higher glucocorticoid exposure, but the differences did not reach significance. Lower-limb artery obstruction (ABI < or =0.9) was not associated with glucocorticoid exposure.

CONCLUSION

In this RA sample, glucocorticoid exposure was associated with carotid plaque and arterial incompressibility, independent of CV risk factors and RA clinical manifestations. This supports a role for glucocorticoids in the CV complications that occur in RA.

Lower limb arterial incompressibility and obstruction in rheumatoid arthritis

BACKGROUND

Despite increased cardiovascular morbidity and mortality in rheumatoid arthritis, the peripheral arteries remain understudied.

OBJECTIVE

To examine the lower limb arteries in age and sex matched, non-smoking subjects with and without rheumatoid arthritis.

METHODS

The ankle-brachial index (ABI) was measured at the posterior tibial and dorsal pedal arteries. Arteries were classified as obstructed with ABI < or =0.9, normal with ABI >0.9 but < or =1.3, and incompressible with ABI >1.3. Multinomial logistic regression was used to estimate differences in ABI between patients and controls, adjusting for cardiovascular risk factors, rheumatoid arthritis manifestations, inflammation markers, and glucocorticoid dose.

RESULTS

234 patients with rheumatoid arthritis and 102 controls were studied. Among the rheumatoid patients, 66 of 931 arteries (7%) were incompressible and 30 (3%) were obstructed. Among the controls, three of 408 arteries (0.7%) were incompressible (p = 0.002) and four (1%) were obstructed (p = 0.06). At the person level, one or more abnormal arteries occurred among 45 rheumatoid patients (19%), v five controls (5%, p = 0.001). The greater frequency of arterial incompressibility and obstruction in rheumatoid arthritis was independent of age, sex, and cardiovascular risk factors. Adjustment for inflammation markers, joint damage, rheumatoid factor, and glucocorticoid use reduced rheumatoid arthritis v control differences. Most arterial impairments occurred in rheumatoid patients with 20 or more deformed joints. This subgroup had more incompressible (15%, p< or =0.001) and obstructed arteries (6%, p = 0.005) than the controls, independent of covariates.

CONCLUSIONS

Peripheral arterial incompressibility and obstruction are increased in rheumatoid arthritis. Their propensity for patients with advanced joint damage suggests shared pathogenic mechanisms.

Intensive diabetes therapy and carotid intima-media thickness in type 1 diabetes mellitus

BACKGROUND

Cardiovascular disease causes severe morbidity and mortality in type 1 diabetes, although the specific risk factors and whether chronic hyperglycemia has a role are unknown. We examined the progression of carotid intima-media thickness, a measure of atherosclerosis, in a population with type 1 diabetes.

METHODS

As part of the Epidemiology of Diabetes Interventions and Complications (EDIC) study, the long-term follow-up of the Diabetes Control and Complications Trial (DCCT), 1229 patients with type 1 diabetes underwent B-mode ultrasonography of the internal and common carotid arteries in 1994-1996 and again in 1998-2000. We assessed the intima-media thickness in 611 subjects who had been randomly assigned to receive conventional diabetes treatment during the DCCT and in 618 who had been assigned to receive intensive diabetes treatment.

RESULTS

At year 1 of the EDIC study, the carotid intima-media thickness was similar to that in an age- and sex-matched nondiabetic population. After six years, the intima-media thickness was significantly greater in the diabetic patients than in the controls. The mean progression of the intima-media thickness was significantly less in the group that had received intensive therapy during the DCCT than in the group that had received conventional therapy (progression of the intima-media thickness of the common carotid artery, 0.032 vs. 0.046 mm; P=0.01; and progression of the combined intima-media thickness of the common and internal carotid arteries, -0.155 vs. 0.007; P=0.02) after adjustment for other risk factors. Progression of carotid intima-media thickness was associated with age, and the EDIC base-line systolic blood pressure, smoking, the ratio of low-density lipoprotein to high-density lipoprotein cholesterol, and urinary albumin excretion rate and with the mean glycosylated hemoglobin value during the mean duration (6.5 years) of the DCCT.

CONCLUSIONS

Intensive therapy during the DCCT resulted in decreased progression of intima-media thickness six years after the end of the trial.

Maternal diabetes mellitus is associated with altered deposition of fibrin-type fibrinoid at the villous surface in term placentae

Placentae from control and diabetic patients were used to test three null hypothesis: (1) there are no significant group differences in the volumes of villous syncytiotrophoblast compartments or intervillous fibrin-type fibrinoid, (2) perivillous fibrin-type fibrinoid is deposited randomly at the surface of trophoblast, and (3) amounts and deposition patterns of perivillous fibrin-type fibrinoid do not vary between groups. Term placentae were collected from non-diabetic subjects and five groups of diabetic women classified according to duration, severity and insulin dependence. Tissue specimens and sections were obtained by uniform random sampling. Volumes and surface areas of fibrin-type fibrinoid and trophoblast compartments (thin, syncytial knot, syncytial bridge and denuded regions) were estimated stereologically and compared using variance, chi-squared and contingency table analyses. As to null hypothesis (1), no group differences in volumes of trophoblast compartments were found but volumes of intervillous fibrin-type fibrinoid were greater in the non-insulin-dependent diabetic group. As to null hypothesis (2), regardless of group, fibrin-type fibrinoid was deposited preferentially at sites of denudation in every placenta examined. As to null hypothesis (3), villous surface areas occupied by perivillous fibrin-type fibrinoid were greater in type 1 (insulin-dependent) diabetics with complications (diabetic nephropathy or retinopathy). The surfaces of trophoblast occupied by fibrin-type fibrinoid were also notably larger in non-insulin-dependent diabetics and type 1 diabetics with complications. Except for the surface of denudation sites (which also increased in diabetes), there were no differences in the surfaces of trophoblast regions. These results confirm that the haemostatic steady state is perturbed in the diabetic placenta, that perivillous fibrin-type fibrinoid is deposited preferentially at sites of epithelial loss/damage, and that some diabetic groups are affected differentially.

The prevalence of peripheral arterial disease and medial arterial calcification in patients with chronic renal failure: requirements for diagnostics

BACKGROUND

Knowledge of the prevalence of peripheral arterial disease (PAD) in patients with chronic renal failure (CRF) is limited because of a lack of uniformity in disease definition and recognition. Furthermore, little is known of the prevalence of medial arterial calcification (MAC) in patients with CRF. Our goal is to study the prevalence of PAD and MAC defined by ankle brachial index (ABI) or toe brachial index (TBI) measurements in a Finnish population of patients with CRF consisting of predialysis and dialysis patients, as well as renal transplant recipients.

METHODS

We examined 136 patients with CRF and 59 control subjects. Fifty-nine of the patients with CRF had moderate to severe predialysis CRF, 36 patients were on dialysis treatment, and 41 were renal transplant recipients. Mean age of patients was 51.9 +/- 11.5 years, and 39 patients (29%) had diabetes. ABI and TBI were measured by means of photoplethysmography. The definition of PAD required an ABI value of 0.90 or less, a TBI value of 0.60 or less, or a previous positive lower-extremity angiogram result. ABI values of 1.3 or greater or incompressible arteries at ankle level indicated MAC. The presence of claudication was determined by an interview.

RESULTS

Prevalences of PAD on this study were 22.0% in patients with predialysis CRF, 30.6% in patients on dialysis treatment, 14.6% in renal transplant recipients, and 1.7% in the control group (P = 0.001). Prevalences of MAC were 23.7%, 41.7%, 23.1%, and 3.4% (P < 0.001), respectively. Only 9 patients had claudication, and 6 of those patients had PAD.

CONCLUSION

Both asymptomatic PAD and MAC are common in patients with CRF. Therefore, we recommend the use of both ABI and TBI measurements in the evaluation of PAD in patients with CRF.

A common promoter polymorphism in the hepatic lipase gene (LIPC-480C>T) is associated with an increase in coronary calcification in type 1 diabetes

Type 1 diabetes is associated with coronary heart disease (CHD) and coronary artery calcification (CAC), a measure of subclinical CHD. The hepatic lipase gene promoter polymorphism (LIPC-480C>T) is a common variant affecting lipid metabolism. This study examined the relation between the LIPC-480C>T and CAC in type 1 diabetes. In the type 1 diabetic patients studied, 56% had CAC >0 Agatston units (AU). These subjects had a longer duration of diabetes (26.2 +/- 1.3 vs. 17.8 +/- 1.4 years; P < 0.001), lower HDL cholesterol levels (55.7 +/- 2.4 vs. 61.0 +/- 2.5 mg/dl; P = 0.05), higher triglyceride levels (101 +/- 17.3 vs. 66 +/- 7.6 mg/dl; P < 0.05), and higher diastolic blood pressure (79.7 +/- 1.0 vs. 76.0 +/- 1.4 mmHg; P < 0.05). The LIPC-480 T allele was more common in subjects with CAC (frequency = 0.31 +/- 0.05 vs. 0.14 +/- 0.04; P = 0.006). The proportion with CAC was 44% in LIPC-480CC subjects, 71% in heterozygotes, and 83% in LIPC-480TT subjects (P < 0.01). LIPC-480 T allele frequency increased as the amount of CAC increased (P = 0.007). LIPC-480 genotype was independently associated with the CAC (odds ratio = 2.90, 95% CI 1.22-6.92, P < 0.05) after adjusting for duration of diabetes, age, sex, diastolic blood pressure, HDL cholesterol, and triglyceride levels. In conclusion, the LIPC-480C>T polymorphism was associated with subclinical CHD in type 1 diabetes. This genetic variant may identify subjects in which early intervention to prevent CHD may be appropriate.

Treating peripheral arterial disease in patients with diabetes

Diabetes is associated with considerably higher risks of developing peripheral arterial disease (PAD) which, when it occurs, is more severe and progresses more rapidly than in nondiabetics. Early detection of PAD in the diabetic patient is therefore important, but may be complicated by the presence of neuropathy and calcification of the arteries such that ischaemic symptoms are not felt by the patient and ankle pressures are not reduced. Toe pressures are an alternative diagnostic tool in these patients. Good glycaemic control, while an essential part of diabetes management, does not appear to bring more than modest benefits in preventing the peripheral vascular complications of diabetes. Therefore, attention to other risk factors is needed. Treatment with the phosphodiesterase III inhibitor, cilostazol, has been shown to improve walking distances significantly in diabetes patients with intermittent claudication and also appears to improve plasma lipid profiles. Further, cilostazol has an antiplatelet action, which may prove to be of benefit in diabetes because hyperglycaemia is associated with increased platelet aggregability. Revascularization in diabetes patients with critical leg ischaemia is complex and associated with poorer outcomes than in non-diabetes patients. While surgical revascularization has better patency rates, in patients at high risk of surgical complications, percutaneous transluminal angioplasty may be a better option.