Anti-diabetic combination therapy with pioglitazone or glimepiride added to metformin on the AGE-RAGE axis: a randomized prospective study.

Introduction: The ratio between advanced glycation end products (AGEs) and soluble form of receptor (s-RAGE) has been proposed as a risk marker for renal and cardiovascular diseases. The aim of this study was to evaluate in the diabetes condition the influence of two different oral anti-diabetic treatments on the AGE/s-RAGE ratio, during a 5-year observation period. Methods: Seventy-three patients with type 2 diabetes mellitus were randomly assigned to a drug therapy with pioglitazone or glimepiride, combined to metformin. Each subject was evaluated at baseline and after 5 years of treatment. Results: In both groups s-RAGE levels did not significantly vary, while the levels of AGE and AGE/s-RAGE were both significantly reduced, basal compared to 5-year values. Within pioglitazone group, as well within glimepiride group, significant variations (Δ, as difference between 5 years of treatment minus basal) were observed for AGE (Δ= -21.1±13.4 µg/ml, P<0.001 for pioglitazone; Δ= -14.4±11.4 µg/ml, P<0.001 for glimepiride) and in AGE/s-RAGE (Δ= -0.037±0.022 µg/pg, P<0.001 for pioglitazone; Δ= -0.024±0.020µg/pg, P<0.001 for glimepiride), suggesting an average decrease of the parameters by more than 50% in both treatments. Pioglitazone was more effective than glimepiride in reducing AGE/s-RAGE ratio after 5 years of therapy. Conclusion: These data can help to explain the benefits of oral anti-diabetic therapy in relation to the reduction of cardiovascular risk, as suggested by variations in AGE/s-RAGE ratio as biochemical marker of endothelial function; in particular, treatment with pioglitazone seems to offer greater long-term benefit on AGE-RAGE axis.

Pathophysiological basis of the cardiological benefits of SGLT-2 inhibitors: a narrative review.

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.

In vitro chronic glycation induces AGEs accumulation reducing insulin-stimulated glucose uptake and increasing GLP1R in adipocytes.

Intracellular AGEs accumulation increases RAGE and GLP1R and reduces glucose uptake in adipocytes.

Role of fructosamine-3-kinase in protecting against the onset of microvascular and macrovascular complications in patients with T2DM.

INTRODUCTION: Microangiopathic and macroangiopathic complications are the main cause of morbidity and mortality in the diabetic population. Numerous publications have highlighted the role of glycation in the onset of complications of diabetes. In this context, the detection of fructosamine-3-kinase (FN3K)-an enzyme capable of counteracting the effect of hyperglycemia by intervening in protein glycation-has attracted great interest. Several studies have linked FN3K genetic variability to its enzymatic activity and glycated hemoglobin (HbA1c) levels. Here, we investigated the role of FN3K polymorphisms in the development of microvascular and macrovascular complications of diabetes. RESEARCH DESIGN AND METHODS: The anthropometric and biochemical parameters, and any medical history of microangiopathic and macroangiopathic complications, were documented in a sample of 80 subjects with type 2 diabetes. All subjects were screened for FN3K gene and analyzed for the combination of three polymorphisms known to be associated with its enzymatic activity (rs3859206 and rs2256339 in the promoter region and rs1056534 in exon 6). RESULTS: The combination of allelic variants of FN3K polymorphisms resulted in 13 distinct genotypic variants within the cohort. Comparison between genotypes showed no significant differences in terms of demographic, anthropometric and biochemical parameters, risk markers and long-term complications, except for a higher age and vitamin E levels associated with the genotype presenting GG at position -385, TT at position -232, and CC at c.900 A. Evaluating the microangiopathic and macroangiopathic complications as a whole, we found that they appeared significantly less present in this genotype compared with all other genotypes (p=0.0306). CONCLUSIONS: The group of patients carrying the favorable allele for the three polymorphisms of the FN3K gene revealed less severe microangiopathy and macroangiopathy, suggesting a protective role of this genotype against the onset of the complications of diabetes.

Long-term effect of pioglitazone vs glimepiride on lipoprotein oxidation in patients with type 2 diabetes: a prospective randomized study.

AIMS: Type 2 diabetes (DM2) is associated to oxidative modifications of high-density lipoproteins (HDL), which can interfere with their function. Pioglitazone has proved effective in raising HDL cholesterol (HDL-C) and lowering small dense low-density lipoprotein (LDL), but no clinical studies have examined its effect on lipoprotein oxidation in patients with DM2. METHODS: We assessed the effect of pioglitazone vs glimepiride after 1 year on HDL oxidation, expressed as relative abundance of peptides containing Met112O in ApoA-I (oxApoA-I) estimated by mass spectrometry (MALDI/TOF/TOF), in 95 patients with DM2. The oxLDL and AGE were quantified by ELISA. RESULTS: Patients receiving pioglitazone showed a significant increase in the concentration of ApoA-I (Δ = 7.2 ± 14.8 mg/dL, p < 0.02) and a reduction in oxApoA-I (Δ = - 1.0 ± 2.6%, p < 0.02); this reduction was not significantly different from glimepiride. oxLDL showed a slight, but not significant increase in both treatment groups. Regression analysis showed a correlation between ΔoxApoA-I and ΔAGE (r = 0.30; p = 0.007) in all patients, while both of these parameters were unrelated to changes in HbA1c, HDL-C, duration of illness, or use of statins. CONCLUSIONS: Long-term treatment with pioglitazone was effective in reducing the oxidation of HDL, but not LDL in patients with DM2, while glimepiride didn't. This finding seems to be associated to the change of glyco-oxidation status, not to any improvement in glycemic control or lipid profile. TRIAL REGISTRATION: NCT00700856, ClinicalTrials.gov Registered June 18, 2008.

Autonomic testing: which value for each cardiovascular test? An observational study.

AIMS: Cardiovascular autonomic testing is time consuming when adopting the entire Ewing battery of tests, hence, clinicians usually adopt an empirically reduced number of tests which may give controversial results. Our purpose was to examine the reliability of the cardiovascular tests most commonly used in autonomic diagnoses. METHODS: We tested 334 subjects, from an original group of 3745, who had shown an altered deep breathing test to both Lying to standing and Valsalva manoeuvre, assuming a value of postural hypotension of more than 15 mmHg as a sign of almost true dysautonomia. RESULTS: VM showed the highest sensitivity (85%) and, when coupled to LS, highest specificity (83%). CONCLUSIONS: VM could be useful when screening for possible or early autonomic neuropathy, VM + LS is useful as a diagnostic tool for probable or advanced autonomic neuropathy, and VM + LS + PH is useful for certain diagnosis of definite or late stage autonomic neuropathy.

The role of mass spectrometry in studies of glycation processes and diabetes management.

In the last decade, mass spectrometry has been widely employed in the study of diabetes. This was mainly due to the development of new, highly sensitive, and specific methods representing powerful tools to go deep into the biochemical and pathogenetic processes typical of the disease. The aim of this review is to give a panorama of the scientifically valid results obtained in this contest. The recent studies on glycation processes, in particular those devoted to the mechanism of production and to the reactivity of advanced glycation end products (AGEs, AGE peptides, glyoxal, methylglyoxal, dicarbonyl compounds) allowed to obtain a different view on short and long term complications of diabetes. These results have been employed in the research of effective markers and mass spectrometry represented a precious tool allowing the monitoring of diabetic nephropathy, cardiovascular complications, and gestational diabetes. The same approaches have been employed to monitor the non-insulinic diabetes pharmacological treatments, as well as in the discovery and characterization of antidiabetic agents from natural products. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 38:112-146, 2019.

Curcumin and Boswellia serrata Modulate the Glyco-Oxidative Status and Lipo-Oxidation in Master Athletes.

BACKGROUND: Chronic intensive exercise is associated with a greater induction of oxidative stress and with an excess of endogenous advanced glycation end-products (AGEs). Curcumin can reduce the accumulation of AGEs in vitro and in animal models. We examined whether supplementation with curcumin and Boswellia serrata (BSE) gum resin for 3 months could affect plasma levels of markers of oxidative stress, inflammation, and glycation in healthy master cyclists. METHODS: Forty-seven healthy male athletes were randomly assigned to Group 1, consisting of 22 subjects given a Mediterranean diet (MD) alone (MD group), and Group 2 consisted of 25 subjects given a MD plus curcumin and BSE (curcumin/BSE group). Interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), high-sensitivity c-reactive protein (hs-CRP), total AGE, soluble receptor for AGE (sRAGE), malondialdehyde (MDA), plasma phospholipid fatty acid (PPFA) composition, and non-esterified fatty acids (NEFA) were tested at baseline and after 12 weeks. RESULTS: sRAGE, NEFA, and MDA decreased significantly in both groups, while only the curcumin/BSE group showed a significant decline in total AGE. Only the changes in total AGE and MDA differed significantly between the curcumin/BSE and MD groups. CONCLUSIONS: Our data suggest a positive effect of supplementation with curcumin and BSE on glycoxidation and lipid peroxidation in chronically exercising master athletes.

Possible role of fructosamine 3-kinase genotyping for the management of diabetic patients.

Diabetes mellitus is a global pandemic and continues to increase in numbers and significance. Several pathogenic processes are involved in the development of such disease and these mechanisms could be influenced by genetic, epigenetic and environmental factors. Non-enzymatic glycation reactions of proteins have been strongly related to pathogenesis of chronic diabetic complications. The identification of fructosamine 3-kinase (FN3K), an enzyme involved in protein deglycation, a new form of protein repair, is of great interest. FN3K phosphorylates fructosamines on the third carbon of their sugar moiety, making them unstable and causing them to detach from proteins, suggesting a protective role of this enzyme. Moreover, the variability in FN3K activity has been associated with some polymorphisms in the FN3K gene. Here we argue about genetic studies and evidence of FN3K involvement in diabetes, together with results of our analysis of the FN3K gene on a Caucasian cohort of diabetic patients. Present knowledge suggests that FN3K could act in concert with other molecular mechanisms and may impact on gene expression and activity of other enzymes involved in deglycation process.

The emerging role of telemedicine in managing glycemic control and psychobehavioral aspects of pregnancy complicated by diabetes.

There is a gradual decline in concern of specialists who follow up the care of pregnant women with diabetes. In addition, due to the dwindling economic resources allocated to health services, access to specialized healthcare facilities is becoming more difficult. Telemedicine, or medicine practiced at a distance, is inserted in this context with applications differing for type of interaction (real-time or deferred, i.e., videoconferencing versus store-and-forward data transmission), type of monitoring (automatic versus requesting cooperation from the patient), and type of devices used (web connections and use of mobile phones or smartphones). Telemedicine can cope with the current lack of ability to ensure these patients frequent direct contact with their caregivers. This approach may have an impact not only on the classical maternal-fetal outcome, but also on some underestimated aspects of patients with diabetes in pregnancy, in this case their quality of life, the perception of "diabetes self-efficacy," and the glycemic variability. In this paper, we will analyze the current evidence regarding the use of telemedicine in pregnancies complicated by diabetes, trying to highlight the main limitations of these studies and possible strategies to overcome them in order to improve the effectiveness of future clinical interventions with these medical applications.

Screening with HbA1c identifies only one in two individuals with diagnosis of prediabetes at oral glucose tolerance test: findings in a real-world Caucasian population.

OBJECTIVE: Discordance between HbA1c and OGTT in screening pre-diabetes may occur because of lack of laboratory standardization, distinct underlying pathophysiological processes or different ethnicity. We evaluated HbA1c efficacy for screening OGTT-defined IFG and IGT conditions in a large Caucasian population using the newly revised IFCC protocol. RESEARCH DESIGN AND METHODS: A total of 501 consecutive subjects were screened for pre-diabetic conditions with OGTT with 75 g of glucose. Testing for HbA1c, lipid profile and fasting insulin levels was also performed. For detecting differences between continuous variables, ANOVA followed by Tukey's honestly significant difference (HSD) post hoc test was used. Logistic regression and ROC curve analysis were also performed for assessing HbA1c screening efficacy. RESULTS: ROC curve analysis showed that optimal HbA1c cut-off for detecting IFG was 5.6 % (sensitivity of 78 % and specificity of 63 %), while for IGT, the optimal cut-off was 5.9 % (sensitivity of 46 % and specificity of 84 %), with AUCs < 0.8. Screening with HbA1c identified 53.4 % of the 193 patients with IFG and/or IGT diagnosed at OGTT. As regards surrogate markers of insulin resistance, we observed a trend towards higher values of HOMA-IR and lower QUICKI values in subjects with IFG than in those with IGT. Patients with pre-diabetes at both tests had similar values of HOMA and QUICKI, compared with those with altered OGTT only. CONCLUSIONS: IFCC-aligned HbA1c assay proved scarcely effective in detecting IFG and/or IGT in a large Caucasian population, identifying only half of the patients with abnormal OGTT. Moreover, adding HbA1c screening to OGTT may be of little benefit in identifying subjects with a worse metabolic profile.

Association between glucose variability as assessed by continuous glucose monitoring (CGM) and diabetic retinopathy in type 1 and type 2 diabetes.

There is a growing debate in the literature on whether glucose variability contributes, as well as high HbA1c levels and longstanding diabetes, to the onset and progression of diabetic retinopathy (DR) in patients with diabetes types 1 (DM1) and 2 (DM2). Few data, obtained only by self-monitoring of blood glucose, support this hypothesis. We used continuous glucose monitoring (CGM) to investigate the association between DR and glucose variability parameters (SD, CONGA 2, MAGE), acute hyperglycemia (HBGI) and chronic exposure to glucose (AG and AUC tot). We studied 68 patients from 19 to 69 years old, 35 with DM1 and 33 with DM2. The prevalence of retinopathy was 43 % in DM 1 patients and 39 % in DM 2 patients. The values of all indicators were obtained by CGM for 72 h. DR was diagnosed on direct or indirect ophthalmoscopic examination, after inducing mydriasis with tropicamide. HbA1c was measured at the baseline and 6 weeks after CGM to test the stability of the patients' glycemic control. Univariate analysis showed a close association between DR and duration of diabetes (OR 1.11; 1.04-1.19), intensive insulin therapy (OR 5.6, CI 1.14-27.30), SD (OR 1.03; CI 1.01-1.06) and CONGA 2 (OR 1.02; CI 1.00-1.04)-both indicators of variability and HBGI (OR 1.1, CI 1.01-1.18)-a parameter reflecting acute hyperglycemia. There was no significant correlation with HbA1c (p = 0.070). Multivariate regression analysis showed that disease duration is the parameter most significantly correlating with DR (OR 1.05; 1.01-1.15). These results reinforce the evidence that longstanding disease is the factor most closely associated with DR. Our data also suggest, however, that glucose variability-regardless of HbA1c-may also have a role as a risk factor for DR, particularly in the case of acute fluctuations (as represented by CONGA 2 and SD) and acute hyperglycemia (as represented by HBGI).

Subclinical diastolic dysfunction in type 2 diabetic patients with and without carotid atherosclerosis: relationship with glyco-oxidation, lipid-oxidation and antioxidant status.

OBJECTIVES: The aim of this study was to evaluate subclinical diastolic dysfunction in type 2 diabetic patients and its relationship with glyco-oxidation, lipo-oxidation and antioxidant capacity in the presence or absence of carotid plaques. BACKGROUND: Subclinical diastolic dysfunction is the early stage of diabetic cardiomyopathy, the pathogenic mechanisms of which are still little known. In particular, few data are available on the role of glyco-oxidation, lipo-oxidation and antioxidant status, factors known to be involved in the atherosclerotic process. METHODS: We assessed myocardial systolic and diastolic functions in 57 consecutive asymptomatic type 2 diabetic patients (24 patients with no carotid plaques; 33 with plaques) and 27 healthy volunteers using transthoracic echocardiography. Glyco-oxidation and lipo-oxidation parameters and antioxidant status were also evaluated in fasting venous blood samples. RESULTS: Systolic function was similar between diabetic patients and controls, while most of the diastolic parameters (A, e', E/A, E/e') differed significantly between diabetics and controls, being worse in the former. Among the diastolic parameters, only the peak late diastolic velocity A differed significantly between the two groups of diabetic patients with no carotid plaques and with plaques (0.72 ± 0.16 m/s vs 0.84 ± 0.25 m/s, p<0.05). The diastolic parameters A and E/e' related to glycemic control, glyco-oxidation and antioxidant capacity, and to LDL size and density. CONCLUSIONS: Glyco-oxidation and antioxidant status, combined with the presence of small, dense LDL correlate with subclinical diastolic dysfunction in type 2 diabetic patients. Atherosclerotic lesions are associated with an altered atrial function.

The importance of HbA1c and glucose variability in patients with type 1 and type 2 diabetes: outcome of continuous glucose monitoring (CGM).

Glucose variability has recently been investigated in diabetic patients in several studies, but most of them considered only a few variability indicators and did not systematically correlate them with patients' HbA1c levels and other important characteristics. In thus study, the correlations between HbA1c levels and metabolic control (average glucose, AG), glucose variability (SD, CONGA, MAGE, MODD, BG ROC), hyperglycemia (HBGI), hypoglycemia (LBGI) and postprandial (AUC PP) indices were investigated in patients with type 1 and type 2 diabetes. The study involved 68 patients divided into 3 groups as follows: 35 patients had type 1 diabetes (group 1); 17 had type 2 diabetes and were taking multiple daily injections (MDI) of insulin (group 2); and 16 patients had type 2 diabetes treated with OHA and/or basal insulin (group 3). The indicators were obtained over at least 48 h using a continuous glucose monitoring (CGM) system. HbA1c levels were measured at the baseline and after CGM. HbA1c correlated significantly with AG (r = 0.74), AUC PP (r = 0.69) and HBGI (r = 0.74), but only in type 1 diabetic patients. Patients with longstanding disease and type 1 diabetes had a greater glucose variability, irrespective of their HbA1c levels. Insulin therapy with MDI correlated strongly with HbA1c, but not with glucose variability. HbA1c levels identify states of sustained hyperglycemia and seem to be unaffected by hypoglycemic episodes or short-lived glucose spikes, consequently revealing shortcomings as a "gold standard" indicator of metabolic control. Glucose variability indicators describe the glucose profile of type 1 diabetic patients and identify any worsening glycemic control (typical of longstanding diabetes) more accurately than HbA1c tests.

Pregnancy and foetal outcome after bariatric surgery: a review of recent studies.

It is well known that maternal obesity has adverse effects on the health of offspring, causing immediate and long-term morbidities. The various types of procedure coming under the heading of bariatric surgery have proved effective in preventing some maternal and foetal complications in morbidly obese pregnant women. This review aims to assess the role, the risks and the benefits of bariatric surgery for mothers and offspring. According to recent findings, pregnancy and neonatal outcomes in morbidly obese women who have undergone bariatric surgery depend to some extent on the type of surgery used. Maternal complications, nutritional defects and intestinal obstruction are more frequently reported after Roux-en-Y gastric bypass (RYGB) and biliopancreatic diversion (BPD) than after laparoscopic adjustable gastric banding (LAGB) procedures, whereas caesarean section, preterm delivery and neonatal death are more commonly reported after RYGB than after LAGB. The authors of the only long-term follow-up study conducted on this subject reported that the rate of obesity in the children dropped by 52% after bariatric surgery for the mother, and the cases of severe obesity decreased by 45%. Data on pregnancy and bariatric surgery confirm that the procedure is more effective than dietary measures alone in morbidly obese women, and that pregnancy outcome is generally favorable after surgery. Some studies have indicated, nonetheless, that pregnancies after bariatric surgery are at higher risk: the women affected require special medical attention, particularly as concerns gastrointestinal symptoms and vitamin deficiencies, warranting nutritional/dietary counselling by a multidisciplinary team before, during and after pregnancy.