Treatment of the patient with diabetes: importance of maintaining target HbA(1c) levels

Red blood cells as biomarkers and mediators in complications of diabetes mellitus: A review

Red blood cells (RBCs), traditionally recognized for their oxygen transport role, have garnered increasing attention for their significance as crucial contributors to the pathophysiology of diabetes mellitus. In this comprehensive review, we elucidate the multifaceted roles of RBCs as both biomarkers and mediators in diabetes mellitus. Amidst the intricate interplay of altered metabolic pathways and the diabetic milieu, RBCs manifest distinct alterations in their structure, function, and lifespan. The chronic exposure to hyperglycemia induces oxidative stress, leading to modifications in RBC physiology and membrane integrity. These modifications, including glycation of hemoglobin (HbA1c), establish RBCs as invaluable biomarkers for assessing glycemic control over extended periods. Moreover, RBCs serve as mediators in the progression of diabetic complications. Their involvement in vascular dysfunction, hemorheological changes, and inflammatory pathways contributes significantly to diabetic microangiopathy and associated complications. Exploring the therapeutic implications, this review addresses potential interventions targeting RBC abnormalities to ameliorate diabetic complications. In conclusion, comprehending the nuanced roles of RBCs as biomarkers and mediators in diabetes mellitus offers promising avenues for enhanced diagnostic precision, therapeutic interventions, and improved patient outcomes. This review consolidates the current understanding and emphasizes the imperative need for further research to harness the full potential of RBC-related insights in the realm of diabetes mellitus.

The Role of Saponins in the Treatment of Neuropathic Pain

Neuropathic pain is a chronic pain caused by tissue injury or disease involving the somatosensory nervous system, which seriously affects the patient's body function and quality of life. At present, most clinical medications for the treatment of neuropathic pain, including antidepressants, antiepileptic drugs, or analgesics, often have limited efficacy and non-negligible side effects. As a bioactive and therapeutic component extracted from Chinese herbal medicine, the role of the effective compounds in the prevention and treatment of neuropathic pain have gradually become a research focus to explore new analgesics. Notably, saponins have shown analgesic effects in a large number of animal models. In this review, we summarized the most updated information of saponins, related to their analgesic effects in neuropathic pain, and the recent progress on the research of therapeutic targets and the potential mechanisms. Furthermore, we put up with some perspectives on future investigation to reveal the precise role of saponins in neuropathic pain.

Exploring HbA1c variation between Australian diabetes centres: The impact of centre-level and patient-level factors

Background

Increasing global diabetes incidence has profound implications for health systems and for people living with diabetes. Guidelines have established clinical targets but there may be variation in clinical outcomes including HbA1c, based on location and practice size. Investigating this variation may help identify factors amenable to systemic improvement interventions. The aims of this study were to identify centre-specific and patient-specific factors associated with variation in HbA1c levels and to determine how these associations contribute to variation in performance across diabetes centres.

Methods

This cross-sectional study analysed data for 5,872 people with type 1 (n = 1,729) or type 2 (n = 4,143) diabetes mellitus collected through the Australian National Diabetes Audit (ANDA). A linear mixed-effects model examined centre-level and patient-level factors associated with variation in HbA1c levels.

Results

Mean age was: 43±17 years (type 1), 64±13 (type 2); median disease duration: 18 years (10,29) (type 1), 12 years (6,20) (type 2); female: 52% (type 1), 45% (type 2). For people with type 1 diabetes, volume of patients was associated with increases in HbA1c (p = 0.019). For people with type 2 diabetes, type of centre was associated with reduction in HbA1c (p <0.001), but location and patient volume were not. Associated patient-level factors associated with increases in HbA1c included past hyperglycaemic emergencies (type 1 and type 2, p<0.001) and Aboriginal and Torres Strait Islander status (type 2, p<0.001). Being a non-smoker was associated with reductions in HbA1c (type 1 and type 2, p<0.001).

Conclusions

Centre-level and patient-level factors were associated with variation in HbA1c, but patient-level factors had greater impact. Interventions targeting patient-level factors conducted at a centre level including sick-day management, smoking cessation programs and culturally appropriate diabetes education for and Aboriginal and Torres Strait Islander peoples may be more important for improving glycaemic control than targeting factors related to the Centre itself.

Imputing HbA1c from capillary blood glucose levels in patients with type 2 diabetes in Sri Lanka: a cross-sectional study

OBJECTIVE

To develop a population-specific methodology for estimating glycaemic control that optimises resource allocation for patients with diabetes in rural Sri Lanka.

DESIGN

Cross-sectional study.

SETTING

Trincomalee, Sri Lanka.

PARTICIPANTS

Patients with non-insulin-treated type 2 diabetes (n=220) from three hospitals in Trincomalee, Sri Lanka.

OUTCOME MEASURE

Cross-validation was used to build and validate linear regression models to identify predictors of haemoglobin A1c (HbA1c). Validation of models that regress HbA1c on known determinants of glycaemic control was thus the major outcome. These models were then used to devise an algorithm for categorising the patients based on estimated levels of glycaemic control.

RESULTS

Time since last oral intake other than water and capillary blood glucose were the statistically significant predictors of HbA1c and thus included in the final models. In order to minimise type II error (misclassifying a high-risk individual as low-risk or moderate-risk), an algorithm for interpreting estimated glycaemic control was created. With this algorithm, 97.2% of the diabetic patients with HbA1c ≥9.0% were correctly identified.

CONCLUSIONS

Our calibrated algorithm represents a highly sensitive approach for detecting patients with high-risk diabetes while optimising the allocation of HbA1c testing. Implementation of these methods will optimise the usage of resources devoted to the management of diabetes in Trincomalee, Sri Lanka. Further external validation with diverse patient populations is required before applying our algorithm more widely.

Hesperidin enhances angiogenesis via modulating expression of growth and inflammatory factor in diabetic foot ulcer in rats

One of the most devastating consequences of diabetes mellitus is a chronic condition, diabetic foot ulcer. Numerous investigations are being targeted to explore newer compounds for treatment of diabetic foot ulcer wounds in diabetic patients. Hesperidin (HSP), an isoflavone glycoside has been established to exhibit antidiabetic and antioxidant potential. In the current investigation, diabetes was induced in rats by administration by streptozotocin (STZ) intraperitoneally (50 mg/kg). Wound-healing capacity was estimated in hind paw of rats by artificially initiating wound injury on the paw dorsal surface. The injured animals were administered with incremental doses of HSP suspension orally (10, 20, 40, 60, and 80 mg/kg) and insulin subcutaneously (10 IU/kg). Parameters such as wound area were estimated every 2 days, and at the end of 20 days of study, biochemical estimations in serum and histopathological observations of the wound were made. HSP (60 and 80 mg/kg) revealed statistically significant ( P < 0.05) improvement in wound dimension, glucose and insulin concentration, and glycated hemoglobin (HbA1C). Administration of HSP indicated significant ( P < 0.05) modulation of mRNA associated with expression of vascular endothelial growth factor (VEGF), whereas the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels were lowered compared to the control group of animals. Real-time quantitative polymerase chain reaction (RT-qPCR) indicated expression of vascular endothelial growth factor receptors 1 and 2 (VEGFR1 and VEGFR2) compared to glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Histological observations indicated higher expression of VEGF in the groups receiving HSP, indicative of angiogenesis stimulation in the diabetic wound. The results advocate angiogenesis activity of HSP was enhanced owing to reduction in hyperglycemia and oxidative stress–induced damage, reduced expression of inflammatory mediators, and enhanced expression of growth-related factors, thereby promoting healing of diabetic foot ulcer.

Comparison of HbA1c detection in whole blood and dried blood spots using an automated ion-exchange HPLC system

AIM

Hemoglobin A1c (HbA1c) is a widely recognized analyte for diagnosing and monitoring diabetes. Dried blood spot (DBS) constitutes a useful alternative to blood collection by venipuncture. Analytical and clinical validation of DBS use is, however, necessary before implementation. Results/methodology: HbA1c levels from whole blood or DBS from a cohort patients with diabetes were compared. DBS specimens were stable at ambient temperature. HbA1c detection on DBS was accurate, robust, and the correlation and agreement with whole blood values was excellent.

CONCLUSION

This study provides for the first time a complete method comparison and validation under the ISO15189 guideline using an automated HPLC system. This approach constitutes, therefore, a useful tool for diagnosing diabetes.

Variability of triglyceride levels and incidence of microalbuminuria in type 2 diabetes

BACKGROUND

Experimental and clinical studies have shown a strong association between hypertriglyceridemia and diabetic nephropathy. A variability of triglyceride (TG) levels has been reported in diabetes.

OBJECTIVES

To investigate the relationship of TG variability with the incidence of microalbuminuria (albumin excretion rate > 20 μg/min), in patients with type 2 diabetes.

METHODS

A longitudinal, retrospective, observational study was performed on a consecutive series of 457 normoalbuminuric outpatients, with measurements of HbA1c, lipids and microalbuminuria thrice per year with 6.8-year follow-up. TG variability, defined as standard deviation of TG (TG-SD) and TG-SD adjusted for the number of visits was calculated. A nested case-control sensitivity analysis was performed to validate the results of the primary cohort study.

RESULTS

Incident microalbuminuria (N = 124, 27.1%) was associated with higher median TG-SD (33.6 mg/dL vs 29.0 mg/dL, P < .05) and TG-SD adjusted for the number of visits (31.4 mg/dL vs 26.7 mg/dL, P < .05). At multivariate (Cox) analysis, logTG-SD and adj-logTG-SD were significant predictors of incident microalbuminuria (hazard ratio 2.1 [1.1-4.2], P = .028 and 1.5 [1.1-3.3], P = .042, respectively). In the case-control analysis, time spent with TG > 150 mg/dL during the follow-up was significantly higher in cases vs controls (27.2 ± 19 vs 16.7 ± 12.5 months, P < .05) with hazard ratio 2.0 (1.1-5.1), P < .05, for adj-logTG-SD.

CONCLUSIONS

A higher intraindividual TG variability is a predictor of incident microalbuminuria in type 2 diabetes. In addition, time of exposure to elevated TG levels (>150 mg/dL) predicts incident microalbuminuria.

Impact of a community health workers-led structured program on blood glucose control among latinos with type 2 diabetes: the DIALBEST trial

OBJECTIVE

Latinos with type 2 diabetes (T2D) face major healthcare access and disease management disparities. We examined the impact of the Diabetes Among Latinos Best Practices Trial (DIALBEST), a community health worker (CHW)-led structured intervention for improving glycemic control among Latinos with T2D.

RESEARCH DESIGN AND METHODS

A total of 211 adult Latinos with poorly controlled T2D were randomly assigned to a standard of healthcare (n = 106) or CHW (n = 105) group. The CHW intervention comprised 17 individual sessions delivered at home by CHWs over a 12-month period. Sessions addressed T2D complications, healthy lifestyles, nutrition, healthy food choices and diet for diabetes, blood glucose self-monitoring, and medication adherence. Demographic, socioeconomic, lifestyle, anthropometric, and biomarker (HbA1c, fasting blood glucose, and lipid profile) data were collected at baseline and 3, 6, 12, and 18 months (6 months postintervention). Groups were equivalent at baseline.

RESULTS

Participants had high HbA1c at baseline (mean 9.58% [81.2 mmol/mol]). Relative to participants in the control group, CHWs had a positive impact on net HbA1c improvements at 3 months (-0.42% [-4.62 mmol/mol]), 6 months (-0.47% [-5.10 mmol/mol]), 12 months (-0.57% [-6.18 mmol/mol]), and 18 months (-0.55% [-6.01 mmol/mol]). The overall repeated-measures group effect was statistically significant (mean difference -0.51% [-5.57 mmol/mol], 95% CI -0.83, -0.19% [-9.11, -2.03 mmol/mol], P = 0.002). CHWs had an overall significant effect on fasting glucose concentration that was more pronounced at the 12- and 18-month visits. There was no significant effect on blood lipid levels, hypertension, and weight.

CONCLUSIONS

DIALBEST is an effective intervention for improving blood glucose control among Latinos with T2D.

The relationship between fasting plasma glucose and HbA1c during intensive periods of glucose control in antidiabetic therapy

OBJECTIVE

HbA1c measurements are typically less variable than fasting plasma glucose (FPG) for diagnosing diabetes, and for assessment of progress on glucose control therapy. However HbA1c reaches steady-state relative to average plasma glucose over about 120 days. HbA1c thus overestimates average FPG during first three months of starting therapy in newly diagnosed diabetic patients, and care needs to be exercised in interpreting HbA1c measurements during this period. At steady-state excellent regression exists between HbA1c and FPG. We hypothesize that this regression can also be used to obtain reliable estimates of HbA1c relative to FPG at 4 and 8 weeks following the onset of therapy.

MATERIALS AND METHODS

We collected FPG and HbA1c data of type 2 diabetic patients over the first 8 weeks of starting antidiabetic treatment. We fit linear and nonlinear regression models to steady-state data, and estimated how much measured HbA1c deviates at 4 and 8 weeks from these theoretical relations.

RESULTS

If measured HbA1c is decremented by 0.7% (8 mmol/mol) at 4 weeks and 0.3% (3 mmol/mol) at 8 weeks, this corrected HbA1c is a better predictor of the corresponding FPG. Using hyperbolic regression, corrections to HbA1c are 0.5 and 0.1% (5 and 1 mmol/mol), respectively.

CONCLUSION

With the corrections proposed here, HbA1c measurements can be better interpreted in the early weeks of antidiabetic treatment.

Hesperidin, a flavanoglycone attenuates experimental diabetic neuropathy via modulation of cellular and biochemical marker to improve nerve functions

AIM

Diabetic neuropathy (DN) is one of the most common long-term complications of diabetes mellitus and clinically can be characterized by an elevated nociceptive response with electrophysiological conduction abnormalities. The present investigation was designed to evaluate the neuroprotective effect of hesperidin against STZ induced diabetic neuropathic pain in laboratory rats.

MATERIALS AND METHODS

DN was induced in Sprague-Dawley rats (150-200 g) by intraperitoneal administration of streptozotocin (STZ) (55 mg/kg, p.o.). Rats were divided into various groups, namely, STZ control (vehicle), hesperidin (25, 50, and 100 mg/kg, p.o.), insulin (10 IU/kg, s.c.), and combination of hesperidin (100 mg/kg, p.o.) with insulin (10 IU/kg, s.c.) for 4 weeks. Various behavioral (allodynia and hyperalgesia), biochemical parameters [oxido-nitosative stress, Na-K-ATPase, aldose reductase (AR)], and molecular changes (TNF-α and IL-1β) along with hemodynamic changes were determined.

RESULTS

Rats treated with hesperidin (50 and 100 mg/kg, p.o., 4 weeks) significantly reduced (p < 0.05) hyperglycemia and its metabolic abnormalities induced by intraperitoneal administration of STZ. The decreased nociceptive threshold, motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV), serum insulin as well as Na-K-ATPase activity were significantly increase (p < 0.05) by hesperidin (50 and 100 mg/kg, p.o.) treatment. It significantly attenuated (p < 0.05) elevated glycated hemoglobin, AR activity, oxido-nitrosative stress, neural calcium, and pro-inflammatory cytokines (TNF-α and IL-1β) levels. Histological aberration induced after STZ administration was restored by administration of hesperidin (50 and 100 mg/kg, p.o.)

CONCLUSION

In combination with insulin, hesperidin not only attenuated the diabetic condition but also reversed neuropathic pain via control over hyperglycemia as well as hyperlipidemia to down-regulate generation of free radical, release of pro-inflammatory cytokines as well as elevation in membrane bound enzyme.

All-cause and cardiovascular mortality risk in U.S. adults with and without type 2 diabetes: Influence of physical activity, pharmacological treatment and glycemic control

AIMS

This study determined the joint association between physical activity, pharmacotherapy, and HbA1c control on all-cause and cardiovascular disease (CVD) mortality risk in adults with and without type 2 diabetes (T2D).

METHODS

12,060 adults from NHANES III and NHANES continuous (1999-2002) surveys were used. Cox proportional hazards analyses were included to estimate mortality risk according to physical activity, pharmacotherapy, and glycemic control (HbA1c <7.0%) status, with physically active, treated and controlled (goal situation) as the referent.

RESULTS

Compared to the referent, adults with T2D who were uncontrolled, or controlled but physically inactive had a higher all-cause mortality risk (p<0.05). Compared to the referent, only adults with T2D who were physically inactive had a higher CVD mortality risk, regardless of treatment or control status (p<0.05). Normoglycemic adults had a similar all-cause and CVD mortality risk as the referent (p>0.05).

CONCLUSIONS

Physical activity and glycemic control are both associated with lower all-cause and CVD mortality risk in adults with T2D. Adults with T2D who are physically active, pharmacologically treated, and obtain glycemic control may attain similar mortality risk as normoglycemic adults.

Role of proteins in insulin secretion and glycemic control

Dietary proteins are essential for the life of all animals and humans at all stages of the life cycle. They serve many structural and biochemical functions and have significant effects on health and wellbeing. Dietary protein consumption has shown an upward trend in developed countries in the past two decades primarily due to greater supply and affordability. Consumption is also on the rise in developing countries as affluence is increasing. Research shows that proteins have a notable impact on glucose homeostasis mechanisms, predominantly through their effects on insulin, incretins, gluconeogenesis, and gastric emptying. Since higher protein consumption and impaired glucose tolerance can be commonly seen in the same population demographics, a thorough understanding of the former's role in glucose homeostasis is crucial both toward the prevention and management of the latter. This chapter reviews the current state of the art on proteins, amino acids, and their effects on blood glucose and insulin secretion.

Double-blind, randomized, multicentre, and active comparator controlled investigation of the effect of pioglitazone, metformin, and the combination of both on cardiovascular risk in patients with type 2 diabetes receiving stable basal insulin therapy: the PIOCOMB study

BACKGROUND

We analyzed specific effects of an add-on therapy with pioglitazone compared to metformin and their combination in patients with basal insulin treatment on biomarkers of CV risk.

METHODS

In this double-blind, randomized, multicentre, active comparator controlled trial, 121 patients with type 2 diabetes were enrolled. Inclusions: treatment with basal insulin, HbA(1C) 6.5%-8.5%, age 30-75 years. After glargine therapy over 2 weeks for titration towards FBG ≤ 7.8 mmol/L, patients received either (A) bid 850 mg metformin (n = 42), (B) bid 15 mg pioglitazone (n = 40), or (C) 30 mg pioglitazone plus 1.7 g metformin (n = 39) over 6 months. Matrix Metal Proteinase 9 (MMP-9) was primary objective, together with biomarkers of CV risk.

RESULTS

Pioglitazone (B) reduced MMP-9 versus baseline by 54.1 ± 187.1 ng/mL, with metformin (A) it was increased by 49.6 ± 336.2 ng/mL (p = 0.0345; B vs. A), and with the combination of both (C) it was decreased by 67.8 ± 231.4 ng/mL (A vs. C: p = 0.0416; B vs. C: p = 0.8695). After logarithmic transformation due to high variances the exploratory results showed significance for A vs. B (p = 0.0043) and for A vs. C (p = 0.0289).Insulin dosage was reduced by 7.3 units in group B (p < 0.0001), by 6.0 units in C (p = 0.0004), but was increased by 2.5 units (p = 0.1539) in A at follow up. Reduction in hs-CRP was significant within treatment groups for B (p = 0.0098) and C (p < 0.0001), and between the groups for A vs. C (p = 0.0124). All three single regimens reduced PAI-1. Adiponectin was significantly elevated in B and C (p < 0.0001) and between-groups. HbA(1C) was only significantly decreased in the combination group. No significant effects were observed for NFkB and PGFα. peripheral edema were seen in 11.9% vs. 40.0% vs. 20.5%, and weight change was -0.7 kg vs. +4.3 kg vs. +2.7 kg (A vs. B vs. C).

CONCLUSIONS

Addition of pioglitazone but not of metformin reduces MMP-9, hs-CRP and increased insulin sensitivity and adiponectin in this study. The combination of both had no additional effect on inflammation. Pioglitazone is suggested to be a rational add-on therapy to basal insulin in patients with high CV risk.

Effects of encapsulated propolis on blood glycemic control, lipid metabolism, and insulin resistance in type 2 diabetes mellitus rats

The present study investigates the encapsulated propolis on blood glycemic control, lipid metabolism, and insulin resistance in type 2 diabetes mellitus (T2DM) rats. The animal characteristics and biological assays of body weight, fasting blood glucose (FBG), fasting serum insulin (FINS), insulin act index (IAI), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured and euglycemic hyperinsulinemic glucose clamp technique were used to determine these effects. Our findings show that oral administration of encapsulated propolis can significantly inhibit the increasing of FBG and TG in T2DM rats and can improve IAI and M value in euglycemic hyperinsulinemic clamp experiment. There was no significant effects on body weight, TC, HDL-C, and LDL-C in T2DM rats treated with encapsulated propolis. In conclusion, the results indicate that encapsulated propolis can control blood glucose, modulate lipid metabolism, and improve the insulin sensitivity in T2DM rats.

The impact of telehome care on health status and quality of life among patients with diabetes in a primary care setting in Poland

BACKGROUND

Telehome care has been proposed as a solution to the challenges of providing effective and affordable care for patients with diabetes.

METHODS

A total of 100 adult patients with type 2 diabetes-divided between insulin and noninsulin requiring-was enrolled in a randomized, controlled trial aimed at investigating the effects of telehome monitoring. The experimental group (n = 50) received an in-home wireless glucose monitor and transmitter, whereas the control group (n = 50) was instructed to follow the conventional arrangement.

RESULTS

There was an overall reduction in HbA1c values in both experimental and control groups after 6 months. A significant difference in HbA1c values between the groups was observed only among the noninsulin-requiring patients (decline from 6.95% ± 0.82% to 6.66% ± 0.86% in IB vs. 7.21% ± 2.02% to 7.2% ± 1.86% in IIB; p = 0.02). The experimental group reported considerably less hyperglycemic and hypoglycemic events. The profile of the patient who benefited the most from telemonitoring consisted of older, more educated patient who had acquired the disease relatively recently, and who spends most of the time at home. The experimental group had higher overall scores on quality of life measures and sense of control over diabetes. There was a positive association between educational attainment and ability to use the telemonitoring system without help (p = 0.045).

CONCLUSIONS

Although not conclusive because of the small sample and short observation period, the study suggests that telehome monitoring is an effective tool in controlling type 2 diabetes in a primary care setting.

Direct healthcare costs of patients with type 2 diabetes using long-acting insulin analogues or NPH insulin in a basal insulin-only regimen

AIMS

To compare direct healthcare costs incurred by patients with type 2 diabetes in Denmark prescribed long-acting insulin analogues (LAIA) or intermediate-acting human insulin (NPH) in a basal-only regimen.

METHODS

Demographic and socio-economic patient characteristics, hospital utilisation data, primary care visits, specialist physician visits and prescription data were extracted from registers covering the Danish population. Patients receiving basal insulin were identified during a 1-year inclusion period (2005) and allocated to a LAIA (n=303) or NPH group (n=8523). LAIA patients were then matched with NPH patients using propensity scores based on observable covariates. Annual direct healthcare costs were determined during a <2-year analysis period (2005-2006).

RESULTS

Direct healthcare costs, including prescription costs, were equivalent between groups. However, while most cost items were similar between groups, ambulatory visit costs were significantly lower in LAIA-treated patients (p=0.03), whereas insulin pharmacy costs were significantly lower in NPH-treated patients (p<0.001).

CONCLUSION

There was no difference in direct healthcare costs between patients using LAIAs or NPH insulin.

Different roles of 12/15-lipoxygenase in diabetic large and small fiber peripheral and autonomic neuropathies

Up-regulation of 12/15-lipoxygenase, which converts arachidonic acid to 12(S)- and 15(S)-hydroxyeicosatetraenoic acids, causes impaired cell signaling, oxidative-nitrosative stress, and inflammation. This study evaluated the role for 12/15-lipoxygenase in diabetic large and small fiber peripheral and autonomic neuropathies. Control and streptozotocin-diabetic wild-type and 12/15-lipoxygenase-deficient mice were maintained for 14 to 16 weeks. 12/15-lipoxygenase gene deficiency did not affect weight gain or blood glucose concentrations. Diabetic wild-type mice displayed increased sciatic nerve 12/15-lipoxygenase and 12(S)-hydroxyeicosatetraenoic acid levels. 12/15-lipoxygenase deficiency prevented or alleviated diabetes-induced thermal hypoalgesia, tactile allodynia, motor and sensory nerve conduction velocity deficits, and reduction in tibial nerve myelinated fiber diameter, but not intraepidermal nerve fiber loss. The frequencies of superior mesenteric-celiac ganglion neuritic dystrophy, the hallmark of diabetic autonomic neuropathy in mouse prevertebral sympathetic ganglia, were increased 14.8-fold and 17.2-fold in diabetic wild-type and 12/15-lipoxygenase-deficient mice, respectively. In addition, both diabetic groups displayed small (<1%) numbers of degenerating sympathetic neurons. In conclusion, whereas 12/15-lipoxygenase up-regulation provides an important contribution to functional changes characteristic for both large and small fiber peripheral diabetic neuropathies and axonal atrophy of large myelinated fibers, its role in small sensory nerve fiber degeneration and neuritic dystrophy and neuronal degeneration characteristic for diabetic autonomic neuropathy is minor. This should be considered in the selection of endpoints for future clinical trials of 12/15-lipoxygenase inhibitors.

Nuclear factor of activated T cells regulates osteopontin expression in arterial smooth muscle in response to diabetes-induced hyperglycemia

OBJECTIVE

Hyperglycemia is a recognized risk factor for cardiovascular disease in diabetes. Recently, we reported that high glucose activates the Ca(2+)/calcineurin-dependent transcription factor nuclear factor of activated T cells (NFAT) in arteries ex vivo. Here, we sought to determine whether hyperglycemia activates NFAT in vivo and whether this leads to vascular complications.

METHODS AND RESULTS

An intraperitoneal glucose-tolerance test in mice increased NFATc3 nuclear accumulation in vascular smooth muscle. Streptozotocin-induced diabetes resulted in increased NFATc3 transcriptional activity in arteries of NFAT-luciferase transgenic mice. Two NFAT-responsive sequences in the osteopontin (OPN) promoter were identified. This proinflammatory cytokine has been shown to exacerbate atherosclerosis and restenosis. Activation of NFAT resulted in increased OPN mRNA and protein in native arteries. Glucose-induced OPN expression was prevented by the ectonucleotidase apyrase, suggesting a mechanism involving the release of extracellular nucleotides. The calcineurin inhibitor cyclosporin A or the novel NFAT blocker A-285222 prevented glucose-induced OPN expression. Furthermore, diabetes resulted in higher OPN expression, which was significantly decreased by in vivo treatment with A-285222 for 4 weeks or prevented in arteries from NFATc3(-/-) mice.

CONCLUSIONS

These results identify a glucose-sensitive transcription pathway in vivo, revealing a novel molecular mechanism that may underlie vascular complications of diabetes.

Combination of nateglinide with thiazolidinediones in Type 2 diabetes

Insulin sensitivity and insulin secretion are reciprocally related such that insulin resistance is adapted by increased insulin secretion to maintain normal glucose and lipid homeostasis. Treatment of Type 2 diabetes should aim to restore and sustain the normal relationship between insulin sensitivity and secretion. Nateglinide is a rapid-onset, short-acting insulin-secretion enhancer that restores early-phase insulin secretion, reduces postprandial glucose excursions and prevents long-term hyperinsulinemia. Given its mechanism of action, it is evident that nateglinide would be more effective when used in combination with an insulin sensitizer, such as the thiazolidinediones. Thiazolidinediones do not stimulate insulin release and, therefore, are potentially suitable candidates for combination therapy with an insulin-secretion enhancer, such as nateglinide. Combination therapy of thiazolidinediones with nateglinide is effective, carries low risk of hypoglycemia and is suitable for patients with moderate renal impairment, although weight gain and edema are common side effects. Further studies are needed to determine whether nateglinide in combination with thiazolidinediones will help clinicians better achieve their treatment goals in targeting Type 2 diabetes. Moreover, comparative studies between nateglinide and medications targeting postprandial glycemia, such as dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 analogues, are necessary. This article summarizes data concerning the mechanism of action, efficacy and safety of therapy with nateglinide and thiazolidinediones as monotherapy and in combination treatment, and aims at a better understanding of the substrate defects their synergy hopes to defy.

Comparison of glycaemic control in patients with Type 2 diabetes on basal insulin and fixed combination oral antidiabetic treatment: results of a pilot study

This randomised, open-label, two-way cross-over study compared the coefficient of variance (CV) of fasting and postprandial blood glucose (FBG and PPBG) with insulin glargine (glargine) versus neutral protamine Hagedorn (NPH) insulin treatment in patients with Type 2 diabetes (T2DM). Patients (N=20) on oral antidiabetic drugs (OADs) were treated with NPH (at bedtime) or glargine (at dinnertime) for 12 weeks of each cross-over treatment period; OADs were continued. The FBG CV was calculated from self-monitored BG values and PPBG using venous blood samples, or continuous glucose monitoring system (CGMS). Both insulins provided similar improvements in glycaemic control; however, PPBG was significantly lower after a standard meal test (performed at 13:00 h the day after insulin injection) with glargine versus NPH (p=0.02). Thirteen versus 15 patients experienced >or=1 episode of hypoglycaemia with glargine versus NPH. The results suggest that glargine plus OADs is more effective in reducing PPBG fluctuations during the day than NPH plus OADs.

An automated telemedicine system improves patient-reported well-being

BACKGROUND

Control of serum glucose levels is essential for the reduction of complications of diabetes. Telemedicine is one strategy through which serum glucose control can be improved.

METHODS

A total of 35 adult, insulin-treated patients with diabetes (type 1 and type 2) were enrolled in the present study (63.0 +/- 10 years of age, 63% female) and randomized to telemedicine monitoring (including cordless, remote glucose monitor, and transmitter, n = 17), or conventional follow-up (n = 18). Metabolic parameters were evaluated, and a quality of life questionnaire was administered both pre- and post-treatment.

RESULTS

Groups were similar at baseline in terms of demographic, quality of life, and metabolic parameters. Significant differences in post-treatment metabolic parameters were not observed, although serum glucose was marginally elevated in the control group compared to the telemedicine group (214 +/- 65 mg/dL vs. 171 +/- 77 mg/dL, P = 0.09). On the other hand, being clinically symptom-free (71% vs. 11%, P = 0.003), having no hypoglycemic events (82% vs. 17%, P = 0.0001), and having no hyperglycemic events (65% vs. 17%, P = 0.004) were all significantly more frequently reported in the telemedicine group compared to the control group. Compared to the control group, the telemedicine group reported experiencing significantly less anxiety, treatment difficulty, depression, disease-associated life complications, and feelings of impotence or ineptitude and significantly greater improvement in personal control over glucose, weight, and overall diabetes.

CONCLUSIONS

Though post-treatment metabolic differences were not observed between treatment groups, the telemedicine group reported significantly greater post-treatment experiences of improved quality of life and sense of control over the disease. Thus patient satisfaction can be enhanced through the use of telemedicine.

Morphological changes of gingiva in streptozotocin diabetic rats

Gingivitis and periodontitis are chronic bacterial diseases of the underlying and surrounding tooth tissues. Diabetes mellitus is responsible for tooth deprivation both by decay and periodontal disease. The streptozotocin-induced diabetes results in a diabetic status in experimental animals similar to that observed in diabetes patients. The aim of the study was to investigate the relationship between the gingival lesions and the microangiopathy changes in streptozotocin-induced diabetes mellitus. Forty male Wistar rats were divided into two groups (control and experimental). Diabetes mellitus was induced by 45 mg/kg IV streptozotocin. The histological investigation of the marginal gingival and the relevant gingival papilla showed inflammation of the lamina propria and the squamous epithelium as well as marked thickness of the arteriole in the diabetic group, but no changes were observed in the control group. The results suggested a probable application of a routine gingival histological investigation in diabetic patients in order to control the progress of disease complications. It may be concluded that histological gingival investigation can be used as a routine assay for the control of the diabetic disease and prevention of its complications.

Initiation of insulin glargine therapy in type 2 diabetes subjects suboptimally controlled on oral antidiabetic agents: results from the AT.LANTUS trial

OBJECTIVE

For many patients with type 2 diabetes, oral antidiabetic agents (OADs) do not provide optimal glycaemic control, necessitating insulin therapy. Fear of hypoglycaemia is a major barrier to initiating insulin therapy. The AT.LANTUS study investigated optimal methods to initiate and maintain insulin glargine (LANTUS, glargine, Sanofi-aventis, Paris, France) therapy using two treatment algorithms. This subgroup analysis investigated the initiation of once-daily glargine therapy in patients suboptimally controlled on multiple OADs.

RESEARCH DESIGN AND METHODS

This study was a 24-week, multinational (59 countries), multicenter (611), randomized study. Algorithm 1 was a clinic-driven titration and algorithm 2 was a patient-driven titration. Titration was based on target fasting blood glucose < or =100 mg/dl (< or =5.5 mmol/l). Algorithms were compared for incidence of severe hypoglycaemia [requiring assistance and blood glucose <50 mg/dl (<2.8 mmol/l)] and baseline to end-point change in haemoglobin A(1c) (HbA(1c)).

RESULTS

Of the 4961 patients enrolled in the study, 865 were included in this subgroup analysis: 340 received glargine plus 1 OAD and 525 received glargine plus >1 OAD. Incidence of severe hypoglycaemia was <1%. HbA(1c) decreased significantly between baseline and end-point for patients receiving glargine plus 1 OAD (-1.4%, p < 0.001; algorithm 1 -1.3% vs. algorithm 2 -1.5%; p = 0.03) and glargine plus >1 OAD (-1.7%, p < 0.001; algorithm 1 -1.5% vs. algorithm 2 -1.8%; p = 0.001).

CONCLUSIONS

This study shows that initiation of once-daily glargine with OADs results in significant reduction of HbA(1c) with a low risk of hypoglycaemia. The greater reduction in HbA(1c) was seen in patients randomized to the patient-driven algorithm (algorithm 2) on 1 or >1 OAD.

Once-daily basal insulin glargine versus thrice-daily prandial insulin lispro in people with type 2 diabetes on oral hypoglycaemic agents (APOLLO): an open randomised controlled trial

BACKGROUND

As type 2 diabetes mellitus progresses, oral hypoglycaemic agents often fail to maintain blood glucose control and insulin is needed. We investigated whether the addition of once-daily insulin glargine is non-inferior to three-times daily prandial insulin lispro in overall glycaemic control in adults with inadequately controlled type 2 diabetes mellitus taking oral hypoglycaemic agents.

METHODS

In the 44-week, parallel, open study that was undertaken in 69 study sites across Europe and Australia, 418 patients with type 2 diabetes mellitus that was inadequately controlled by oral hypoglycaemic agents were randomly assigned to either insulin glargine taken once daily at the same time every day or to insulin lispro administered three times per day. The primary objective was to compare the change in haemoglobin A(1c) from baseline to endpoint (week 44) between the two regimens. Randomisation was done with a central randomisation service. Analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT00311818.

FINDINGS

205 patients were randomly assigned to insulin glargine and 210 to insulin lispro. Mean haemoglobin A(1c) decrease in the insulin glargine group was -1.7% (from 8.7% [SD 1.0] to 7.0% [0.7]) and -1.9% in the insulin lispro group (from 8.7% [1.0] to 6.8% [0.9]), which was within the predefined limit of 0.4% for non-inferiority (difference=0.157; 95% Cl -0.008 to 0.322). 106 (57%) patients reached haemoglobin A(1c) of 7% or less in the glargine group and 131 (69%) in the lispro group. In the glargine group, the fall in mean fasting blood glucose (-4.3 [SD 2.3] mmol/L vs -1.8 [2.3] mmol/L; p<0.0001) and nocturnal blood glucose (-3.3 [2.8] mmol/L vs -2.6 [2.9] mmol/L; p=0.0041) was better than it was in the insulin lispro group, whereas insulin lispro better controlled postprandial blood glucose throughout the day (p<0.0001). The incidence of hypoglycaemic events was less with insulin glargine than with lispro (5.2 [95% CI 1.9-8.9] vs 24.0 [21-28] events per patient per year; p<0.0001). Respective mean weight gains were 3.01 (SD 4.33) kg and 3.54 (4.48) kg. The improvement of treatment satisfaction was greater for insulin glargine than for insulin lispro (mean difference 3.13; 95% CI 2.04-4.22).

INTERPRETATION

A therapeutic regimen involving the addition of either basal or prandial insulin analogue is equally effective in lowering haemoglobin A(1c). We conclude that insulin glargine provides a simple and effective option that is more satisfactory to patients than is lispro for early initiation of insulin therapy, since it was associated with a lower risk of hypoglycaemia, fewer injections, less blood glucose self monitoring, and greater patient satisfaction than was insulin lispro.

FUNDING

Sanofi-Aventis.

Association of arachidonate 12-lipoxygenase genotype variation and glycemic control with albuminuria in type 2 diabetes

BACKGROUND

Glycemic exposure activates 12-lipoxygenase (12LO) expression and formation of arachidonic acid-derived products. These products can induce cell hypertrophy, cell proliferation, and extracellular matrix deposition, potentially leading to diabetic nephropathy.

STUDY DESIGN

Cross-sectional study.

SETTINGS & PARTICIPANTS

955 European-American siblings from 369 Diabetes Heart Study families. Participants were categorized as nondiabetic, diabetic with hemoglobin A(1c) level less than 6.5%, and diabetic with hemoglobin A(1c) level greater than 6.5% (uncontrolled type 2 diabetes mellitus).

PREDICTOR

Four haplotype-tagging variants in the arachidonate 12LO gene (ALOX12), glycemic control, and other covariates.

OUTCOMES & MEASUREMENTS

Albuminuria measured by means of urinary albumin-creatinine ratio (ACR).

RESULTS

Median ACR was 11.9 mg/g (interquartile range, 5.6 to 39.1). The overall test of the Arg261Gln genotypic association with ACR was significant (P = 0.009). Compared with 261Arg allele carriers, adjusted mean ACR was 42% greater in the 189 carriers of two 261Gln alleles (95% confidence interval, 10 to 83; P = 0.007). This association was confined to the group with uncontrolled type 2 diabetes mellitus (N = 623) with the greatest ACRs (P < 0.001). Adjustments for additional determinants of ACR yielded similar results.

LIMITATIONS

Urine ACR was measured in duplicate on only a single occasion. This study was limited to European Americans.

CONCLUSIONS

Consistent with animal and cellular studies, these results provide additional evidence of the importance of the 12LO pathway in the pathogenesis of human diabetic nephropathy.

HIS modelling and simulation based cost–benefit analysis of a telemedical system for closed-loop diabetes therapy

OBJECTIVES

INCA (Intelligent Control Assistant for Diabetes) is an EU funded project aimed at improving diabetes therapy by creating a personal closed-loop system interacting with telemedical remote control. This study aims at identifying and applying suitable methods for a cost-benefit analysis from the perspective of the payor for health services.

METHODS

For cost analysis MOSAIK-M was used, a method and tool for health information systems analysis and design. Two MOSAIK-M models were created describing conventional insulin pump based diabetes care (CSII), and INCA based diabetes care. Both models were parameterized with costs and simulated to determine yearly costs of diabetes management and treatment for a patient with no diabetes related complications. Probability of developing complications and their duration were determined based on the Archimedes model. It was parameterized with results of a clinical study concerning HbA1c-value changes using the INCA system compared with conventional CSII. The simulation results in form of years of disease within a 30-year time frame were multiplied with corresponding treatment costs.

RESULTS

Yearly costs of conventional insulin CSII for a diabetes type 1 patient are euro 5908 (German health care system). Using INCA based on the clinical study setting would raise yearly costs by euro 2233. 24% of the INCA costs are generated by the continuous blood glucose measurement device, 5% by IT devices and services. Considering also diabetes related complications in a 30-year time frame and HbA1c value reductions from 7.9 and 7.6% (conventional CSII) to 7.5 and 7.3% (INCA) reduces the additional costs of INCA to euro 2102 and euro 2162.

CONCLUSIONS

The approach produces an estimation of a lower bound for cost savings concerning the treatment of diabetes related complications in a 30-year time frame. These savings alone do not prove cost efficiency of the INCA approach. Further work is needed to improve the approximation and to include indirect and intangible costs.

Telemedicine-based KADIS combined with CGMS has high potential for improving outpatient diabetes care

BACKGROUND

The Karlsburg Diabetes Management System (KADIS) was developed over almost two decades by modeling physiological glucose-insulin interactions. When combined with the telemedicine-based communication system TeleDIAB and a continuous glucose monitoring system (CGMS), KADIS has the potential to provide effective, evidence-based support to doctors in their daily efforts to optimize glycemic control.

METHODS

To demonstrate the feasibility of improving diabetes control with the KADIS system, an experimental version of a telemedicine-based diabetes care network was established, and an international, multicenter, pilot study of 44 insulin-treated patients with type 1 and 2 diabetes was performed. Patients were recruited from five outpatient settings where they were treated by general practitioners or diabetologists. Each patient underwent CGMS monitoring under daily life conditions by a mobile monitoring team of the Karlsburg diabetes center at baseline and 3 months following participation in the KADIS advisory system and telemedicine-based diabetes care network. The current metabolic status of each patient was estimated in the form of an individualized "metabolic fingerprint." The fingerprint characterized glycemic status by KADIS-supported visualization of relationships between the monitored glucose profile and causal endogenous and exogenous factors and enabled evidence-based identification of "weak points" in glycemic control. Using KADIS-based simulations, physician recommendations were generated in the form of patient-centered decision support that enabled elimination of weak points. The analytical outcome was provided in a KADIS report that could be accessed at any time through TeleDIAB. The outcome of KADIS-based support was evaluated by comparing glycosylated hemoglobin (HbA1c) levels and 24-hour glucose profiles before and after the intervention.

RESULTS

Application of KADIS-based decision support reduced HbA1c by 0.62% within 3 months. The reduction was strongly related to the level of baseline HbA1c, diabetes type, and outpatient treatment setting. The greatest benefit was obtained in the group with baseline HbA1c levels >9% (1.22% reduction), and the smallest benefit was obtained in the group with baseline HbA1c levels of 6-7% (0.13% reduction). KADIS was more beneficial for patients with type 1 diabetes (0.79% vs 0.48% reduction) and patients treated by general practitioners (1.02% vs 0.26% reduction). Changes in HbA1c levels were paralleled by changes in mean daily 24-hour glucose profiles and fluctuations in daily glucose.

CONCLUSION

Application of KADIS in combination with CGMS and the telemedicine-based communication system TeleDIAB successfully improved outpatient diabetes care and management.

PROTECTIVE EFFECTS OF BENDAZAC LYSINE ON DIABETIC PERIPHERAL NEUROPATHY IN STREPTOZOTOCIN-INDUCED DIABETIC RATS

1. Diabetic neuropathy is a many faceted complication of both type I and II diabetes. The aim of the present study was to investigate the effects of bendazac lysine (BDL), an anticataract drug, on experimental diabetic peripheral neuropathy (DPN) in rats. 2. Diabetes was induced in rats by intraperitoneal injection of 75 mg/kg streptozotocin (STZ) dissolved in 0.1 mol/L citrate buffer (pH 4.4). Bendazac lysine was administered to rats at doses of 50, 100 and 200 mg/kg twice a day for 12 weeks. 3. Diabetic rats without treatment showed hypopraxia, polydipsia, polyuria, slow weight gain, cataract, increased tail-flick threshold temperature, decreased motor nerve conduction velocity (nd induced pathological morphological changes of myelinated nerve fibres. All these symptoms were ameliorated in diabetic rats treated with BDL. Bendazac lysine ameliorated the blood glucose concentration, glycosylated haemoglobin levels and insulin levels in the plasma of diabetic rats, reduced aldose reductase activity in erythrocytes and advanced glycation end-products in both nerves and serum and increase the activity of glutathione peroxidase in the nerves and Na(+)/K(+)-ATPase in the nerves and erythrocytes. 4. Bendazac lysine exerts its protective effects against the progression of diabetic peripheral neuropathy in STZ-diabetic rats through multiple mechanisms and is a potential drug for the prevention of deterioration in DPN.

Dose accuracy of a reusable insulin pen using a cartridge system with an integrated plunger mechanism

Pen injection devices are a common method of administering insulin for patients with diabetes. Pen devices must comply with guidelines prepared by the International Organization for Standardization, which include device dose accuracy and precision. OptiClik (sanofi-aventis) was developed to fulfil unmet needs of patients with diabetes, including: easier cartridge changing, clearer dose display and readability, and a larger dose of insulin to be delivered with a single injection. In this paper, the authors report on the dose accuracy of the OptiClik pen device, which uses a novel cartridge system with an integrated plunger for easier cartridge changing. The authors show that OptiClik accurately delivers a required dose of insulin, which is maintained over the lifetime of the pen. OptiClik offers a significant contribution to the treatment of diabetes.

Cognitive dysfunction associates with white matter hyperintensities and subcortical atrophy on magnetic resonance imaging of the elderly diabetes mellitus Japanese elderly diabetes intervention trial (J-EDIT)

BACKGROUND

Type 2 diabetes is associated with cognitive dysfunction and increases the risk of dementia in the elderly. The aim of this study was to explore, by means of magnetic resonance (MR) imaging, possible relationships among clinical profiles of diabetes, cognitive function, white matter hyperintensities (WMHs) and subcortical brain atrophy.

METHODS

Data were obtained from 95 nondemented type 2 diabetic participants aged 65 years or over, enrolled in an intervention trial for Japanese elderly diabetic patients. Cognitive function was measured with neuropsychiatric tests, including mini-mental state examination (MMSE), verbal memory, digit symbol substitution and Stroop tests. Hyperintensity was classified into periventricular, deep white matter, thalamic and basal ganglia. Four ventricle-to-brain ratios were used to measure subcortical atrophy. To identify clinical features of diabetes, indices of glycemic control, lipid metabolism, blood pressure and complications were examined. Canonical correlation analysis and regression analysis were used to assess correlation.

RESULTS

Scores for digit symbol substitution and MMSE negatively correlated with WMHs in the parietal lobe and hyperintensities in the thalamus, respectively. Lower scores for memory and digit symbol substitution showed positive association with enlarged subcortical atrophy adjacent to lateral ventricles. There was no association between clinical pictures of diabetic patients with cognitive dysfunction and of those with morphological changes in the brain.

CONCLUSIONS

Impaired cognitive domains of the speed of mental processes and memory were associated with WMHs and subcortical atrophy. Degenerative changes in the cerebral small vessels may constitute predictive factors for the rate of cognitive dysfunction in elderly diabetic patients.

Diabetes, aging and physical activity

Diabetes mellitus (DM) is a metabolic disease affecting the regulation of insulin and glucose causing a disruption in the normal control of counterregulatory hormones and macronutrients, resulting in blood glucose accumulation. Metabolic deregulation leads to the production of noxious substances that have a particular propensity for damaging vascular and nervous structures. Physiological changes observed with aging are correlated with a concomitant increase in DM and its associated complications. Long-term complications, including peripheral and central neuropathies, micro- and macrovascular damage, retinopathy, and nephropathy are the major causes of mortality in diabetics [cardiovascular disease (CVD) being the primary complication causing death in this population]. All-cause mortality is three to four times greater in the DM population; hence, management of DM is of timely importance, particularly with a projected prevalence increase of 134% within the next 25 years among individuals over the age of 65 years. Exercise modalities, including endurance and resistance training, were employed to improve glycemic/metabolic control and to ameliorate the progression of DM-related complications. Several risk factors, including glucose levels, blood pressure, lipid/cholesterol profile, and BMI, are reportedly improved with these modes of exercise. However, not all studies demonstrate an improvement in risk factors, but consistently note improvement in complications and a reduction of DM incidence. There is convincing evidence that exercise, with or without specific improvements to traditional DM-related risk factors, is an effective therapy for the management of DM.

Case study: lessons learned in the care of a 63-year-old woman with type 2 diabetes

Control of type 2 diabetes mellitus (DM) has deteriorated rather than improved during the last decade in the United States, despite a greater understanding of the disease and the availability of various therapeutic options. Achieving recommended glycemic targets in patients with type 2 DM requires overcoming several barriers, including the fear of hypoglycemia and its associated consequences. Insulin analogues offer new options in diabetes management and may help patients achieve better glycemic control while limiting the incidence of hypoglycemic episodes. Greater awareness of the symptoms of hypoglycemia, intensified blood glucose self-monitoring, and new diabetes treatment options allow for achievement of glycemic targets without increased risk of hypoglycemic episodes. A case study of a 63-year-old woman with type 2 DM offers important lessons learned in diabetes management.

Inhibitory effects of astragaloside IV on diabetic peripheral neuropathy in rats

Astragaloside IV (AGS-IV), a new glycoside of cycloartane-type triterpene isolated from the root of Astragalus membranaceus (Fisch.) Bunge, has been used experimentally for its potent immune-stimulating, anti-inflammatory, and antioxidative actions. A recent study has shown AGS-IV to be an aldose-reductase inhibitor and a free-radical scavenger. This study examined the effects of AGS-IV on motor nerve conduction velocity (MNCV), tailflick threshold temperature, biochemical indexes, and the histology of the sural nerve after diabetes was induced in rats with 75 mg/kg streptozotocin (STZ). AGS-IV (3, 6, 12 mg/kg, twice a day) was administered by oral gavage for 12 weeks after diabetes was induced. Compared with control (nondiabetic) rats, obvious changes in physiological behaviors and a significant reduction in sciatic MNCV in diabetic rats were observed after 12 weeks of STZ administration. Morphological analysis showed that AGS-IV suppressed a decrease in myelinated fiber area, an increase in myelinated fiber density, and an increase in segmental demyelination in diabetic rats. The protective mechanism of AGS-IV involved a decrease in declining blood glucose concentration and HbA1C levels, and an increase in plasma insulin levels. AGS-IV increased the activity of glutathione peroxidase in nerves, depressed the activation of aldose reductase in erythrocytes, and decreased the accumulation of advanced glycation end products in both nerves and erythrocytes. Moreover, AGS-IV elevated Na+,K+-ATPase activity in both the nerves and erythrocytes of diabetic rats. These results indicate that AGS-IV exerts protective effects against the progression of peripheral neuropathy in STZ-induced diabetes in rats through several interrelated mechanisms.

High glucose activates nuclear factor of activated T cells in native vascular smooth muscle

OBJECTIVE

Hyperglycemia has been suggested to play a role in the development of vascular disease associated with diabetes. Atypical Ca2+ signaling and gene expression are characteristic of vascular dysfunction; however, little is known regarding the effects of high glucose on Ca2+-dependent transcription in the vascular wall.

METHODS AND RESULTS

Using confocal immunofluorescence, we show that modest elevation of extracellular glucose (ie, from 2 to 11.5 mmol/L) increased [Ca2+]i, leading to nuclear accumulation of nuclear factor of activated T cells (NFAT) in intact cerebral arteries from mouse. This was accompanied by increased NFAT-dependent transcriptional activity. Both the increase in Ca2+ and NFAT activation were prevented by the ectonucleotidase apyrase, suggesting a mechanism involving the release of extracellular nucleotides. We provide evidence that the potent vasoconstrictors and growth stimulators UTP and UDP mediate glucose-induced NFAT activation via P2Y receptors. NFAT nuclear accumulation was inhibited by the voltage-dependent Ca2+ channel blockers verapamil and nifedipine, the calcineurin inhibitor cyclosporine A, and the novel NFAT blocker A-285222. High glucose also regulated glycogen synthase kinase 3beta and c-Jun N-terminal kinase activity, yielding decreased kinase activity and reduced export of NFAT from the nucleus, providing additional mechanisms underlying the glucose-induced NFAT activation.

CONCLUSIONS

Our results identify the calcineurin/NFAT signaling pathway as a potential metabolic sensor for the arterial smooth muscle response to high glucose.

Time trends in the epidemiology of renal transplant patients with type 1 diabetes mellitus over the last four decades

BACKGROUND

Diabetes mellitus (DM) type 1 is an important contributor to end-stage renal disease (ESRD) among younger transplant recipients. However, little is known about the changes in epidemiological characteristics of this population. Especially, time to reach ESRD may have changed in type 1 diabetic patients referred for transplantation, resulting in higher age at time of grafting. Such time trends may allow anticipating future developments regarding the demand for organ replacement in this patient group.

METHODS

We retrospectively analysed 173 patients with type 1 DM undergoing renal transplantation at our institution, stratified into four groups according to year of reaching ESRD (A = 1973-1983, B = 1984-1990, C = 1991-1995 and D = 1996-2002). For each group we determined age at diagnosis of DM, age at time of reaching ESRD and age at time of transplantation. From these data, the interval from diagnosis of DM to ESRD and from ESRD to transplantation was calculated. The results were analysed in relation to gender, year of and age at onset of diabetes.

RESULTS

Patients reaching ESRD in more recent years (group D) tended to be both younger at diagnosis of DM and older when reaching ESRD, resulting in higher mean age at transplantation (35.0, 37.5, 39.6 and 41.0 years in groups A, B, C and D, respectively). Accordingly, median duration to ESRD has significantly been prolonged over the last five decades in patients with type 1 DM undergoing renal transplantation (group A: 21.0, B: 20.7, C: 22.3 and D: 28.5 years; P < 0.0001), this finding being more pronounced in female patients.

CONCLUSIONS

The results of our analysis are compatible with a change in epidemiology in patients undergoing kidney transplantation. Older age at time of reaching ESRD may impact significantly on the demand for renal grafts, as patients are already clearly older nowadays when being transplanted. From our data it cannot be concluded whether this development is due to a change in the progression of diabetic nephropathy or may simply reflect a change in the selection of type 1 diabetic patients referred for transplantation.