Microvascular complications of impaired glucose tolerance

Elevated neurofilament light chain (NFL) mRNA levels in prediabetic peripheral neuropathy

Evidence suggests that peripheral nerve injury occurs during the early stages of disease with mild glycemic dysregulation. Two proteins, neuron-specific enolase (NSE) and neurofilament light chain (NFL), have been examined previously as possible markers of neuronal damage in the pathophysiology of neuropathies. Herein, we aimed to determine the potential value of circulatory NSE and NFL mRNA levels in prediabetic patients and in those with peripheral neuropathy. This prospective clinical study included 45 prediabetic patients and 30 age- and sex-matched controls. All prediabetic patients were assessed with respect to diabetes-related microvascular complications, such as peripheral neuropathy, retinopathy and nephropathy. mRNA levels of NSE and NFL were determined in the blood by real-time polymerase chain reaction. NSE mRNA levels were similar between prediabetic and control groups (p > 0.05), whereas NFL mRNA levels were significantly higher in prediabetics than in controls (p < 0.001). NSE mRNA levels did not significantly differ between prediabetic patients with and without peripheral neuropathy (p > 0.05), while NFL mRNA levels were significantly higher in prediabetics with peripheral neuropathy than in those without (p = 0.038). According to correlation analysis, NFL mRNA levels were positively correlated with the Douleur Neuropathique 4 questionnaire score in prediabetic patients (r = 0.302, p = 0.044). This is the first study to suggest blood NFL mRNA as a surrogate marker for early prediction of prediabetic peripheral neuropathy, while NSE mRNA levels may be of no diagnostic value in prediabetic patients.

Exercising with peripheral or autonomic neuropathy: what health care providers and diabetic patients need to know

Both peripheral and autonomic neuropathies are characterized by a progressive loss of nerve fiber function. Most peripheral neuropathy affects the extremities, particularly the lower legs and the feet, but also the hands, whereas damage to the autonomic nervous system may lead to imbalances between the sympathetic and parasympathetic nerve fibers that innervate the heart and blood vessels, as well as abnormalities in heart rate control and vascular dynamics. To prescribe or engage in exercise that is both safe and effective, health care providers and patients with diabetes mellitus need to increase their understanding of the pathophysiological nature of neuropathies and the physical activity hurdles that may arise from the presence of a neuropathy. With proper care and preventative measures, patients with diabetes mellitus that experience either type of neuropathy can benefit from regular participation in mild to moderate aerobic, resistance, and balance activities, assuming they take any potential alterations into account to ensure that exercise is safe and effective.

General aspects of diabetes mellitus

Diabetes mellitus is a heterogeneous group of disorders characterized by hyperglycemia due to an absolute or relative deficit in insulin production or action. The chronic hyperglycemia of diabetes mellitus is associated with end organ damage, dysfunction, and failure, including the retina, kidney, nervous system, heart, and blood vessels. The International Diabetes Federation (IDF) estimated an overall prevalence of diabetes mellitus to be 366 million in 2011, and predicted a rise to 552 million by 2030. The treatment of diabetes mellitus is determined by the etiopathology and is most commonly subdivided in type 1 and type 2 diabetes mellitus. There is a greater propensity towards hyperglycemia in individuals with coexisting genetic predisposition or concomitant drug therapy such as corticosteroids. The screening for diabetes mellitus may either be in the form of a 2hour oral glucose tolerance test, or via HbA1c testing, as recently recommended by the American Diabetes Association (ADA). Strong associations have been shown in observational studies suggesting poor clinical outcomes both with chronic hyperglycemia and acutely in intensive care settings. However, tight glycemic control in this setting is a contentious issue with an increased incidence of hypoglycemia and possible increase in morbidity and mortality. In a critically ill patient a glucose range of 140-180mg/dL (7.8-10.0mmol/L) should be maintained via continuous intravenous insulin infusion.

TOR-centric view on insulin resistance and diabetic complications: perspective for endocrinologists and gerontologists

This article is addressed to endocrinologists treating patients with diabetic complications as well as to basic scientists studying an elusive link between diseases and aging. It answers some challenging questions. What is the link between insulin resistance (IR), cellular aging and diseases? Why complications such as retinopathy may paradoxically precede the onset of type II diabetes. Why intensive insulin therapy may initially worsen retinopathy. How nutrient- and insulin-sensing mammalian target of rapamycin (mTOR) pathway can drive insulin resistance and diabetic complications. And how rapamycin, at rational doses and schedules, may prevent IR, retinopathy, nephropathy and beta-cell failure, without causing side effects.

Relationship between fermented papaya preparation supplementation, erythrocyte integrity and antioxidant status in pre-diabetics

Erythrocytes and their membranes are favorable models to study the relationship between diabetes and susceptibility of erythrocytes to oxidative stress damage. The recommendation for the use of fermented papaya preparation (FPP) as a functional food for dietary management of type 2 diabetes was evaluated by assessing its effect on the human antioxidant status and erythrocyte integrity on a multi-ethnical pre-diabetic population. The in vivo effect of FPP was compared with its in vitro free radical scavenging potentials. FPP exhibited potent in vitro free radical scavenging activities thought to be attributed to residual phenolic or flavonoid compounds. Low doses of FPP significantly reduced the susceptibility of human erythrocytes to undergo free radical-induced hemolysis. The intake of 6g FPP/day for a period of 14weeks was observed to significantly reduce the rate of hemolysis and accumulation of protein carbonyls in the blood plasma of pre-diabetics. That FPP consumption on a daily basis can strengthen the antioxidant defense system in vivo was clearly demonstrated by the marked increase of total antioxidant status in the FPP-supplemented pre-diabetics. That FPP maintains the integrity of erythrocytes could benefit the strategies to improve the quality of future blood products.

Impact of diabetes and peripheral arterial occlusive disease on the functional microcirculation at the plantar foot

BACKGROUND

Plastic and reconstructive surgeons are commonly faced with chronic ulcerations and consecutive wound infections of the feet as complications in patients with diabetes and/or peripheral arterial occlusive disease (PAOD). Microcirculatory changes seem to play an important role. However, the evaluation of functional changes in the soft tissue microcirculation at the plantar foot using combined Laser-Doppler and Photospectrometry System has not yet been performed in patients with DM or PAOD.

METHODS

A prospective, controlled cohort study was designed consisting of a total of 107 subjects allocated to 1 of 3 groups-group A: healthy subjects (57% males, 63.3 y); group B: patients with diabetes mellitus (DM) (53% males, 59.4 y); and group C: patients with PAOD (81% males, 66.1 y). Microcirculatory data were assessed using a combined Laser-Doppler and Photospectrometry System.

RESULTS

Global cutaneous oxygen saturation microcirculation at the plantar foot of healthy individuals was 8.4% higher than in patients with DM and 8.1% higher than in patients with PAOD (both P = 0.033). Patients with diabetes did not show significant differences in global cutaneous blood flow when compared with either healthy subjects or patients suffering from PAOD.

CONCLUSIONS

Functional microcirculation at the plantar foot differs between healthy subjects and patients suffering from diabetes or PAOD of the same age. Patients with either diabetes or PAOD demonstrate deteriorated cutaneous oxygen saturation with equivalent blood perfusion at the plantar foot. More clinical studies have to be conducted to evaluate therapeutical methods that might ameliorate cutaneous oxygen saturation within diabetic foot disease and PAOD.

Sodium-glucose cotransporter inhibition: therapeutic potential for the treatment of type 2 diabetes mellitus

Results from randomized controlled trials have demonstrated that the risk of microvascular complications can be reduced by intensive glycaemic control in patients with type 2 diabetes mellitus (T2DM). However, only about half of patients with diagnosed diabetes achieve recommended glycaemic goals. New therapies with complementary mechanisms of action that are independent of insulin secretion or action may provide additional therapeutic options to enable patients to achieve glycaemic control. The kidney plays an important role in glucose homeostasis, primarily by the reabsorption of filtered glucose. The sodium-glucose cotransporter 2 (SGLT2), located in the proximal convoluted tubule, is responsible for the majority of glucose reabsorption by the kidney. SGLT2 inhibitors offer a novel approach to treat T2DM and reduce hyperglycaemia by increasing urinary excretion of glucose. Dapagliflozin, an SGLT2 inhibitor recently approved in Europe for the treatment of T2DM, improves glycaemic control in patients with T2DM when used as monotherapy or when added to other diabetes medications, such as metformin, sulfonylureas, pioglitazone, and insulin. As a class, SGLT2 inhibitors are well tolerated and have a low propensity to cause hypoglycaemia. An increase in signs, symptoms, and other events suggestive of genital and, in some studies, urinary tract infections has been reported with SGLT2 inhibitors. Results from ongoing and future clinical trials will help define the role for this new class of investigational compounds, with its unique mechanism of action, as a treatment option for reducing hyperglycaemia in patients with T2DM.

Genome-wide association study of retinopathy in individuals without diabetes

Background

Mild retinopathy (microaneurysms or dot-blot hemorrhages) is observed in persons without diabetes or hypertension and may reflect microvascular disease in other organs. We conducted a genome-wide association study (GWAS) of mild retinopathy in persons without diabetes.

Methods

A working group agreed on phenotype harmonization, covariate selection and analytic plans for within-cohort GWAS. An inverse-variance weighted fixed effects meta-analysis was performed with GWAS results from six cohorts of 19,411 Caucasians. The primary analysis included individuals without diabetes and secondary analyses were stratified by hypertension status. We also singled out the results from single nucleotide polymorphisms (SNPs) previously shown to be associated with diabetes and hypertension, the two most common causes of retinopathy.

Results

No SNPs reached genome-wide significance in the primary analysis or the secondary analysis of participants with hypertension. SNP, rs12155400, in the histone deacetylase 9 gene (HDAC9) on chromosome 7, was associated with retinopathy in analysis of participants without hypertension, −1.3±0.23 (beta ± standard error), p = 6.6×10⁻⁹. Evidence suggests this was a false positive finding. The minor allele frequency was low (∼2%), the quality of the imputation was moderate (r² ∼0.7), and no other common variants in the HDAC9 gene were associated with the outcome. SNPs found to be associated with diabetes and hypertension in other GWAS were not associated with retinopathy in persons without diabetes or in subgroups with or without hypertension.

Conclusions

This GWAS of retinopathy in individuals without diabetes showed little evidence of genetic associations. Further studies are needed to identify genes associated with these signs in order to help unravel novel pathways and determinants of microvascular diseases.

Lifestyle impact on meal-induced insulin sensitization in health and prediabetes: A focus on diet, antioxidants, and exercise interventions

The augmented whole-body glucose uptake response to insulin during the postprandial state is described as meal-induced insulin sensitization (MIS). MIS occurs when the presence of food in the upper gastrointestinal tract activates 2 feeding signals (activation of hepatic parasympathetic nerves and elevation of hepatic glutathione level), and causes insulin to release hepatic insulin sensitizing substance (HISS), which stimulates glucose uptake in skeletal muscle, heart, and kidneys. HISS action results in nutrient storage, primarily as glycogen. Impairment of HISS release results in the absence of meal-induced insulin sensitization (AMIS), which causes postprandial hyperglycemia and hyperinsulinemia, and chronically leads to the progression to a cluster of metabolic, vascular, and cardiac dysfunctions, which we refer to as components of the AMIS syndrome. Manipulation of the MIS process in health and in disease, by pharmacological and nonpharmacological interventions, is outlined in this review. High fat or sugar supplemented diet reduces MIS; exercise elevates MIS; and antioxidants protect MIS against reductions associated with diet and age.

Serial anthropometry predicts peripheral nerve dysfunction in a community cohort

BACKGROUND

Obesity is a risk factor for glucose intolerance, but the independent role of obesity in the development of peripheral neuropathy is unclear. This study assessed the impact of body size trajectories on prevalent nerve dysfunction in community-dwelling women with and without glucose intolerance.

METHODS

Annual (1996-2008) anthropometric measures of weight, height, waist circumference and body mass index [BMI, weight (kg)/height (m(2) )] were assessed in the Study of Women's Health Across the Nation - Michigan site. Glucose intolerance was defined annually on the basis of current use of diabetes medications, self-reported diabetes diagnosis and, when available, fasting glucose. Peripheral nerve dysfunction in 2008 was defined as abnormal monofilament testing or ≥4 symptoms or signs. Linear mixed models were used to determine trajectories of anthropometry by subsequently identified nerve dysfunction status.

RESULTS

Mean BMI was 32.4 kg/m(2) at baseline, and 27.8% of the women had nerve dysfunction in 2008. BMI, weight and waist circumference increased over time. Women who would have nerve dysfunction were significantly larger than women without dysfunction, independent of glucose intolerance. At mean baseline age of 46, BMI, weight and waist circumference differed significantly (p-value < 0.01) by subsequent nerve dysfunction status, independent of glucose intolerance and hypertension. These body size differences were maintained but not exacerbated over time.

CONCLUSIONS

Peripheral nerve dysfunction is prevalent among community-dwelling women. Twelve years before the nerve assessment, anthropometry differed between women who would and would not have nerve dysfunction, differences that were maintained over time. Obesity deserves attention as an important and potentially modifiable risk factor for peripheral nerve dysfunction.

Retinal not systemic oxidative and inflammatory stress correlated with VEGF expression in rodent models of insulin resistance and diabetes

PURPOSE

To correlate changes between VEGF expression with systemic and retinal oxidative stress and inflammation in rodent models of obesity induced insulin resistance and diabetes.

METHODS

Retinal VEGF mRNA and protein levels were assessed by RT-PCR and VEGF ELISA, respectively. Urinary 8-hydroxydeoxyguanosine (8-OHdG), blood levels of C-reactive protein (CRP), malondialdehyde (MDA), and CD11b/c positive cell ratio were used as systemic inflammatory markers. Retinal expression of Nox2, Nox4, and p47phox mRNA levels were measured as oxidative stress markers. TNF-α, inter-cellular adhesion molecule-1 (ICAM-1), IL1β, and activation of nuclear factor κB (NF-κB) were used as retinal inflammatory markers.

RESULTS

Retinal VEGF mRNA and protein expression increased in Zucker diabetic fatty (ZDF(fa/fa)) rats and streptozotosin (STZ) induced diabetic Sprague-Dawley rats, after two months of disease, but not in Zucker fatty (ZF) rats. Systemic markers of oxidative stress and inflammation were elevated in insulin resistant and diabetic rats. Some oxidative stress and inflammatory markers (TNF-α, IL-6, ICAM-1, and IL1-β) were upregulated in the retina of ZDF(fa/fa) and STZ diabetic rats after 4 months of disease. In contrast, activation of NF-κB in the retina was observed in high fat fed nondiabetic and diabetic cis-NF-κB(EGFP) mice, ZF, ZDF(fa/fa), and STZ-induced diabetic rats.

CONCLUSIONS

Only persistent hyperglycemia and diabetes increased retinal VEGF expression. Some markers of inflammation and oxidative stress were elevated in the retina and systemic circulation of obese and insulin resistant rodents with and without diabetes. Induction of VEGF and its associated retinal pathologies by diabetes requires chronic hyperglycemia and factors in addition to inflammation and oxidative stress.

A very low carbohydrate ketogenic diet prevents the progression of hepatic steatosis caused by hyperglycemia in a juvenile obese mouse model

Objective:

To investigate whether the improvement in hyperglycemia by dietary control influences hyperglycemia-induced pathologies in tissues of juvenile obese (ob/ob) mice.

Design:

Five-week-old ob/ob mice were fed a very low carbohydrate ketogenic diet (KD) for 7 weeks. The blood glucose levels and body weight were monitored during this period. Biochemical parameters in the serum and tissue pathologies of the mice were analyzed at the end of the 7-week period.

Results:

The hyperglycemic phenotype of the ob/ob mice was improved by KD feeding for 7 weeks. Surprisingly, we found that KD feeding also drastically reduced the hepatic steatosis phenotype in ob/ob mice, while their obesity phenotype was unaltered. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that several proteins found in the liver of ob/ob mice fed a regular chow diet were undetectable after being fed KD. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) MASCOT search and western blot analysis revealed that the proteins absent from the mice fed KD included fatty acid synthase (FAS) and acetyl-CoA carboxylase 1 (ACC1), which are key enzymes for lipogenesis in the liver. Fatty acid analysis supported the results because the ratio of C18:1, which is a major product of lipogenesis, was reduced by KD feeding. However, C18:2, which cannot be synthesized in mammalian cells but is present in the KD, was found to be a major component in the liver of KD-fed ob/ob mice.

Conclusion:

Hyperglycemia promotes hepatic steatosis via the lipogenic pathway in the liver of juvenile ob/ob mice. However, the development of steatosis is prevented by feeding KD owing to an improvement in hyperglycemia. We found that the progression of steatosis is reflected by the composition of fatty acids in the total lipids of the liver and serum.

Variables associated with corneal confocal microscopy parameters in healthy volunteers: implications for diabetic neuropathy screening

AIM

Corneal confocal microscopy is a promising screening method for diabetic neuropathy. Although much research in this field has been accomplished, we aimed to determine and confirm the known clinical and eyewear variables associated with the parameters of corneal confocal microscopy specifically in healthy volunteers, in particular associations with corneal nerve fibre length.

METHODS

Clinical characteristics, electrophysiological examination and a general clinical eye history were collected from 64 healthy volunteers. Corneal confocal microscopy was performed to determine corneal nerve fibre length, corneal nerve branch density, corneal nerve fibre density and tortuosity coefficient. Univariate and multivariate linear regression analysis was used to determine clinical variables associated with corneal nerve fibre length parameters.

RESULTS

We observed that corneal nerve fibre length has a broad distribution in healthy volunteers (18 ± 4 mm/mm(2), 95% confidence interval, 12.3-25.7 mm/mm(2)). Multivariate regression analysis demonstrated that HbA(1c) was the only independent clinical factor to account for variations in corneal nerve fibre length, independent of age and status of contact lens wear.

CONCLUSIONS

This study does not provide convincing evidence that corneal nerve fibre length is independently associated with age or the wearing of contact lenses, and that these factors are therefore unlikely to hinder valid screening for polyneuropathies such as diabetic neuropathy. Furthermore, the strong inverse association of corneal nerve fibre length with glycaemic exposure may support the use of this parameter to detect subclinical pre-diabetic nerve injury.

Impaired glucose tolerance and metabolic syndrome in idiopathic neuropathy

Idiopathic neuropathy is one of the most common clinical problems encountered in general medical and neurological practices, accounting for up to 40% of all neuropathies in referral series. Several groups have reported an elevated prevalence of impaired glucose tolerance (IGT) in idiopathic neuropathy subjects, although the only carefully conducted case-control study suggested hypertriglyceridemia was a more important risk factor. The nature of the relationship between IGT and neuropathy is a subject of active debate. An evolving literature suggests metabolic syndrome, particularly dyslipidemia and obesity, are potent neuropathy risk factors for both idiopathic and diabetic neuropathy patients. Once established, diabetic neuropathy is likely to be very difficult to reverse. IGT-associated neuropathy, however, may be more amenable to therapy and could represent an ideal population in which to examine potential therapies for diabetes and obesity related neuropathies. Further research is needed to better define the epidemiological relation between IGT, metabolic syndrome, and neuropathy, its underlying pathophysiology, and to develop appropriate surrogate measures and clinical trials strategies.

Pré-diabetes: diagnóstico, avaliação de complicações crônicas e tratamento

O diabetes melito do tipo 2 (DM2) é responsável por 90% dos casos de diabetes e está associado a complicações micro e macrovasculares de elevada morbimortalidade. Os indivíduos com maior risco de desenvolvimento de DM incluem aqueles com glicemia de jejum alterada (GJA) e tolerância diminuída à glicose (TDG) e especialmente aqueles com as duas condições combinadas. Esses indivíduos fazem parte de um grupo hoje conhecido como pré-diabetes. Aproximadamente 25% dos indivíduos com pré-diabetes desenvolverão DM2 em três a cinco anos. A hiperglicemia, na ausência de DM, também foi associada ao aumento no risco de doença cardiovascular. Estudos demonstraram que mudanças no estilo de vida e intervenções medicamentosas são efetivas em retardar ou prevenir o DM2 em pacientes com pré-diabetes. GJA e TDG estão associadas ao desenvolvimento de DM2 e, apesar das controvérsias, a maioria dos estudos epidemiológicos reforça a importância dessas duas condições também no desenvolvimento de doença micro e macrovascular. Assim, intervenções em pacientes com pré-diabetes são importantes na prevenção primária do DM2 e de suas complicações crônicas.

Glucose tolerance status is a better predictor of diabetes and cardiovascular outcomes than metabolic syndrome: a prospective cohort study

BACKGROUND

To evaluate the importance of oral glucose tolerance test (OGTT) in predicting diabetes and cardiovascular disease in patients with and without Metabolic Syndrome from a population treated in a primary care unit.

RESEARCH DESIGN AND METHODS

A prospective cohort study was conducted with subjects regularly attending the primary care unit of Hospital de Clínicas de Porto Alegre. Participants underwent a 75 g OGTT. Metabolic syndrome definition was based on the criteria of IDF/AHA/NHLBI-2010.

RESULTS

Participants mean age was 61 ± 12 years (males: 38%; whites: 67%). Of the 148 subjects included, 127 (86%) were followed for 36 ± 14 months, 21 (14%) were lost. Subjects were classified into four groups based on baseline OGTT: 29% normal (n = 43), 28% impaired fasting glucose (IFG; n = 42), 26% impaired glucose tolerance (IGT; n = 38), and 17% diabetes (n = 25). Metabolic syndrome prevalence was lower in normal group (28%), intermediate in IFG (62%) and IGT (65%) groups, and higher among subjects with diabetes (92%; P <0.001). Incidence of diabetes increased along with the stages of glucose metabolism disturbance (normal: 0%, IFG: 16%, IGT: 28%; P = 0.004). No patient with normal OGTT developed diabetes, regardless metabolic syndrome presence. Diabetes at baseline was the major determinant of cardiovascular disease occurrence (normal: 0%, IFG: 4%, IGT: 0%, diabetes: 24%; P = 0.001). In Cox-regression analysis, only the 2 h OGTT results were associated with diabetes (OR = 1.03; 95%CI 1.01-1.06; P <0.001) and cardiovascular disease development (OR = 1.013; 95%CI 1.002-1.025; P = 0.024).

CONCLUSIONS

In this sample of subjects undergoing diabetes screening, the OGTT predicted diabetes and cardiovascular disease more effectively than the metabolic syndrome status.

Preoperative hyperglycemia and complication risk following neurosurgical intervention: A study of 918 consecutive cases

Background:

Little is known about the relation between preoperative glycemic state and neurosurgical outcomes. Improved understanding of this relationship may identify patients at increased risk of complicated recovery and guide postoperative treatment strategies.

Methods:

Data were collected about 918 consecutive craniotomy or spine-related neurosurgical cases at the University of Michigan Hospitals. Univariate statistics, bivariate chi-square tests, and analysis of variance were used to assess relations between preoperative blood glucose, demographics, medical comorbidities, systemic glucocorticoid use, and postoperative complication risk and postoperative hospital and intensive care unit (ICU) stay. We fit a multivariable logistic regression model of 30-day complication risk by preoperative blood glucose adjusted for potential confounders, and used analysis of covariance to assess the relation between preoperative blood glucose and hospital, as well as ICU stay, adjusted for potential confounders.

Results:

Among all patients, 56.1% had peri-operative blood glucose levels below 100 mg/dl. 20.7% had levels from 100 to 120 mg/dl, 16.3% had levels from 121 to 160 mg/dl, and 6.9% had levels greater than 160 mg/dl. In multivariable regression models, blood glucose greater than 120 mg/dl was associated with increased risk of postoperative complications at all levels. Analysis of covariance showed that preoperative blood glucose above 120 mg/dl was associated with both increased length of ICU stay and length of hospital stay.

Conclusions:

Our findings suggest that even mild preoperative hyperglycemia is a predictor of postoperative complication risk, and prolonged hospital and ICU stay following neurosurgical intervention. Tight glycemic control may be in order when attempting to reduce risk of complications and limit postoperative recovery time.

Potential antidiabetic effect of the Semecarpus anacardium in a type 2 diabetic rat model

Semecarpus anacardium Linn. nut milk extract (SA) was evaluated for its antidiabetic role in type 2 diabetic rats. Type 2 diabetes was induced in rats by feeding high-fat diet for 2 weeks followed by single intraperitoneal injection of streptozotocin 35 mg/kg body weight. Diabetic rats were treated with SA orally at a dosage of 200 mg/kg body weight daily for 30 days. Metformin (500 mg/kg body weight, orally) was used as a reference drug. SA significantly (p < 0.05) reduced the blood glucose levels and decreased the levels of HbA1c and the glucose intolerance. SA treatment significantly (p < 0.05) decreased the increase in lipid profile. The levels of urea, uric acid and creatinine were restored to near normal levels when compared with control diabetic rats. The histopathological abnormalities were also found to be normalized after treatment with SA nut milk extract. The potential antihyperglycemic action of SA is plausibly due to its underlying antioxidant role.

Insulin resistance is independently associated with peripheral and autonomic neuropathy in Korean type 2 diabetic patients

In addition to chronic hyperglycemia, insulin resistance itself has been proposed to cause a diabetic neuropathy. We evaluated the role of insulin resistance in the pathogenesis of peripheral and autonomic neuropathy in patients with type 2 diabetes. Eighty-six patients with type 2 diabetes were evaluated for the anthropometric and biochemical profiles, and Kitt value was calculated from insulin tolerance test to assess the insulin resistance. Various autonomic function tests, nerve conduction velocity, and quantitative sensory tests were performed to assess autonomic and peripheral neuropathy. In univariate analysis, both autonomic and peripheral neuropathy were significantly associated with glycemic exposure index (GE index), HDL-cholesterol, duration of DM, and Kitt value. In stepwise linear regression analysis, GE index was an independent predictor of autonomic and peripheral neuropathy (β = 0.643, P < 0.001; β = 0.207, P = 0.013, respectively), and Kitt value was also an independent factor for the autonomic and peripheral neuropathy (β = - 0.306, P < 0.001; β = - 0.329, P < 0.001, respectively). Low HDL-cholesterol increased the odds ratio for peripheral neuropathy. Insulin resistance is independently associated with peripheral and autonomic neuropathy in Korean Type 2 diabetic patients along with hyperglycemia and HDL-cholesterol.

Pre-diabetes, metabolic syndrome, and cardiovascular risk

Pre-diabetes represents an elevation of plasma glucose above the normal range but below that of clinical diabetes. Pre-diabetes can be identified as either impaired fasting glucose (IFG) or impaired glucose tolerance (IGT). The latter is detected by oral glucose tolerance testing. Both IFG and IGT are risk factors for type 2 diabetes, and risk is even greater when IFG and IGT occur together. Pre-diabetes commonly associates with the metabolic syndrome. Both in turn are closely associated with obesity. The mechanisms whereby obesity predisposes to pre-diabetes and metabolic syndrome are incompletely understood but likely have a common metabolic soil. Insulin resistance is a common factor; systemic inflammation engendered by obesity may be another. Pre-diabetes has only a minor impact on microvascular disease; glucose-lowering drugs can delay conversion to diabetes, but whether in the long run the drug approach will delay development of microvascular disease is in dispute. To date, the drug approach to prevention of microvascular disease starting with pre-diabetes has not been evaluated. Pre-diabetes carries some predictive power for macrovascular disease, but most of this association appears to be mediated through the metabolic syndrome. The preferred clinical approach to cardiovascular prevention is to treat all the metabolic risk factors. For both pre-diabetes and metabolic syndrome, the desirable approach is lifestyle intervention, especially weight reduction and physical activity. When drug therapy is contemplated and when the metabolic syndrome is present, the primary consideration is prevention of cardiovascular disease. The major targets are elevations of cholesterol and blood pressure.

Pilot study for the evaluation of morphological and functional changes in retinal blood flow in patients with insulin resistance and/or type 2 diabetes mellitus

BACKGROUND

The aim of this study was to investigate early morphological and functional pathology in the retinal micro-circulation in patients with insulin resistance and/or type 2 diabetes mellitus (T2DM).

METHODS

Fifty-four subjects, without features of retinopathy under ophthalmological investigation, were recruited for study participation and were classified into three study groups according to their metabolic staging: (1) Group C comprised nondiabetic, insulin-sensitive subjects with a BMI <28 kg/m(2); (2) Group IR comprised nondiabetic, insulin-resistant, obese subjects with a BMI ≥28 kg/m(2); and (3) Group DM comprised patients with manifested T2DM. Retinal microvascular blood flow was assessed using scanning laser doppler flowmetry (Heidelberg Retina Flowmeter) before and after flicker light stimulation (10 Hz; Photo Stimulater 750).

RESULTS

No significant difference was observed in retinal blood flow (RBF) among the three groups, neither at baseline nor after stimulating the retina with flicker light. The arterial wall-to-lumen ratio (WLR) tended to be smaller in Group DM compared with Group C, and was significantly lower when comparing Group IR with Group C. When the subjects were grouped according to their insulin resistance, a steady decline in RBF and WLR could be observed with increasing insulin resistance.

CONCLUSIONS

In conclusion, laser scanner flowmetry of the retina was found to detect very early changes in microvascular blood flow. Development of insulin resistance seems to be an important component in the deterioration of RBF.

IMproving the imPlemEntation of cuRrent guidelines for the mAnagement of major coronary hearT disease rIsk factors by multifactorial interVEntion. The IMPERATIVE renal analysis

INTRODUCTION

The short-term effects of multifactorial intervention for cardiovascular disease (CVD) prevention on renal function and serum uric acid (SUA) levels in patients with stage 3 chronic kidney disease (CKD) and multiple CVD risk factors are unclear. The aim of the study was to prospectively assess these effects.

MATERIAL AND METHODS

This post hoc analysis of 5 "best practice" studies involved patients with multiple CVD risk factors. Estimated glomerular filtration rate (eGFR) was assessed using the Modification of Diet in Renal Disease (MDRD) formula. Among the 4,153 patients, 1,235 (29.7%) had stage 3 CKD (eGFR between 30 and 59 ml/min/1.73 m(2)). A baseline visit was followed by a concerted effort from previously trained physicians to improve adherence to lifestyle advice and optimize drug treatment, including a statin, for all vascular risk factors. After 6 months eGFR and SUA levels were re-evaluated.

RESULTS

The intervention improved compliance to lifestyle measures and increased the use of evidence-based medication, including a statin. There was also a 5.6% increase in eGFR (p < 0.001) in patients with stage 3 CKD and a 6.1% reduction in SUA levels (p < 0.001). Among patients with stage 3 CKD, 127 (10.3%) improved to stage 2 CKD and 9 (0.7%) advanced to stage 4 CKD by the end of the 6-month study period. There were no major side-effects.

CONCLUSIONS

Multitargeted intervention, including a statin, may improve renal function and reduce SUA levels within 6 months, thus offsetting 2 potential CVD risk factors in high-risk patients.

Intramuscular injection of soluble receptor for advanced glycation endproducts expression vector prevents the development of streptozotocin-induced diabetes mellitus in rats on high fat diet

BACKGROUND

In order to study if advanced glycation endproducts (AGE) in high-temperature cooked high fat diet could be the cause of type 2 diabetes, a expressing vector encoding soluble form of receptor for AGE (sRAGE) was injected intramuscularly, and the incidence of streptozotocin (STZ)-induced diabetes mellitus in rats on high fat diet were observed.

METHODS

Rat sRAGE gene, cloned to a pLNCX(2) expression vector (pLNCX(2) -sRAGE), was injected into the hind leg muscles of Sprague-Dawley rats. Rats were fed with high fat diet for 8 weeks before pLNCX(2) -sRAGE injection (designed as T group), or pLNCX2 (as H group), and rats on normal chow (as N group). The diet remained the same until end of the study. Serum malondialdehyde (MDA) and superoxide dismutase (SOD) levels were studied in one serial of rats (n = 8) under the treatment of different vectors without STZ injection. For a second serial of study (n = 20), rats were injected with 30 mg/kg STZ intraperitoneally 2 weeks after the second injection of vectors, and tail blood glucose was detected 1 week later.

RESULTS

Malondialdehyde levels were found to be decreased 1 week after injection of sRAGE and lasted for at least 3 weeks after each injection. SOD activities were found to be increased slowly in the second week after each injection. As determined with fasting and random glycemia only two rats were in diabetic level (fasting glycemia ≥7.0 mmol/L and random glycemia ≥11.1 mmol/L) in T group while eight mice were in the diabetic level in H group.

CONCLUSIONS

Intramuscular injection of sRAGE decreases the MDA level and increases SOD activities, and decreases the STZ-induced incidence of diabetes in rats in high fat diet.

Elevated serum levels of advanced glycation end products and their monocyte receptors in patients with type 2 diabetes

BACKGROUND AND AIMS

Animal experiments showed that interaction between advanced glycation end products (AGE) and their receptors (RAGE) play an important role in the pathogenesis of diabetic complications. Soluble RAGE (sRAGE) can function as a decoy for RAGE ligands. The present study aimed to examine the levels of AGEs, RAGE and sRAGE in patients with type 2 diabetes (T2D).

METHODS

RAGE gene expression was determined by real-time PCR in 50 patients with T2D (27 men, mean age 52 ± 7.7 years) and 50 age-matched controls without T2D. Serum AGEs and sRAGEs were assayed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Serum level of AGEs was increased in patients with T2D (10.35 ± 2.27 μg/mL vs.7.69 ± 0.56 μg/mL, p <0.05). sRAGE was decreased in patients with T2D (573.6 ± 172.5 pg/mL vs. 603.4 ± 120.8 pg/mL p <0.01). RAGE gene expression was higher in T2D than in controls (p <0.01). There was an association between monocyte RAGE and serum levels of AGEs in both T2D patients (r = 0.29, p = 0.03) and controls (r = 0.31, p = 0.02). Serum AGEs correlated with homeostasis model assessment of insulin resistance (HOMA-IR) in both patients with T2D (r = 0.322, p = 0.004) and controls (r = 0.281, p = 0.003).

CONCLUSIONS

Serum AGEs and monocyte RAGE expression are increased in patients with T2D, whereas serum sRAGE is decreased. Pharmacological intervention on serum AGEs and sRAGE may be a potential therapy for diabetes.

Is there a divergence in time trends in the prevalence of impaired glucose tolerance and diabetes? A systematic review in South Asian populations

OBJECTIVE

Recently, diabetes prevalence has increased in South Asians making it a global public health priority. There are suggestions that pre-diabetes, including impaired glucose tolerance (IGT), may not be increasing. We conducted a systematic review to explore the paradox. Research Design and Methods We searched electronic databases from inception to June 2009 for cross-sectional studies providing prevalence of pre-diabetes (using WHO criteria) in South Asian adult populations. Two reviewers independently screened articles, performed data extraction, quality appraisal and study classification with any discrepancies resolved by consensus. Repeated cross-sectional studies, categorized by pre-specified criteria, were used for the primary analysis, supplemented by analysis of comparable and all studies.

RESULTS

In total, 79 cross-sectional data sets (from 69 published studies) were identified resulting in the inclusion of 179 408 people. Four sets of repeated cross-sectional studies, conducted in Chennai, rural Tamil Nadu, Mauritius and Singapore (n = 30,399), provided time trend information. Three of them showed an increase in diabetes prevalence (P < 0.001) whereas IGT fell in two (P < 0.05), and was stable in the remainder. A similar pattern was seen among three other sets of comparable studies (n = 58,820) and in scatterplots of all 79 data sets.

CONCLUSION

This novel systematic review is the first to assess secular trends of pre-diabetes in any population. The data show diabetes prevalence is rising, whereas IGT prevalence is stable or falling. Explanations include: recent environmental or lifestyle changes favouring an increased rate of conversion from IGT to diabetes, or a cohort effect with improving maternal and infant nutrition resulting in reduced IGT with a fall in diabetes to follow.

Reactivity of the aorta and mesenteric resistance arteries from the obese spontaneously hypertensive rat: effects of glitazones

The obese spontaneously hypertensive rat (SHROB) is a model of metabolic syndrome in which, to our knowledge, vascular function has never been studied. The actions of insulin sensitizers (glitazones) on vascular function have not been analyzed either. Our purpose was to characterize microvascular and macrovascular responses of the SHROB and to study the effects of glitazones on these responses. The reactivity of mesenteric resistance arteries (MRAs) and the aorta from SHROBs and control rats to cumulative concentrations of phenylephrine, ACh, and sodium nitroprusside (SNP) was myographically analyzed. Some animals were orally treated with rosiglitazone (3 mg·kg−1·day−1, 3 wk), and myography was performed. Phenylephrine, ACh, and SNP dose-response curves were impaired to different extents in arteries of SHROBs. Incubation with N-nitro-l-arginine methyl ester caused little effects on phenylephrine and ACh curves in MRAs but enhanced phenylephrine contractions and abolished ACh-induced relaxations of aortae. Incubation with indomethacin reduced phenylephrine reactivity and improved ACh-induced relaxations of all vessels studied. NS-398 and tempol increased relaxations to ACh of MRAs. Incubation with pioglitazone or rosiglitazone (both 10−5 M) or oral treatment with rosiglitazone improved, to different extents, ACh and SNP curves in all vessels. Glitazone incubation diminished aortic ACh sensitivity. The release of thromboxane A2 and PGI2 metabolites (thromboxane B2 and 6-keto-PGF1α) was analyzed. ACh increased the MRA release of thromboxane B2 from SHROBs but not control rats, and the former was prevented by rosiglitazone coincubation. In contrast, in aortae, ACh failed to alter the release of metabolites, and rosiglitazone treatment increased that of 6-keto-PGF1α. Thus, SHROBs displayed microvascular and macrovascular dysfunction. MRAs, but not aortae, of SHROBs revealed an impaired endothelial nitric oxide pathway, whereas both, but especially MRAs, displayed an impaired cyclooxygenase pathway. Glitazones elicited beneficial effects on macrovascular and, especially, microvascular function of SHROBs.

One-hour postload plasma glucose levels and diastolic function in hypertensive patients

OBJECTIVE

To address whether glucose tolerance status, and in particular 1-h postload plasma glucose levels, may affect diastolic function in 161 never-treated hypertensive white subjects. Impaired left ventricular relaxation, an early sign of diastolic dysfunction, represents the first manifestation of myocardial involvement in diabetic cardiomyopathy. A plasma glucose value ≥155 mg/dL for the 1-h postload plasma glucose during an oral glucose tolerance test (OGTT) is able to identify subjects with normal glucose tolerance (NGT) at high risk for type 2 diabetes and with subclinical organ damage.

RESEARCH DESIGN AND METHODS

Subjects underwent OGTT and standard echocardiography. Diastolic function was assessed by pulsed Doppler transmitral flow velocity and tissue Doppler imaging. Insulin sensitivity was assessed by Matsuda index.

RESULTS

Among the participants, 120 had NGT, 26 had impaired glucose tolerance (IGT), and 15 had type 2 diabetes. According to the 1-h postload plasma glucose cutoff point of 155 mg/dL, we divided NGT subjects as follows: NGT <155 mg/dL (n = 90) and NGT ≥155 mg/dL (n = 30). Those with NGT ≥155 mg/dL had higher left atrium dimensions (P < 0.0001) and isovolumetric relaxation time (IVRT) (P = 0.037) than those with NGT <155 mg/dL. By contrast, early/late transmitral flow velocity and all tissue Doppler parameters were significantly lower in those with NGT ≥155 mg/dL than in those with NGT<155 mg/dL. At multiple regression analysis, 1-h glucose was the major determinant of left atrium area, IVRT, septal e', septal e'-to-a' ratio, lateral e', and lateral e'-to-a' ratio.

CONCLUSIONS

The main finding of this study is that 1-h postload plasma glucose is associated with left ventricular diastolic dysfunction. Subjects with NGT ≥155 mg/dL had significantly worse diastolic function than those with NGT<155 mg/dL.

Diabetic polyneuropathies: update on research definition, diagnostic criteria and estimation of severity

Prior to a joint meeting of the Neurodiab Association and International Symposium on Diabetic Neuropathy held in Toronto, Ontario, Canada, 13-18 October 2009, Solomon Tesfaye, Sheffield, UK, convened a panel of neuromuscular experts to provide an update on polyneuropathies associated with diabetes (Toronto Consensus Panels on DPNs, 2009). Herein, we provide definitions of typical and atypical diabetic polyneuropathies (DPNs), diagnostic criteria, and approaches to diagnose sensorimotor polyneuropathy as well as to estimate severity. Diabetic sensorimotor polyneuropathy (DSPN), or typical DPN, usually develops on long-standing hyperglycaemia, consequent metabolic derangements and microvessel alterations. It is frequently associated with microvessel retinal and kidney disease-but other causes must be excluded. By contrast, atypical DPNs are intercurrent painful and autonomic small-fibre polyneuropathies. Recognizing that there is a need to detect and estimate severity of DSPN validly and reproducibly, we define subclinical DSPN using nerve conduction criteria and define possible, probable, and confirmed clinical levels of DSPN. For conduct of epidemiologic surveys and randomized controlled trials, it is necessary to pre-specify which attributes of nerve conduction are to be used, the criterion for diagnosis, reference values, correction for applicable variables, and the specific criterion for DSPN. Herein, we provide the performance characteristics of several criteria for the diagnosis of sensorimotor polyneuropathy in healthy subject- and diabetic subject cohorts. Also outlined here are staged and continuous approaches to estimate severity of DSPN.

A new approach to glucose control in type 2 diabetes: the role of kidney sodium-glucose co-transporter 2 inhibition

Hyperglycemia is a defining characteristic of type 2 diabetes mellitus and is a major risk factor associated with the development of many microvascular complications. There are numerous therapies currently available to treat hyperglycemia, but glycemic control rates remain poor. One potential reason is the decline in ß-cell function over time, which decreases the effectiveness of therapies that rely on insulin action. The kidney occupies a central position in the control of glucose homeostasis by its role in gluconeogenesis and by regulating glucose excretion. Under normal conditions, glucose filtered by the kidney is virtually totally reabsorbed in the proximal tubule by the sodium-glucose co-transporter 2 (SGLT2). Inhibition of SGLT2 is an attractive, insulin-independent target for increasing glucose excretion in the setting of hyperglycemia. A number of SGLT2 inhibitors have been synthesized, and results from preclinical studies have shown that they increase glucose excretion and normalize plasma glucose in diabetic models. Initial clinical data are promising and suggest that SGLT2 inhibitors may be a new therapeutic option for treating type 2 diabetes mellitus.

The antidiabetic effect of ginsenoside Rb2 via activation of AMPK

Ginsenosides, which are active compounds found in ginseng (Panax ginseng), are used as antidiabetic treatments. The aim of this study was to determine whether Rb2, a type of ginsenoside, regulates hepatic gluconeogenesis through AMP-activated protein kinase (AMPK) and the orphan nuclear receptor small heterodimer partner (SHP) in hyperlipidemic conditions used as an in vitro model of type 2 diabetes. Considering these results, we concluded that Rb2 may inhibit palmitate-induced gluconeogenesis via AMPK-induced SHP by relieving ER stress, a cause of gluconeogenesis.

Treatment of diabetic sensory polyneuropathy

OPINION STATEMENT

No current disease-modifying treatments have been shown definitively in randomized clinical trials to reduce or reverse diabetic sensory polyneuropathy (DSP). It is increasingly recognized that individuals with "prediabetes" or impaired glucose regulation can already have a "small-fiber" neuropathy, or mild DSP, in which sensory axons of both small and larger diameter are damaged. Small-fiber neuropathy is frequently associated with pain, and these patients may present to a neurologist for evaluation before the underlying glucose dysregulation has been diagnosed. It is important to identify these individuals, because aggressive diabetic control and lifestyle interventions can delay the onset of diabetes and may reverse small-fiber neuropathy associated with early diabetes mellitus. Although treatment currently focuses on pain associated with DSP, attention should be paid to potential risk factors for neuropathy. For example, glycemic control and hyperlipidemia should be improved with diet, exercise, and medications. Hypertension that is a risk marker for more severe neuropathy should be treated. Angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers not only treat hypertension but also may directly reduce the progression of neuropathy. Class I or II clinical studies support the use of sodium valproate, pregabalin, duloxetine, amitriptyline, gabapentin, venlafaxine, opioids, and topical capsaicin in treating diabetic neuropathic pain. Pregabalin and gabapentin are relatively well tolerated and have few medication interactions. Sodium valproate has been shown to be effective but is not recommended for use in women of childbearing potential, and patients must be monitored for hepatotoxicity and thrombocytopenia. Tricyclic antidepressants such as amitriptyline are often used for nocturnal pain but require caution in the elderly or anyone with cardiac disease. Venlafaxine and duloxetine successfully treat neuropathic pain independently of their effect on depression. Opioid medications are associated with a high rate of adverse effects but with careful monitoring, they can be effective in treating resistant neuropathic pain. Capsaicin is an effective topical treatment that lacks systemic side effects. The lidocaine patch is effective in relieving pain associated with postherpetic neuralgia, but only class III evidence supports its use for diabetic neuropathic pain. No current Class I or II studies support other treatment modalities.

Neuropathy in prediabetes: does the clock start ticking early?

Between 25% and 62% of patients with idiopathic peripheral neuropathy are reported to have prediabetes, and among individuals with prediabetes 11-25% are thought to have peripheral neuropathy, and 13-21% have neuropathic pain. Population-based studies suggest a gradient for the prevalence of neuropathy, being highest in patients with manifest diabetes mellitus, followed by individuals with impaired glucose tolerance then impaired fasting glucose and least in those with normoglycemia. The most sensitive test to assess glucose metabolism status is the oral glucose tolerance test. Pathogenesis involves hyperglycemia, microvascular abnormalities, dyslipidemia and the metabolic syndrome. Individuals with prediabetes have less severe neuropathy than those with manifest diabetes mellitus. Sensory modalities are more frequently affected than motor modalities, but impairment of small nerve fibers could be the earliest detectable sign. Diagnosis should rely on careful clinical examination, with emphasis on the evaluation of small fibers. An oral glucose tolerance test should be performed in patients with idiopathic neuropathy. The only treatment with any efficacy is lifestyle modification to improve control of hyperglycemia and cardiovascular risk factors, but long-term efficacy of this approach has not been established. This Review summarizes the current evidence on the association between prediabetes and neuropathy.

Exercise and type 2 diabetes: American College of Sports Medicine and the American Diabetes Association: joint position statement. Exercise and type 2 diabetes

Although physical activity (PA) is a key element in the prevention and management of type 2 diabetes mellitus (T2DM), many with this chronic disease do not become or remain regularly active. High-quality studies establishing the importance of exercise and fitness in diabetes were lacking until recently, but it is now well established that participation in regular PA improves blood glucose control and can prevent or delay T2DM, along with positively affecting lipids, blood pressure, cardiovascular events, mortality, and quality of life. Structured interventions combining PA and modest weight loss have been shown to lower T2DM risk by up to 58% in high-risk populations. Most benefits of PA on diabetes management are realized through acute and chronic improvements in insulin action, accomplished with both aerobic and resistance training. The benefits of physical training are discussed, along with recommendations for varying activities, PA-associated blood glucose management, diabetes prevention, gestational diabetes, and safe and effective practices for PA with diabetes-related complications.

Neuropathy and impaired glucose tolerance: an updated review of the evidence

There has been considerable interest in the possible association between impaired glucose tolerance (IGT) and neuropathy. A systematic literature search (Medline) and review was here performed. Twenty-three studies were evaluated. Fourteen investigated for the presence of neuropathy in patients with IGT. Nine studied patients with chronic idiopathic axonal polyneuropathy (CIAP), for the prevalence of IGT. The findings suggest that a significant proportion of patients with IGT may have neuropathy, particularly of the small-fibre and painful type. Similarly, a significant percentage of patients without another identifiable cause for painful axonal neuropathy may have IGT. This may however not be applicable to all populations. There are issues relating to the reproducibility, reliability and timing of a single glucose tolerance test (GTT) in establishing a diagnosis of IGT. Furthermore, it is possible neuropathic damage may occur at lower glucose levels than those defining IGT. In conclusion, further prospective long-term study of large IGT cohorts with known prestudy IGT duration is required to confirm and answer the many remaining questions about this presumed association. However, at present time, consideration of IGT as potential cause of painful small-fibre neuropathy appears justified, especially as patients may benefit from dietary and physical exercise interventions.

Peripheral vascular disease and peripheral neuropathy in individuals with cardiometabolic clustering and obesity: National Health and Nutrition Examination Survey 2001-2004

OBJECTIVE

Two lower-extremity diseases (LEDs), including peripheral neuropathy and peripheral vascular disease (PVD), are leading causes of disability in the U.S. Although LEDs can be complications of diabetes, their prevelances and risk factors apart from diabetes are poorly described. This study describes the prevalence of LEDs and examines the association of obesity and cardiometabolic clustering in a population-based sample.

RESEARCH DESIGN AND METHODS

Adults aged≥40 years (n=2,514) were evaluated in the 2001-2004 National Health and Nutrition Examination Survey for clustering of two or more cardiometabolic characteristics, including elevated triglycerides or plasma glucose, low HDL cholesterol levels, increased waist circumference, or hypertension. Clustering was combined with BMI (dichotomized at ≥30 kg/m2) to generate three groups: obese (with or without clustering); nonobese with clustering; and nonobese without clustering. Multivariate logistic regression procedures incorporated the complex survey sampling design.

RESULTS

Overall, 9.0% of individuals had peripheral neuropathy alone, 8.5% had PVD alone, and 2.4% had both LEDs. The obese group was more likely to have peripheral neuropathy (odds ratio 2.20 [95% CI 1.43-3.39]), PVD (3.10 [1.84-5.22]), and both LEDs (6.91 [2.64-18.06]) compared with nonobese subjects without clustering. Within the nonobese group, clustering increased the odds of peripheral neuropathy (1.50 [1.00-2.25]) and PVD (2.48 [1.38-4.44]) compared with no clustering.

CONCLUSIONS

Obesity and clustering markedly increased the likelihood of LEDs in this sample and identified a group for whom preventive activities may reduce the risk of future disability.

Risk evaluation for coronary artery disease in patients with impaired glucose tolerance after a successful coronary intervention

PURPOSE

Patients with coronary artery disease (CAD) often have risk factors that may influence endothelial function. The purpose of this study was to evaluate the endothelial function and its association with coronary risk factors after percutaneous coronary intervention (PCI).

MATERIALS AND METHODS

A total of 14 patients with impaired glucose tolerance and CAD underwent positron emission tomography with N-13 ammonia to measure myocardial blood flow (MBF) at rest and during a cold pressor test (CPT), to estimate endothelial function as a percent increase (%increase) of MBF. The results were compared among normal segments (normal), reperfused segments with PCI (PCI), and nonculprit CAD segments without PCI (non-PCI). Correlations between the %increase and major risk factors were also investigated.

RESULTS

CPT induced significant increase in MBF in all groups. The %increase of normal, non-PCI, and PCI groups were 33% ± 22%, 21% ± 23%, and 26% ± 23%, respectively. Comparison with risk factors demonstrated significant correlations only in the non-PCI group. Specifically, there were negative correlations between %increase and fasting blood sugar (r = -0.64, P < 0.05), hemoglobin A1c (r = -0.74, P < 0.05), total cholesterol (r = -0.87, P < 0.05), triglyceride (r = -0.71, P < 0.05), and low-density lipoprotein cholesterol (r = -0.92, P < 0.005), respectively.

CONCLUSIONS

Although impaired glucose tolerance patients with a PCI-treated coronary stenosis showed preserved response to CPT, the %increase negatively correlated with risk factors in the non-PCI segments. Therefore, coronary risk factors may affect CAD lesions in PCI-treated patients.

One-hour postload plasma glucose levels and left ventricular mass in hypertensive patients

OBJECTIVE

Left ventricular hypertrophy (LVH), an independent risk factor for cardiovascular (CV) morbidity and mortality, recognizes a multifactorial pathogenesis. A plasma glucose value ≥155 mg/dL for the 1-h postload plasma glucose during an oral glucose tolerance test (OGTT) identifies subjects with normal glucose tolerance (NGT) at high risk for type 2 diabetes. We addressed the question if glucose tolerance status, particularly 1-h postload plasma glucose levels, affects left ventricular mass (LVM) and cardiac geometry in essential hypertension.

RESEARCH DESIGN AND METHODS

We enrolled 767 never-treated hypertensive subjects, 393 women and 374 men (mean age 49.6 ± 8.5 years). All patients underwent an OGTT for the evaluation of glucose tolerance and standard echocardiography. LVM was calculated using the Devereux formula and normalized by body surface area (LVM index [LVMI]). Insulin sensitivity was assessed by the Matsuda index. Among all participants, 514 had NGT, 168 had impaired glucose tolerance (IGT), and 85 had type 2 diabetes. According to the 1-h postload plasma glucose cutoff point of 155 mg/dL, we divided normotolerant subjects into two groups: NGT <155 mg/dL (n = 356) and NGT ≥155 mg/dL (n = 158).

RESULTS

Subjects in the NGT ≥155 mg/dL group had worse insulin sensitivity than subjects in the NGT <155 mg/dL group (Matsuda index 63.9 vs. 88.8; P < 0.0001). Men with NGT ≥155 mg/dL had a higher LVMI than men with NGT <155 mg/dL (126.6 vs. 114.3 g/m(2); P = 0.002) and a different LVH prevalence (41.1 vs. 25.8%; P < 0.0001). At multiple regression analysis, 1-h glucose resulted in the major determinant of LVMI in normotolerant, IGT, and diabetic groups.

CONCLUSIONS

These data show that NGT ≥155 mg/dL subjects, compared with NGT <155 mg/dL subjects, have a higher LVMI and a greater prevalence of LVH similar to that of IGT and diabetic patients.

Screening for type 2 diabetes and dysglycemia

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

Prediabetes influences cardiac rehabilitation in coronary artery disease patients

Background: An abnormal glucose tolerance (AGT) in coronary artery disease (CAD) patients could negatively influence recovery after an acute event but the question, relevant in the field of cardiac rehabilitation (CR), is still controversial.

Design: Prospective study, aiming to establish the prevalence of AGT and its possible influence on functional recovery in CAD patients without a previous diagnosis of diabetes mellitus (DM).

Methods: An oral glucose tolerance test was performed on 230 CAD patients without known DM, submitted to a 2-week period of intensive exercise-based CR after a recent acute myocardial infarction or coronary artery bypass graft. Functional capacity was assessed by a cardiopulmonary exercise test (CPET) and by 6-minute walking tests (6MWT) performed both on admission and at discharge.

Results: The prevalence of AGT in our population was 53%. Exercise capacity was lower in AGT patients (maximum workload achieved at CPET 79.3 ± 29.9 vs. 91.8 ± 36.9 W, p = 0.01; peak-VO2 17.8 ± 4.7 vs. 19.8 ± 5.6 ml/kg/min, p = 0.01). In the subgroup of AGT patients characterized by an inferior walking capacity at baseline, the increment in the distance walked was less than in the controls (Δ6MWT: 81.9 ± 60.1 vs. 109.1 ± 72.1, p = 0.04). An independent, negative, association was observed between AGT and Δ6MWT in patients with lower baseline test, and between maximum workload and peak-VO2 in the whole population.

Conclusions: A high prevalence of AGT was observed in a population of CAD patients without known DM after an acute coronary event. AGT is associated to a lower functional recovery, and to a reduced exercise capacity at the end of CR.

Monitoring Brain Oxygen Saturation During Coronary Bypass Surgery Improves Outcomes in Diabetic Patients: A Post Hoc Analysis

Background: Having previously demonstrated in a prospective study of 200 coronary artery bypass (CAB) patients that by using the brain as an index organ, interventions to improve cerebral oxygenation would have systemic outcome benefits, we undertook a post hoc analysis of the diabetic subset (n = 57) of the overall study group to determine whether the outcomes of these patients were similarly improved.Methods: Case-report forms for the 200 CAB patients study patients with a preoperative diagnosis of diabetes mellitus were stratified to intraoperative cerebral regional oxygen saturation (rSO2) monitoring with active display and a treatment intervention protocol (intervention group, n = 28) or to blinded rSO2 monitoring (control group, n = 29) and analyzed.Results: There were no significant differences between the 2 groups in overall risk factors, although there were trends toward a higher body mass index, a worse angina score, a worse grade of ventricle, and greater use of off-pump coronary revascularization in the control group of patients. The 2 groups were similar with respect to overall insulin dosage and perioperative blood glucose concentrations. Significantly more diabetic patients in the control group demonstrated profound cerebral desaturation, with an area under the curve of 2 postoperative complications (P = .006; = 0.37). An analysis after removing the patients who underwent off-pump surgery revealed that the control group had significantly more patients with sternal wound infections (5 versus 0; P = .047) and 2 postoperative complications (6 versus 0; P = .008) than the intervention group, as well as a trend toward longer ICU and postoperative hospitalization stays in the control group.Conclusion: Monitoring and management of cerebral rSO2 in diabetic CAB patients avoid profound cerebral desaturation and are associated with significantly lower incidences of complications and shorter postoperative lengths of stay.Implication Statement: A post hoc analysis of the diabetic cohort of a prospective, randomized, and blinded study of CAB patients revealed that those in whom cerebral oxygen saturation was actively monitored and maintained demonstrated significantly lower incidences of complications, resulting in shorter ICU and postoperative hospital stays compared with an unmonitored control group.

Neurovascular interaction and the pathophysiology of diabetic retinopathy

Diabetic retinopathy (DR) is the most severe of the several ocular complications of diabetes, and in the United States it is the leading cause of blindness among adults 20 to 74 years of age. Despite recent advances in our understanding of the pathogenesis of DR, there is a pressing need to develop novel therapeutic treatments that are both safe and efficacious. In the present paper, we identify a key mechanism involved in the development of the disease, namely, the interaction between neuronal and vascular activities. Numerous pathological conditions in the CNS have been linked to abnormalities in the relationship between these systems. We suggest that a similar situation arises in the diabetic retina, and we propose a logical strategy aimed at therapeutic intervention.

Effect of Treatment of Sprague Dawley Rats with AVE7688, Enalapril, or Candoxatril on Diet-Induced Obesity

The objective of this study was to determine the effect of AVE7688, a drug that inhibits both angiotensin converting enzyme (ACE) and neutral endopeptidase (NEP) activity, on neural and vascular defects caused by diet induced obesity (DIO). Rats at 12 weeks of age were fed a standard or high fat diet with or without AVE7688 for 24 weeks. DIO rats had impaired glucose tolerance and developed sensory neuropathy. Vascular relaxation to acetylcholine and calcitonin gene-related peptide was decreased in epineurial arterioles of DIO rats. Rats fed a high fat diet containing AVE7688 did not become obese and vascular and sensory nerve dysfunction and impaired glucose tolerance were improved. DIO is associated with increased expression of NEP in epineurial arterioles. NEP degrades vasoactive peptides which may explain the decrease in neurovascular function in DIO.