Cardiovascular effects of acute hyperglycaemia: pathophysiological underpinnings

Suppression of the postprandial hyperglycemia in patients with type 2 diabetes by a raw medicinal herb powder is weakened when consumed in ordinary hard gelatin capsules: A randomized crossover clinical trial

INTRODUCTION

Contradictory claims about the efficacy of several medicinal plants to promote glycemic control in patients with type 2 diabetes mellitus (T2DM) have been explained by divergences in the administration form and by extrapolation of data obtained from healthy individuals. It is not known whether the antidiabetic effects of traditional herbal medicines are influenced by gelatin capsules. This randomized crossover trial aimed to evaluate the acute effect of a single dose of raw cinnamon consumed orally either dissolved in water as a beverage or as ordinary hard gelatin capsules on postprandial hyperglycemia (>140 mg/dL; >7.8 mmol/L) in T2DM patients elicited by a nutritionally-balanced meal providing 50 g of complex carbohydrates.

METHODS

Fasting T2DM patients (n = 19) randomly ingested a standardized meal in five experimental sessions, one alone (Control) and the other after prior intake of 3 or 6 g of crude cinnamon in the form of hard gelatin capsules or powder dissolved in water. Blood glucose was measured at fasting and at 0.25, 0.5, 0.75, 1, 1.5 and 2 hours postprandially. After each breakfast, its palatability scores for visual appeal, smell and pleasantness of taste were assessed, as well as the taste intensity sweetness, saltiness, bitterness, sourness and creaminess.

RESULTS

The intake of raw cinnamon dissolved in water, independently of the dose, decreased the meal-induced large glucose spike (peak-rise of +87 mg/dL and Δ1-hour glycemia of +79 mg/dL) and the hyperglycemic blood glucose peak. When cinnamon was taken as capsules, these anti-hyperglycemic effects were lost or significantly diminished. Raw cinnamon intake did not change time-to-peak or the 2-h post-meal glycaemia, but flattened the glycemic curve (lower iAUC) without changing the shape that is typical of T2DM patients.

CONCLUSIONS

This cinnamon's antihyperglycemic action confirms its acarbose-like property to inhibit the activities of the carbohydrate-digesting enzymes α-amylases/α-glucosidases, which is in accordance with its exceptionally high content of raw insoluble fiber. The efficacy of using raw cinnamon as a diabetes treatment strategy seems to require its intake at a specific time before/concomitantly the main hyperglycemic daily meals. Trial registration: Registro Brasileiro de Ensaios Clínicos (ReBEC), number RBR-98tx28b.

In vivo photoacoustic monitoring of vasoconstriction induced by acute hyperglycemia

Postprandial hyperglycemia, blood glucose spikes, induces endothelial dysfunction, increasing cardiovascular risks. Endothelial dysfunction leads to vasoconstriction, and observation of this phenomenon is important for understanding acute hyperglycemia. However, high-resolution imaging of microvessels during acute hyperglycemia has not been fully developed. Here, we demonstrate that photoacoustic microscopy can noninvasively monitor morphological changes in blood vessels of live animals' extremities when blood glucose rises rapidly. As blood glucose level rose from 100 to 400 mg/dL following intraperitoneal glucose injection, heart/breath rate, and body temperature remained constant, but arterioles constricted by approximately -5.7 ± 1.1% within 20 min, and gradually recovered for another 40 min. In contrast, venular diameters remained within about 0.6 ± 1.5% during arteriolar constriction. Our results experimentally and statistically demonstrate that acute hyperglycemia produces transitory vasoconstriction in arterioles, with an opposite trend of change in blood glucose. These findings could help understanding vascular glucose homeostasis and the relationship between diabetes and cardiovascular diseases.

Admission hyperglycemia, stroke subtypes, outcomes in acute ischemic stroke

AIMS

Whether admission hyperglycemia is differentially associated with early vascular outcomes in acute ischemic stroke (AIS) depending on stroke subtype has been incompletely delineated.

METHODS

In a multicenter, prospective stroke registry, patients with AIS were categorized based on admission glucose levels into normoglycemia, moderate hyperglycemia, and severe hyperglycemia (<140mg/dl, 140-179mg/dl, and ≥180mg/dl, respectively) groups. Multivariate analysis assessed the interaction between the hyperglycemia and ischemic stroke subtypes of large artery atherothrombosis (LAA), cardioembolism (CE), and small vessel occlusion (SVO) and early vascular outcomes (3-month stroke, all-cause mortality, and composite of stroke, MI, and all-cause mortality).

RESULTS

Among the 32,772 patients (age:69.0±12.6yrs, male:58.4%) meeting eligibility criteria, 61.9% were in the normoglycemia group, 19.5% were in the moderate hyperglycemia group, and 18.7% were in the severe hyperglycemia group. Substantial interactions between hyperglycemia groups and stroke subtypes were observed for 3-month stroke (P_interaction = 0.003) and composite of stroke, MI, and all-cause mortality (P_interaction = 0.001), with differential recurrence strongest among CE, intermediate among LAA, and least among SVO.

CONCLUSIONS

Hyperglycemia was differently associated with the risk of 3-month stroke by ischemic stroke subtype. The associations of hyperglycemia with 3-month stroke were greatest in CE subtype but not in SVO subtype. These results suggest that the effect of glucose-lowering treatment after AIS may differ according to stroke subtype.

Association between haemoglobin A1c and all-cause and cause-specific mortality in middle-aged and older Koreans: a prospective cohort study

Background

This study aimed to examine associations between haemoglobin A1c (HbA1c) levels over time and all-cause and cause-specific mortality in middle-aged and older Koreans.

Methods

Using 16 years of follow-up data from the Korean Genome and Epidemiology Study, we analysed 9294 individuals aged 40–69 years with no history of cardiovascular disease (CVD) or cancer. Participants were divided into a known diabetes group and five groups categorized by HbA1c levels (< 5.0%, 5.0–5.4%, 5.5–5.9%, 6.0–6.4%, and ≥ 6.5%). Hazard ratios (HRs) for all-cause and cause-specific mortality associated with HbA1c levels were calculated using a conventional and a time-dependent Cox proportional hazards model. Restricted cubic spline models were fitted to investigate the relationship between continuous HbA1c levels and mortality among people without known diabetes. Subgroup analyses were performed for age, sex, smoking, hypertension, liver diseases, and red blood cell counts.

Results

During a median follow-up period of 15.7 years, there were 944 deaths, including 185 deaths from CVD, 359 from cancer, and 125 from all external causes. Compared with participants with HbA1c levels of 5.5–5.9%, multivariate-adjusted HRs and 95% confidence intervals for all-cause death of participants with levels < 5.0%, 5.0–5.4%, 6.0–6.4%, and ≥ 6.5% and participants with known diabetes were 1.84 (1.35–2.51), 1.13 (0.95–1.34), 1.30 (1.04–1.62), 1.37 (0.97–1.93), and 2.03 (1.70–2.44), respectively. The risk of cancer mortality was significantly increased in HbA1c < 5.0% (HR, 2.21; 95% CI 1.42–3.44) and known diabetes (HR, 1.60; 95% CI 1.18–2.15). When we performed diverse subgroup analyses, low HbA1c levels at baseline were strongly associated with mortality in participants with liver diseases.

Conclusions

We found U-shaped associations between HbA1c levels at baseline and over time and all-cause mortality in middle-aged and older Koreans. Additionally, the risk of cancer mortality increased both in low and high HbA1c groups, but CVD mortality increased only in high HbA1c group. In particular, people with liver diseases and low HbA1c levels had a high risk of all-cause mortality. Therefore, more careful management of these groups is suggested to identify any deteriorating health conditions.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00682-4.

Impact of Stress Hyperglycemia on No-Reflow Phenomenon in Patients with ST Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Background:

Stress hyperglycemia is a common finding during acute myocardial infarction and associated with poor prognosis. To reduce the occurrence of no-reflow, prognostic factors must be identified before primary percutaneous coronary intervention (PPCI). Our objective was to investigate the impact of stress hyperglycemia in non-diabetic and diabetic patients on no-reflow phenomenon after PPCI.

Methods:

The study comprised 480 patients with ST elevation myocardial infarction (STEMI) who were managed by PPCI. Patients were classified into two groups according to thrombolysis in myocardial infarction (TIMI) flow grade: Group I (Patients with normal flow, TIMI 3 flow) and Group II (Patients with no-reflow, TIMI 0-2 flow). Patients were analyzed for clinical outcomes including mortality and major adverse cardiac events.

Results:

Incidence of stress hyperglycemia was 14.8% in non-diabetic patients and 22.2% in diabetic patients; the incidence of no-reflow phenomenon was 13.5% and no-reflow was significantly higher in patients with stress hyperglycemia. Multivariate regression analysis identified the independent predictors of no-reflow phenomenon: stress hyperglycemia OR 3.247 (CI95% 1.656–6.368, P = 0.001), Killip class >1 OR 1.893 (CI95% 1.004–3.570, P = 0.049) and cardiogenic shock OR 3.778 (CI95% 1.458–9.790, P = 0.006).

Conclusion:

Stress hyperglycemia was associated with higher incidence of no-reflow phenomenon. The independent predictors of no-reflow were stress hyperglycemia, Killip class >1 and cardiogenic shock.

A Primer on Repeated Sitting Exposure and the Cardiovascular System: Considerations for Study Design, Analysis, Interpretation, and Translation

Sedentary behavior, particularly sitting, is ubiquitous in many contemporary societies. This is a major societal concern considering the evidence for a strong association between sitting behavior and cardiovascular disease morbidity and mortality. Unsurprisingly, leading public health agencies have begun to advocate “reduction” in sitting behavior. Though, the guidelines are typically vague and non-specific. The lack of specific guidelines for prolonged sitting is attributable to the absence of available evidence to facilitate guideline development. To inform policy, well-designed randomized controlled trials are required to test the efficacy of specific and translatable sitting reduction strategies. To guide the design of randomized controlled trials, this review postulates that several gaps in the literature first need to be filled. Following a general discussion of the importance of sitting behavior to contemporary societies, each of the following are discussed: (i) acute sitting exposure and systems physiology; (ii) recommendations for a systems physiology toolbox; (iii) study design considerations for acute sitting exposure; and (iv) translation of sitting-focused research.

The Role of Pulses in Cardiovascular Disease Risk for Adults With Diabetes

Cardiovascular disease (CVD) is a leading cause of death among adults while associated comorbidities like diabetes further increase risks of CVD-related complications and mortality. Strategies to prevent and manage CVD risk, such as dietary change, are a key component for CVD and diabetes prevention and management. Pulses, defined as the dried edible seeds of plants in the legume family, have received attention for their superior nutritional composition as high-fiber, low-glycemic index foods and have been studied for their potential to reduce CVD and diabetes risk. Both observational and experimental studies conducted among adults with and without diabetes have provided support for pulses in their ability to improve lipid profiles, glycemic control, and blood pressure, all of which are major modifiable risk factors of CVD. These capabilities have been attributed to various mechanisms associated with the nutrient and phytochemical composition of pulses. Overall, this evidence provides support for the consumption of pulses as an important dietary strategy to reduce risk of CVD for those living with and without diabetes.

Pre-Procedural Hyperglycemia Increases the Risk of Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography: A Systematic Review and Meta-Analysis

BACKGROUND

Contrast-induced nephropathy (CIN) frequently occurs following coronary angiography (CAG) and is associated with worse outcomes, including both short and long-term mortality. Previous studies reported an association between procedural hyperglycemia (PH) and CIN, with or without diabetes mellitus (DM). We performed a systematic review and meta-analysis to explore the association of PH and CIN in patients undergoing CAG.

METHODS

We searched the databases of MEDLINE and EMBASE from inception to January 2020. Included studies investigated CIN incidence in patients undergoing CAG. Data from each study were combined using the random-effects model.

RESULTS

A total of eight studies were included in this meta-analysis. We found that PH was associated with an increased risk of CIN following CAG (pooled OR = 1.71, 95%CI:1.35-2.16, where PH was defined as ≥140 mg/dl; and pooled OR = 2.07, 95%CI:1.80-2.37, where PH was defined as ≥200 mg/dl). In subgroup analysis of non-diabetic patients and STEMI patients undergoing primary percutaneous coronary intervention, we found that PH was associated with an increased risk of CIN in both subgroups, where PH was defined as ≥140 mg/dl and ≥200mg/dl (p-value < 0.05).

CONCLUSIONS

Our meta-analysis demonstrated that PH significantly increases the risk of CIN following CAG, in both diabetic and non-diabetic populations. Further studies are needed to evaluate whether strict blood glucose control can reduce the incidence of CIN in this population.

Acute hyperglycemia and contrast-induced nephropathy in patients with non-ST elevation myocardial infarction

Acute hyperglycemia and contrast-induced nephropathy (CIN) are frequently observed in non-ST elevation myocardial infarction (NSTEMI) patients undergoing percutaneous coronary intervention (PCI), and both are associated with an increased mortality rate. We investigated the possible association between acute hyperglycemia and CIN in patients with NSTEMI undergoing PCI.

Materials and methods

We retrospectively enrolled 281(149, 53% men) NSTEMI patients undergoing PCI. For each patient, plasma glucose levels were secreened at hospital admission. Acute hyperglycemia was defined as glucose levels > 198 mg/dl. CIN was defined as an increase in serum creatinine 25% or 0.5 mg/dl from baseline in the first 48-72 hours.

Results

Overall, 44 (15.7%) patients had acute hyperglycemia. Patients with acute hyperglycemia had higher incidence of CIN than those without acute hyperglycemia (29.5 vs 5.1%, P < 0.001). Also, in-hospital mortality, length of hospital stay, major bleeding, requirement of mechanical ventilation and dialysis were observed significantly higher in patients with hyperglycemia. Patients were then reallocated to two groups according to the presence or absence of CIN. Overall, 25 cases (8.9%) of CIN were diagnosed. Diabetes mellitus, weight, age, glucose level and estimated glomerular filtration rate (eGFR) were detected as independent risk factors of CIN. Additionally, admission glucose levels were significantly correlated with creatinine levels after PCI, eGFR and contrast volume/eGFR ratio.

Conclusion

In NSTEMI patients undergoing primary PCI, acute hyperglycemia may be associated with an increased risk for CIN and in-hospital mortality and morbidity.

The Influence of Light on Reactive Oxygen Species and NF-кB in Disease Progression

Reactive oxygen species (ROS) are important secondary metabolites that play major roles in signaling pathways, with their levels often used as analytical tools to investigate various cellular scenarios. They potentially damage genetic material and facilitate tumorigenesis by inhibiting certain tumor suppressors. In diabetic conditions, substantial levels of ROS stimulate oxidative stress through specialized precursors and enzymatic activity, while minimum levels are required for proper wound healing. Photobiomodulation (PBM) uses light to stimulate cellular mechanisms and facilitate the removal of oxidative stress. Photodynamic therapy (PDT) generates ROS to induce selective tumor destruction. The regulatory roles of PBM via crosstalk between ROS and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-кB) are substantial for the appropriate management of various conditions.

Glycaemic variability is associated with severity of coronary artery disease in patients with poorly controlled type 2 diabetes and acute myocardial infarction

BACKGROUND

In patients with type 2 diabetes (T2D), glycaemic variability (GV), another component of glycaemic abnormalities, is a novel potentially aggravating factor for coronary artery disease (CAD).

OBJECTIVES

The aim of our study was to identify interactions between GV and severity of CAD in diabetes patients admitted for acute myocardial infarction (AMI).

METHODS

All patients with T2D admitted to our university hospital for AMI from March 2015 to February 2017 who received intravenous (IV) insulin therapy and underwent coronary angiography were included. GV was assessed by mean amplitude of blood glucose excursion (MAGE) values taken within 2 days of admission. Patients with higher GV (highest MAGE tertile) were compared with those with lower GV (first and second MAGE tertiles).

RESULTS

A total of 204 patients were included: median age was 72 (61-81) years; 32% were female; HbA_1c was 7.3% (6.4-8.2%); diabetes duration was 10 (2-17.5) years; and MAGE value was 0.65 (0.43-0.92) g/L. Compared with those with lower GV, patients with the highest GV were more often women, treated with previous insulin, and had higher blood glucose and HbA_1c levels. In addition, patients with elevated GV had significantly higher SYNTAX scores: 17 (10-28) vs. 12 (6-22) (P = 0.009). Indeed, SYNTAX scores (OR: 1.05, 95% CI: 1.02-1.08; P = 0.001) remained independently associated with high GV beyond HbA_1c levels (OR: 1.51, 95% CI: 1.2-1.89; P <  0.001).

CONCLUSION

In AMI patients with poorly controlled diabetes, GV is associated with CAD severity beyond chronic hyperglycaemia. Although no causality can be determined from our observational study, the results suggest that, in AMI, early evaluation of GV might contribute to the identification of those diabetes patients at high risk, and serve as a therapeutic target for both primary and secondary prevention.

Oxidative stress and adipokine levels were significantly correlated in diabetic patients with hyperglycemic crises

BACKGROUND

To investigate the relationship between blood adipokine level and oxidative stress in diabetic patients with hyperglycemic crises before and after treatment.

METHODS

We measured superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, total antioxidant capacity (TAC), and levels of 8-iso-prostaglandin F2α (8-iso-PGF2α), adiponectin, leptin, and resistin in 63 diabetic patients with hyperglycemic crises.

RESULTS

Prior to treatment, patients with hyperglycemic crises had significantly lower serum SOD activity, TAC, and adiponectin and leptin levels, and higher serum levels of MDA, 8-iso-PGF2α, and resistin compared with the healthy control individuals (all at P < 0.05). After treatment, SOD, TAC, adiponectin, and leptin levels increased significantly, while MDA, 8-iso-PGF2α, and resistin levels decreased significantly (all at P < 0.05) in the patients.

CONCLUSIONS

Diabetic patients with hyperglycemic crises have increased oxidative stress, which is associated with serum adipokine abnormalities; improved oxidative stress after treatment suggests that oxidative stress may serve as target and/or indicator for the treatment of hyperglycemic crises.

L-Cysteine in vitro can restore cellular glutathione and inhibits the expression of cell adhesion molecules in G6PD-deficient monocytes

L-Cysteine is a precursor of glutathione (GSH), a potent physiological antioxidant. Excess glucose-6-phosphate dehydrogenase (G6PD) deficiency in African Americans and low levels of L-cysteine diet in Hispanics can contributes to GSH deficiency and oxidative stress. Oxidative stress and monocyte adhesion was considered to be an initial event in the progression of vascular dysfunction and atherosclerosis. However, no previous study has investigated the contribution of GSH/G6PD deficiency to the expression of monocyte adhesion molecules. Using human U937 monocytes, this study examined the effect of GSH/G6PD deficiency and L-cysteine supplementation on monocyte adhesion molecules. G6PD/GSH deficiency induced by either siRNA or inhibitors (6AN/BSO, respectively) significantly (p < 0.005) increased the levels of cell adhesion molecules (ICAM-1, VCAM-1, SELL, ITGB1 and 2); NADPH oxidase (NOX), reactive oxygen species (ROS) and MCP-1 were upregulated, and decreases in levels of GSH, and nitric oxide were observed. The expression of ICAM-1 and VCAM-1 mRNA levels increased in high glucose, MCP-1 or TNF-α-treated G6PD-deficient compared to G6PD-normal cells. L-Cysteine treatment significantly (p < 0.005) increased G6PD activity and levels of GSH, and decreased NOX, ROS, and adhesion molecules. Thus, GSH/G6PD deficiency increases susceptibility to monocyte adhesion processes, whereas L-cysteine supplementation can restore cellular GSH/G6PD and attenuates NOX activity and expression of cell adhesion molecules.

Postprandial glucose and healthcare resource use: a cross-sectional survey of adults with diabetes treated with basal-bolus insulin

AIMS

Postprandial glucose (PPG) control is a well-known challenge for diabetes management, yet there is limited research on how PPG affects healthcare resource utilization. This study investigated the association between PPG levels and healthcare resource utilization among adults with diabetes treated with basal-bolus insulin.

METHODS

A web-based, cross-sectional survey (n = 940) of adults with type 1 or type 2 diabetes and treated with basal and bolus insulins was conducted in Italy, the UK, and the US. Descriptive analyses included frequencies, cross-tabulations, and comparison of means. Incidence-rate ratios (IRR) were calculated using negative binomial regression analysis to investigate the relationship between elevated PPG and healthcare resource utilization. Models controlled for demographic characteristics, duration of diabetes, and diabetes-related complications.

RESULTS

Among respondents who measured PPG regularly and reported their two highest PPG values in the past week (n = 691), the mean average highest PPG value was 11.9 mmol/L (SD = 4.0). On average, holding other variables constant at their means, a 1 mmol/L increase in PPG was associated with an increase in healthcare resource utilization related to diabetes and elevated PPG, including the expected number of healthcare provider (HCP) visits in the past 6 months (IRR [95% CI] = 1.14 [1.08-1.21], p < .001), the expected number of calls/emails to HCPs in the past 6 months (IRR [95% CI] = 1.12 [1.06-1.19], p < .001), and the expected number of overnight hospitalizations in the past year (IRR [95% CI] = 1.14 [1.07-1.23], p < .001).

LIMITATIONS

The study relied on self-reported data, which may be subject to recall bias. Given the cross-sectional nature of the study, results should be interpreted with caution.

CONCLUSIONS

Increased PPG levels were significantly associated with increased healthcare resource utilization among adults with diabetes. Additional education regarding PPG monitoring may help improve the day-to-day management of diabetes and reduce healthcare costs.

Protective effect of angiotensin-(1-7) against hyperglycaemia-induced injury in H9c2 cardiomyoblast cells via the PI3K̸Akt signaling pathway

Angiotensin-(1-7) [Ang-(1-7)], a heptapeptide mainly generated from cleavage of AngⅠ and AngⅡ, possesses physiological and pharmacological properties, including anti‑inflammatory and antidiabetic properties. Activation of the phosphoinositide 3-kinase and protein kinase B (PI3K̸Akt) signaling pathway has been confirmed to participate in cardioprotection against hyperglycaemia-induced injury. The aim of the present study was to test the hypothesis that Ang-(1-7) protects H9c2 cardiomyoblast cells against high glucose (HG)-induced injury by activating the PI3K̸Akt pathway. To examine this hypothesis, H9c2 cells were treated with 35 mmol/l (mM) glucose (HG) for 24 h to establish a HG-induced cardiomyocyte injury model. The cells were co-treated with 1 µmol/l (µM) Ang-(1-7) and 35 mM glucose. The findings of the present study demonstrated that exposure of H9c2 cells to HG for 24 h markedly induced injury, as evidenced by an increase in the percentage of apoptotic cells, generation of reactive oxygen species and level of inflammatory cytokines, as well as a decline in cell viability and mitochondrial luminosity. These injuries were significantly attenuated by co-treatment of the cells with Ang-(1-7) and HG. In addition, PI3K̸Akt phosphorylation was suppressed by HG treatment, but this effect was abolished when the H9c2 cells were co-treated with Ang-(1-7) and HG. Furthermore, the cardioprotection of Ang-(1-7) against HG-induced injury in H9c2 cardiomyoblasts was highly attenuated in the presence of either D-Ala7-Ang-(1-7) (A-779, an antagonist of the Mas receptor) or LY294002 (an inhibitor of PI3K̸Akt). In conclusion, the present study provided new evidence that Ang-(1-7) protects H9c2 cardiomyoblasts against HG-induced injury by activating the PI3K̸Akt signaling pathway.

Angiotensin-(1-7) protects cardiomyocytes against high glucose-induced injuries through inhibiting reactive oxygen species-activated leptin-p38 mitogen-activated protein kinase/extracellular signal-regulated protein kinase 1/2 pathways, but not the leptin-c-Jun N-terminal kinase pathway in vitro

Aims/Introduction

Angiotensin‐(1–7) (Ang‐[1–7]), recognized as a new bioactive peptide in the renin–angiotensin system, shows biological and pharmacological properties in diabetic cardiovascular diseases. The leptin‐induced p38 mitogen‐activated protein kinase (MAPK) pathway has been reported to contribute to high glucose (HG)‐induced injury. In the present study, we showed the mechanism of how Ang‐(1–7) can protect against HG‐stimulated injuries in H9c2 cells.

Materials and Methods

H9c2 cells were treated with 35 mmol/L glucose (HG) for 24 h to establish a model of HG‐induced damage. Apoptotic cells were observed by Hoechst 33258 staining. Cell viability was analyzed by cell counter kit‐8. The expression of protein was detected by western blot. Reactive oxygen species was tested by 2′,7′‐dichlorodihydrofluorescein diacetate staining. Mitochondrial membrane potential was measured by 5,5′,6,6′‐Tetrachloro‐1,1′,3,3′‐tetraethyl‐imidacarbocyanine iodide staining.

Results

The present results showed that treating H9c2 cells with HG obviously enhanced the expressions of both the leptin and phosphorylated (p)‐MAPK pathway. However, the overexpression levels of leptin and p‐p38 MAPK/p‐extracellular signal‐regulated protein kinase 1/2 (ERK1/2), but not p‐c‐Jun N‐terminal kinase, were significantly suppressed by treatment of the cells with Ang‐(1–7). Additionally, leptin antagonist also markedly suppressed the overexpressions of p38 and ERK1/2 induced by HG, whereas leptin antagonist had no influence on the overexpression of c‐Jun N‐terminal kinase. More remarkable, Ang‐(1–7), leptin antagonist, SB203580 or SP600125, respectively, significantly inhibited the injuries induced by HG, such as the increased cell viability, decreased apoptotic rate, reduction of ROS production and increased mitochondrial membrane potential. Furthermore, the overexpressions of p38 MAPK, ERK1/2 and leptin were suppressed by N‐actyl‐L‐cystine.

Conclusions

The present findings show that Ang‐(1–7) protects from HG‐stimulated damage as an inhibitor of the reactive oxygen species–leptin–p38 MAPK/ERK1/2 pathways, but not the leptin–c‐Jun N‐terminal kinase pathway in vitro.

Naringin protects cardiomyocytes against hyperglycemia-induced injuries in vitro and in vivo

We previously reported that naringin (NRG) protects cardiomyocytes against high glucose (HG)-induced injuries by inhibiting the MAPK pathway. The aim of this study was to test the hypothesis that NRG prevents cardiomyocytes from hyperglycemia-induced insult through the inhibition of the nuclear factor kappa B (NF-κB) pathway and the upregulation of ATP-sensitive K(+) (KATP) channels. Our results showed that exposure of cardiomyocytes to HG for 24h markedly induced injuries, as evidenced by a decrease in cell viability and oxidative stress, and increases in apoptotic cells as well as the dissipation of mitochondrial membrane potential (MMP). These injuries were markedly attenuated by the pretreatment of cells with either NRG or pyrrolidine dithiocarbamate (PDTC) before exposure to HG. Furthermore, in streptozotocin (STZ)-induced diabetic rats and in HG-induced cardiomyocytes, the expression levels of caspase-3, bax and phosphorylated (p)-NF-κB p65 were increased. The increased protein levels were ameliorated by pretreatment with both NRG and PDTC. However, the expression levels of bcl-2 and KATP and superoxide dismutase (SOD) activity were decreased by hyperglycemia; the expression level of Nox4 and the ADP/ATP ratio were increased by hyperglycemia. These hyperglycemia-induced indexes were inhibited by the pretreatment of cardiomyocytes with NRG or PDTC. In addition, in STZ-induced diabetic rats, we also observed that NRG or PDTC contributed to protecting mitochondrial injury and myocardium damage. This study demonstrated that NRG protects cardiomyocytes against hyperglycemia-induced injury by upregulating KATP channels in vitro and inhibiting the NF-κB pathway in vivo and in vitro.

Understanding Post-Prandial Hyperglycemia in Patients with Type 1 and Type 2 Diabetes: A Web-based Survey in Germany, the UK, and USA

INTRODUCTION

To explore how patients with diabetes experience post-prandial hyperglycemia (PPH) or elevated blood glucose (BG) following a meal.

METHODS

A web-based survey of patients with type 1 or type 2 diabetes using bolus insulin in Germany, the USA, and the UK was conducted.

RESULTS

A total of 906 respondents completed the survey. PPH was a frequent occurrence among patients with type 1 and type 2 diabetes; 61.9% of respondents had experienced PPH in the past week, and differences by diabetes type were not significant. More than half of the respondents reported that they knew they were experiencing PPH because they had measured their BG (64.8%) and/or because they "just didn't feel right" (51.9%). The most frequently reported reasons given for PPH were eating more fat/sugar than estimated (31.2%) and over-eating in terms of their calculated bolus insulin dose (30.4%). The most common situations/factors contributing to PPH were stress (27.4%), eating at a restaurant (24.9%), being busy (21.1%), and/or feeling tired (19.2%). The most frequent corrective actions respondents took following PPH were testing BG and taking bolus insulin based on the reading (62.0%), and/or eating less/more carefully at their next meal or snack (18.8%). Additionally, significant differences in the reasons and contributing factors given for PPH and corrective actions following PPH, as well as emotions experienced when taking bolus insulin, were found by diabetes type.

CONCLUSION

These findings shed light on how patients with diabetes experience and manage PPH on a day-to-day basis and have implications for improving diabetes self-management. Clinicians and diabetes educators should help patients address eating habits and lifestyle issues that may contribute to PPH.

FUNDING

This study was sponsored by Novo Nordisk.

Determinants of growth differentiation factor 15 in patients with stable and acute coronary artery disease. A prospective observational study

Background

Growth differentiation factor 15 (GDF-15) is a member of the transforming growth factor ß family and has been associated with inflammation, cancer, aging, diabetes mellitus (DM) and atherosclerosis. Determinants of GDF-15 have been investigated in several conditions. We aimed to investigate determinants of GDF-15 plasma levels in patients with angiographically proven coronary artery disease (CAD).

Methods

Four hundred and seventy three consecutive patients with CAD were investigated between May 2009 and February 2011. Patients were separated into those with stable CAD (SCAD) and with ST-elevation and non-ST-elevation myocardial infarction (STEMI and NSTEMI). Blood samples for determination of GDF-15 were obtained before coronary angiography. Determinant of GDF-15 levels were analyzed by logistic regression analysis in unadjusted and adjusted models. Study endpoints were cardiovascular death (CV-death), myocardial infarction, unstable angina, unplanned revascularization, stent thrombosis and stroke assessed at a mean follow-up of 188 (177.2–243) days.

Results

Overall median and (25–27th percentile) GDF-15 level was 1212.8 pg/ml (833.2–1957 pg/ml). GDF-15 was significantly higher in STEMI compared to SCAD and NSTEMI groups (P < 0.0001). In a multivariate regression analysis advanced age, DM, acute hyperglycemia (AHG), CRP and chronic kidney disease (CKD) were independent predictors of elevated GDF-15 levels (P < 0.05). Receiver operating curve analysis of GDF-15 for prediction of CV-death showed an area under the curve of 0.852 with a confidence interval of 0.745-0.960, P < 0.0001. The estimated cut-off was 2094.6 pg/ml with a sensitivity of 76 % and specificity of 80 %.

Conclusion

In patients with CAD undergoing PCI with stent implantation, GDF-15 is determined by advanced age, acute and chronic hyperglycemia, inflammation and CKD. GDF-15 is a valuable predictor of CV-death in a population of CAD patients after PCI.

The Economic Burden of Post-prandial Hyperglycemia (PPH) Among People with Type 1 and Type 2 Diabetes in Three Countries

INTRODUCTION

Post-prandial hyperglycemia (PPH) among people with diabetes is a well-known clinical challenge to diabetes management. While the economic burden of diabetes is well studied, little is known about economic costs specific to PPH. The purpose of this study was to investigate costs of PPH related to work, diabetes management, and use of healthcare resources among people with diabetes taking bolus insulin.

METHODS

Data were collected in a web survey of 906 adults with type 1 (39%) and type 2 (61%) diabetes taking bolus insulin in Germany (34%), the UK (26%), and the USA (40%).

RESULTS

Sixty-two percent of respondents experienced PPH in the past week, and respondents averaged 1.7 episodes per week. Working respondents indicated that PPH affected their work productivity: 27% missed work time and 71% experienced work productivity issues while at work due to a recent episode of PPH. In terms of diabetes management, respondents with PPH in the past week measured their blood glucose (BG) more frequently than those without PPH (3.7 vs. 2.5 times/day, P < 0.001). PPH was also significantly associated with greater use of healthcare resources. Compared to those without PPH, respondents with PPH reported greater contact with healthcare professionals related to diabetes in the past year (5.5 vs. 4.4 visits, P < 0.001; 2.7 vs. 1.4 calls/emails, P < 0.001) and were more likely to report medical complications related to diabetes (72% vs. 55%, P < 0.001). Average annual costs associated with PPH due to missed work time, additional BG test strips, and physician visits were estimated to be $1239 USD per employed person in the USA.

CONCLUSION

Results indicate that PPH is associated with greater economic costs and that reducing the incidence of PPH would help mitigate such costs. Additional research is needed to better understand costs associated with PPH that may be more difficult to measure, as well as more long-term impacts and costs.

FUNDING

Novo Nordisk.

The relationship between fasting plasma glucose and MPO in patients with acute coronary syndrome

Background

Inflammation plays a critical role in the progression of atherosclerosis, and hyperglycemia is a common feature in patients with ACS. We investigated the relationship between fasting plasma glucose (FPG) levels and the levels of the inflammatory factor, myeloperoxidase (MPO), in patients with acute coronary syndrome (ACS).

Method

A total of 85 patients with no prior history of diabetes mellitus were recruited. The patients were divided into three groups based on their FPG levels as follows: group A, FPG < 5.6 mmol/l; group B, 5.6 mmol/l ≤ FPG < 6.1 mmol/l; and group C, FPG ≥ 6.1 mmol/l. The FPG concentrations and plasma MPO levels were determined, coronary angioplasty was performed, and the Gensini scores were used to evaluate the severity of the coronary lesion. The MPO expression in peripheral blood mononuclear cells (PBMCs) in patients with ACS was determined using western blot analysis.

Result

The results demonstrated that the levels of FPG were significantly and positively correlated with plasma MPO levels, Gensini scores, high sensitive C reaction protein(hs-CRP)levels, leukocyte and neutrophils count. In multivariate regression analyses the FPG levels were positively correlated with plasma MPO levels, Gensini score and hs-CRP. The plasma MPO levels in the group C [68.68(52.62–91.88) U/L] were significantly higher than in the group A [63.04(26.18–97.75) U/L] and group B [58.22(23.95–89.54) U/L]. The plasma hs-CRP concentrations are also higher in group C [42.28 (0.31–169.40) mg/L] than in the group A [12.51(0.28–176.25) mg/L] and group B [14.7 (0.14–89.68) mg/L].

Conclusion

This study demonstrates that FPG values are positively correlated with plasma MPO levels, suggesting MPO may play a role in the proatherogenesis of high FPG.

Glycemic Variability Assessed by Continuous Glucose Monitoring and Short-Term Outcome in Diabetic Patients Undergoing Percutaneous Coronary Intervention: An Observational Pilot Study

Poor glycemic control is associated with unfavorable outcome in patients undergoing percutaneous coronary intervention (PCI), irrespective of diabetes mellitus. However a complete assessment of glycemic status may not be fully described by glycated hemoglobin or fasting blood glucose levels, whereas daily glycemic fluctuations may influence cardiovascular risk and have even more deleterious effects than sustained hyperglycemia. Thus, this paper investigated the effectiveness of a continuous glucose monitoring (CGM), registering the mean level of glycemic values but also the extent of glucose excursions during coronary revascularization, in detecting periprocedural outcome such as renal or myocardial damage, assessed by serum creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and troponin I levels. High glycemic variability (GV) has been associated with worse postprocedural creatinine and NGAL variations. Moreover, GV, and predominantly hypoglycemic variations, has been observed to increase in patients with periprocedural myocardial infarction. Thus, our study investigated the usefulness of CGM in the setting of PCI where an optimal glycemic control should be achieved in order to prevent complications and improve outcome.

Glycated hemoglobin and all-cause and cause-specific mortality in Singaporean Chinese without diagnosed diabetes: the Singapore Chinese Health Study

OBJECTIVE

Glycated hemoglobin (HbA₁c) is a robust biomarker of the preceding 2 to 3 months average blood glucose level. The aim of this study was to examine the association between HbA₁c and mortality in a cohort of Southeast Asians.

RESEARCH DESIGN AND METHODS

Analysis of 7,388 men and women, mean age 62 years, from the Singapore Chinese Health Study who provided a blood sample at the follow-up I visit (1999-2004) and reported no history of diabetes, previous adverse cardiovascular events, or cancer. A total of 888 deaths were identified through 31 December 2011 via registry linkage. Participants represented a random study sample of potential control subjects for a nested case-control genome-wide association study of type 2 diabetes in the population. Hazard ratios (HRs) for all-cause and cause-specific mortality by six categories of HbA1c were estimated with Cox regression models.

RESULTS

Relative to participants with an HbA₁c of 5.4-5.6% (36-38 mmol/mol), participants with HbA₁c ≥6.5% (≥48 mmol/mol) had an increased risk of all-cause, cardiovascular, and cancer mortality during an average of 10.1 years of follow-up; HRs (95% CIs) were 1.96 (1.56-2.46), 2.63 (1.77-3.90), and 1.51 (1.04-2.18), respectively. No level of HbA1c was associated with increased risk of respiratory mortality. Levels <6.5% HbA₁c were not associated with mortality during follow-up. The results did not materially change after excluding observation of first 3 years post-blood draw.

CONCLUSIONS

HbA₁c levels consistent with undiagnosed type 2 diabetes (≥6.5%) are associated with an increased risk of all-cause and cause-specific mortality in Chinese men and women.

Dipeptidyl peptidase-4 inhibitor linagliptin attenuates neointima formation after vascular injury

BACKGROUND

Recently, glucagon-like peptide-1 (GLP-1)-based therapy, including dipeptidyl peptidase-4 (DPP-4) inhibitors and GLP-1 receptor agonists, has emerged as one of the most popular anti-diabetic therapies. Furthermore, GLP-1-based therapy has attracted increased attention not only for its glucose-lowering ability, but also for its potential as a tissue-protective therapy. In this study, we investigated the vascular-protective effect of the DPP-4 inhibitor, linagliptin, using vascular smooth muscle cells (VSMCs).

METHODS

Six-week-old male C57BL/6 mice were divided into control (n =19) and linagliptin (3 mg/kg/day, n =20) treated groups. Endothelial denudation injuries were induced in the femoral artery at 8 weeks of age, followed by evaluation of neointima formation at 12 weeks. To evaluate cell proliferation of rat aortic smooth muscle cells, a bromodeoxyuridine (BrdU) incorporation assay was performed.

RESULTS

Linagliptin treatment reduced vascular injury-induced neointima formation, compared with controls (p <0.05). In these non-diabetic mice, the body weight and blood glucose levels did not change after treatment with linagliptin. Linagliptin caused an approximately 1.5-fold increase in serum active GLP-1 concentration, compared with controls. In addition, the vascular injury-induced increase in the oxidative stress marker, urinary 8-OHdG, was attenuated by linagliptin treatment, though this attenuation was not statistically significant (p =0.064). Moreover, linagliptin did not change the serum stromal cell-derived factor-1α (SDF-1α) or the serum platelet-derived growth factor (PDGF) concentration. However, linagliptin significantly reduced in vitro VSMC proliferation.

CONCLUSION

Linagliptin attenuates neointima formation after vascular injury and VSMC proliferation beyond the glucose-lowering effect.

The association of oxidative stress and pro-inflammatory cytokines in diabetic patients with hyperglycemic crisis

AIMS

To investigate the relationship between oxidative stress and serum levels of pro-inflammatory cytokines in diabetic patients with hyperglycemic crisis.

METHODS

Seventy-three patients presenting to hospital with diabetic ketoacidosis or non-ketotic hyperglycemia were studied. Superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, total antioxidant capacity (TAC), 8-iso-prostaglandin F2α (8-iso-prostaglandinF2α, 8-iso-PGF2α), tumor necrosis factor receptor-I (TNF-RI), interleukin -1β (IL-1β), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels were measured in all patients. The patients were then given an intravenous infusion of insulin 0.1U • kg-1 • h-1, as well as fluids, symptomatic therapy and parenteral and intravenous nutrition.

RESULTS CONCLUSION

Patients with hyperglycemic crises have significantly increased oxidative stress and dysregulated serum pro-inflammatory cytokines that can be effectively treated by intensive insulin therapy.

Association between Glycosylated Haemoglobin Level and Contrast-Induced Acute Kidney Injury in Patients with Type 2 Diabetes Mellitus

BACKGROUND

There are several reports suggesting that admission hyperglycaemia increases the risk of contrast-induced acute kidney injury (CI-AKI). However, it is not clear whether there has been an association between long-standing poor glycaemic control and the incidence of CI-AKI. The purpose of this study was to examine the impact of poor glycaemic control or elevated glycosylated haemoglobin (HbA1c) on the incidence of CI-AKI in patients with type 2 diabetes mellitus (T2DM).

METHODS

The present study prospectively enrolled 133 patients with T2DM undergoing elective coronary angiography (CAG) and/or intervention. All patients had an estimated glomerular filtration rate (eGFR) of ≥60 ml/min/1.73 m(2). Patients were divided into two groups: those with an optimal HbA1c (<7%) and those with an elevated HbA1c (≥7%). All had similar baseline characteristics and were hydrated appropriately. The outcome was assessed by the incidence of CI-AKI.

RESULTS

CI-AKI occurred in 2 of 41 patients (4.9%) with optimal HbA1c levels and 5 of 92 patients (5.4%) with elevated HbA1c levels (p = 0.89). The cutoff point of HbA1c was set at 6.5%, but no statistically significant difference between the two groups was observed [1 of 24 patients (4.1%) vs. 6 of 109 patients (5.5%), p = 0.79]. However, despite a high variability in the incidence of CI-AKI, there was no statistically significant difference between the two groups when varying CI-AKI definitions were considered.

CONCLUSION

An elevated HbA1c level is not associated with a higher incidence of CI-AKI compared to optimal HbA1c levels in patients with T2DM (patients with an eGFR of ≥60 ml/min/1.73 m(2)) undergoing CAG and/or intervention.

ACUTE MYOCARDIAL INFARCTION SPECIFICS IN PATIENTS WITH CHRONIC TONSILLITIS

Aim. To investigate the clinical specifics of acute myocardial infarction

(AMI) in patients with chronic tonsillitis.

Material and methods. The study included 70 patients at early AMI stages (Days 1–2). The following parameters were analysed: anthropometry, blood biochemistry, myocardial necrosis markers, QT interval dispersion, echocardiography and Holter ECG monitoring parameters, and a confirmed medical diagnosis of chronic tonsillitis in medical history.

Results. In 31 patients with confirmed chronic tonsillitis, higher body mass index values, a significantly higher incidence of acute heart failure (19,4%; p<0,05) and anterior AMI (70%), higher glucose levels at admission (7,58±0,62 mmol/l), and a higher end-diastolic size of right ventriculum (3,04±0,19 cm vs. 2,66±0,05 cm) were observed. Mean daytime and peak nighttime heart rate values were higher than in other patients.

Conclusion. Patients with confirmed chronic tonsillitis were characterised by a more severe clinical course of AMI. There is some evidence that chronic tonsillitis is also associated with metabolic syndrome.

Inhibition of the leptin-induced activation of the p38 MAPK pathway contributes to the protective effects of naringin against high glucose-induced injury in H9c2 cardiac cells

Leptin, a product of the obese gene, has been reported to contribute to the development of cardiomyocyte hypertrophy in patients with diabetes and to activate the p38 mitogen-activated protein kinase (MAPK) pathway in cardiomyocytes. In this study, we demonstrate that naringin, a citrus flavonone, protects cardiomyoblasts (H9c2 cells) against high glucose (HG)-induced apoptosis by modulating the activation of the p38 MAPK pathway. We investigated the hypothesis that naringin prevents HG-induced injury by inhibiting the leptin-induced activation of the p38 MAPK pathway in H9c2 cells. Our results demonstrated that the exposure of H9c2 cells to HG (35 mmol/l) for a 24 h markedly upregulated the expression levels of both leptin and leptin receptors. However, the increase in the expression levels of leptin and leptin receptors was greatly attenuated by treatment of the H9c2 cells with 80 µmol/l naringin 2 h prior to exposure to HG. In addition, treatment of the cells with 50 ng/ml leptin antagonist (LA) for 24 h prior to exposure to HG markedly ameliorated the increased expression of phosphorylated (p)-p38 MAPK induced by HG. Of note, pre-treatment of the cells with either 80 µmol/l naringin or 50 ng/ml LA markedly inhibited the HG-induced injury, leading to an increase in cell viability and a decrease in the total number of apoptotic cells, preventing reactive oxygen species (ROS) generation, as well as the dissipation of mitochondrial membrane potential (MMP). In conclusion, the findings of the present study provide the first evidence that the leptin-induced activation of the p38 MAPK pathway is involved in HG-induced injury, including cytotoxicity, apoptosis, ROS generation and the dissipation of MMP in H9c2 cardiac cells. Our data demonstrate that naringin protects cardiac cells against HG-induced injury by inhibiting the leptin-induced activation of the p38 MAPK pathway.

Mitigation of starch and glucose-induced postprandial glycemic excursion in rats by antioxidant-rich green-leafy vegetables' juice

Objective:

Consumption of green-leafy vegetables is being advocated beneficial for type 2 diabetes mellitus individuals possibly because they are cost effective source of potent biological antioxidants. This research analyzed various phytochemicals, free radicals scavenging antioxidant potentials and starch digesting enzymes inhibitory activities in fresh juice of nine green-leafy vegetables. Furthermore, this study also investigated influence of these vegetables juice on starch and glucose induced postprandial glycemic load.

Materials and Methods:

Phytochemical constituents, in vitro free radicals scavenging antioxidant and enzymes inhibitory activities were evaluated applying various reported methods. Post-prandial glycemic excursion was induced in rats pretreated with vegetables juice by oral administration of starch and glucose.

Results:

All the leafy vegetables juice displayed potent free radicals scavenging activities. Juice of amaranthus, rumex, palak and raphanus displayed potential anti-oxidative property by reducing H₂O₂ induced hemolysis in rats red blood cells RBCs. Ajwain and rumex juice showed pancreatic α-amylase inhibitory activity. Alternanthera, ajwain, methi, amaranthus and sowa leaves juice displayed intestinal α-glucosidase inhibitory activity. Juice of raphanus, ajwain and sowa significantly mitigated starch-induced postprandial glycemic load. Amaranthus leaves juice potently mitigated glucose-induced postprandial glycemic load and also reduced hemoglobin glycation induced by glucose in vitro.

Conclusions:

This investigation finds that juice of leafy vegetables is potent source of biological antioxidants. In addition, juice of raphanus, ajwain and sowa leaves possess capacity to mitigate starch induced postprandial glycemic burden and amaranthus leaves’ juice can reduce glucose induced postprandial glycemic excursion.

Synthesis and α-glucosidase inhibitory activity evaluation of N-substituted aminomethyl-β-d-glucopyranosides

A series of N-substituted 1-aminomethyl-β-d-glucopyranoside derivatives was prepared. These novel synthetic compounds were assessed in vitro for inhibitory activity against yeast α-glucosidase and both rat intestinal α-glucosidases maltase and sucrase. Most of the compounds displayed α-glucosidase inhibitory activity, with IC50 values covering the wide range from 2.3μM to 2.0mM. Compounds 19a (IC50=2.3μM) and 19b (IC50=5.6μM) were identified as the most potent inhibitors for yeast α-glucosidase, while compounds 16 (IC50=7.7 and 15.6μM) and 19e (IC50=5.1 and 10.4μM) were the strongest inhibitors of rat intestinal maltase and sucrase. Analysis of the kinetics of enzyme inhibition indicated that 19e inhibited maltase and sucrase in a competitive manner. The results suggest that the aminomethyl-β-d-glucopyranoside moiety can mimic the substrates of α-glucosidase in the enzyme catalytic site, leading to competitive enzyme inhibition. Moreover, the nature of the N-substituent has considerable influence on inhibitory potency.

The role of oxidative stress in postprandial endothelial dysfunction

Endothelial dysfunction is a turning point in the initiation and development of atherosclerosis and its complications and is predictive of future cardiovascular events. Ingestion of high-carbohydrate or high-fat meals often results in postprandial hyperglycaemia and/or hypertriacylglycerolaemia that may lead to a transient impairment in endothelial function. The present review will discuss human studies evaluating the impact of high-carbohydrate and high-fat challenges on postprandial endothelial function as well as the potential role of oxidative stress in such postprandial metabolic alterations. Moreover, the present review will differentiate the postprandial endothelial and oxidative impact of meals rich in varying fatty acid types.

Molecular mechanisms involved in the bidirectional relationship between diabetes mellitus and periodontal disease

Both diabetes and periodontitis are chronic diseases. Diabetes has many adverse effects on the periodontium, and conversely periodontitis may have deleterious effects further aggravating the condition in diabetics. The potential common pathophysiologic pathways include those associated with inflammation, altered host responses, altered tissue homeostasis, and insulin resistance. This review examines the relationship that exists between periodontal diseases and diabetes mellitus with a focus on potential common pathophysiologic mechanisms.

A new series of N2-substituted-5-(p-toluenesulfonylamino)phthalimide analogues as α-glucosidase inhibitors

Several members of a new family of non-sugar-type α-glycosidase inhibitors, bearing a 5-(p-toluenesulfonylamino)phthalimide moiety and various substituent at the N2 position, were synthesized and their activities were investigated. The newly synthesized compounds displayed different inhibition profile towards yeast α-glycosidase and rat intestinal α-glycosidase. Almost all the compounds had strong inhibitory activities against yeast α-glycosidase. Regarding rat intestinal α-glycosidase, only analogs with N2-aromatic substituents displayed varying degrees of inhibitory activities on rat intestinal maltase and lactase and nearly all compounds showed no inhibition against rat intestinal α-amylase. Structure-activity relationship studies indicated that 5-(p-toluenesulfonylamino)phthalimide moiety is a favorable scaffold to exert the α-glucosidase inhibitory activity and substituents at the N2 position have considerable influence on the efficacy of the inhibition activities.

Chemo-enzymatic synthesis and glycosidase inhibitory properties of DAB and LAB derivatives

A chemo-enzymatic strategy for the preparation of 2-aminomethyl derivatives of (2R,3R,4R)-2-(hydroxymethyl)pyrrolidine-3,4-diol (also called 1,4-dideoxy-1,4-imino-D-arabinitol, DAB) and its enantiomer LAB is presented. The synthesis is based on the enzymatic preparation of DAB and LAB followed by the chemical modification of their hydroxymethyl functionality to afford diverse 2-aminomethyl derivatives. This strategy leads to novel aromatic, aminoalcohol and 2-oxopiperazine DAB and LAB derivatives. The compounds were preliminarily explored as inhibitors of a panel of commercial glycosidases, rat intestinal disaccharidases and against Mycobacterium tuberculosis, the causative agent of tuberculosis. It was found that the inhibitory profile of the new products differed considerably from the parent DAB and LAB. Furthermore, some of them were active inhibiting the growth of M. tuberculosis.

Phaseolus beans: impact on glycaemic response and chronic disease risk in human subjects

Consumption of Phaseolus vulgaris bean species such as pinto, black, navy or kidney may be beneficial in the prevention and treatment of chronic diseases. In particular, conditions that are promoted by increased glycaemic stress (hyperglycaemia and hyperinsulinaemia) including diabetes, CVD and cancer seem to be reduced in individuals who eat more of these beans. The present paper discusses the influence of P. vulgaris species on glycaemic response and the impact that relationship may have on the risk of developing diabetes, CVD and cancer.

The relationship between oxidative stress and the levels of serum circulating adhesion molecules in patients with hyperglycemia crises

OBJECTIVE

To investigate the relationship between oxidative stress and the levels of serum circulating adhesion molecules in patients with hyperglycemia crises.

METHODS

A total of 73 patients with diabetic ketoacidosis and nonketotic hyperglycemia were treated on a low-dose insulin protocol using intravenous infusion of insulin with the established rate of 0.1U·kg(-1)·h(-1). The patients received intravenous fluids and nutrition orally and intravenously. The levels of serum ICAM-1, E-selectin, and 8-iso-prostaglandin F(2α) (8-iso-PGF(2α)); the activities of superoxide dismutase (SOD); the total antioxidant capacity (TAC) and the contents of malondialdehyde (MDA) in 68 patients with hyperglycemia crisis on admission and after insulin therapy with resolution of hyperglycemia and ketoacidosis (72 h after resolution) were measured. Another 33 healthy individuals served as normal controls.

RESULTS

The activities of SOD and TAC at admission were lower in patients with hyperglycemia crisis than in normal controls, and the levels of MDA, 8-iso-PGF(2α), ICAM-1 and E-selectin were higher in patients with hyperglycemia crisis than in normal controls (all p<0.05). The activities of SOD and TAC in patients at resolution were significantly lower than in patients at admission and were significantly higher than in controls (p<0.05). The levels of MDA, 8-iso-PGF(2α), ICAM-1 and E-selectin in patients at resolution were markedly lower than in patients at admission (all p<0.05) and were significantly higher than in normal controls (p<0.05). There was a significant positive correlation between ICAM-1 and SOD (r=0.32, p<0.05) and between E-selectin and MDA (r=0.30, p<0.05) in patients at admission, and the level of E-selectin was positively correlated with MDA and 8-iso-PGF(2α) in patients at resolution (r=0.33, 0.36, p<0.05). In stepwise regression analysis, MDA and 8-iso-PGF(2α) showed a significant association with E-selectin, and 8-iso-PGF(2α) showed a significant association with ICAM-1.

CONCLUSION

The oxidative stress and the levels of serum circulating adhesion molecules are significantly changed in patients with hyperglycemia crisis. Intensive insulin therapy can attenuate the abnormity of oxidative stress and the levels of serum circulating adhesion molecules in patients with hyperglycemia crisis.

In-hospital death in acute coronary syndrome was related to admission glucose in men but not in women

Background

Admission hyperglycaemia is associated with mortality in patients with acute coronary syndrome (ACS), but controversy exists whether hyperglycaemia uniformly affects both genders. We evaluated coronary risk factors, gender, hyperglycaemia and their effect on hospital mortality.

Methods

959 ACS patients (363 women and 596 men) were grouped based on glycaemia ≥ or < 200 mg/dL and gender: men with glucose < 200 mg/dL (menG-); women with glucose < 200 mg/dL (womenG-); men with glucose ≥ 200 mg/dL (menG+); and women with glucose ≥ 200 mg/dL (womenG+). A logistic regression analysis compared the relation between gender and glycaemia groups and death, adjusted for coronary risk factors and laboratory data.

Results group

menG- had lower mortality than menG + (OR = 0.172, IC95% 0.062-0.478), and womenG + (OR = 0.275, IC95% 0.090-0.841); womenG- mortality was lower than menG + (OR = 0.230, IC95% 0.074-0.717). No difference was found between menG + vs womenG + (p = 0.461), or womenG- vs womenG + (p = 0.110). Age (OR = 1.067, IC95% 1.031–1.104), EF (OR = 0.942, IC95% 0.915-0.968), and serum creatinine (OR = 1.329, IC95% 1.128-1.566) were other independent factors related to in-hospital death.

Conclusions

Death was greater in hyperglycemic men compared to lower blood glucose men and women groups, but there was no differences between women groups in respect to glycaemia after adjustment for coronary risk factors.

Influence of antioxidant rich fresh vegetable juices on starch induced postprandial hyperglycemia in rats

This research analyzed the major chemical components and multiple antioxidant activities present in the fresh juice of eight vegetables, and studied their influence on starch induced postprandial glycemia in rats. A SDS-PAGE based protein fingerprint of each vegetable juice was also prepared. The yields of juice, chemical components like total proteins, total polyphenols, total flavonoids, total anthocyanins and free radicals like the ABTS˙(+) cation, DPPH, H(2)O(2), scavenging activities and reducing properties for NBT and FeCl(3) showed wide variations. Vegetable juice from brinjal ranked first in displaying total antioxidant capacity. Pretreatment of rats with vegetable juices moderated starch induced postprandial glycemia. The fresh juice from the vegetables ridge gourd, bottle gourd, ash gourd and chayote significantly mitigated postprandial hyperglycemic excursion. Total polyphenol concentrations present in vegetable juices positively influenced ABTS˙(+) scavenging activity and total antioxidant capacity. However, NBT reducing activity of juices was positively affected by total protein concentration. Contrarily, however, high polyphenol content in vegetable juice was observed to adversely affect the postprandial antihyperglycemic activity of vegetable juices. This is the first report exploring antihyperglycemic activity in these vegetable juices and highlights the possible adverse influence of high polyphenol content on the antihyperglycemic activity of the vegetable juices.

Impact of acute hyperglycaemia on endothelial function and retinal vascular reactivity in patients with Type 2 diabetes

AIM

  In diabetes, endothelial dysfunction and an altered retinal blood flow have been reported and precede overt macrovascular and microvascular disease. Furthermore, an association between postprandial hyperglycaemia, retinopathy and cardiovascular disease has been observed.

METHODS

  Endothelial function and retinal vascular reactivity have been measured in baseline conditions in 10 healthy control subjects and 21 patients with Type 2 diabetes. In the patients with Type 2 diabetes, endothelial function and retinal vascular reactivity have been also measured every hour, for 4 h, during an oral glucose tolerance test. Endothelial function has been evaluated by measuring flow-mediated vasodilation of the brachial artery, while retinal vascular reactivity has been measured using a retinal vessel analyser, during a flicker.

RESULTS

  At 1 and 2 h after glucose ingestion, endothelial function decreased (P<0.05), while retinal vascular reactivity increased, even at 3 h (P<0.05), vs. the baseline values.

CONCLUSION

  Our data highlight that acute hyperglycaemia impacts on endothelial function simultaneously at both macrovascular and at microvascular levels, inducing functional change, which could contribute towards explaining the clinical evidence of a strong association between postprandial hyperglycaemia, cardiovascular disease and retinopathy.