Search

Background This study aimed at investigating the effects of genetic angiotensin-converting enzyme (ACE) 2 deficiency on glucose homeostasis in the pancreas and skeletal muscle and their reversibility following ACE inhibition. Procedures ACE2 -knockout and C57bl6J mice were placed on a standard diet (SD) or a high-fat diet (HFD) for 12weeks. An additional group of ACE2 -knockout mice was fed a SD and treated with the ACE inhibitor, perindopril (2mgkg −1 day −1 ). Glucose and insulin tolerance tests, indirect calorimetry measurements and EchoMRI were performed. Non-esterfied ‘free' fatty acid oxidation rate in skeletal muscle was calculated by measuring the palmitate oxidation rate. β-cell mass was determined by immunostaining. Insulin, collectrin, glucose transporter protein, and peroxisome proliferator-activated receptor-γ expression were analysed by RT-PCR. Markers of mithocondrial biogenesis/content were also evaluated. Main Findings ACE2 -knockout mice showed a β-cell defect associated with low insulin and collectrin levels and reduced compensatory hypertrophy in response to a HFD, which were not reversed by perindopril. On the other hand, ACE2 deficiency shifted energy metabolism towards glucose utilization, as it increased the respiratory exchange ratio, reduced palmitate oxidation and PCG-1α expression in the skeletal muscle, where it up-regulated glucose transport proteins. Treatment of ACE2 -knockout mice with perindopril reversed the skeletal muscle changes, suggesting that these were dependent on Angiotensin II (Ang II). Principal Conclusions ACE2 -knockout mice display a β-cell defect, which does not seem to be dependent on Ang II but may reflect the collectrin-like action of ACE2. This defect seemed to be compensated by the fact that ACE2 -knockout mice shifted their energy consumption towards glucose utilisation via Ang II.

Quality of care monitoring is a key strategy for health policy. In Italy, the AMD Annals continuous monitoring and quality improvement initiative has been in place since 2006. Results after 8 years are now available.Quality of diabetes care indicators during the years 2004-2011 were extracted from electronic medical records of 300 diabetes clinics. From 200,000 to 500,000 patients with type 2 diabetes were analyzed per year. Six process indicators, eight intermediate outcome indicators, seven indicators of treatment intensity/appropriateness, and a quality of care summary score (Q score) were evaluated. Previous studies documented that the risk of developing a new cardiovascular event was 80 % higher in patients with a Q score15 and 20 % higher in those with a score between 15 and 25, as compared to those with a score25.The proportion of patients with HbA1c ≤7 %, LDL cholesterol100 mg/dl, and blood pressure ≥140/90 mmHg increased by 4.8, 21.9, and 10.0 %, respectively. Process and treatment intensity/appropriateness indicators consistently improved. The proportion of patients with a Q score15 decreased from 13.5 to 6.5 %, while those with a Q score25 increased from 22.9 to 38.5 %.AMD Annals document the progress in quality of diabetes care. Longitudinal improvements in Q score can translate into less cardiovascular events, with evident clinical and economic implications. AMD Annals represent a physician-led effort not requiring allocation of extra-economic resources, which is easy to implement and deeply rooted in routine clinical practice. They are a potential case model for other healthcare systems.

Background Osteoprotegerin (OPG) is a glycoprotein that plays an important regulatory role in the skeletal, vascular, and immune system. It has been shown that OPG predicts chronic kidney disease (CKD) in diabetic patients. We hypothesized that OPG could be a risk marker of CKD development also in non-diabetic hypertensive patients. Methods A case-control study was carried out to measure circulating OPG levels in 42 hypertensive patients with CKD and in 141 hypertensive patients without CKD. A potential relationship between OPG and the presence of CKD was investigated and a receiver-operating characteristic (ROC) curve was designed thereafter to identify a cut-off value of OPG that best explained the presence of CKD. Secondly, to evaluate whether OPG increase could affect the kidney, 18 C57BL/6J mice were randomized to be treated with saline or recombinant OPG every 3 weeks for 12 weeks. Results Circulating OPG levels were significantly higher in hypertensive patients with CKD, and there was a significant inverse association between OPG and renal function, that was independent from other variables. ROC analysis showed that OPG levels had a high statistically predictive value on CKD in hypertensive patients, which was greater than that of hypertension. The OPG best cut-off value associated with CKD was 1109.19 ng/L. In the experimental study, OPG delivery significantly increased the gene expression of pro-inflammatory and pro-fibrotic mediators, as well as the glomerular nitrosylation of proteins. Conclusions This study shows that OPG is associated with CKD in hypertensive patients, where it might have a higher predictive value than that of hypertension for CKD development. Secondly, we found that OPG delivery significantly increased the expression of molecular pathways involved in kidney damage. Further longitudinal studies are needed not only to evaluate whether OPG predicts CKD development but also to clarify whether OPG should be considered a risk factor for CKD. Electronic supplementary material The online version of this article (doi:10.1186/s12882-017-0625-3) contains supplementary material, which is available to authorized users.

Objectives The preferred countermeasure to avoid exercise-related hypoglycemia was investigated in a group of patients with type 1 diabetes participating in a stressful event, a 24×1-hour relay marathon. The carbohydrates actually consumed were compared to those estimated for each patient by applying a customizable algorithm, Exercise Carbohydrates Requirement Estimating Software (ECRES), based on patient's usual therapy and diet and on the exercise characteristics. Methods Glycemia was tested at the start, middle and end of the races. Usual therapies and diets and the adopted countermeasures were recorded in detail. Results We studied 19 patients who walked/ran 10.4±2.8 km with a heart rate of 167±11 beats per minute. Of the 19 patients, 7 patients reduced the administered insulin (premeal bolus or basal infusion rate). Glycemia fell by the end of the races (p=0.006; median −1.8 mmol⋅L −1 ; interquartile range −0.4 mmol⋅L −1 to −5.3 mmol⋅L −1 ), despite 9 patients being hyperglycemic at the start. Of the patients, 14 concluded the race with glycemia on target, and 4 patients were hyperglycemic. Amounts of carbohydrates actually consumed (median 30 g; interquartile range 0 g to 71 g) were not significantly different from those estimated by ECRES (median 38 g; interquartile range 24 g to 68 g), the 2 quantities being significantly related (R=0.64; p=0.003). ECRES estimated lower carbohydrate levels (−13 g) than the amounts actually consumed by the 4 patients who concluded their exercises with hyperglycemia. Conclusions Patients preferred to consume extra carbohydrates to avoid the possible exercise-induced hypoglycemia. ECRES would provide satisfactory estimates of the carbohydrate requirements, even for a stressful condition, and almost equal to the quantities consumed following medical advice.

Since the advent of insulin, the improvements in diabetes detection and the therapies to treat hyperglycemia have reduced the mortality of acute metabolic emergencies, such that today chronic complications are the major cause of morbidity and mortality among diabetic patients. More than half of the mortality that is seen in the diabetic population can be ascribed to cardiovascular disease (CVD), which includes not only myocardial infarction due to premature atherosclerosis but also diabetic cardiomyopathy. The importance of renin-angiotensin-aldosterone system (RAAS) antagonism in the prevention of diabetic CVD has demonstrated the key role that the RAAS plays in diabetic CVD onset and development. Today, ACE inhibitors and angiotensin II receptor blockers represent the first line therapy for primary and secondary CVD prevention in patients with diabetes. Recent research has uncovered new dimensions of the RAAS and, therefore, new potential therapeutic targets against diabetic CVD. Here we describe the timeline of paradigm shifts in RAAS understanding, how diabetes modifies the RAAS, and what new parts of the RAAS pathway could be targeted in order to achieve RAAS modulation against diabetic CVD.

Background. The mechanisms of uraemia-induced atherosclerosis have not been fully delineated. The aims of this study were (i) to investigate the extent and the phenotype of atherosclerosis, including the activation of local renin―angiotensin system (RAS), in a mouse model of mild uraemia and (ii) to determine the effects of angiotensin II typel (AT1) receptor blockade on the uraemic atherosclerosis, clarifying the mechanisms of its action. Methods. Mild uraemia was induced by 5/6 nephrectomy in 8-week-old apo E-deficient mice (apoE-KO). After nephrectomy, the animals received either treatment with candesartan or no treatment for 12-weeks. Sham-operated apoE-KO mice were used as controls. Results. Uraemia led to a two-fold increase in aortic plaque area. This was associated with a significant upregulation of aortic angiotensin-converting enzyme (ACE), AT1 receptor, connective tissue growth factor (CTGF), monocyte chemoattractant protein (MCP)-1 and vascular cell adhesion molecule (VCAM)-1. Candesartan significantly reduced aortic atherosclerosis, prevented the upregulation of the uraemia-induced genes and led to changes predicting greater stability of the plaques, without influencing blood pressure or serum lipids. Conclusions. This study indicates that uraemia leads to an acceleration of aortic atherosclerosis. The upregulation of aortic RAS and the reduced atherosclerosis following AT1 receptor blocker treatment highlights the pivotal role of the local RAS in the development and acceleration of atherosclerosis in uraemia.

Background Inflammation is believed to link obesity to insulin resistance, as in the setting of metabolic syndrome (MetS). Osteoprotegerin (OPG) is a soluble protein that seems to exert proatherogenic and prodiabetogenic effects. This study aims at determining OPG levels in MetS and whether OPG might contribute to MetS development and progression. Methodology/principal findings Circulating OPG was measured in 46 patients with MetS and 63 controls, and was found significantly elevated in those with MetS. In addition, circulating and tissue OPG was significantly increased in high-fat diet (HFD) fed C57BL6 mice, which is one of the animal models for the study of MetS. To evaluate the consequences of OPG elevation, we delivered this protein to C57BL6 mice, finding that it promoted systemic and adipose tissue proinflammatory changes in association with metabolic abnormalities. Conclusions/significance These data suggest that OPG may trigger adipose tissue proinflammatory changes in MetS/HFD-induced obesity.

TRAIL [TNF (tumour necrosis factor)-related apoptosis-inducing ligand] has recently been shown to ameliorate the natural history of DM (diabetes mellitus). It has not been determined yet whether systemic TRAIL delivery would prevent the metabolic abnormalities due to an HFD [HF (high-fat) diet]. For this purpose, 27 male C57bl6 mice aged 8 weeks were randomly fed on a standard diet, HFD or HFD+TRAIL for 12 weeks. TRAIL was delivered weekly by intraperitoneal injection. Body composition was evaluated; indirect calorimetry studies, GTT (glucose tolerance test) and ITT (insulin tolerance test) were performed. Pro-inflammatory cytokines, together with adipose tissue gene expression and apoptosis, were measured. TRAIL treatment reduced significantly the increased adiposity associated with an HFD. Moreover, it reduced significantly hyperglycaemia and hyperinsulinaemia during a GTT and it improved significantly the peripheral response to insulin. TRAIL reversed the changes in substrate utilization induced by the HFD and ameliorated skeletal muscle non-esterified fatty acids oxidation rate. This was associated with a significant reduction of pro-inflammatory cytokines together with a modulation of adipose tissue gene expression and apoptosis. These findings shed light on the possible anti-adipogenic and anti-inflammatory effects of TRAIL and open new therapeutic possibilities against obesity, systemic inflammation and T2DM (Type 2 DM).

Summary Background & aims The development and/or progression of metabolic syndrome (MetS) in overweight and obese individuals have been associated to low-grade inflammation, but few studies have simultaneously analyzed the circulating levels of several cytokines. Methods In this pilot study, a group of 27 cytokines and growth factors was analyzed in the serum of obese patients (n = 40) diagnosed for MetS in comparison with sex- and age-matched control subjects without MetS (n = 53) by using a multiplex immunoassay. Release of cytokines was measured in culture supernatants of human primary endothelial cells, THP-1 macrophagic cells and HuH-7 hepatoma cells upon exposure to a high fat mixture. Results While the majority of cytokines did not show significant differences between the investigated groups, the circulating levels of CXCL10/IP-10 and IL-6 were higher in the MetS group versus overweight control group. In contrast, PDGF-BB serum levels were significantly decreased in MetS patients. The in vitro addition of a high fat mixture increased the release of IL-6 and/or CXCL10/IP-10 in the culture supernatant of human primary endothelial cells and THP-1 macrophagic cells, while the same mixture significantly decreased the release of PDGF-BB by human THP-1 macrophagic and HuH-7 hepatoma cells. Conclusions The current demonstration that MetS is associated with decrease of the pro-fibrotic PDGF cytokine is a completely novel finding, which adds complexity to the interplay between inflammation and fibrosis in patients affected by MetS.

The mechanisms underlying the increased cardiovascular risk after menopause are poorly understood. Estrogens modulate the cardiac renin-angiotensin system (RAS) and influence cardiac adaptation to afterload. To investigate whether the loss of the natural inhibition of the RAS by estrogen may be linked to an increase of cardiac apoptosis, we studied 17β-estradiol (E2) and/or angiotensin-converting enzyme (ACE) inhibitor treatment effects on cardiomyocyte survival in ovariectomized spontaneously hypertensive rats (SHRs).Five groups of female SHRs were evaluated for 8 weeks. One group served as nonovariectomized control; the other four groups underwent bilateral ovariectomy and were randomized to receive 60-day-release pellets containing placebo or 0.5 mg of E2, the ACE inhibitor ramipril at the dosage of 2.5 mg/kg per day, or the combination of the two treatments.Ovariectomy increased cardiomyocyte apoptosis and induced proapoptotic changes of Bcl-2 and Bax genes and proteins. These modifications were associated with an upregulation of ACE and angiotensin II type 1 (AT1) receptor genes. Ramipril was as effective as E2 in preventing cardiac apoptosis and in restoring cardiac brain natriuretic peptide in association with reduced cardiac ACE and AT1 receptor gene expression. In contrast to the ramipril treatment, the favorable effect of E2 on cardiac apoptosis occurred independently from changes in SBP. No synergistic effect was observed when the two treatments were combined.These data show that ovariectomy stimulates myocardium apoptosis by a mechanism involving Bax and Bcl-2 genes. The antiapoptotic effect of E2 and ACE inhibitor treatment was linked to a downregulation of cardiac RAS.

Objective To verify if innate immunity, and namely the assembly of terminal complement complex (TCC) could be involved in the development of early diabetic vascular damage. Methods and results At first in 2 groups of diabetic or non-diabetic Wistar rats the occurrence of basal or stimulated stable adherence to the endothelial layer and extravasation of circulating fluorescently-labelled leukocytes was assessed by using an in vivo videomicroscopy technique. In a second part of the study, the development of vascular damage in short term diabetes was studied in the genetically C6 deficient rats of the PVG strain, and compared with those observed in the wild-type C6 sufficient animals. Here, the analysis of mesentery vascular expression of mRNA for vascular cell adhesion molecule (VCAM)-1, transforming growth factor-β (TGF-β), connective tissue growth factor (CTGF), and platelet-derived growth factor (PDGF), the evaluation of intravascular protein levels of VCAM-1, TGF-β, CTGF, proliferative cell nuclear antigen (PCNA), as well as the assessment of structural changes and Complement components deposition at the mesentery arterial vascular wall were also performed. Conclusions Leukocyte trafficking, mesentery arteries hypertrophy, extracellular matrix deposition, local vascular gene and protein expression of VCAM-1, TGF-β, CTGF and PCNA, as well as PGDF gene expression were all increased by short term diabetes, but all significantly reduced in the C6 deficient diabetic animals, thus suggesting an active role for TCC in the development of vascular inflammation in the early phases of experimental diabetes.

Cardiovascular diseases (CVDs) are the major causes of morbidity and mortality in persons with diabetes, and many factors, including hypertension, contribute to this high prevalence of macrovascular complications. Hypertension is approximately twice as frequent in subjects with diabetes compared with non-diabetic patients. Furthermore, up to 75Y% of CVD in diabetes may be attributable to hypertension, leading to recommendations for more aggressive treatment (i.e. reducing blood pressure to < 130/80 mmHg) in persons with coexistent diabetes and hypertension. Macroangiopathy in diabetes is manifested by accelerated atherosclerosis which affects heart, brain and peripheral arteries. The pathogenesis of this accelerated atherosclerosis is multifactorial and includes a very complex interaction. Several data suggest a key role for renin-angiotensin system (RAS) activation in the pathophysiology of macrovascular complications in diabetic hypertensive subjects. Consequently, RAS blockade exerts potent antiatherosclerotic effects, which are mediated by their antihypertensive, anti-inflammatory, antiproliferative, and oxidative stress lowering properties. Inhibitors of the system, ie, angiotensin converting enzyme inhibitors and angiotensin receptor blockers, are now first line treatment to prevent CVD in patients with diabetes and hypertension. In addition, recent clinical trials have suggested that RAS blockade may protect against the development of de-novo diabetes in at-risk patients. Finally, the recent identification of new components of the RAS should provide fertile territory to not only examine new targets linked to the RAS but potentially to design more rational treatments for the prevention of CVD in patients with diabetes and hypertension.

Aim Diabetic nephropathy is the leading cause of end-stage kidney disease in developed countries and is related to chronic hyperglycaemia. The increased production and tissue deposition of advanced glycation end products (AGE) are known to play a major role in the pathogenesis of diabetic kidney damage. This study was undertaken to determine if lysozyme (LZ), microencapsulated in orally administrable chitosan-coated alginate microspheres (MS), is effective against the early changes seen in the initial stages of diabetic nephropathy. Methods LZ-containing MS (MSLZ) and an equivalent dose (equidose) of nonencapsulated LZ were given as oral treatments. LZ was administered to Wistar rats for seven weeks after diabetes induction with streptozotocin. Results The results showed that microencapsulated LZ treatment significantly reduced the concentration of serum AGE in the circulation and their deposition in the kidneys. Likewise, MSLZ significantly prevented the development of microalbuminuria compared with untreated diabetic rats. Furthermore, MSLZ significantly prevented the development of glomerular and renal hypertrophy as well as overexpression of AGE receptors (RAGE). An equidose of free LZ had little or no effect whatsoever. Conclusion Our study supports a relationship between serum AGE and nephropathy in diabetes, and suggests that orally administered microencapsulated LZ can exert kidney-protective activity in a diabetic animal model.

A glomerular permeability defect occurs early in the course of type 1 diabetes and precedes the onset of microalbuminuria and renal morphological changes. Recently, ACE inhibitors have been shown to prevent loss of glomerular membrane permselective function, but the mechanism of this nephroprotective effect is still being debated. The objective of the present study was to evaluate the effects of hypotensive and subhypotensive dosages of the ACE inhibitor quinapril ex vivo and of its active metabolite quinaprilat in vitro on the glomerular albumin permeability (Palb) defect in the early phases of experimental diabetes. For the ex vivo study, six groups of male Wistar rats were evaluated for 4 weeks. One group served as a nondiabetic control (C); the other five groups were rendered diabetic and included untreated diabetic rats (D) and diabetic rats receiving quinapril at the dosages of 5 (DQ1), 2.5 (DQ2), 1.25 (DQ3), and 0.625 (DQ4) mg · kg−1 · day−1. Dosage-dependent effects of quinapril on systolic blood pressure and the glomerular filtration rate were observed. In contrast, control of Palb in isolated glomeruli exposed to oncotic gradients, proteinuria, and glomerular and tubular hypertrophy was obtained with subhypotensive dosages (DQ3 and DQ4 groups) of the ACE inhibitor. In the in vitro study, quinaprilat reduced Palb significantly in concentration ranges from 10−6 to 10−14 mol/l compared with results in control glomeruli. The effect on Palb may have occurred by mechanisms different from kidney ACE inhibitor. These study results indicated that ACE inhibitor treatment prevents the early onset of the Palb defect in experimental diabetes. This effect seemed to occur independently of systemic or glomerular hemodynamic changes and, at least partially, from kidney ACE inhibition.

The aim of the present study was to determine whether changes of carotid wall shear stress induced by changes in blood viscosity after diuretic administration cause carotid arterial dilatation in elderly hypertensives, as reported in the cat. Arterial wall shear rate (ultrasound technique, profilmeter FRP III), the systo-diastolic diameter (echotracking technique) and the mean blood flow velocity and volume of the common carotid artery, the blood viscosity (rotational viscometer) and the finger arterial blood pressure (Finapress Ohmeda) were measured in 12 young volunteers (aged 25+/-2 years) and in 12 elderly hypertensives (aged 80+/-4 years) treated with short-acting calcium antagonists up to 24h before the study, both at baseline and after intravenous furosemide infusion (0.5mg/min), when the haematocrit had increased by at least two percentage points. After furosemide administration the mean arterial blood pressure decreased and blood viscosity and carotid systolic shear stress increased in both groups. However, common carotid artery diameter increased only in the young controls but not in the elderly hypertensives. These data show that an increase in carotid shear stress caused by haemoconcentration induces carotid vasodilatation only in young healthy subjects, and not in elderly hypertensives. This effect may be related to impaired endothelium function and/or arterial wall mechanics.

Hypothesis: Type 2 diabetes mellitus (T2DM) and chronic heart failure (CHF) are associated with renal dysfunction. We tested the hypothesis that the degree of renal dysfunction influences the negative impact on the outcome of T2DM in patients with CHF and reduced left ventricular ejection fraction (LVEF). Methods: From November 1, 2009 to December 31, 2012, the “Trieste Registry of CV Diseases” enrolled 19,589 patients. Those with diagnosis of CHF and reduced LVEF were analyzed. The primary end-point was all-cause mortality. Results: 554 patients were selected (73 ± 10 years old, 32% females), 192 had T2DM (35%). During followup (23±11 months), all-cause death occurred in 57 patients (30%) who had T2DM and in 58 (16%, p b 0.001)who had not; T2DM was associated with an increased risk of death (adjusted HR 2.55 [95% CI 1.02-6.36], p= 0.04). The prognostic impact of T2DM was lost when patients were selected according to renal function: adjusted HR 1.44 [0.21-9.93], p= 0.71, in patients with normal renal function, defined as estimated glomerular filtration rate (eGFR) N60, and adjusted HR 3.37 [0.96-11.80], p = 0.08 in patients with renal dysfunction (eGFR b 60 ml/min ∗ 1.73 m2). T2DM predicted all-cause mortality only in the subgroup with eGFR between 90 and 30 ml/min ∗ 1.73 m2 (adjusted HR 2.52 [1.01-6.30], p= 0.04). Conclusions: In patients with CHF and reduced LVEF the prognostic impact of T2DM depends on the degree of renal dysfunction. Its contribution in all-causemortality risk prediction is limited tomild–moderate renal dysfunction subgroup, while prognostic power is lost in normal renal function and in severe renal dysfunction patients.

Objective Glomerular hyperfiltration and renal hypertrophy are both considered important in the progression of diabetic nephropathy. The aim of this study was to compare the effects of an equivalent reduction in blood pressure produced by the angiotensin-converting enzyme (ACE) inhibitor spirapril (SPI) and an antihypertensive triple drug combination of hydralazine, reserpine and hydrochlorothiazide (HRH) on kidney function, proteinuria and renal structure in hypertensive diabetic rats. Design and methods Four groups of animals were evaluated in short-term and long-term studies. In both studies one group served as a non-diabetic hypertensive control (H). The other three groups were rendered diabetic and were allocated to one of the following groups: the first diabetic group received no specific therapy (HD), the second diabetic group was treated with SPI (HD-SPI) and the third diabetic group was treated with HRH (HD-HRH). In each of the two studies the systolic blood pressure (SBP), 24 h urinary total protein, glomerular filtration rate (GFR), glomerular area, proximal tubular area and glomerular sclerosis were evaluated. Results The blood pressure reduction was equal in rats receiving either SPI or HRH. The GFR, proteinuria, glomerular area and tubular area were significantly increased in the HD group, both in the short-term and the long-term study. In the HD-SPI group the diabetic hyperfiltration and renal hypertrophy responses were prevented. In the HD-HRH group the GFR and proteinuria were slightly reduced in the later phases of diabetes, while the glomerular area and tubular area were not affected. Semiquantitative analysis of renal lesions showed that SPI was more effective than HRH in the prevention of the development of glomerulosclerosis. Conclusions The results of this study suggest that the control of early adaptive hyperfiltration and renal hypertrophy by SPI may be relevant in the prevention of glomerulosclerosis.