ABSTRACT
In recent years, GLP-1 receptor agonists (GLP-1RA), and SGLT-2 inhibitors (SGLT-2i) have become available, which have become valuable additions to therapy for type 2 diabetes as they are associated with low risk for hypoglycemia and cardiovascular benefits. Indeed, SGLT-2i have emerged as a promising class of agents to treat heart failure (HF). By inhibiting SGLT-2, these agents lead to excretion of glucose in urine with subsequent lowering of plasma glucose, although it is becoming clear that the observed benefits in HF cannot be explained by glucose-lowering alone. In fact, multiple mechanisms have been proposed to explain the cardiovascular and renal benefits of SGLT-2i, including hemodynamic, anti-inflammatory, anti-fibrotic, antioxidant, and metabolic effects. Herein, we review the available evidence on the pathophysiology of the cardiological benefits of SGLT-2i. In diabetic heart disease, in both clinical and animal models, the effect of SGLT-2i have been shown to improve diastolic function, which is even more evident in HF with preserved ejection fraction. The probable pathogenic mechanisms likely involve damage from free radicals, apoptosis, and inflammation, and therefore fibrosis, many of which have been shown to be improved by SGLT-2i. While the effects on systolic function in models of diabetic heart disease and HF with preserved ejection fraction is limited and contrasting, it is a key element in patients with HF and reduced ejection fraction both with and without diabetes. The significant improvement in systolic function appears to lead to subsequent structural remodeling of the heart with a reduction in left ventricle volume and a consequent reduction in pulmonary pressure. While the effects on cardiac metabolism and inflammation appear to be consolidated, greater efforts are still warranted to further define the entity to which these mechanisms contribute to the cardiovascular benefits of SGLT-2i.
Subject(s)
Diabetes Mellitus, Type 2 , Heart Failure , Sodium-Glucose Transporter 2 Inhibitors , Animals , Sodium-Glucose Transporter 2 Inhibitors/adverse effects , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/drug therapy , Glucose , Heart Ventricles , InflammationABSTRACT
BACKGROUND AND AIMS: The aim of the present study is to evaluate whether advanced coronary atherosclerosis analysis by CCTA may improve prognostic stratification among diabetic patients at high cardiovascular risk (CV risk). METHODS AND RESULTS: The study population consisted of 265 consecutive diabetic patients at high CV risk who underwent CCTA for suspected CAD between January 2011 and December 2016. For every patients both traditional and advanced, qualitative and quantitative coronary plaque analysis were performed. The occurrence of cardiac death, ACS, and non-urgent revascularization were recorded at follow-up. Among the 265 patients enrolled, 21 were lost to follow-up, whereas 244 (92%) had a complete follow-up (mean 45 ± 22 months) and were classified at high (n = 67) or very high cardiovascular risk (n = 177), according to ESC Guidelines. A total of 63 events were recorded (3 Cardiac Death, 3 NSTEMI, 8 unstable angina, 36 late non-urgent revascularization and 13 non-cardiac death) in 57 different patients. Elevated fibro-fatty plaque volume was the only predictor of events over age, gender and traditional risk factor when ACS and MACE were considered as end-points [HR (95% CI) 6.01 (1.65-21.87), p = 0.006 and 3.46 (2.00-5.97); p < 0.001]. CONCLUSION: The present study confirms the prognostic role of advance coronary atherosclerosis evaluation beyond risk factors and stenosis severity, even in diabetics. Despite the very high cardiovascular risk of study population, a not negligible portion (23%) of patients exhibited totally normal coronaries.
Subject(s)
Coronary Artery Disease , Diabetes Mellitus , Plaque, Atherosclerotic , Computed Tomography Angiography , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/therapy , Diabetes Mellitus/diagnosis , Follow-Up Studies , Humans , Plaque, Atherosclerotic/diagnostic imaging , Plaque, Atherosclerotic/therapy , Predictive Value of Tests , Prognosis , Risk Assessment , Risk FactorsABSTRACT
Diabetes mellitus (DM) is one of the most common and costly disorders that affect humans around the world. Recently, clinicians and scientists have focused their studies on the effects of glycemic variability (GV), which is especially associated with cardiovascular diseases. In healthy subjects, glycemia is a very stable parameter, while in poorly controlled DM patients, it oscillates greatly throughout the day and between days. Clinically, GV could be measured by different parameters, but there are no guidelines on standardized assessment. Nonetheless, DM patients with high GV experience worse cardiovascular disease outcomes. In vitro and in vivo studies showed that high GV causes several detrimental effects, such as increased oxidative stress, inflammation, and apoptosis linked to endothelial dysfunction. However, the evidence that treating GV is beneficial is still scanty. Clinical trials aiming to improve the diagnostic and prognostic accuracy of GV measurements correlated with cardiovascular outcomes are needed. The present review aims to evaluate the clinical link between high GV and cardiovascular diseases, taking into account the underlined biological mechanisms. A clear view of this challenge may be useful to standardize the clinical evaluation and to better identify treatments and strategies to counteract this DM aspect.
Subject(s)
Cardiovascular Diseases/etiology , Diabetes Complications/complications , Hyperglycemia/complications , Animals , Blood Glucose/metabolism , Cardiovascular Diseases/metabolism , Diabetes Complications/metabolism , Diabetes Mellitus/metabolism , Humans , Hyperglycemia/metabolism , Oxidative StressABSTRACT
Background: Current knowledge regarding the relationship between aortic valve sclerosis (AVSc), cardiovascular risk factors, and mortality in patients with known coronary artery disease (CAD) is still unclear. The present study aimed at investigating the prevalence of AVSc as well as its association with long-term all-cause mortality in high-risk CAD patients that has never been explored in large cohorts thus far. Methods and Results: In this retrospective and observational cohort study we enrolled high-risk CAD patients, hospitalized at Centro Cardiologico Monzino (CCM), Milan, Italy, between January 2006 and December 2016. The morphology and function of the aortic valve were assessed from the recorded echocardiographic images to evaluate the presence of AVSc, defined as a non-uniform thickening of the aortic leaflets with no consequences on hemodynamics. Data on 5-year all-cause mortality was retrieved from a Regional database. Of the 5,489 patients initially screened, 4,938 (mean age 67 ± 11 years, 3,954 [80%] men) were enrolled in the study. In the overall population, AVSc was detected in 2,138 (43%) patients. Multivariable LASSO regression revealed that age, female gender, diabetes mellitus, previous MI, and left ventricular ejection fraction were independently associated with AVSc. All-cause mortality (adjusted hazard ratio: 1.29, 95%CI: 1.05-1.58) was significantly higher in AVSc than in non-AVSc patients. Conclusions: AVSc is frequently detected in high-risk CAD patients and is associated with long-term mortality. Our findings corroborate the hypothesis that AVSc is an underestimated marker of systemic cardiovascular risk. Thus, AVSc detection may be used to improve long-term risk stratification of high-risk CAD patients.
ABSTRACT
BACKGROUND: High-sensitivity C-reactive protein (hs-CRP) elevation frequently occurs in acute myocardial infarction (AMI) and is associated with adverse outcomes. Since diabetes mellitus (DM) is characterized by an underlying chronic inflammation, hs-CRP may have a different prognostic power in AMI patients with and without DM. METHODS: We prospectively included 2064 AMI patients; hs-CRP was measured at hospital admission. Patients were grouped according to hs-CRP quartiles and DM status. The primary endpoint was a composite of in-hospital mortality, cardiogenic shock, and acute pulmonary edema. Two-year all-cause mortality was the secondary endpoint. RESULTS: Twenty-six percent (n = 548) of patients had DM and they had higher hs-CRP levels than non-DM patients (5.32 vs. 3.24 mg/L; P < 0.0001). The primary endpoint incidence in the overall population (7%, 9%, 13%, 22%; P for trend < 0.0001), in DM (14%, 9%, 21%, 27%; P = 0.0001), and non-DM (5%, 8%, 10%, 19%; P < 0.0001) patients increased in parallel with hs-CRP quartiles. The adjusted risk of the primary endpoint increased in parallel with hs-CRP quartiles in DM and non-DM patients but this relationship was less evident in DM patients. In the overall population, the adjusted OR of the primary endpoint associated with an hs-CRP value ≥ 2 mg/L was 2.10 (95% CI 1.46-3.00). For the same risk, hs-CRP was 7 and 2 mg/L in patients with and without DM. A similar behavior was observed for the secondary endpoint when the HR associated with an hs-CRP value ≥ 2 mg/L found in the overall population was 2.25 (95% CI 1.57-3.22). For the same risk, hs-CRP was 8 and 1.5 mg/L in DM and non-DM patients. CONCLUSIONS: This study shows that hs-CRP predicts in-hospital outcome and two-year mortality in AMI patients with and without DM. However, in DM patients, the same risk of developing events as in non-DM patients is associated to higher hs-CRP levels.
Subject(s)
C-Reactive Protein/analysis , Diabetes Mellitus/blood , Inflammation Mediators/blood , Non-ST Elevated Myocardial Infarction/blood , Patient Admission , ST Elevation Myocardial Infarction/blood , Aged , Aged, 80 and over , Biomarkers/blood , Diabetes Mellitus/diagnosis , Diabetes Mellitus/mortality , Female , Hospital Mortality , Humans , Incidence , Male , Middle Aged , Non-ST Elevated Myocardial Infarction/diagnosis , Non-ST Elevated Myocardial Infarction/mortality , Predictive Value of Tests , Prognosis , Prospective Studies , Pulmonary Edema/blood , Pulmonary Edema/mortality , Risk Assessment , Risk Factors , ST Elevation Myocardial Infarction/diagnosis , ST Elevation Myocardial Infarction/mortality , Shock, Cardiogenic/blood , Shock, Cardiogenic/mortality , Up-RegulationABSTRACT
OBJECTIVE: ST-segment elevation myocardial infarction (STEMI) patients with type 2 diabetes mellitus (DM) have higher in-hospital mortality than those without. Since cardiac and renal functions are the main variables associated with outcome in STEMI, we hypothesized that this prognostic disparity may depend on a higher rate of cardiac and renal dysfunction in DM patients. RESEARCH DESIGN AND METHODS: We retrospectively analyzed 5,152 STEMI patients treated with primary angioplasty. Left ventricular ejection fraction (LVEF) and estimated glomerular filtration rate (eGFR) were evaluated at hospital admission. The primary end point was in-hospital mortality. A composite of in-hospital mortality, cardiogenic shock, and acute kidney injury was the secondary end point. RESULTS: There were 879 patients (17%) with DM. The incidence of LVEF ≤40% (30% vs. 22%), eGFR ≤60 mL/min/1.73 m2 (27% vs. 18%), or both (12% vs. 6%) was higher (P < 0.001 for all comparisons) in DM patients. In-hospital mortality was higher in DM patients than in non-DM patients (6.1% vs. 3.5%; P = 0.002), with an unadjusted odds ratio (OR) of 1.81 (95% CI 1.31-2.49; P < 0.001). However, DM was no longer associated with an increased mortality risk after adjustment for cardiac and renal function (OR 1.03, 95% CI 0.68-1.56; P = 0.89). A similar behavior was observed for the secondary end point, with an unadjusted OR for DM of 1.52 (95% CI 1.25-1.85; P < 0.001) and an OR after adjustment for cardiac and renal function of 1.07 (95% CI 0.85-1.36; P = 0.53). CONCLUSIONS: The study indicates that the increased in-hospital mortality and morbidity of DM patients with STEMI is mainly driven by their underlying cardio-renal dysfunction.
Subject(s)
Diabetes Mellitus, Type 2/epidemiology , Glomerular Filtration Rate/physiology , Hospital Mortality , Percutaneous Coronary Intervention , ST Elevation Myocardial Infarction/epidemiology , ST Elevation Myocardial Infarction/surgery , Ventricular Function, Left/physiology , Acute Kidney Injury/complications , Acute Kidney Injury/epidemiology , Acute Kidney Injury/physiopathology , Acute Kidney Injury/surgery , Aged , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/physiopathology , Diabetes Mellitus, Type 2/surgery , Diabetic Angiopathies/epidemiology , Diabetic Angiopathies/surgery , Diabetic Nephropathies/complications , Diabetic Nephropathies/epidemiology , Diabetic Nephropathies/physiopathology , Diabetic Nephropathies/surgery , Female , Heart/physiopathology , Humans , Incidence , Kidney/physiopathology , Male , Middle Aged , Morbidity , Percutaneous Coronary Intervention/adverse effects , Percutaneous Coronary Intervention/mortality , Percutaneous Coronary Intervention/statistics & numerical data , Retrospective Studies , Risk Factors , ST Elevation Myocardial Infarction/complications , Treatment OutcomeABSTRACT
Liddle syndrome is considered a rare Mendelian hypertension. We have previously described 3 reportedly unrelated families, native of an Italian area around the Strait of Messina, carrying the same mutation (ßP617L) of the epithelial sodium channel. The aims of our study were (1) to evaluate whether a close genomic relationship exists between the 3 families through the analysis of mitochondrial DNA and Y chromosome; and (2) to quantify the genomic relatedness between the patients with Liddle syndrome belonging to the 3 families and assess the hypothesis of a mutation shared through identity by descent. HVRI (the hypervariable region I) of the mitochondrial DNA genome and the Y chromosome short tandem repeats profiles were analyzed in individuals of the 3 families. Genotyping 542 585 genome-wide single nucleotide polymorphisms was performed in all the patients with Liddle syndrome of the 3 families and some of their relatives. A panel of 780 healthy Italian adult samples typed for the same set of markers was used as controls. espite different lineages between the 3 families based on the analysis of mitochondrial DNA and Y chromosome, the 3 probands and their 6 affected relatives share the same ≈5 Mbp long haplotype which encompasses the mutant allele. Using an approach based on coalescent theory, we estimate that the 3 families inherited the mutant allele from a common ancestor ≈13 generations ago and that such an ancestor may have left ≈20 carriers alive today. The prevalence of Liddle syndrome in the region of origin of the 3 families may be much higher than that estimated worldwide.
Subject(s)
Epithelial Sodium Channels/genetics , Liddle Syndrome/genetics , Adolescent , Adult , Child , Chromosomes, Human, Y/genetics , DNA, Mitochondrial/genetics , Family , Female , Genotyping Techniques , Humans , Italy , Male , Mutation , Pedigree , Polymorphism, Single Nucleotide , Young AdultABSTRACT
Wolfram syndrome (WFS) is a rare autosomal premature aging syndrome that shows signs of diabetes mellitus, optic atrophy, and deafness in addition to central nervous system and endocrine complications. The frequent form of WFS type 1 (WFS1) harbors causative mutations in the WFS1 gene, whereas the rare form or WFS type 2 (WFS2) involves CISD2. Mutations in these two genes are recognized by a subset of variable clinical symptoms and a set of overlapping features. In this study, we report on the generation of stable human-induced pluripotent stem cells (hiPSCs) derived from primary fibroblasts of a previously reported Italian family with CISD2 mutation (c.103 + 1G>A), occurring in the consensus intron 1 splicing site in two sisters, deleting the first exon of the transcript. The generated hiPSCs provide a cell model system to study the mutation's role in the multisystemic clinical disorders previously described and test eventual drug effects on the specific and associated clinical phenotype.
Subject(s)
Aging, Premature/genetics , Hearing Loss, Sensorineural/genetics , Induced Pluripotent Stem Cells/metabolism , Membrane Proteins/genetics , Mitochondrial Diseases/genetics , Mutation , Optic Atrophy/genetics , Aging, Premature/pathology , Cell Proliferation/genetics , Cells, Cultured , Family Health , Female , Fibroblasts/metabolism , Hearing Loss, Sensorineural/pathology , Humans , Introns/genetics , Male , Mitochondrial Diseases/pathology , Optic Atrophy/pathology , RNA Splice Sites/genetics , SiblingsABSTRACT
BACKGROUND: Mutations in the gene that encodes CDGSH iron sulfur domain 2 (CISD2) are causative of Wolfram syndrome type 2 (WFS2), a rare autosomal recessive neurodegenerative disorder mainly characterized by diabetes mellitus, optic atrophy, peptic ulcer bleeding and defective platelet aggregation. Four mutations in the CISD2 gene have been reported. Among these mutations, the homozygous c.103 + 1G > A substitution was identified in the donor splice site of intron 1 in two Italian sisters and was predicted to cause a exon 1 to be skipped. METHODS: Here, we employed molecular assays to characterize the c.103 + 1G > A mutation using the patient's peripheral blood mononuclear cells (PBMCs). 5'-RACE coupled with RT-PCR were used to analyse the effect of the c.103 + 1G > A mutation on mRNA splicing. Western blot analysis was used to analyse the consequences of the CISD2 mutation on the encoded protein. RESULTS: We demonstrated that the c.103 + 1G > A mutation functionally impaired mRNA splicing, producing multiple splice variants characterized by the whole or partial absence of exon 1, which introduced amino acid changes and a premature stop. The affected mRNAs resulted in either predicted targets for nonsense mRNA decay (NMD) or non-functional isoforms. CONCLUSIONS: We concluded that the c.103 + 1G > A mutation resulted in the loss of functional CISD2 protein in the two Italian WFS2 patients.
Subject(s)
Aging, Premature/genetics , Hearing Loss, Sensorineural/genetics , Membrane Proteins/genetics , Mitochondrial Diseases/genetics , Mutation , Optic Atrophy/genetics , RNA Splice Sites/genetics , Base Sequence , Blood Cells , Codon, Nonsense , Exons/genetics , Female , Humans , Introns/genetics , Leukocytes, Mononuclear , Membrane Proteins/chemistry , Protein Isoforms/genetics , RNA Splice Sites/physiology , RNA Splicing , RNA, Messenger/genetics , Sequence Analysis , Sequence DeletionABSTRACT
PURPOSE: An observational retrospective study was conducted by 2 diabetes clinics in Italy to assess patterns of use and long-term effectiveness of liraglutide on established and emerging parameters. METHODS: Data from 261 patients with type 2 diabetes who started treatment with liraglutide between 2010 and 2014 were collected. Hierarchical linear regression models were applied to assess trends over time of clinical parameters. Factors associated with higher likelihood of dropout were identified through multivariate logistic analysis. FINDINGS: Liraglutide was initiated as a switch in 42.5% of patients and as an add-on in 49.8%; in 7.7% of the patients initiation of liraglutide was associated with a reduction in the number of pharmacologic agents. A statistically significant reduction after 36 months was found for the following parameters (mean change [95% CIs]): glycosylated hemoglobin (HbA1c; -1.01% [1.34% to -0.68%]), fasting blood glucose (-27.5 [-40.6 to -14.4] mg/dL), weight (-2.9 [-4.5 to -1.3] kg), body mass index (-1.13 [-1.76 to -0.50] kg/m2), waist circumference (-1.74 [-3.85 to -0.37] cm), and LDL-C (-24.7 [-36.67 to -12.8] mg/dL). Improvements in systolic (-3.5 mm Hg) and diastolic (-2.3 mm Hg) blood pressures were observed at 24 months. Albuminuria was reduced by -16.6 mg/L during 36 months, although statistical significance was not reached. Glomerular filtration rate and heart rate were unchanged. Reductions in HbA1c between -0.6% and -1.3% were obtained in specific subgroups. Treatment was effective also in patients with >20 years of diabetes duration, although the likelihood of dropout was 6% higher for each additional year of disease duration (RR = 1.06; 95% CI, 1.01-1.12). The likelihood of dropout was almost four times higher for subjects treated with insulin (RR = 3.82; 95% CI, 1.22-11.96) and more than twice for those treated with sulfonylureas (RR = 2.39; 95% CI, 1.16-4.94) compared with patients not treated with these agents. IMPLICATIONS: Liraglutide used in routine clinical conditions maintains its effectiveness on metabolic control and weight after 3 years. Improvements in terms of metabolic control were found when liraglutide was used as both switch and add-on treatment. In addition, improvements were sustained when liraglutide replaced sulfonylureas or insulin. Diabetes duration had no impact on drug efficacy. Long-term benefits relative to blood pressure and LDL-C were also found, which could not be entirely explained by antihypertensive/lipid-lowering treatment intensification. No major effect on renal parameters was documented. Diabetes duration and some concomitant treatments were associated with a higher likelihood of liraglutide discontinuation. These data can contribute to improve appropriateness and cost-effectiveness profile of liraglutide.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Liraglutide/therapeutic use , Aged , Blood Pressure/drug effects , Body Mass Index , Body Weight/drug effects , Female , Glycated Hemoglobin/metabolism , Heart Rate/drug effects , Humans , Insulin/therapeutic use , Italy , Lipids/blood , Male , Middle Aged , Retrospective Studies , Treatment OutcomeABSTRACT
BACKGROUND: In type 2 diabetes, acute hyperglycemia worsens endothelial function and inflammation,while resistance to GLP-1 action occurs. All these phenomena seem to be related to the generation of oxidative stress. A Mediterranean diet, supplemented with olive oil, increases plasma antioxidant capacity, suggesting that its implementation can have a favorable effect on the aforementioned phenomena. In the present study, we test the hypothesis that a Mediterranean diet using olive oil can counteract the effects of acute hyperglycemia and can improve the resistance of the endothelium to GLP-1 action. METHODS: Two groups of type 2 diabetic patients, each consisting of twelve subjects, participated in a randomized trial for three months, following a Mediterranean diet using olive oil or a control low-fat diet. Plasma antioxidant capacity, endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels were evaluated at baseline and at the end of the study. The effect of GLP-1 during a hyperglycemic clamp, was also studied at baseline and at the end of the study. RESULTS: Compared to the control diet, the Mediterranean diet increased plasma antioxidant capacity and improved basal endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels. The Mediterranean diet also reduced the negative effects of acute hyperglycemia, induced by a hyperglycemic clamp, on endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels. Furthermore, the Mediterranean diet improved the protective action of GLP-1 on endothelial function, nitrotyrosine, 8-iso-PGF2a, IL-6 and ICAM-1 levels, also increasing GLP-1-induced insulin secretion. CONCLUSIONS: These data suggest that the Mediterranean diet, using olive oil, prevents the acute hyperglycemia effect on endothelial function, inflammation and oxidative stress, and improves the action of GLP-1, which may have a favorable effect on the management of type 2 diabetes, particularly for the prevention of cardiovascular disease.
Subject(s)
Cardiovascular Diseases/prevention & control , Diabetes Mellitus, Type 2/drug therapy , Diet, Mediterranean , Endothelium, Vascular/drug effects , Glucagon-Like Peptide 1/metabolism , Hyperglycemia/prevention & control , Adult , Aged , Blood Glucose/metabolism , Drug Resistance/drug effects , Female , Humans , Inflammation/drug therapy , Male , Middle Aged , Oxidative Stress/drug effectsABSTRACT
Liddle's syndrome (LS) is a rare heritable form of hypertension that often affects young patients. It is caused by gain-of-function mutations of the kidney epithelial sodium channel (ENaC) and it is classically associated with hypokalemia and suppression of renin and aldosterone. LS is characterized by responsiveness to ENaC inhibitors but not to mineralocorticoid receptor inhibitors. Consequently the most effective treatment is amiloride. This drug is not used in pregnancy, as it has not been sufficiently studied during gestation. However for pregnant LS patient amiloride is the most effective drug in decreasing blood pressure. Herein we report the case of a LS patient, who has been followed up by a multidisciplinary teamwork during her first pregnancy. Hypertension worsened after the 25th week of gestation and amiloride was safely administered, firstly in combination with hydrochlorothiazide (the only formulation commercially available in Italy) and, thereafter, as a single drug. Genetic testing was performed in the patient's family in order to support diagnosis and clinical management.
ABSTRACT
OBJECTIVE: To test the hypothesis that the simultaneous administration of GLP-1 and insulin may increase their vasodilatory, antiinflammatory, and antioxidant action in type 2 diabetes. RESEARCH DESIGN AND METHODS: In two groups of persons with type 2 diabetes, two sets of experiments were performed. The first group had two normoglycemic-normoinsulinemic clamps with or without GLP-1 and two normoglycemic-hyperinsulinemic clamps with or without GLP-1. The second group had two hyperglycemic-normoinsulinemic clamps and two hyperglycemic-hyperinsulinemic clamps with or without GLP-1. RESULTS: During the normoglycemic-hyperinsulinemic clamp, flow-mediated dilatation (FMD) increased, while soluble intercellular adhesion molecule (sICAM-1), plasma 8-iso-prostaglandin F2α (8-iso-PGF2α), nitrotyrosine, and interleukin (IL)-6 decreased compared with normoglycemic-normoinsulinemic clamp. Similar results were obtained with the infusion of GLP-1 during the normoglycemic-normoinsulinemic clamp. The combination of hyperinsulinemia and GLP-1 in normoglycemia was accompanied by a further FMD increase and sICAM-1, 8-iso-PGF2α, nitrotyrosine, and IL-6 decrease. During the hyperglycemic-normoinsulinemic clamp, FMD significantly decreased, while sICAM-1, 8-iso-PGF2α, nitrotyrosine, and IL-6 significantly increased. When hyperglycemia was accompanied by hyperinsulinemia or by the simultaneous infusion of GLP-1, these phenomena were attenuated. The simultaneous presence of hyperinsulinemia and GLP-1 had an increased beneficial effect. CONCLUSIONS: Our results show that the combination of insulin and GLP-1 is more effective than insulin or GLP-1 alone in improving endothelial dysfunction, inflammation, and oxidative stress in type 2 diabetes.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Glucagon-Like Peptide 1/administration & dosage , Hypoglycemic Agents/therapeutic use , Insulin/administration & dosage , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/therapeutic use , Antioxidants/administration & dosage , Antioxidants/therapeutic use , Diabetes Mellitus, Type 2/physiopathology , Dinoprost/analogs & derivatives , Dinoprost/blood , Female , Glucagon-Like Peptide 1/pharmacology , Glucagon-Like Peptide 1/therapeutic use , Humans , Hyperglycemia/physiopathology , Hyperinsulinism/physiopathology , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/pharmacology , Insulin/pharmacology , Insulin/therapeutic use , Interleukin-6/blood , Male , Middle Aged , Oxidative Stress/drug effects , Vasodilator Agents/administration & dosage , Vasodilator Agents/therapeutic useABSTRACT
OBJECTIVE: To test the hypothesis that acute hypoglycemia induces endothelial dysfunction and inflammation through the generation of an oxidative stress. Moreover, to test if the antioxidant vitamin C can further improve the protective effects of glucagon-like peptide 1 (GLP-1) on endothelial dysfunction and inflammation during hypoglycemia in type 1 diabetes. RESEARCH DESIGN AND METHODS: A total of 20 type 1 diabetic patients underwent four experiments: a period of 2 h of acute hypoglycemia with or without infusion of GLP-1 or vitamin C or both. At baseline, after 1 and 2 h, glycemia, plasma nitrotyrosine, plasma 8-iso prostaglandin F2a (PGF2a), soluble intracellular adhesion molecule-1a (sICAM-1a), interleukin-6 (IL-6), and flow-mediated vasodilation were measured. At 2 h of hypoglycemia, flow-mediated vasodilation significantly decreased, while sICAM-1, 8-iso-PGF2a, nitrotyrosine, and IL-6 significantly increased. The simultaneous infusion of GLP-1 or vitamin C significantly attenuated all of these phenomena. Vitamin C was more effective. When GLP-1 and vitamin C were infused simultaneously, the deleterious effect of hypoglycemia was almost completely counterbalanced. RESULTS: At 2 h of hypoglycemia, flow-mediated vasodilation significantly decreased, while sICAM-1, 8-iso-PGF2a, nitrotyrosine, and IL-6 significantly increased. The simultaneous infusion of GLP-1 or vitamin C significantly attenuated all of these phenomena. Vitamin C was more effective. When GLP-1 and vitamin C were infused simultaneously, the deleterious effect of hypoglycemia was almost completely counterbalanced. CONCLUSIONS: This study shows that vitamin C infusion, during induced acute hypoglycemia, reduces the generation of oxidative stress and inflammation, improving endothelial dysfunction, in type 1 diabetes. Furthermore, the data support a protective effect of GLP-1 during acute hypoglycemia, but also suggest the presence of an endothelial resistance to the action of GLP-1, reasonably mediated by oxidative stress.
Subject(s)
Ascorbic Acid/administration & dosage , Diabetes Mellitus, Type 1/drug therapy , Endothelium, Vascular/drug effects , Glucagon-Like Peptide 1/administration & dosage , Hypoglycemia/drug therapy , Inflammation/prevention & control , Oxidative Stress/drug effects , Acute Disease , Antioxidants/therapeutic use , Blood Glucose/metabolism , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/physiopathology , Dose-Response Relationship, Drug , Drug Therapy, Combination , Endothelium, Vascular/physiopathology , Female , Follow-Up Studies , Humans , Hypoglycemia/blood , Hypoglycemia/chemically induced , Hypoglycemic Agents/adverse effects , Hypoglycemic Agents/therapeutic use , Incretins/therapeutic use , Inflammation/blood , Infusions, Intravenous , Insulin/adverse effects , Insulin/therapeutic use , Male , Vasodilation/drug effects , Young AdultABSTRACT
BACKGROUND: It has been reported that hyperglycemia following hypoglycemia produces an ischemia-reperfusion-like effect in type 1 diabetes. In this study the possibility that GLP-1 has a protective effect on this phenomenon has been tested. METHODS: 15 type 1 diabetic patients underwent to five experiments: a period of two hours of hypoglycemia followed by two hours of normo-glycemia or hyperglycemia with the concomitant infusion of GLP-1 or vitamin C or both. At baseline, after 2 and 4 hours, glycemia, plasma nitrotyrosine, plasma 8-iso prostaglandin F2alpha, sCAM-1a, IL-6 and flow mediated vasodilation were measured. RESULTS: After 2 h of hypoglycemia, flow mediated vasodilation significantly decreased, while sICAM-1, 8-iso-PGF2a, nitrotyrosine and IL-6 significantly increased. While recovering with normoglycemia was accompanied by a significant improvement of endothelial dysfunction, oxidative stress and inflammation, a period of hyperglycemia after hypoglycemia worsens all these parameters. These effects were counterbalanced by GLP-1 and better by vitamin C, while the simultaneous infusion of both almost completely abolished the effect of hyperglycemia post hypoglycemia. CONCLUSIONS: This study shows that GLP-1 infusion, during induced hyperglycemia post hypoglycemia, reduces the generation of oxidative stress and inflammation, improving the endothelial dysfunction, in type 1 diabetes. Furthermore, the data support that vitamin C and GLP-1 may have an additive protective effect in such condition.