Current concepts of cardiovascular diseases in diabetes mellitus

Investigating the relationship between insulin use and all-cause mortality, breast cancer mortality, and recurrence risk in diabetic patients with breast cancer: A comprehensive systematic review and meta-analysis

BACKGROUND

The co-occurrence of breast cancer and diabetes presents complex clinical challenges, as each condition may influence the progression and management of the other, potentially worsening patient outcomes. This study aims to examine the association between insulin use and the risks of all-cause mortality, breast cancer-specific mortality, and recurrence in diabetic patients with breast cancer.

METHODS

A systematic review and meta-analysis were conducted using studies identified from multiple databases, including Web of Science, Scopus, PubMed, Cochrane, Google Scholar, and Embase. The meta-analysis approach was used to estimate the relative risk (RR) of the relationship between insulin use and the risks of all-cause mortality, breast cancer-specific mortality, and recurrence in diabetic patients with breast cancer. Heterogeneity among studies was assessed using statistical tests such as the Chi-square test, I2, and forest plots. Meta-regression and sensitivity analyses were performed to explore sources of heterogeneity. The quality of the included studies was assessed using the Newcastle-Ottawa Scale checklist. Data were analyzed using Stata version 17 (Stata Corp, College Station, Texas).

RESULTS

Data from 22 studies conducted between 2002 and 2023, with a total of 159,674 participants, were analyzed. Nineteen studies were rated as high quality, and three as moderate quality. Diabetic patients with breast cancer who received insulin had a 1.65 (95% CI: 1.36-2.02; P < 0.001; I2 = 89.7%) times higher risk of overall mortality compared to those who did not use insulin. Meta-regression revealed that sample size and study quality were significant contributors to heterogeneity (P ≤ 0.10). Furthermore, insulin use was associated with a 1.22 (95% CI: 1.05-1.42; P = 0.009; I2 = 37.9%) times higher risk of breast cancer-specific mortality. For breast cancer recurrence, insulin use was associated with a 1.45 (95% CI: 1.19-1.77; P < 0.001; I2 = 3.4%) times higher risk. Sensitivity analysis confirmed the stability of the results across all outcomes.

CONCLUSION

This meta-analysis provides strong evidence that insulin use in diabetic patients with breast cancer is associated with increased risks of overall mortality, breast cancer-specific mortality, and recurrence. These findings underscore the need for careful consideration of insulin therapy in this patient population.

The effect of overexpression of CyPA on gene expression in human umbilical vein endothelial cells

The aim of this study is to screen the differentially expressed genes and genes with alternative splicing in PPIA overexpressing cells by transcriptome sequencing. Transcriptome sequencing was performed to identify differentially expressed genes and genes with altered alternative splicing in PPIA overexpressing cells and results were validated by real-time quantitative polymerase chain reaction. The biological function and pathways of those genes were further explored through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses. A total of 157 significantly upregulated genes and 171 significantly downregulated genes were identified in PPIA overexpressing cells, and the splicing pattern of LHPP, APH1A, BRD1, and ORAI3 was found to be altered. GO analyses showed that the most enriched GO terms of the 157 upregulated genes included extracellular region, protein binding, and metal ion, and the most enriched GO terms of the 171 downregulated genes included binding neuron projection, protein binding, and endoplasmic reticulum unfolded protein response. Kyoto Encyclopedia of Genes and Genomes analyses showed that the 157 upregulated genes were mainly enriched in gastric acid secretion, Mitogen-activated protein kinase signaling pathway, etc, and the 171 downregulated genes were mainly enriched in transcriptional misregulation in cancer, Tumor necrosis factor signaling pathway, etc. The overexpression of PPIA in human umbilical vein endothelial cells causes changes in the expression of downstream genes and induces alternative splicing in multiple genes. PPIA alters the expression or the alternative splicing pattern of downstream genes, leading to pathogenesis of vascular endothelial injury by high glucose mediated through CyPA.

The association between the AIP and undiagnosed diabetes in ACS patients with different body mass indexes and LDL-C levels: findings from the CCC-ACS project

BACKGROUND

The atherogenic index of plasma (AIP) has been demonstrated to be significantly associated with the incidence of prediabetes and diabetes. This study aimed to investigate the association between the AIP and undiagnosed diabetes in acute coronary syndrome (ACS) patients.

METHODS

Among 113,650 ACS patients treated with coronary angiography at 240 hospitals in the Improving Care for Cardiovascular Disease in China-ACS Project from 2014 to 2019, 11,221 patients with available clinical and surgical information were included. We analyzed these patients' clinical characteristics after stratification according to AIP tertiles, body mass index (BMI) and low-density lipoprotein cholesterol (LDL-C) levels.

RESULTS

The AIP was independently associated with a greater incidence of undiagnosed diabetes. The undiagnosed diabetes was significantly greater in the T3 group than in the T1 group after adjustment for confounders [T3 OR 1.533 (1.199-1.959) p < 0.001]. This relationship was consistent within normal weight patients and patients with an LDL-C level ≥ 1.8 mmol/L. In overweight and obese patients, the AIP was significantly associated with the incidence of undiagnosed diabetes as a continuous variable after adjustment for age, sex, and BMI but not as a categorical variable. The area under the receiver operating characteristic curve (AUC) of the AIP score, triglyceride (TG) concentration, and HDL-C concentration was 0.601 (0.581-0.622; p < 0.001), 0.624 (0.603-0.645; p < 0.001), and 0.493 (0.472-0.514; p = 0.524), respectively. A nonlinear association was found between the AIP and the incidence of undiagnosed diabetes in ACS patients (p for nonlinearity < 0.001), and this trend remained consistent between males and females. The AIP may be a negative biomarker associated with undiagnosed diabetes ranging from 0.176 to 0.738.

CONCLUSION

The AIP was significantly associated with the incidence of undiagnosed diabetes in ACS patients, especially in those with normal weight or an LDL-C level ≥ 1.8 mmol/L. A nonlinear relationship was found between the AIP and the incidence of undiagnosed diabetes, and this trend was consistent between male and female patients. The AIP may be a negative biomarker associated with undiagnosed diabetes and ranges from 0.176 to 0.738.

Association of T-wave electrocardiogram changes and type 2 diabetes: a cross-sectional sub-analysis of the MASHAD cohort population using the Minnesota coding system

BACKGROUND

Type 2 Diabetes Mellitus (T2DM) has become a major health concern with an increasing prevalence and is now one of the leading attributable causes of death globally. T2DM and cardiovascular disease are strongly associated and T2DM is an important independent risk factor for ischemic heart disease. T-wave abnormalities (TWA) on electrocardiogram (ECG) can indicate several pathologies including ischemia. In this study, we aimed to investigate the association between T2DM and T-wave changes using the Minnesota coding system.

METHODS

A cross-sectional study was conducted on the MASHAD cohort study population. All participants of the cohort population were enrolled in the study. 12-lead ECG and Minnesota coding system (codes 5-1 to 5-4) were utilized for T-wave observation and interpretation. Regression models were used for the final evaluation with a level of significance being considered at p < 0.05.

RESULTS

A total of 9035 participants aged 35-65 years old were included in the study, of whom 1273 were diabetic. The prevalence of code 5-2, 5-3, major and minor TWA were significantly higher in diabetics (p < 0.05). However, following adjustment for age, gender, and hypertension, the presence of TWAs was not significantly associated with T2DM (p > 0.05). Hypertension, age, and body mass index were significantly associated with T2DM (p < 0.05).

CONCLUSIONS

Although some T-wave abnormalities were more frequent in diabetics, they were not statistically associated with the presence of T2DM in our study.

Green synthesized silver nanoparticles for the treatment of diabetes and the related complications of hyperlipidemia and oxidative stress in diabetic rats

This study was conducted to compare the impact of cinnamon silver nanoparticles (C-Ag-NPs) and cinnamon aqueous extract (CAE) on the total body weight (TBW), body weight gain (BWG), blood count (BC), fasting blood glucose (FBG), triglycerides (TGs), total cholesterol (TC), low-density (LDL-C) and high-density (HDL-C) lipoprotein cholesterol, liver function enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) of normal and streptozotocin (STZ) diabetic rats. The CAE was administered to rats at different doses (50.0 and 100.0 mg/kg bw), whereas the C-Ag-NPs were ingested at doses of 25.0 and 50.0 mg/kg bw for 30 days. At the end of the experiment, the administration of high or low dosages of CAE or C-Ag-NPs to diabetic rats significantly reduced the FBG, TC, TG, and LDL-C and significantly increased the HDL-C compared with the diabetic control rats. The highest dose (50.0 mg/kg bw) of the C-Ag-NPs was the most efficient at significantly reducing (P < 0.05) the levels of all the analyzed parameters compared with the CAE. However, the treated and normal rats did not show any hypoglycemic activity after ingesting the CAE or C-Ag-NPs. Such effects were associated with considerable increases in their BWG. The diabetic rats that ingested the CAE or C-Ag-NPs showed a gradual decrease in their FBG, TC, LDL, and TG levels, but they were still higher than those in the normal rats. Furthermore, the C-Ag-NPs and CAE considerably enhanced the hepatic (GPT, GOT, ALP, and GGT) and antioxidant biomarker enzyme activities (SOD, CAT, and GPx) in diabetic rats. Relative to the untreated diabetic control, the C-Ag-NPs were more effective than the CAE in the diabetic rats. The C-Ag-NPs exhibited a protective role against hyperglycemia and hyperlipidemia in the diabetic rats and modulated their liver function enzyme biomarkers and antioxidant enzyme activities more than the CAE.

Determinants of hypertensive crisis among hypertensive patients at adult emergency departments of public hospitals in Addis Ababa, Ethiopia, 2021: a case-control study

BACKGROUND

Hypertension (HTN) is a major global health problem that affects approximately 1.13 billion people worldwide, and 1-2% of this population has hypertensive crisis. Hypertensive crisis is becoming a major health issue in low-income countries. However, few studies have been conducted in developing countries such as Ethiopia. This study aimed to assess the determinants of hypertensive crisis among patients visiting adult emergency departments of public hospitals in Addis Ababa.

METHOD

A hospital-based unmatched case-control study was conducted among 85 cases with a hypertensive crisis and 170 controls with hypertension without a hypertensive crisis in the adult emergency departments of public hospitals in Addis Ababa from March 15 to May 15, 2021. Data were collected using a structured questionnaire and analyzed using SPSS version 26. Binary logistic regression and multivariable logistic regression were performed. Finally, a statistically significant level was declared at a p value of less than 0.05. The result was summarized and presented in text, tables, and graph.

RESULT

The odds of having hypertensive crisis were 3.6 times (AOR = 3.621) higher among participants with a history of hypertension compared to those without a history of hypertension. There was also 4 times increased risk of hypertensive crisis among participants who presented with diabetes mellitus than participants who presented without it (AOR = 4.179). Similarly, participants who presented with stroke had 7 times higher odds of having hypertensive crisis (AOR = 7.174) than participants without stroke.

CONCLUSION

This study demonstrated a statistically significant association between unemployment, diabetes mellitus, stroke, heart failure, history of hypertension, family history of hypertension, and regular follow-up with a hypertensive crisis. The Ethiopian Ministry of Health, Ababa City Administration Health Bureau, and hospitals shall give due attention to the HTN crisis. Health care workers, hospital managers, and other stakeholders shall work towards the early detection and management of HTN-crisis to prevent related morbidity, disability, and mortality.

Assessment of Cardiovascular Risk Factors and Their Interactions in the Risk of Coronary Heart Disease in Patients with Type 2 Diabetes with Different Weight Levels, 2013-2018

PURPOSE

In addition to hyperglycemia and hyperlipidemia, obesity and hypertension are important cardiovascular risk factors for coronary heart disease (CHD) in patients with type 2 diabetes mellitus (T2DM). This study aims to explore the interaction of these risk factors.

PATIENTS AND METHODS

Data of hospitalized patients with T2DM from 2013 to 2018 were collected. A multivariate logistic regression model was established. Patients with normal weight and blood pressure were recruited as controls. The interaction on the risk of CHD was evaluated by relative excess risk due to interaction (RERI).

RESULTS

Among the 30,693 patients with T2DM, 7202 (23.5%) had CHD. In the low weight group, the prevalence of CHD in patients with hypertension was nearly four times higher than that in patients without hypertension (42.7% vs 11.3%, P < 0.01). The OR value of hypertension alone on CHD increased from 1.29 (95% CI 1.06-1.56) in the body mass index (BMI) 30.0-34.9 kg/m² group to 1.35 (95% CI 1.11-1.62) in the BMI ≤ 18.5 kg/m² group. Additive interaction was observed between hypertension and BMI in CHD risk, especially in the low weight group (RERI:2.2, 95% CI 0.9-3.5). BMI and CHD risk showed a smile curve relationship. The attributive proportion in the low weight group was higher than that in the severe obesity group, that is, 0.52 (95% CI 0.35-0.69) vs 0.18 (95% CI -0.59 to 0.95).

CONCLUSION

Maintaining normal weight and avoiding low weight are particularly important for patients with co-occurring diabetes and hypertension to prevent the risk of CHD.

The effects of green cardamom supplementation on blood pressure and endothelium function in type 2 diabetic patients: A study protocol for a randomized controlled clinical trial

INTRODUCTION

Cardamom possesses antioxidant, anti-inflammation, and blood pressure lowering properties, which might improve endothelial function in type 2 diabetic patients. However, no study has examined the effect of cardamom on diabetic patients. The present study aimed to examine the effects of 10-week green cardamom intake on blood pressure, concentrations of inflammatory and endothelial function biomarkers in type 2 diabetes mellitus patients, and its potential mechanisms.

METHODS AND ANALYSIS DESIGN

Eighty overweight or obese patients with type 2 diabetes mellitus (aged 30-60 years) will be recruited into the trial and will assign to receive either cardamom (3 g/day, 6 capsules) or placebo (rusk powder, 6 capsules) for a period of 10 weeks. Systolic blood pressure and diastolic blood pressure, asymmetric dimethylarginine, and nitric oxide will be measured. Serum inflammatory markers namely interleukin 6, tumor necrosis factor-α, high-sensitivity C-reactive protein, and factors related to endothelial function including intercellular adhesion molecule-1, vascular cell adhesion molecule 1, CD62 antigen-like family member E, and cluster of differentiation 163 will be measured at baseline and at the end of the trial. Sociodemographic, International Physical Activity Questionnaire, and three 24-hour dietary recall questionnaires will be collected for each participant.

ETHICS AND DISSEMINATION

The study has been approved by The Ethics Committee of Tehran University of Medical Sciences (IR.TUMS.REC.1395.2700). Each participant will sign a written informed consent at the beginning of the study. At the end of the study, results will be published timely manner.

TRIAL REGISTRATION NUMBER

(http://www.irct.ir, identifier: IRCT-2016042717254N5) Date of registration: 2016-11-23.

Effect of Gum Arabic (Acacia Senegal) supplementation on visceral adiposity index (VAI) and blood pressure in patients with type 2 diabetes mellitus as indicators of cardiovascular disease (CVD): a randomized and placebo-controlled clinical trial

BACKGROUND

There is a strong association between cardiometabolic risk and adipose tissue dysfunction with great consequences on type 2 diabetic patients. Visceral Adiposity Index (VAI) is an indirect clinical marker of adipose tissue dysfunction. Gum Arabic (GA) is a safe dietary fiber, an exudate of Acacia Senegal. Gum Arabic had shown lipid lowering effect in both humans and animals. The aim of this trial was to determine the effect of GA supplementation on anthropometric obesity marker, Visceral Adiposity Index (VAI) and blood pressure in patients with type 2 diabetes mellitus.

METHODS

This randomized, double blinded, placebo controlled trial recruited a total of 91 type 2 diabetic patients (73 females, 18 males), age (mean ± SD) 50.09 ± 9.3 years on hypoglycemic agents and were randomly assigned into two groups, either to consume 30 g of GA or 5 g of placebo daily for 3 months. Anthropometric obesity markers were measured and indices were calculated. Blood pressure was measured and high density lipoprotein (HDL) and triglycerides (TG) were determined in fasting blood samples at the start and end of the study period.

RESULTS

After intervention, Gum Arabic decreased BMI and VAI significantly (P < 0.05) in GA group by 2 and 23.7% respectively. Body adiposity index significantly decreased by 3.9% in GA group while there were no significant changes in waist circumference or waist-to-hip ratio (WHR). Systolic blood pressure significantly decreased by 7.6% in GA group and by 2.7% in placebo group from baseline with no significant changes in diastolic blood pressure in the two groups.

CONCLUSION

Gum Arabic consumption at a dose of 30 g/d for 3 months may play an effective role in preventing weight gain and modulating adipose tissue dysfunction in type 2 diabetic patients, although no effect has been shown in waist-to-hip ratio.

TRIAL REGISTRATION

The trial had been registered as prospective interventional clinical trials in the Pan African Clinical Trial Registry (PACTR) PACTR201403000785219 , on 7th March 2014.

Effects of acute blood pressure elevation on biochemical-metabolic parameters in individuals with hypertensive crisis

Hypertensive crisis is a common clinical situation that presents a high rate of morbidity and mortality and it is characterized by symptomatic rise of blood pressure (BP), systolic (SBP) ≥ 180 mmHg and/or diastolic (DBP) ≥ 120 mmHg. It is classified as emergency (HE) or hypertensive urgency (HU). There is no description of laboratory findings in patients who present acute BP elevation. Thus, this study had the objective to assess the biochemical-metabolic parameters of patients with HC. We studied 74 normotensive individuals (NT), 74 controlled hypertensive patients (ContrHT), 50 subjects with HU, and 78 with HE for evaluating biochemical-metabolic parameters. HE occurs in older individuals and more frequently in those with known hypertension. More patients with HE had dyslipidemia than those with HU (58% vs. 38%). The diastolic BP and heart rate were higher in the HE group (120 mmHg and 87 bpm) compared to ContrHT (71 mmHg and 71 bpm; p < 0.0001) and NT groups (75 mmHg and 68 bpm; p < 0.0001). Glycemia was higher in HE vs. NT and ContrHT (p < 0.05). HDL cholesterol was lower in HE than NT (p = 0.0088). Potassium was lower in HE vs. NT, ContrHT and HU groups (p < 0.05). Creatinine was higher in the HC group vs. NT and ContrHT (p < 0.05). The GFR was significantly lower in HE group vs. HU, ContrHT and NT (p < 0.001). In conclusion, individuals with HC show biochemical alterations when compared to ContrHT and NT. Acute BP elevations are associated with hyperglycemia, dyslipidemia, and higher potassium and creatinine levels and lower renal function. Abbreviations BMI = body mass index BP = blood pressure CH = hypertensive crisis ContrHT = controlled hypertensive DBP = diastolic blood pressure GFR = glomerular filtration rate HbA1c = glycated hemoglobin HDLc = high-density lipoprotein cholesterol HE = hypertensive emergency HPLC = high-performance liquid chromatography HR = heart rate HU = hypertensive urgency JNC 7 = VII Joint National Committee on the Detection, Evaluation, and Treatment of High Blood Pressure LDLc = low-density lipoprotein cholesterol MDRD = Modification of Diet in Renal Disease NT = normotensive RASB = renin-angiotensin system blockers SBP = systolic blood pressure TC = total cholesterol TG = triglycerides.

Effect of cinnamon supplementation on glucose, lipids levels, glomerular filtration rate, and blood pressure of subjects with type 2 diabetes mellitus

A randomized, double-blind, placebo-controlled trial was performed to investigate the effect of cinnamon supplementation on glucose, triglyceride (TG), and high density lipoprotein-cholesterol (HDL-C) levels, TG/HDL-C ratio, blood pressure (BP), and estimated glomerular filtration rate (eGFR) for ninety-nine type 2 diabetes mellitus (T2DM) patients. Forty nine (49) patients with T2DM were in the cinnamon group whereas 50 were in the placebo group. All participants received either a cinnamon or placebo capsule daily for the 60-day study period. At the end of the study, median glucose, TG, TG/HDL-C ratio, and BP were significantly decreased (p < 0.005) whereas HDL-C and eGFR levels were significantly increased (p < 0.005) in the cinnamon supplementation group. Interestingly, the study also revealed reduction of HbA1c levels after the 60-day study period. In the placebo group, glucose, TG levels tended to increase and HDL-C levels tended to decrease whereas systolic and diastolic BP, HbA1c, and BUN CT were significantly increased and eGFR was significantly reduced (p < 0.005). Cinnamon supplementation reduced plasma glucose, HbA1c, triglyceride, TG/HDL-C ratio, and BP and increased HDL-C levels and eGFR in subjects with T2DM. Cinnamon supplementation may be beneficial for those with T2DM to prevent and control diabetic complications.

Metformin Protects H9C2 Cardiomyocytes from High-Glucose and Hypoxia/Reoxygenation Injury via Inhibition of Reactive Oxygen Species Generation and Inflammatory Responses: Role of AMPK and JNK

Metformin is a first-line drug for the management of type 2 diabetes. Recent studies suggested cardioprotective effects of metformin against ischemia/reperfusion injury. However, it remains elusive whether metformin provides direct protection against hypoxia/reoxygenation (H/R) injury in cardiomyocytes under normal or hyperglycemic conditions. This study in H9C2 rat cardiomyoblasts was designed to determine cell viability under H/R and high-glucose (HG, 33 mM) conditions and the effects of cotreatment with various concentrations of metformin (0, 1, 5, and 10 mM). We further elucidated molecular mechanisms underlying metformin-induced cytoprotection, especially the possible involvement of AMP-activated protein kinase (AMPK) and Jun NH(2)-terminal kinase (JNK). Results indicated that 5 mM metformin improved cell viability, mitochondrial integrity, and respiratory chain activity under HG and/or H/R (P < 0.05). The beneficial effects were associated with reduced levels of reactive oxygen species generation and proinflammatory cytokines (TNF-α, IL-1α, and IL-6) (P < 0.05). Metformin enhanced phosphorylation level of AMPK and suppressed HG + H/R induced JNK activation. Inhibitor of AMPK (compound C) or activator of JNK (anisomycin) abolished the cytoprotective effects of metformin. In conclusion, our study demonstrated for the first time that metformin possessed direct cytoprotective effects against HG and H/R injury in cardiac cells via signaling mechanisms involving activation of AMPK and concomitant inhibition of JNK.

Glutamine Reduces the Apoptosis of H9C2 Cells Treated with High-Glucose and Reperfusion through an Oxidation-Related Mechanism

Mitochondrial overproduction of reactive oxygen species (ROS) in diabetic hearts during ischemia/reperfusion injury and the anti-oxidative role of glutamine have been demonstrated. However, in diabetes mellitus the role of glutamine in cardiomyocytes during ischemia/reperfusion injury has not been explored. To examine the effects of glutamine and potential mechanisms, in the present study, rat cardiomyoblast H9C2 cells were exposed to high glucose (33 mM) and hypoxia-reoxygenation. Cell viability, apoptosis, intracellular glutamine, and mitochondrial and intracellular glutathione were determined. Moreover, ROS formation, complex I activity, membrane potential and adenosine triphosphate (ATP) content were also investigated. The levels of S-glutathionylated complex I and mitochondrial apoptosis-related proteins, including cytochrome c and caspase-3, were analyzed by western blot. Data indicated that high glucose and hypoxia-reoxygenation were associated with a dramatic decline of intercellular glutamine and increase in apoptosis. Glutamine supplementation correlated with a reduction in apoptosis and increase of glutathione and glutathione reduced/oxidized ratio in both cytoplasm and mitochondria, but a reduction of intracellular ROS. Glutamine supplementation was also associated with less S-glutathionylation and increased the activity of complex I, leading to less mitochondrial ROS formation. Furthermore, glutamine supplementation prevented from mitochondrial dysfunction presented as mitochondrial membrane potential and ATP levels and attenuated cytochrome c release into the cytosol and caspase-3 activation. We conclude that apoptosis induced by high glucose and hypoxia-reoxygenation was reduced by glutamine supplementation, via decreased oxidative stress and inactivation of the intrinsic apoptotic pathway.

Endothelial nitric oxide synthase Glu298Asp (G894T) gene polymorphism in coronary artery disease patients with type 2 diabetes mellitus

AIMS

Endothelial dysfunction is thought to be a significant risk factor for cardiovascular disease. This study determined the role of endothelial nitric oxide synthase (eNOS) Glu298Asp polymorphism and intergenotypic variation of plasma nitric oxide (NO) levels in coronary artery disease (CAD) patients with type 2 diabetes mellitus (DM).

METHODS

This case-control study included 28 documented CAD patients with type 2 DM and 32 non-diabetic patients with CAD. Fifty healthy volunteers without any major cardiovascular risk factors served as controls. NO was estimated by modified Griess method. The eNOS gene polymorphism was studied by amplifying DNA by PCR and digesting with BanII restriction enzyme. Restriction fragment length polymorphism was studied by using a gel documentation system.

RESULTS

The genotype frequencies for Glu298Asp (GT) genotype were 10.71% in diabetic CAD patients, 28.1% in non-diabetic CAD patients and 12% in controls. The T allele frequency was higher in the non-diabetic CAD group (14%) as compared with the diabetic CAD (5.4%) and control group (6%). NO level was significantly lower in non-diabetic CAD patients (10.25 mmol/L) but not in diabetic CAD patients (13.89 mmol/L) as compared to controls (16.78 mmol/L).

CONCLUSION

Glu298Asp polymorphism is not the mediator of increased incidence of CAD in diabetic patients.

Diabetic inhibition of preconditioning- and postconditioning-mediated myocardial protection against ischemia/reperfusion injury

Ischemic preconditioning (IPC) or postconditioning (Ipost) is proved to efficiently prevent ischemia/reperfusion injuries. Mortality of diabetic patients with acute myocardial infarction was found to be 2-6 folds higher than that of non-diabetic patients with same myocardial infarction, which may be in part due to diabetic inhibition of IPC- and Ipost-mediated protective mechanisms. Both IPC- and Ipost-mediated myocardial protection is predominantly mediated by stimulating PI3K/Akt and associated GSK-3β pathway while diabetes-mediated pathogenic effects are found to be mediated by inhibiting PI3K/Akt and associated GSK-3β pathway. Therefore, this review briefly introduced the general features of IPC- and Ipost-mediated myocardial protection and the general pathogenic effects of diabetes on the myocardium. We have collected experimental evidence that indicates the diabetic inhibition of IPC- and Ipost-mediated myocardial protection. Increasing evidence implies that diabetic inhibition of IPC- and Ipost-mediated myocardial protection may be mediated by inhibiting PI3K/Akt and associated GSK-3β pathway. Therefore any strategy to activate PI3K/Akt and associated GSK-3β pathway to release the diabetic inhibition of both IPC and Ipost-mediated myocardial protection may provide the protective effect against ischemia/reperfusion injuries.

The comparison of coronary angiographic profiles between diabetic and nondiabetic patients with coronary artery disease in a Chinese population

BACKGROUND

It is well known that diabetes mellitus (DM) is a crucial risk factor for coronary artery disease (CAD). The present study aimed to investigate angiographic profiles of the coronary arteries in diabetic CAD patients in comparison with nondiabetics.

METHODS

A total of 546 Chinese patients were angiographically documented for CAD, 375 of whom were diabetics and 171 were nondiabetics according to the WHO diabetes criteria (1999). The patients in these two groups were matched for age, sex, and body mass index (BMI). The 75 g oral glucose tolerance test (OGTT) was performed in all patients, for whom blood glucose, insulin, glycosylated hemoglobin (HbA1c), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoprotein A (ApoA), apolipoprotein B (ApoB), and lipoprotein(a) [Lp(a)] were measured. Insulin resistance (Homa-IR) and insulin secretion index (Homa-IS) were determined by the HOMA model. The clinical features and the data from selective coronary angiographies were compared between the diabetic and nondiabetic CAD patients.

RESULTS

Diabetic CAD patients had significantly higher waist to hip ratio (WHR) (p=0.016), fasting plasma glucose (FPG), 2h plasma glucose (2hPG), glycosylated hemoglobin (HbA1c) (p<0.001), insulin resistance index (Homa-IR) (p=0.001), and apolipoprotein A (ApoA) (p=0.008), with a significantly lower insulin secretion index (Homa-IS) level (p<0.001). Diabetic patients had one-vessel disease less frequently (28.8% vs 46.2%, p<0.001), and three-vessel disease more frequently (35.2% vs 24.0%, p=0.009), and they also had significantly higher cumulative coronary atherosclerosis score (CAS) (p=0.003). The right coronary artery was significantly more frequently involved in diabetics (66.4% vs 52.6%, p=0.002), with a clearly higher CAS at the same time (p=0.002).

CONCLUSIONS

Diabetics were presented with more severe and diffuse angiographically documented coronary artery disease compared to nondiabetics. The right coronary artery was significantly more frequently involved in the diabetics. Duration of CAD, Homa-IR, and diabetes mellitus were the independent risk factors for CAD found in the present study, while ApoA was the protective one.

Eicosapentaenoic acid reduces ABCA1 serine phosphorylation and impairs ABCA1-dependent cholesterol efflux through cyclic AMP/protein kinase A signaling pathway in THP-1 macrophage-derived foam cells

ABCA1 is a key mediator of cholesterol efflux to apoA-I in cholesterol loaded macrophages, a first step of RCT in vivo. Unsaturated fatty acids can inhibit cholesterol efflux from macrophages by increasing degradation of ABCA1. However, the detailed mechanisms of ABCA1 regulation by unsaturated fatty acids are not fully understood. In the present study, we investigated the effects of EPA on ABCA1 expression and ABCA1-dependent cholesterol efflux and examined the role of cAMP/PKA pathway on the regulation of ABCA1 by EPA in THP-1 macrophage-derived foam cells. Results showed that EPA significantly destabilized ABCA1 protein and reduced ABCA1-dependent cholesterol efflux but had no effect on ABCA1 mRNA expression. We also revealed that EPA markedly reduced cAMP level and PKA activity and ABCA1 serine phosphorylation. PKA-specific activation by PKA agonist markedly compensated the down-regulation of ABCA1 serine phosphorylation and ABCA1-mediated cholesterol efflux by EPA, while, siRNA of PKA leaded to reduce of ABCA1 serine phosphorylation and ABCA1-mediated cholesterol efflux more significantly than EPA. However, EPA-Induced enhancement of degradation rate of ABCA1 protein did not change by treatment with PKA agonist or PKA-siRNA. These results provide evidence that EPA may have dual negative effects on ABCA1 activity by decreasing ABCA1 protein level and by reducing PKA-mediated ABCA1 serine phosphorylation in THP-1 macrophage-derived foam cells.

Prevalence of the impaired glucose metabolism and its association with risk factors for coronary artery disease in women with gestational diabetes

Gestational diabetes (GDM) has increased risk of diabetes (DM2), a coronary artery disease (CAD) equivalent. The aim of this study was to determine the prevalence of impaired glucose metabolism (IGM) in GDM and its association with risk factors for CAD. A cohort of 109 women with GDM underwent a glucose tolerance test which classified them into three groups: diabetic (DM2) (fasting glucose (G) >or=126mg/dl or plasma glucose 2h (2-h G) >or=200mg/dl); impaired glucose tolerance (IGT) (G 100-125mg/dl and/or 2-h G 140-199mg/dl); and normal (N) (G<100mg/dl and/or 2-h<140mg/dl). They were compared for pre-gestational (PBMI) and current (CBMI) body mass index, systolic (SBP) and diastolic blood pressure (DBP), G, lipids, fibrinogen and C-reactive protein (hsCRP). Thirty two months after delivery, 17.4% presented DM2, 39.4% IGT and 43.1% were N. PBMI, CBMI, SBP and DBP were significantly higher in the DM2 than N. G was higher in DM2 and IGT. HDL-cholesterol (HDL-C) was higher in the N (p=0.02) and the triglycerides (TG) were higher in DM2 (p=0.02). The groups showed significantly different levels of hsCRP (p=0.002). We conclude that the high prevalence of IGM, overweight/obesity, dyslipidemia and altered inflammatory markers, make GDM a high-risk situation for CAD.

Intracardiac lipid accumulation, lipoatrophy of muscle cells and expansion of myocardial infarction in type 2 diabetic patients

The overall mortality of diabetic patients after myocardial infarction is 3-4 times higher than non-diabetics. The cellular mechanisms underlying such a poor clinical prognosis remain incompletely understood. Recent reports suggest that lipotoxicity associated with impaired liporegulation is among the leading factors in the pathogenesis of type 2 diabetes. The goal of this study was to investigate whether excess lipid accumulation specifically in heart muscle cells contributes to the expansion of myocardial infarction in type 2 diabetic patients. Comparative structural analysis of cardiac tissue was performed on autopsy samples from the infracted hearts of diabetic and non-diabetic individuals with special reference to the expansion of the infarction, degenerative changes, lipoatrophy, cell death, and replacement fibrosis. We found that progressive accumulation of lipids in cardiac myocytes was accompanied by considerable loss of myofibrils and was frequently observed in the heart tissue of type 2 diabetic patients. This indicates that disassembly of the contractile apparatus in the cells infiltrated with lipids weakens their capability for functional activity. Analysis of degenerative changes in the diabetic tissue has shown that lipid-laden cardiac myocytes were more susceptible to necrotic and apoptotic cells death leading to expansion of the infarction and the development of progressive focal replacement fibrosis both in the perinecrotic zone and in the areas located far from the site of injury. Our data show that lipoatrophy and loss of muscle cells during the post-infarction period aggravate the functional impairment in the diabetic heart and limits its adaptive capacity for compensatory remodeling. This suggests that lipotoxic myocardial injury associated with defects of lipid metabolism in type 2 diabetes predisposes its evolution toward congestive heart failure and is an important factor contributing to a high mortality following infarction.

Coronary heart disease outcomes in patients receiving antidiabetic agents

BACKGROUND

There is conflicting evidence on the reduction of cardiovascular risk in diabetic patients treated with oral antidiabetic agents.

OBJECTIVES

To compare the risk of myocardial infarction (MI) and coronary revascularization (CR) in type 2 diabetic patients treated with rosiglitazone, metformin, or sulfonylurea.

METHODS

Using data from a large US insurer, we created propensity-matched cohorts. We identified hospitalizations for MI or CR. We calculated incidence rates and 95% confidence intervals for the outcomes and estimated risks from Cox proportional hazards models.

RESULTS

We identified 26,931 initiators of monotherapy, 4,086 initiators of dual-therapy, and 2,346 initiators of combination with insulin therapy. There was no difference between the risk of the composite outcome with rosiglitazone monotherapy compared to metformin monotherapy (HR 1.07, 95% CI: 0.85, 1.34), and similarly with rosiglitazone monotherapy compared to sulfonylurea monotherapy (HR 0.82, 95% CI: 0.67, 1.02). There was no difference in the risk of outcome with rosiglitazone in combination with insulin therapy compared to other oral antidiabetic agents in combination with insulin (HR 0.88, 95% CI: 0.59, 1.32). Overall, there was little difference in the risk of the composite outcome or of the individual outcomes of MI and CR comparing rosiglitazone therapies to non-rosiglitazone therapies (HR for composite outcome 0.93, 95% CI: 0.80, 1.10).

CONCLUSIONS

The results from the monotherapy and the dual-therapy comparisons, though not individually significant, are consistent in suggesting that the risk of cardiovascular outcome events in patients using rosiglitazone may lie between the risks associated with sulfonylureas (higher incidence) and metformin (lower incidence).

Atherogenic vascular and lipid phenotypes in young patients with Type 1 diabetes are associated with diabetes high-risk HLA genotype

Expression of human leukocyte antigen (HLA) class II molecules on islet endothelial cells is a central vascular event in the pathogenesis of Type 1 diabetes. Previous studies demonstrated the ability of other vascular endothelial cells to express HLA and thereby to process islet autoantigens on their surface. We investigated whether the HLA-DQ2/8 genotype, which confers the highest risk for Type 1 diabetes, is associated with early atherosclerosis in youths with this disease. Brachial artery endothelium-dependent, flow-mediated dilation (BA-FMD) and carotid artery intima-media thickness (CA-IMT), as well as markers of systemic inflammation [C-reactive protein (CRP), fibrinogen, and orosomucoid], HbA(1C), LDL, HDL, and total cholesterol, were assessed in 86 children and adolescents with Type 1 diabetes (mean age and diabetes duration, 15 and 7 yr, respectively) between 2004 and 2006. HLA genotypes were determined in dried blood spots by an oligoblot hybridization method. As a result, HLA-DQ2/8 was detected in 34 patients (DQ2/8). When this group was compared with the remaining patients (non-DQ2/8, n = 52), there were no differences in age, diabetes duration, HbA(1C), body mass index, inflammatory markers, and IMT (P > or = 0.4). In the DQ2/8 group, LDL-to-HDL ratio was elevated compared with that in the non-DQ2/8 group (1.8 vs. 1.3, respectively; P = 0.001), whereas FMD did not significantly differ between the groups (5.3% vs. 6.7%, respectively; P = 0.08). When patients were further categorized in relation to CRP (cut-off value, 1 mg/l), BA-FMD was significantly lower (3%, P < 0.01), whereas LDL-to-HDL ratio increased further (2.2, P < 0.001) in the subgroup of DQ2/8 and CRP > or = 1 patients compared with the remaining three subgroups. These associations remained significant after adjustment for age, diabetes duration, and HbA(1C) by analysis of covariance. The brachial artery responses to nitroglycerine were similar in all subgroups. In conclusion, the diabetes-predisposing HLA-DQ2/8 genotype in children and adolescents with Type 1 diabetes interferes with endothelial and lipid-related mechanisms of early atherosclerosis, possibly in part through inflammatory pathways.

The risk of coronary heart disease in type 2 diabetic patients exposed to thiazolidinediones compared to metformin and sulfonylurea therapy

PURPOSE

To evaluate whether the risk of coronary heart disease (CHD) differs among adult diabetic patients treated with thiazolidinediones (TZDs) and similar patients treated with combined oral metformin and sulfonylurea (M + S) therapy.

METHODS

We conducted a retrospective cohort study involving 25 140 diabetic patients aged 18 and older who had at least one pharmacy claim for a TZD or combined M + S therapy between 1 January 1999 and 30 June 2002. We used propensity score matching to adjust for observable differences between initiators of combined M + S therapy and TZD initiators. The data were analyzed in two ways: first based on the original matched groups, 'as balanced', without accounting for switching to another medication during follow-up, and second based on actual antidiabetic drug use during follow-up, 'as treated'. Cox proportional hazards regression and multivariable Poisson regression were performed to compare the risk of CHD events.

RESULTS

In the 'as balanced' analysis, the risk for CHD among TZD users relative to combination drug users was close to the null value (adjusted hazard ratio: 1.02, 95% confidence intervals (CI): 0.87-1.20). In the 'as treated' analysis, the risk of CHD was similar for periods of current use of TZDs compared to periods of non-use (incidence rate ratio: 1.10, 95%CI: 0.96-1.25).

CONCLUSIONS

These results do not suggest a cardioprotective or deleterious effects of TZDs compared with combined M + S oral therapy on the short-term CHD event risk in persons with type 2 diabetes after accounting for the greater baseline CHD risk in TZD initiators.

Calpains and their multiple roles in diabetes mellitus

Type 2 diabetes mellitus (T2DM) can lead to death without treatment and it has been predicted that the condition will affect 215 million people worldwide by 2010. T2DM is a multifactorial disorder whose precise genetic causes and biochemical defects have not been fully elucidated, but at both levels, calpains appear to play a role. Positional cloning studies mapped T2DM susceptibility to CAPN10, the gene encoding the intracellular cysteine protease, calpain 10. Further studies have shown a number of noncoding polymorphisms in CAPN10 to be functionally associated with T2DM while the identification of coding polymorphisms, suggested that mutant calpain 10 proteins may also contribute to the disease. Here we review recent studies, which in addition to the latter enzyme, have linked calpain 5, calpain 3, and its splice variants, calpain 2 and calpain 1 to T2DM-related metabolic pathways along with T2DM-associated phenotypes, such as obesity and impaired insulin secretion, and T2DM-related complications, such as epithelial dysfunction and diabetic cataract.

Cardio-cerebrovascular complications in elderly with diabetes

Authors have considered the prevalence of hypertension (HT), myocardial infarction (MI) and stroke (S), in elderly subjects with diabetes, impaired fasting glucose (IFG) and normal fasting glucose (NFG), respectively. A high occurrence of diabetes in elderly subjects has been found. MI and S were more frequent in diabetic group than in IFG and NFG ones. HT proved to be elevated in the total pool, especially in older olds, and with a higher prevalence among those with diabetes. A 5-year follow-up has been carried out. The index of survival for MI and S was lower in subjects with diabetes. The subjects affected by both MI and S displayed the worst index of survival in all the three categories considered, therefore, it can be stated that such an association is a determinant factor of mortality.

The influence of race and gender on time to initial electrocardiogram for patients with chest pain

OBJECTIVES

To determine whether race or gender affected time to initial electrocardiogram (ECG) for patients who presented to an emergency department with chest pain.

METHODS

This was a prospective cohort study of patients with chest pain. Patients were divided into three groups based on final diagnosis of acute myocardial infarction or unstable angina and all others with noncardiac chest pain. Data were analyzed using ranks in a two-way analysis of covariance adjusted for age.

RESULTS

A total of 4,358 patients were studied; 58.6% were women and 41.4% men, and 70.3% were African American, 26.0% white, and 3.6% other. Overall, nonwhite patients had longer times to initial ECG compared with white patients. These effects were consistent regardless of ultimate diagnosis. Overall, women had longer times to initial ECG than men. However, ECG time differed by final diagnosis. There were no differences in time to ECG for women compared with men with acute myocardial infarction or unstable angina, but women received an ECG significantly slower than men for noncardiac chest pain.

CONCLUSIONS

The first screening test for acute coronary syndrome, the ECG, took longer to obtain for nonwhite patients, regardless of final diagnosis. This was unfortunately consistent with the literature that shows racial disparities in all aspects of emergent cardiac care. For women, the overall delay in ECG time can be explained by delays for those women with noncardiac chest pain.

Pioglitazona. Revisión de sus efectos metabólicos y sistémicos

Type 2 diabetes mellitus has become a true epidemic and significant growth is expected in the next decades. Thus it could be expected that the impact it may have on the incidence and prevalence of cardiovascular morbidity-mortality will have considerable magnitudes. It has been demonstrated that adequate metabolic control (glycemic and lipid) of these patients, beginning with diet and exercise programs and then with drug measures, decreases the risk of complications. However, several studies have shown that metabolic control deteriorates over time regardless of the treatment used. In recent years, a new drug family has been incorporated into the therapeutic armamentarium to treat type 2 diabetes mellitus. These are thiazolidinediones or glitazones, which have differential aspects regarding other drugs. In this article, the metabolic and systemic effects of pioglitazone, that have recently demonstrated a positive effect in the secondary prevention of cardiovascular episodes in the PROactive study have been reviewed.

Prevention of cardiovascular complications of diabetes mellitus by aspirin

Eighteen million Americans have type 2 Diabetes Mellitus (DM) while another 40 million have impaired glucose tolerance. Atherosclerotic heart disease is the leading cause of death in patients with diabetes mellitus. In addition to the increased risk for CardioVascular Disease (CVD), patients with diabetes have a worse prognosis than nondiabetics when they suffer an ischemic event. Insulin resistance is increasingly recognized as a chronic, low-level, inflammatory state. Hyperinsulinemia has been proposed as the forerunner of hypertension, low high-density lipoprotein cholesterolemia, hypertriglyceridemia, abdominal obesity, and altered glucose tolerance, linking all these abnormalities to the development of coronary vascular disease. Atherosclerosis and insulin resistance share similar pathophysiological mechanisms, due to the actions of proinflammatory cytokines. The dynamic inflammatory milieu found in diabetes explains the susceptibility of diabetics to CVD and the potential mechanism by which aspirin may prevent CVD in diabetics. Aspirin decreases the risk for CVD in diabetic patients by a variety of established and novel mechanisms. Therapeutic strategies that lesson the CVD risk in diabetic patients, including the use of aspirin for primary and secondary prevention, are potentially very important. This review article addresses the antiatherosclerotic effects of aspirin, the potential anti-diabetic effects of aspirin, and the clinical trial evidence for CVD prevention by aspirin in diabetics. We also present recommendations for the use of aspirin in the diabetic population and the current guidelines put forth by the American Heart Association and by the American Diabetes Association.

Cardiac risk factors in patients with diabetes mellitus and major depression

OBJECTIVE

The prevalence of major depression is approximately 2-fold higher in patients with diabetes mellitus compared to medical controls. We explored the association of major depression with 8 cardiac risk factors in diabetic patients with and without evidence of cardiovascular disease (CVD).

DESIGN

A mail survey questionnaire was administered to a population-based sample of 4,225 patients with diabetes to obtain data on depression status, diabetes self-care (diet, exercise, and smoking), diabetes history, and demographics. On the basis of automated data we measured diabetes complications, glycosylated hemoglobin, medical comorbidity, low-density lipid levels, triglyceride levels, diagnosis of hypertension, and evidence of microalbuminuria. Separate analyses were conducted for subgroups according to the presence or absence of CVD.

SETTING

Nine primary care clinics of a nonprofit health maintenance organization.

MAIN RESULTS

Patients with major depression and diabetes were 1.5- to 2-fold more likely to have 3 or more cardiovascular risk factors as patients with diabetes without depression (62.5% vs 38.4% in those without CVD, and 61.3% vs 45% in those with CVD). Patients with diabetes without CVD who met criteria for major depression were significantly more likely to be smokers, to have a body mass index (BMI) > or = 30 kg/m2, to lead a more sedentary lifestyle, and to have HbA1c levels of >8.0% compared to nondepressed patients with diabetes without heart disease. Patients with major depression, diabetes, and evidence of heart disease were significantly more likely to have a BMI > or = 30 kg/m2, a more sedentary lifestyle, and triglyceride levels > 400 mg/dl than nondepressed diabetic patients with evidence of heart disease.

CONCLUSIONS

Patients with major depression and diabetes with or without evidence of heart disease have a higher number of CVD risk factors. Interventions aimed at decreasing these risk factors may need to address treatment for major depression in order to be effective.

Cinnamon improves glucose and lipids of people with type 2 diabetes

OBJECTIVE

The objective of this study was to determine whether cinnamon improves blood glucose, triglyceride, total cholesterol, HDL cholesterol, and LDL cholesterol levels in people with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 60 people with type 2 diabetes, 30 men and 30 women aged 52.2 +/- 6.32 years, were divided randomly into six groups. Groups 1, 2, and 3 consumed 1, 3, or 6 g of cinnamon daily, respectively, and groups 4, 5, and 6 were given placebo capsules corresponding to the number of capsules consumed for the three levels of cinnamon. The cinnamon was consumed for 40 days followed by a 20-day washout period.

RESULTS

After 40 days, all three levels of cinnamon reduced the mean fasting serum glucose (18-29%), triglyceride (23-30%), LDL cholesterol (7-27%), and total cholesterol (12-26%) levels; no significant changes were noted in the placebo groups. Changes in HDL cholesterol were not significant.

CONCLUSIONS

The results of this study demonstrate that intake of 1, 3, or 6 g of cinnamon per day reduces serum glucose, triglyceride, LDL cholesterol, and total cholesterol in people with type 2 diabetes and suggest that the inclusion of cinnamon in the diet of people with type 2 diabetes will reduce risk factors associated with diabetes and cardiovascular diseases.