MASLD, hepatic steatosis and fibrosis are associated with the prevalence of chronic kidney disease and retinopathy in adults with type 1 diabetes mellitus

AIM

We examined whether metabolic dysfunction-associated steatotic liver disease (MASLD) with or without significant fibrosis (assessed by validated non-invasive biomarkers) was associated with an increased risk of prevalent chronic kidney disease (CKD) or diabetic retinopathy in people with type 1 diabetes mellitus (T1DM).

METHODS

We performed a retrospective multicenter cross-sectional study involving 1,409 adult outpatients with T1DM, in whom hepatic steatosis index (HSI) and fibrosis (FIB)-4 index were calculated for non-invasively detecting hepatic steatosis (defined by HSI > 36), with or without coexisting significant fibrosis (FIB-4 index ≥ 1.3 or < 1.3). CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 or urine albumin/creatinine ratio ≥ 3.0 mg/mmol. The presence of diabetic retinopathy was also recorded in all participants.

RESULTS

Patients with MASLD and significant fibrosis (n = 93) had a remarkably higher prevalence of CKD and diabetic retinopathy than their counterparts with MASLD without fibrosis (n = 578) and those without steatosis (n = 738). After adjustment for sex, diabetes duration, hemoglobin A1c, hypertension, and use of antihypertensive or lipid-lowering medications, patients with SLD and significant fibrosis had a higher risk of prevalent CKD (adjusted-odds ratio 1.76, 95 % confidence interval 1.05-2.96) than those without steatosis. Patients with MASLD without fibrosis had a higher risk of prevalent retinopathy (adjusted-odds ratio 1.49, 95 % CI 1.13-1.46) than those without steatosis.

CONCLUSION

This is the largest cross-sectional study showing that MASLD with and without coexisting significant fibrosis was associated, independently of potential confounders, with an increased risk of prevalent CKD and retinopathy in adults with T1DM.

Association between different modalities of insulin administration and metabolic dysfunction-associated fatty liver disease in adults with type 1 diabetes mellitus

AIM

We examined whether different insulin administration modalities, i.e., multiple daily injections (MDI) or continuous subcutaneous insulin infusion (CSII by insulin pumps), are differently associated with the risk of having metabolic dysfunction-associated fatty liver disease (MAFLD), with or without coexisting significant liver fibrosis (assessed by validated non-invasive biomarkers), in adults with type 1 diabetes mellitus (T1DM).

METHODS

We conducted a retrospective, multicenter, cross-sectional study involving 1,417 adult individuals with established T1DM treated with MDI or CSII. We calculated hepatic steatosis index (HSI) and fibrosis (FIB)-4 index for non-invasively detecting MAFLD (defined by HSI >36), with or without coexisting significant fibrosis (defined by FIB-4 index ≥ 1.3 or <1.3, respectively).

RESULTS

Compared to the MDI group (n = 1,161), insulin-pump users (n = 256; 18.1%) were more likely to be younger (mean age: 40 vs. 48 years, P < 0.001), had better glycemic control (mean hemoglobin A1c: 7.7%  vs. 7.9%, P = 0.025) and a markedly lower prevalence of MAFLD with coexisting significant fibrosis (2.7%  vs. 8.1%, P = 0.010), but a comparable prevalence of MAFLD without fibrosis. In multinomial logistic regression analysis, CSII therapy was associated with a ∼70%-lower risk of MAFLD with significant fibrosis (unadjusted odds ratio 0.32, 95% confidence interval 0.14-0.70; P = 0.004), but this association was no longer significant after adjustment for age, hemoglobin A1c and other potential confounders.

CONCLUSION

The lower prevalence of MAFLD with coexisting significant fibrosis we observed in adults with T1DM using CSII therapy, compared to those using MDI therapy, is primarily mediated by inter-group differences in age.

Sex Differences in Cardiovascular Disease and Cardiovascular Risk Estimation in Patients With Type 1 Diabetes

CONTEXT

Patients with type 1 diabetes (T1D) have higher cardiovascular disease (CVD) risk than the general population.

OBJECTIVE

This observational study aims to evaluate sex-related differences in CVD prevalence and CVD risk estimates in a large cohort of T1D adults.

METHODS

We conducted a multicenter, cross-sectional study involving 2041 patients with T1D (mean age 46 years; 44.9% women). In patients without pre-existing CVD (primary prevention), we used the Steno type 1 risk engine to estimate the 10-year risk of developing CVD events.

RESULTS

CVD prevalence (n = 116) was higher in men than in women aged ≥55 years (19.2 vs 12.8%, P = .036), but comparable between the 2 sexes in those aged <55 years (P = .91). In patients without pre-existing CVD (n = 1925), mean 10-year estimated CVD risk was 15.4 ± 0.4% without any significant sex difference. However, stratifying this patient group by age, the 10-year estimated CVD risk was significantly higher in men than in women until age 55 years (P < .001), but this risk equalized after this age. Carotid artery plaque burden was significantly associated with age ≥55 years and with a medium and high 10-year estimated CVD risk, without any significant sex difference. Diabetic retinopathy and sensory-motor neuropathy were also associated with higher 10-year CVD risk and female sex.

CONCLUSION

Both men and women with T1D are at high CVD risk. The 10-year estimated CVD risk was higher in men aged <55 years than in women of similar age, but these sex differences disappeared at age ≥55 years, suggesting that female sex was no longer protective.

Hepatic steatosis with significant fibrosis is associated with an increased 10-year estimated risk of cardiovascular disease in adults with type 1 diabetes mellitus

BACKGROUND

We assessed whether hepatic steatosis with or without significant fibrosis (determined by validated non-invasive biomarkers) is associated with an increased 10-year estimated risk for cardiovascular disease (CVD) in people with type 1 diabetes mellitus (T1DM).

METHODS

We conducted a retrospective, multicenter, cross-sectional study involving 1,254 adults with established T1DM without pre-existing CVD. We used the hepatic steatosis index (HSI) and fibrosis (FIB)-4 index for non-invasively detecting hepatic steatosis (defined as HSI > 36), with or without coexisting significant fibrosis (defined as FIB-4 index ≥ 1.3 or < 1.3). We calculated the Steno type 1 risk engine and the atherosclerotic CVD (ASCVD) risk score to estimate the 10-year risk of developing a first fatal or nonfatal CVD event.

RESULTS

Using the Steno type 1 risk engine, a significantly greater proportion of patients with hepatic steatosis and significant fibrosis (n = 91) had a high 10-year estimated CVD risk compared to those with hepatic steatosis alone (n = 509) or without steatosis (n = 654) (75.8% vs. 23.2% vs. 24.9%, p < 0.001). After adjustment for sex, BMI, diabetes duration, hemoglobin A1c, chronic kidney disease, and lipid-lowering medication use, patients with hepatic steatosis and significant fibrosis had an increased 10-year estimated risk of developing a first fatal or nonfatal CVD event (adjusted-odds ratio 11.4, 95% confidence interval 3.54-36.9) than those without steatosis. We observed almost identical results using the ASCVD risk calculator.

CONCLUSIONS

The 10-year estimated CVD risk is remarkably greater in T1DM adults with hepatic steatosis and significant fibrosis than in their counterparts with hepatic steatosis alone or without steatosis.

Circulating Small Noncoding RNA Profiling as a Potential Biomarker of Atherosclerotic Plaque Composition in Type 1 Diabetes

OBJECTIVE

Cardiovascular disease (CVD) accounts for most deaths in patients with type 1 diabetes (T1D); however, the determinants of plaque composition are unknown. miRNAs regulate gene expression, participate in the development of atherosclerosis, and represent promising CVD biomarkers. This study analyzed the circulating miRNA expression profile in T1D with either carotid calcified (CCP) or fibrous plaque (CFP).

RESEARCH DESIGN AND METHODS

Circulating small noncoding RNAs were sequenced and quantified using next-generation sequencing and bioinformatic analysis in an exploratory set of 26 subjects with T1D with CCP and in 25 with CFP. Then, in a validation set of 40 subjects with CCP, 40 with CFP, and 24 control subjects with T1D, selected miRNA expression was measured by digital droplet PCR. Putative gene targets enriched for pathways implicated in atherosclerosis/vascular calcification/diabetes were analyzed. The patients' main clinical characteristics were also recorded.

RESULTS

miR-503-5p, let-7d-5p, miR-106b-3p, and miR-93-5p were significantly upregulated, while miR-10a-5p was downregulated in patients with CCP compared with CFP (all fold change >±1.5; P < 0.05). All candidate miRNAs showed a significant correlation with LDL-cholesterol, direct for the upregulated and inverse for the downregulated miRNA, in CCP. Many target genes of upregulated miRNAs in CCP participate in osteogenic differentiation, apoptosis, inflammation, cholesterol metabolism, and extracellular matrix organization.

CONCLUSIONS

These findings characterize miRNAs and their signature in the regulatory network of carotid plaque phenotype in T1D, providing new insights into plaque pathophysiology and possibly novel biomarkers of plaque composition.

Glucose-lowering drugs with cardiovascular benefits as modifiers of critical elements of the human life history

The life history theory assumes that all organisms are under selective pressure to harvest external resources and allocate them to maximise fitness: only organisms making the best use of energy obtain the greatest fitness benefits. The trade-off of energy spans four functions: maintenance, growth, reproduction, and defence against pathogens. The innovative antihyperglycaemic agents glucagon-like peptide 1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors decrease bodyweight and have the potential to counter low-grade inflammation. These key activities could rewire two components of the life history theory operative in adulthood-ie, maintenance and defence. In this Personal View, we postulate that the benefits of these medications on the cardiovascular system, beyond their glucose-lowering effects, could be mediated by the reduction of the maintenance cost driven by obesity and efforts spent on blunting low-grade inflammation.

A miR-125/Sirtuin-7 pathway drives the pro-calcific potential of myeloid cells in diabetic vascular disease

AIMS/HYPOTHESIS

Ectopic calcification is a typical feature of diabetic vascular disease and resembles an accelerated ageing phenotype. We previously found an excess of myeloid calcifying cells in diabetic individuals. We herein examined molecular and cellular pathways linking atherosclerotic calcification with calcification by myeloid cells in the diabetic milieu.

METHODS

We first examined the associations among coronary calcification, myeloid calcifying cell levels and mononuclear cell gene expression in a cross-sectional study of 87 participants with type 2 diabetes undergoing elective coronary angiography. Then, we undertook in vitro studies on mesenchymal stem cells and the THP-1 myeloid cell line to verify the causal relationships of the observed associations.

RESULTS

Coronary calcification was associated with 2.8-times-higher myeloid calcifying cell levels (p=0.037) and 50% elevated expression of the osteogenic gene RUNX2 in mononuclear cells, whereas expression of Sirtuin-7 (SIRT7) was inversely correlated with calcification. In standard differentiation assays of mesenchymal stem cells, SIRT7 knockdown activated the osteogenic program and worsened calcification, especially in the presence of high (20 mmol/l) glucose. In the myeloid cell line THP-1, SIRT7 downregulation drove a pro-calcific phenotype, whereas SIRT7 overexpression prevented high-glucose-induced calcification. Through the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, high glucose induced miR-125b-5p, which in turn targeted SIRT7 in myeloid cells and was directly associated with coronary calcification.

CONCLUSIONS/INTERPRETATION

We describe a new pathway elicited by high glucose through the JAK/STAT cascade, involving regulation of SIRT7 by miR-125b-5p and driving calcification by myeloid cells. This pathway is associated with coronary calcification in diabetic individuals and may be a target against diabetic vascular disease.

DATA AVAILABILITY

RNA sequencing data are deposited in GEO (accession number GSE193510; https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE193510 ).

Telemedicine for the Clinical Management of Diabetes; Implications and Considerations After COVID-19 Experience

Telemedicine is a clinical approach that was seldom used in the day-to-day practice, if not only in certain settings, before the COVID-19 pandemic. As stated by the WHO, telemedicine is: the delivery of health care services, where distance is a critical factor, by all health care professionals using information and communication technologies (ICT) for the exchange of valid information for diagnosis, treatment and prevention of disease and injuries, …. Telemedicine has actually represented the most useful and employed tool to maintain contacts between patients and physicians during the period of physical distance imposed by the pandemic, especially during the lockdown. Diabetes in particular, a chronic disease that often needs frequent confronting between patient and health professionals has taken advantage of the telehealth approach. Nowadays, technological tools are more and more widely used for the management of diabetes. In this review results obtained by telemendicine application in type 1 and type 2 diabetic individuals during COVID-19 are revised, and future perspectives for telemedicine use to manage diabetes are discussed.

Improving statin treatment strategies to reduce LDL-cholesterol: factors associated with targets' attainment in subjects with and without type 2 diabetes

BACKGROUND

This cross-sectional study aimed to identify actionable factors to improve LDL-cholesterol target achievement and overcome underuse of lipid-lowering treatments in high- or very-high-cardiovascular risk patients.

METHODS

We evaluated healthcare records of 934,332 subjects from North-Italy, including subjects with available lipid profile and being on statin treatments up to December 2018. A 6-month-period defined adherence with proportion-of-days-covered ≥ 80%. Treatment was classified as high-intensity-statin (HIS) + ezetimibe, HIS-alone, non-HIS (NHIS) + ezetimibe or NHIS alone.

RESULTS

We included 27,374 subjects without and 10,459 with diabetes. Among these, 30% and 36% were on secondary prevention, respectively. Adherence was high (78-100%) and increased with treatment intensity and in secondary prevention. Treatment intensity increased in secondary prevention, but only 42% were on HIS. 2019-guidelines LDL-cholesterol targets were achieved in few patients and more often among those with diabetes (7.4% vs. 10.7%, p < 0.001). Patients in secondary prevention had mean LDL-cholesterol levels aligned slightly above 70 mg/dl (range between 68 and 73 mg/dl and between 73 and 85 mg/dl in patients with and without diabetes, respectively). Moreover, the differences in mean LDL-cholesterol levels observed across patients using treatments with well-stablished different LDL-lowering effect were null or much smaller than expected (HIS vs. NHIS from - 3 to - 11%, p < 0.001, HIS + ezetimibe vs. HIS-from - 4 to + 5% n.s.). These findings, given the observational design of the study, might suggest that a "treat to absolute LDL-cholesterol levels" approach (e.g., targeting LDLc of 70 mg/dl) was mainly used by physicians rather than an approach to also achieve the recommended 50% reduction in LDL-cholesterol levels. Our analyses suggested that female sex, younger age, higher HDL-c, and elevated triglycerides are those factors delaying prescription of statin treatments, both in patients with and without diabetes and in those on secondary prevention.

CONCLUSIONS

Among patients on statin treatment and high adherence, only a small proportion of patients achieved LDL-cholesterol targets. Late initiation of high-intensity treatments, particularly among those with misperceived low-risk (e.g., female subjects or those with high HDL-cholesterol), appears as pivotal factors needing to be modified to improve CVD prevention.

PAR-4/Ca2+-calpain pathway activation stimulates platelet-derived microparticles in hyperglycemic type 2 diabetes

Background

Patients with type 2 diabetes (T2DM) have a prothrombotic state that needs to be fully clarified; microparticles (MPs) have emerged as mediators and markers of this condition. Thus, we investigate, in vivo, in T2DM either with good (HbA1c ≤ 7.0%; GGC) or poor (HbA1c > 7.0%; PGC) glycemic control, the circulating levels of MPs, and in vitro, the molecular pathways involved in the release of MPs from platelets (PMP) and tested their pro-inflammatory effects on THP-1 transformed macrophages.

Methods

In 59 T2DM, and 23 control subjects with normal glucose tolerance (NGT), circulating levels of CD62E+, CD62P+, CD142+, CD45+ MPs were determined by flow cytometry, while plasma levels of ICAM-1, VCAM-1, IL-6 by ELISA. In vitro, PMP release and activation of isolated platelets from GGC and PGC were investigated, along with their effect on IL-6 secretion in THP-1 transformed macrophages.

Results

We found that MPs CD62P⁺ (PMP) and CD142⁺ (tissue factor-bearing MP) were significantly higher in PGC T2DM than GGC T2DM and NGT. Among MPs, PMP were also correlated with HbA1c and IL-6. In vitro, we showed that acute thrombin exposure stimulated a significantly higher PMP release in PGC T2DM than GGC T2DM through a more robust activation of PAR-4 receptor than PAR-1 receptor. Treatment with PAR-4 agonist induced an increased release of PMP in PGC with a Ca²⁺-calpain dependent mechanism since this effect was blunted by calpain inhibitor. Finally, the uptake of PMP derived from PAR-4 treated PGC platelets into THP-1 transformed macrophages promoted a marked increase of IL-6 release compared to PMP derived from GGC through the activation of the NF-kB pathway.

Conclusions

These results identify PAR-4 as a mediator of platelet activation, microparticle release, and inflammation, in poorly controlled T2DM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01267-w.

Silent coronary artery disease in type 2 diabetes: a narrative review on epidemiology, risk factors, and clinical studies

Silent coronary artery disease (CAD) is one of the manifestations of heart disease that particularly affects subjects with type 2 diabetes mellitus (T2DM). From a clinical point of view, silent CAD represents a constant challenge for the diabetologist, who has to decide whether a patient could or could not be screened for this disease. In the present narrative review, several aspects of silent CAD are considered: the epidemiology of the disease, the associated risk factors, and main studies conducted, in the last 20 years, especially aimed to demonstrate the usefulness of the screening of silent CAD, to improve cardiovascular outcomes in type 2 diabetes.

Recommendations for Cardiovascular Prevention During the Sars-Cov-2 Pandemic: An Executive Document by the Board of the Italian Society of Cardiovascular Prevention

In 2020, the Sars-Cov-2 pandemic is causing a huge and dramatic impact on healthcare systems worldwide. During this emergency, fragile patients suffering from other comorbidities, especially patients susceptible to or affected by cardiovascular disease, are the ones most exposed to the poorer outcomes. Therefore, it is still mandatory to continue to strictly adhere to the rules of cardiovascular prevention. This document aims to provide all doctors with simple and clear recommendations in order to spread useful messages to the widest number of subjects in order to continue the battle against cardiovascular diseases even in times of pandemic.

Effects of Basal Insulin on Lipid Profile Compared to Other Classes of Antihyperglycemic Agents in Type 2 Diabetic Patients

OBJECTIVE

The lipid profile represents a driver of cardiovascular risk in type 2 diabetes. The effect of chronic insulin therapy on cholesterol levels is unclear. We aim to evaluate the effect of basal insulin on lipid profile compared to other classes of antihyperglycemic agents in type 2 diabetic patients.

DESIGN

We performed a meta-analysis of randomized controlled trials reporting changes of lipid parameters in type 2 diabetic patients randomly assigned to basal insulin or other classes of anti-hyperglycemic agents.

RESULTS

The levels of total (TC) and low-density lipoprotein cholesterol (LDL-C) appeared to be significantly reduced by therapies with glucagon-like peptide-1 receptor agonists (GLP-1RA) in comparison to basal insulin (mean difference [MD] -3.80; 95% CI [-6.30 to -1.30] mg/dL, P < .001 and -4.17; 95% CI [-6.04 to -2.30] mg/dL, P < .0001), whereas no difference was detected between basal insulin and dipeptidyl peptidase-4 inhibitors (DPP4-I) or standard therapy (sulfonylurea ± metformin). Thiazolidinediones (TZD) produced a significant improvement in high-density lipoprotein cholesterol (HDL-C) (MD 3.55; 95% CI: 0.55 to 6.56 mg/dL, P = .02) but were associated with an increase in TC and LDL-C (MD 16.20; 95% CI: 9.09 to 23.31 mg/dL, P < .001 and 5.19: 95% CI: -3.00 to 13.39 mg/dL, P = .21). Basal insulin was superior to standard therapy in triglyceride reduction (MD 3.8; 95% CI: 0.99 to 6.63 mg/dL, P = .008).

CONCLUSIONS

GLP-1RA were superior to basal insulin in the control of TC and LDL-C. Basal insulin effectively reduced serum triglycerides. TZD led to improvement in HDL-C. DPP4-I and standard therapy did not have any significant effect on lipid levels.

[Consensus document and recommendations for the prevention of cardiovascular disease in Italy - 2018]

Cardiovascular prevention represents a cornerstone of modern strategies to reduce the burden of cardiovascular disease. It is of key importance to prevent cardiovascular diseases and associated events, not only to reduce morbidity and mortality, but also to increase the years of wellness in the aging population and to make the growing socio-economic burden imposed by cardiovascular events more sustainable.The current approach to prevention is based on an integrated use of effective lifestyle measures and, whenever appropriate, of antihypertensive and antidiabetic drugs, lipid-lowering agents and antiplatelet drugs.Given that population characteristics, in terms of ethnicity, demography and lifestyle habits, and healthcare system organizations differ among countries, international guidelines are not always applicable to specific countries and, often, are difficult to translate into daily clinical practice.In order to afford the specific features of Italy, 10 Scientific Societies and Research Institutions, mostly involved in preventive strategies, contributed to the present Italian consensus document, which includes brief, practical recommendations to support the preventive actions within the physician community and the general practice setting.

Improved long-term cardiovascular outcomes after intensive versus standard screening of diabetic complications: an observational study

Background

Complication screening is recommended for patients with type 2 diabetes (T2D), but the optimal screening intensity and schedules are unknown. In this study, we evaluated whether intensive versus standard complication screening affects long-term cardiovascular outcomes.

Methods

In this observational study, we included 368 T2D patients referred for intensive screening provided as a 1-day session of clinical–instrumental evaluation of diabetic complications, followed by dedicated counseling. From a total of 4906 patients, we selected control T2D patients who underwent standard complication screening at different visits, by 2:1 propensity score matching. The primary endpoint was the 4p-MACE, defined as cardiovascular mortality, or non-fatal myocardial infarction, stroke, or heart failure. The Cox proportional regression analyses was used to compare outcome occurrence in the two groups, adjusted for residual confounders.

Results

357 patients from the intensive screening group (out of 368) were matched with 683 patients in the standard screening group. Clinical characteristics were well balanced between the two groups, except for a slightly higher prevalence of microangiopathy in the intensive group (56% vs 50%; standardized mean difference 0.11, p = 0.1). Median follow-up was 5.6 years. The adjusted incidence of 4p-MACE was significantly lower in the intensive versus standard screening group (HR 0.70; 95% CI 0.52–0.95; p = 0.02). All components of the primary endpoint had nominally lower rates in the intensive versus standard screening group, which was particularly significant for heart failure (HR 0.43; 95% CI 0.22–0.83; p = 0.01).

Conclusion

Among T2D patients attending a specialist outpatient clinic, intensive complication screening is followed by better long-term cardiovascular outcomes. No significant effect was noted for cardiovascular and all-cause mortality and the benefit was mainly driven by a reduced rate of hospitalization for heart failure.

Dysfunctional eating in type 2 diabetes mellitus: A multicenter Italian study of socio-demographic and clinical associations

BACKGROUND AND AIMS

Dysfunctional eating might impact on the management and metabolic control of type 2 diabetes (T2DM), modifying adherence to healthy diet and food choices.

METHODS AND RESULTS

In a multicenter study, we assessed the prevalence of dysfunctional eating in 895 adult outpatients with T2DM (51% males, median age 67, median BMI 30.3 kg/m²). Socio-demographic and clinical characteristics were recorded; dysfunctional eating was tested by validated questionnaires (Eating Attitude Test-EAT-26, Binge Eating Scale-BES; Night Eating Questionnaire-NEQ); food intake and adherence to Mediterranean diet were also measured (in-house developed questionnaire and Mediterranean Diet Score-MDS). Obesity was present in 52% of cases (10% obesity class III), with higher rates in women; 22% had HbA1c ≥ 8%. The EAT-26 was positive in 19.6% of women vs. 10.2% of men; BES scores outside the normal range were recorded in 9.4% of women and 4.4% of men, with 3.0% and 1.5% suggestive of binge eating disorder, respectively. Night eating (NEQ) was only present in 3.2% of women and 0.4% of men. Critical EAT and BES values were associated with higher BMI, and all NEQ + ve cases, but one, were clustered among BES + ve individuals. Calorie intake increased with BES, NEQ, and BMI, and decreased with age and with higher adherence to Mediterranean diet. In multivariable logistic regression analysis, female sex, and younger age were associated with increase risk of dysfunctional eating.

CONCLUSION

Dysfunctional eating is present across the whole spectrum of T2DM and significantly impacts on adherence to dietary restriction and food choices.

Effects of the SGLT2 inhibitor dapagliflozin on cardiac function evaluated by impedance cardiography in patients with type 2 diabetes. Secondary analysis of a randomized placebo-controlled trial

BACKGROUND AND AIMS

Cardiovascular outcome trials have documented a strong benefit of sodium glucose cotransporter-2 inhibitors (SGLT2i) on the risk of hospitalization for heart failure (HF) in patients with type 2 diabetes (T2D) with or without established cardiovascular disease or prior history of HF. The mechanisms, however, are not entirely clear. We aimed to evaluate whether treatment with SGLT2i affected cardiac function using impedance cardiography (ICG) in a randomized placebo-controlled trial.

MATERIALS AND METHODS

Thirty-three patients with T2D were randomized to receive blind dapagliflozin 10 mg or matching placebo for 12-week on top of their ongoing glucose lowering medication regimen. Cardiac function was evaluated by resting ICG at baseline and at the end of the 12-week treatment period. ICG is a non-invasive technology based on the continuous measurement of thoracic electrical conductivity to process a cardiodynamic parameters related to fluid content, blood flow, cardiac function, and circulatory function. We also evaluated changes in glycaemic control, blood pressure, and body weight.

RESULTS

Thirty-one patients completed the study, 1 was excluded because ICG data was missing. Patients included in the final analysis were on average 63.4-year-old, with a known diabetes duration of 14.1 years and a baseline HbA1c of 8.2% (66 mmol/mol). 63.3% of patients had established cardiovascular disease (symptomatic or asymptomatic) and 36.7% had microangiopathy, but none had a prior history of HF. After 12 weeks, patients randomized to dapagliflozin, as compared to those randomized to placebo, showed improvements in HbA1c (- 1.2%; 13 mmol/mol), systolic blood pressure (- 3.7 mmHg), and body weight (- 3.3 kg). Based on ICG, in both groups, we detected no significant change in parameters of blood flow (stroke volume, cardiac output, cardiac index), systolic function (ejection fraction, acceleration and velocity indexes, systolic time ratio), circulatory function (systemic vascular resistance index), and fluid status (thoracic fluid content) after treatment.

CONCLUSION

This is the first study exploring cardiac effects of SGLT2i using ICG in T2D. We observed no change in cardiac function parameters estimated by ICG in T2D patients who received dapagliflozin versus placebo for 12 weeks. Trial registration ClinicalTrial.gov NCT02327039. Registered 30 December 2014.

miR-30c-5p regulates macrophage-mediated inflammation and pro-atherosclerosis pathways

Aims

Atherosclerosis is an inflammatory disease wherein cholesterol-loaded macrophages play a major role. MicroRNAs and microparticles propagate inflammatory pathways and are involved in cardiovascular disease. We aimed to screen and validate circulating microRNAs correlated with atherosclerosis development in humans, and to dissect the molecular mechanisms associated with atherogenesis using in vitro and in vivo approaches.

Methods and results

A panel of 179 secreted microRNAs was screened in plasma samples of patients with and without atherosclerosis, and validated cross-sectionally and prospectively in patients followed for up to 11 years. miR-30c-5p was inversely correlated with total and LDL cholesterol, carotid intimal media thickness (CIMT), presence and future development of plaques. Using a human macrophage line and in vitro gene silencing strategies, we found that miR-30c-5p was downregulated by oxidized LDL (oxLDL) via the scavenger receptor CD36 and inhibition miR processing by Dicer. In turn, miR-30c-5p downregulation was responsible for the effects of oxLDL on macrophage IL-1β release, caspase-3 expression, and apoptosis. miR-30c-5p loaded into microparticles was uptaken by macrophages and regulated target genes, like caspase-3, at transcriptional level. To establish the relevance of this pathway on endothelial damage as the earliest step of atherogenesis, we show that systemic miR-30c-5p knockdown induced caspase-3 and impaired endothelial healing after carotid injury in C57Bl/6 J mice.

Conclusions

With an unbiased screening of secreted microRNAs, we identify reduction of miR-30c-5p in microparticles as a promoter of early atherosclerosis, by conveying pro-inflammatory pro-apoptotic signals and impairing endothelial healing. Therefore, stimulation of miR-30c-5p is a candidate direct anti-atherosclerotic therapy.

p66Shc gene expression in peripheral blood mononuclear cells and progression of diabetic complications

Background

The risk of diabetic complications is modified by genetic and epigenetic factors. p66Shc drives the hyperglycaemic cell damage and its deletion prevents experimental diabetic complications. We herein tested whether p66Shc expression in peripheral blood mononuclear cells (PBMCs) predicts adverse outcomes in people with diabetes.

Methods

In a cohort of 100 patients with diabetes (16 type 1 and 84 type 2), we quantified baseline p66Shc expression in PBMCs by quantitative PCR. Patients were extensively characterized for demographics, anthropometrics, biochemical data, prevalence of complications, and medications. With a pseudo-prospective design, we retrieved cardiovascular death, major adverse cardiovascular events (MACE), and new occurrence of micro- or macroangiopathy during follow-up.

Results

At baseline, patients were on average 60 year old, with 10-year diabetes duration, and overall poor glycaemic control (HbA1c 7.8%). Patients with high versus low p66Shc expression (based on median value) had very similar baseline characteristics. Average p66Shc expression did not differ by presence/absence of complications. During a median 5.6-year follow-up, the primary endpoint of cardiovascular death or MACE occurred in 22 patients, but no relation was detected between cardiovascular outcomes and p66Shc expression. In patients who developed new complications at follow-up, baseline p66Shc was significantly higher, especially for macroangiopathy. The incidence of new macroangiopathy was > 3-times higher in patients with high versus those with low baseline p66Shc expression.

Conclusions

p66Shc expression in PBMCs was not associated with prevalent diabetic complications but predicted new onset of complications, especially macroangiopathy, although no relation with hard cardiovascular endpoints was detected.

Intraclass differences in the risk of hospitalization for heart failure among patients with type 2 diabetes initiating a dipeptidyl peptidase-4 inhibitor or a sulphonylurea: Results from the OsMed Health-DB registry

AIMS

To re-analyse data from a previous retrospective study on 127 555 patients, in which we showed that dipeptidyl peptidase-4 (DPP-4) inhibitor therapy was associated with a lower risk of hospitalization for HF (HHF) than sulphonylurea (SU) therapy, in order to evaluate intraclass differences among DPP-4 inhibitors and SUs.

METHODS

We included patients with type 2 diabetes (T2D) initiating DPP-4 inhibitor or SU therapy, alone or in combination with metformin. Patients undergoing intraclass switch, those with a previous HHF, those receiving insulin treatment, and those with <6 months observation were excluded. We calculated the incidence of first and total HHF events/1000 person-years. Cox proportional hazard and Poisson multiple regression models, as well as propensity-score matching, were used to account for baseline confounders.

RESULTS

The analysis included 17 615 DPP-4 inhibitor users (60.1% sitagliptin; 27.0% vildagliptin; 12.9% saxagliptin) and 86 734 SU users (37.5% glibenclamide; 34.6% glimepiride; 27.9% gliclazide). No intraclass difference in the incidence rate of first and total HHF events was noted among the 3 DPP-4 inhibitors or among the 3 SUs. Multivariable adjustments for baseline confounders or propensity-score matching did not change the results. In addition, no intraclass difference in HHF risk was observed in patients at high compared with low cardiovascular risk.

CONCLUSIONS

In a cohort of patients with T2D taken from approximately one-third of the Italian population, no intraclass difference was noted for DPP-4 inhibitor and SU therapy with regard to HHF risk.

Circulating levels and characterization of microparticles in patients with different degrees of glucose tolerance

Background

Microparticles (MPs) are vesicular structures shed from endothelial or circulating blood cells, after activation or apoptosis, and can be considered markers of vascular damage. We aimed to determine the levels of circulating MPs, their content of miRNA-126-3p and 5p, and their relationship with early endothelial activation/damage, in patients with different degree of glucose tolerance.

Methods

CD62E⁺, CD62P⁺, CD142⁺, CD45⁺ circulating MPs, their apoptotic (AnnexinV⁺) fractions, and miRNA-126 expression were determined in 39 prediabetic (PreDM), 68 type 2 diabetic (T2DM), and 53 control (NGT) subjects, along with main anthropometric and biochemical measurements. MPs were analysed by flow cytometry. miRNA-126 was measured by quantitative real-time PCR. Plasma antioxidant capacity was determined by electronic spin resonance; ICAM-1, and VCAM-1 by ELISA.

Results

Activated endothelial cell-derived MPs (CD62E⁺) were significantly increased in PreDM and T2DM in comparison to NGT (p < 0.0001). AnnexinV⁺/CD62E⁺ MPs and Annexin V⁺ MPs were significantly increased in T2DM compared to PreDM and NGT (p < 0.001); other MPs were not significantly different among groups. Plasma antioxidant capacity was significantly decreased in PreDM and T2DM compared to NGT (p = 0.001); VCAM-1 significantly increased in PreDM and T2DM in comparison to NGT (p = 0.001). miR-126-3p expression, but not miR-126-5p, in MPs, decreased significantly and progressively from NGT, to PreDM, and T2DM (p < 0.001). In PreDM and T2DM, CD62E⁺ MPs level was significantly and negatively associated with plasma glucose (p = 0.004).

Conclusion

We show for the first time that circulating CD62E⁺ MPs level and miR-126-3p content in MPs are abnormal in subjects with pre-diabetes; the content of miR-126-3p correlates with markers of endothelial inflammation, such as VCAM-1, plasma antioxidant capacity, and microparticles, well-accepted markers of endothelial dysfunction.

Persistent Reduction of Circulating Myeloid Calcifying Cells in Acromegaly: Relevance to the Bone-Vascular Axis

CONTEXT

Acromegaly is a systemic disease characterized by persistent bone pathology and excess cardiovascular mortality. Despite multiple concomitant risk factors, atherosclerosis does not seem to be accelerated in acromegaly.

OBJECTIVE

To compare the levels of circulating myeloid calcifying cells (MCCs), which promote ectopic calcification and inhibit angiogenesis, in individuals with and without acromegaly.

DESIGN

Cross-sectional case-control study.

SETTING

Tertiary ambulatory referral endocrinology center.

PATIENTS

44 acromegalic patients (25 active; 19 inactive), 44 control subjects matched by age, sex, risk factors, and medications, and 8 patients cured of acromegaly.

INTERVENTION

MCCs were measured using flow cytometry based on the expression of osteocalcin (OC) and bone alkaline phosphatase (BAP) on monocytes and circulating CD34+ stem cells.

MAIN OUTCOME MEASURE

Differences in MCCs between patients and controls.

RESULTS

OC+BAP+ MCCs were severely reduced in acromegalic compared with control patients (0.17% ± 0.02% vs 1.00% ± 0.24%; P < 0.001), as were the total OC+ and BAP+ monocytic cells. Patients with inactive acromegaly and those cured of acromegaly displayed persistently reduced levels of MCCs. In the controls, but not acromegalic patients, MCCs were increased in the presence of diabetes or cardiovascular disease. A direct correlation was noted between MCCs and parathyroid hormone (r = 0.61; P < 0.0001), supporting a link between bone biology and MCCs.

CONCLUSIONS

In patients with acromegaly, the levels of MCCs are reduced and remain low, even years after a complete cure. This finding might be related to low atherosclerotic calcification and the persistence of bone pathology after acromegaly remission or cure.

Silent coronary heart disease in patients with type 2 diabetes: application of a screening approach in a follow-up study

AIMS

The cost-effectiveness of screening for silent coronary heart disease (CHD) in type 2 diabetes (DM2) is still debated.

METHODS

We applied a diagnostic algorithm for silent CHD detection, in a cohort of 102 asymptomatic DM2 subjects (57±7years), attending 5 Italian outpatient clinics, to verify its predictive value. The risk of silent CHD was calculated considering classical risk factors, and presence of microangiopathy/macroangiopathy. Patients were divided in 3 groups, i.e. group 1: normal ECG and low silent CHD risk; group 2: abnormal ECG, irrespective of silent CHD risk; group 3: high silent CHD risk, irrespective of ECG. To group 2 and 3, a functional test was recommended and performed in 78% of patients.

RESULTS

Silent CHD prevalence was similar in group 2 and 3 (25 vs. 17% respectively; p=0.495). However, evaluating the entire cohort, a significant higher prevalence of silent CHD was observed in subjects with abnormal vs. normal ECG (23 vs. 4%; P=0.004), but not in subjects with high vs. low pre-test silent CHD risk (14 vs. 9%; p=0.472).

CONCLUSIONS

An abnormal ECG was a strong, independent predictor of silent CHD (OR 8.9; CI 1.27-62.5; p=0.028) in DM2. Therefore, a functional stress testing should be considered in DM2 patients with ECG abnormalities.

Hypovitaminosis D is associated with erectile dysfunction in type 2 diabetes

Diabetes is an established risk factor for erectile dysfunction (ED). The pathophysiology of ED in diabetic men is multifactorial, but it mainly involves a vascular disorder related to a reduction of endothelial function. Recently, several studies have correlated ED risk factors with vitamin D deficiency. In this study, we evaluate the relationship between 25-hydroxyvitamin D [25(OH)D] levels, erectile dysfunction, and vascular disease, in type 2 diabetes mellitus men (T2DM). In this observational study, 92 T2DM males (58.83 ± 9.73 years) underwent medical history collection, International Index of Erectile Function (IIEF-5) questionnaire, that allows the identification and grading of DE, physical examination, biochemical/hormonal blood tests, and penile echo-color Doppler ultrasonography. T2DM patients with lower 25(OH)D levels (<25 nmol/l) showed higher penile IMT (p < 0.05), waist circonference (p < 0.05), glucose concentrations (p < 0.05), and lower IIEF-5 score (p < 0.005), testosterone concentrations (p < 0.05), and cavernous peak systolic velocity (PSV) (p < 0.05), compared to patients with 25(OH)D >50 nmol/l. 25(OH)D levels were directly correlated with IIEF-5 (R = 0.39; p = 0.0001), testosterone (R = 0.24; p = 0.02), and PSV (R = 0.24; p = 0.04) and inversely with waist (R = -0.33; p = 0.002), HbA1c (R = -0.22; p = 0.03), triglyceride (R = -0.21; p = 0.06), and penile IMT (R = -0.30; p = 0.009). At multivariate analysis, 25(OH)D deficiency remained an independent predictor of DE. We demonstrate a significant association between 25(OH)D deficiency and erectile dysfunction in T2DM men. This association may be due to the influence of 25(OH)D deficiency on cardiovascular risk factor (glycaemia, HDL cholesterol, and triglycerides), testosterone plasma levels and endothelial dysfunction.

NETosis Delays Diabetic Wound Healing in Mice and Humans

Upon activation, neutrophils undergo histone citrullination by protein arginine deiminase (PAD)4, exocytosis of chromatin and enzymes as neutrophil extracellular traps (NETs), and death. In diabetes, neutrophils are primed to release NETs and die by NETosis. Although this process is a defense against infection, NETosis can damage tissue. Therefore, we examined the effect of NETosis on the healing of diabetic foot ulcers (DFUs). Using proteomics, we found that NET components were enriched in nonhealing human DFUs. In an independent validation cohort, a high concentration of neutrophil elastase in the wound was associated with infection and a subsequent worsening of the ulcer. NET components (elastase, histones, neutrophil gelatinase-associated lipocalin, and proteinase-3) were elevated in the blood of patients with DFUs. Circulating elastase and proteinase-3 were associated with infection, and serum elastase predicted delayed healing. Neutrophils isolated from the blood of DFU patients showed an increased spontaneous NETosis but an impaired inducible NETosis. In mice, skin PAD4 activity was increased by diabetes, and FACS detection of histone citrullination, together with intravital microscopy, showed that NETosis occurred in the bed of excisional wounds. PAD4 inhibition by Cl-amidine reduced NETting neutrophils and rescued wound healing in diabetic mice. Cumulatively, these data suggest that NETosis delays DFU healing.

Carotid plaque calcification predicts future cardiovascular events in type 2 diabetes

OBJECTIVE

The presence of carotid plaques is associated with future cardiovascular events, with local plaque composition being an independent outcome predictor. We examined the association between ultrasonographically determined carotid plaque calcification and incident major adverse cardiovascular events (MACE) and death in type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

We enrolled 581 patients with T2D who underwent routine carotid ultrasonography. Plaques were classified as echolucent (lipid rich), heterogenous, and echogenic (calcific). We collected demographic, anthropometric, and clinical data at baseline and followed the patients for up to 9 years.

RESULTS

Plaques were detected in 81.8% of the patients (echolucent in 16.4%, heterogenous in 43.2%, and echogenic in 22.2%). During follow-up (4.3 ± 0.1 years), 58 deaths (27 cardiovascular) and 236 fatal and nonfatal MACE occurred. In univariate analyses, presence versus absence of any carotid plaque was associated with incident MACE, and the hazard ratio (95% CI) progressively increased from echolucent (1.97 [0.93-3.44]), to heterogeneous (3.10 [2.09-4.23]), to echogenic (3.71 [2.09-5.59]) plaques. Compared with echolucent plaques, echogenic plaques were associated with incident MACE independently from confounders. This association was attenuated after adjusting for the degree of stenosis, but in patients with stenosis ≤30%, echogenic plaque type still predicted total and atherosclerotic MACE, even after further adjusting for mean intima-media thickness.

CONCLUSIONS

In T2D, carotid plaque calcification predicts MACE, especially in patients with a low degree of stenosis. The biology of atherosclerotic calcification in diabetes needs to be further elucidated to understand the basis of this association.

NETosis is induced by high glucose and associated with type 2 diabetes

AIMS

The role of neutrophils in diabetes and its complications is unclear. Upon challenge with microbes and inflammatory triggers, neutrophils release enzymes and nuclear material, forming neutrophils extracellular traps (NETs) and thereby dying by NETosis. We herein tested NET formation and NETosis products in high glucose and in the setting of type 2 diabetes (T2D).

METHODS

NETosis was assessed in vitro in cells exposed to 0, 5, 25 mM glucose and 25 mM mannitol, DMSO and PMA using immunofluorescence staining for elastase, DNA and chromatin. Single-cell morphometric analysis was used to detect enter of elastase in the nucleus and extrusion of nuclear material. Release of NETs was quantified by staining with Hoechst 33342. In 38 T2D and 38 age- and sex-matched non-diabetic individuals, we determined plasma elastase, mono- and oligonucleosomes and double-strand (ds) DNA, as circulating NETosis products.

RESULTS

NETosis was accurately reproduced in vitro: high (25 mM) glucose increased NETosis rate and release of NETs compared with 5 mM glucose and 25 mM mannitol. T2D patients showed increased plasma elastase, mono- and oligonucleosomes and dsDNA compared with non-diabetic control individuals. A positive correlation was found between HbA1c and mono- and oligonucleosomes, whereas dsDNA was correlated with the presence of nephropathy and cardiovascular disease. Serum IL-6 concentrations were higher in T2D compared with CTRL and correlated with serum dsDNA levels.

CONCLUSIONS

High glucose and hyperglycemia increase release of NETs and circulating markers of NETosis, respectively. This finding provides a link among neutrophils, inflammation and tissue damage in diabetes.

NAD(+)-dependent SIRT1 deactivation has a key role on ischemia-reperfusion-induced apoptosis

Ischemia-reperfusion (IR) leads to severe organ injury and dysfunction. Sirtuins (SIRTs) are a family of histone deacetylases (HDACs) that require nicotinamide adenine dinucleotide (NAD(+)) for the deacetylation reaction. SIRTs play a major role in counteracting cellular stress and apoptosis. This study aimed to investigate the mechanisms of heart protection against apoptosis by SIRTs and the molecular pathways involved in SIRTs regulation and function in a rat model of IR injury. Hearts of male Wistar-Kyoto rats were subjected to 30-min ischemia followed by reperfusion up to 6h. IR increased cardiomyocyte apoptosis; the cleavage of caspase 3, induced a transient upregulation of SIRT1 and downregulation of SIRT6 expression, but decreased SIRT1 activity and reduced NAD(+) content. IR also increased forkhead box protein O1 (FoxO1) expression and FoxO1 binding to SIRT1 promoter region. Resveratrol restored SIRT1 activity and NAD(+) level by an AMPK-dependent mechanism, reduced cardiomyocyte apoptosis, and attenuated caspase 3 cleavage via heat shock factor-1 deacetylation and heat shock protein (HSP) expression upregulation. Our data show new potential molecular mechanisms of up and downstream regulation of SIRT1 in IR. The interplay among FoxO1, SIRT1, NAD(+), AMPK, HSP, and SIRT6 depicts a complex molecular network that protects the heart from apoptosis during IR and may be susceptible to therapeutic interventions.

Endothelial progenitor cells are reduced in acromegalic patients and can be restored by treatment with somatostatin analogs

CONTEXT

Acromegaly increases cardiovascular risk, possibly due to the high prevalence of classical risk factors. However, in vitro studies show a protective role of GH/IGF-1 on the endothelium.

OBJECTIVE

The objective of the study was to investigate circulating endothelial progenitor cells (EPCs), a marker of vascular regeneration, in acromegalic patients and how they are affected by acromegaly treatment.

DESIGN

This was a cross-sectional case-control and observational study.

SETTING

The study was conducted at a tertiary ambulatory referral endocrinology center.

PATIENTS

Forty-three acromegalic patients (26 active; 17 inactive) and 43 control subjects matched by age, gender, and degree of glucose tolerance participated in the study.

INTERVENTION

Circulating EPCs were quantified by flow cytometry based on the expression of CD34, CD133, and kinase insert domain-containing receptor (KDR). Nine patients with active acromegaly were reevaluated after 24 weeks of treatment with somatostatin analogs (SSAs).

MAIN OUTCOME MEASURE

Differences in EPC levels between patients and controls were measured.

RESULTS

Acromegalic patients showed a significant reduction of the total CD34(+)KDR(+) EPC population compared with controls, which was more evident in patients without diabetes or hypertension. More definite CD34(+)CD133(+)KDR(+) EPCs were reduced in patients with active compared with those with inactive acromegaly and compared with controls. The number of CD34(+)CD133(+)KDR(+) EPCs correlated with IGF-1 levels (r = -0.45; P < .001), fasting plasma glucose (r = -0.40; P = .004), and the homeostasis model assessment index of insulin resistance (r = -0.32; P = .026). CD34(+)CD133(+)KDR(+) EPCs increased 2-fold after SSA treatment.

CONCLUSIONS

Acromegalic patients have a reduced endothelial regenerative capacity, possibly due to activation of the GH/IGF-1, rather than concomitant risk factors. Treatment with SSAs can restore immature EPCs to normal levels.

Pro-inflammatory monocyte-macrophage polarization imbalance in human hypercholesterolemia and atherosclerosis

Monocyte-macrophages (MoMas) play a major role in atherosclerosis. In mice, hypercholesterolemia increases pro-inflammatory monocytes that promote plaque growth, but whether this is true also in humans in unknown. We herein analyzed monocyte subsets and MoMa phenotypes in familiar (FH, n = 22) and non-familiar (NFH, n = 20) hypercholesterolemic compared with normocholesterolemic (CTRL, n = 20) patients. We found that FH and NFH had higher circulating pro-inflammatory CD68(+)CCR2(+) M1 MoMas than CTRL, while anti-inflammatory CX3CR1(+)CD163(+)/CD206(+) M2 MoMas were reduced only in NFH. As a result, the M1/M2 polarization balance was increased in FH and, more markedly in NFH. M1 MoMas and the M1/M2 polarization ratio were directly correlated to pre-treatment LDL cholesterol levels and strongly associated with the presence of atherosclerotic plaques. In conclusion, we show for the first time that human hypercholesterolemia is associated with a pro-inflammatory imbalance of circulating monocytic cells, which can predispose to the development of atherosclerosis.

Insulin-induced glucose control improves HDL cholesterol levels but not reverse cholesterol transport in type 2 diabetic patients

Type 2 diabetes (T2D) is characterized by low HDL cholesterol (HDL-C) and HDL dysfunction. We herein tested whether lowering HbA1c affects HDL-C and reverse cholesterol transport (RCT). Forty-two uncontrolled T2D patients initiating basal insulin were included. HbA1c, HDL-C and RCT were assessed at baseline and after 6 months. At baseline, HDL-C and RCT were directly correlated (r = 0.50; p < 0.001). After 6 months of insulin therapy, HbA1c dropped from 8.8 ± 0.16% to 7.1 ± 0.1%, while average HDL-C and RCT did not change. Follow-up HDL-C and RCT were still correlated (r = 0.31; p = 0.033) and ΔHDL-C correlated with ΔRCT (r = 0.32; p = 0.029). ΔHbA1c correlated with ΔHDL-C (r = 0.43, p = 0.001), but not with ΔRCT. In patients with ΔHbA1c above the median value (1.3%), HDL-C (but not RCT) increased significantly. In conclusion, glucose control correlates with increased HDL-C, but not with improved RCT. Thus, persistent HDL dysfunction despite improved HbA1c and HDL-C can contribute to residual cardiovascular risk in T2D.

Diabetes causes bone marrow autonomic neuropathy and impairs stem cell mobilization via dysregulated p66Shc and Sirt1

Diabetes compromises the bone marrow (BM) microenvironment and reduces the number of circulating CD34(+) cells. Diabetic autonomic neuropathy (DAN) may impact the BM, because the sympathetic nervous system is prominently involved in BM stem cell trafficking. We hypothesize that neuropathy of the BM affects stem cell mobilization and vascular recovery after ischemia in patients with diabetes. We report that, in patients, cardiovascular DAN was associated with fewer circulating CD34(+) cells. Experimental diabetes (streptozotocin-induced and ob/ob mice) or chemical sympathectomy in mice resulted in BM autonomic neuropathy, impaired Lin(-)cKit(+)Sca1(+) (LKS) cell and endothelial progenitor cell (EPC; CD34(+)Flk1(+)) mobilization, and vascular recovery after ischemia. DAN increased the expression of the 66-kDa protein from the src homology and collagen homology domain (p66Shc) and reduced the expression of sirtuin 1 (Sirt1) in mice and humans. p66Shc knockout (KO) in diabetic mice prevented DAN in the BM, and rescued defective LKS cell and EPC mobilization. Hematopoietic Sirt1 KO mimicked the diabetic mobilization defect, whereas hematopoietic Sirt1 overexpression in diabetes rescued defective mobilization and vascular repair. Through p66Shc and Sirt1, diabetes and sympathectomy elevated the expression of various adhesion molecules, including CD62L. CD62L KO partially rescued the defective stem/progenitor cell mobilization. In conclusion, autonomic neuropathy in the BM impairs stem cell mobilization in diabetes with dysregulation of the life-span regulators p66Shc and Sirt1.

Cardiovascular actions of GLP-1 and incretin-based pharmacotherapy

Incretin-based therapy became recently available as antihyperglycemic treatment for patients with type 2 diabetes (T2DM). Incretin therapy comprises glucagon-like peptide receptor agonists (GLP-1RA) and dipeptidyl-peptidase 4 inhibitors (DPP4-I): these classes of drugs not only have the ability to reduce blood glucose, but also can exert several cardioprotective effects. They have been shown to positively influence some risk factors for cardiovascular disease (CVD), to improve endothelial function, and to directly affect cardiac function. For these reasons incretins are considered not only antidiabetic drugs, but also cardiovascular effective. The first clinical trials aimed to demonstrate the safety of DPP4 inhibitors have been recently published: their clinical significance will be discussed in light of the prior experimental findings.

Monocyte-macrophage polarization balance in pre-diabetic individuals

Pre-diabetes is characterized by increased cardiovascular risk and chronic inflammation. The activation of monocyte-macrophages plays major roles in vascular biology. Herein, we aimed to analyze monocyte-macrophage polarization status in subjects with IFG and/or IGT compared with normal glucose tolerant (NGT) individuals. We enrolled 87 middle-aged individuals with low prevalence of cardiovascular disease. Based on OGTT, they were divided into 49 NGT and 38 pre-diabetic (IFG and/or IGT). Using flow cytometry analysis of peripheral blood cells, we quantified traditional monocyte subsets based on CD14 and CD16 expression as well as novel monocyte-macrophage pro-inflammatory CD68(+)CCR2(+) M1 and anti-inflammatory CX3CR1(+)CD163(+)/CD206(+) M2 phenotypes. The M1/M2 ratio was taken to represent the polarization balance. There were no differences in traditional classical (CD14(++)CD16(-)), intermediate (CD14(++)CD16(+)) and nonclassical (CD14(+)CD16(+)) monocytes between groups. Rather, compared to NGT, pre-diabetic subjects showed a significant increase in pro-inflammatory M1 cells and percent expression of the oxLDL scavenger receptor CD68, without changes in anti-inflammatory M2 cells. M1 levels and CD68 expression were directly correlated with HbA1c. We show for the first time that otherwise healthy pre-diabetic subjects have excess M1 inflammatory cells in peripheral blood, which may contribute to cardiovascular risk.

Diabetes impairs stem cell and proangiogenic cell mobilization in humans

OBJECTIVE

Diabetes mellitus (DM) increases cardiovascular risk, at least in part, through shortage of vascular regenerative cells derived from the bone marrow (BM). In experimental models, DM causes morphological and functional BM alterations, but information on BM function in human DM is missing. Herein, we sought to assay mobilization of stem and proangiogenic cells in subjects with and without DM.

RESEARCH DESIGN AND METHODS

In a prospective trial (NCT01102699), we tested BM responsiveness to 5 μg/kg human recombinant granulocyte colony-stimulating factor (hrG-CSF) in 24 individuals with DM (10 type 1 and 14 type 2) and 14 individuals without DM. Before and 24 h after hrG-CSF, we quantified circulating stem/progenitor cells and total and differential white blood cell counts. We also evaluated in vivo the proangiogenic capacity of peripheral blood mononuclear cells using the Matrigel plug assay.

RESULTS

In response to hrG-CSF, levels of CD34(+) cells and other progenitor cell phenotypes increased in subjects without DM. Patients with DM had significantly impaired mobilization of CD34(+), CD133(+), and CD34(+)CD133(+) hematopoietic stem cells and CD133(+)KDR(+) endothelial progenitors, independently of potential confounders. The in vivo angiogenic capacity of peripheral blood mononuclear cells significantly increased after hrG-CSF in control subjects without DM, but not in patients with DM. DM was also associated with the inability to upregulate CD26/DPP-4 on CD34(+) cells, which is required for the mobilizing effect of granulocyte colony-stimulating factor.

CONCLUSIONS

Stem and proangiogenic cell mobilization in response to hrG-CSF is impaired in DM, possibly because of maladaptive CD26/DPP-4 regulation. These alterations may hamper tissue repair and favor the development of cardiovascular complications.

Elevated white blood cell count is associated with prevalence and development of the metabolic syndrome and its components in the general population

The metabolic syndrome (MS) is characterized by chronic inflammation. We aimed to determine the association of white blood cell (WBC) count with prevalence and development of the MS and its components in the general population. A cohort of 1,329 subjects from the local working population aged 41.3 ± 7.5 years and recruited since 2000-2008 was followed up for 4.0 ± 1.2 years. WBC count and MS components were determined at baseline and follow-up. To determine whether WBC predicted incident MS, we used a logistic regression analysis adjusted for demographics, baseline variables that define MS components, smoke, medications, and follow-up duration. Cross-sectionally in the whole population, WBC count increased in parallel with the number of MS components in the same individual, and the presence of each component was associated with higher WBC count. Baseline WBC count was significantly higher in subjects with prevalent MS. Among subjects without MS at baseline, those who developed MS had significantly higher WBC than those who did not develop MS at follow-up. Development of each MS component was associated with increased WBC count. WBC count remained significantly associated with MS development after correction for several potential confounders (OR for 1 SD increase in WBC 1.26; 95 % CI 1.01-1.58). In conclusion, elevated WBC is intimately linked to the prevalence and future development of the MS in a young population of working subjects.

Characteristics and outcomes of the hyperglycemic hyperosmolar non-ketotic syndrome in a cohort of 51 consecutive cases at a single center

AIMS

The hyperglycemic hyperosmolar syndrome (HHS) is a life-threatening diabetic complication. We aimed to portrait the short and long term outcome after a HHS episode and to describe features associated with increased early mortality.

METHODS

We collected data from consecutive HHS cases, defined based on rigorous glucose and osmolality criteria. We retrieved anthropometric measures, history of diabetes, other cardiovascular risk factors and chronic co-morbidity. Clinical and biochemical parameters were recorded at admission, after 24h and at discharge. We assessed incidence of complications, as well as short (≤ 30 days) and long term mortality.

RESULTS

Patients were about 80-year old. Fifty-one cases were included, characterized by severe hyperglycemia (55.5 mosm/L) and hyperosmolality (385 mosm/L). Thirty-three percent developed at least one complication. Short term mortality was 16%; lower Glasgow Coma Scale, higher plasma glucose and mild acidosis were predictive of short term mortality. The long term mortality (median follow-up 1.27 years) was not significantly different from historical mortality data after hypoglycemic coma.

CONCLUSION

In this study, early mortality of HHS was 16% and some clinical features at presentation were predictive of an adverse short term outcome. Long term survival after a HHS episode did not appear to be severely impaired.

The metabolic syndrome influences the response to incretin-based therapies

We hypothesize that type 2 diabetic patients with different phenotypes may show different response to incretin-based therapies. Therefore, we tested whether the presence of metabolic syndrome (MS) influences glycemic response to these drugs. We prospectively followed 211 patients, treated with the GLP-1 analog exenatide (n = 102) or a DPP-4 inhibitor (n = 109) for at least 4 months. Treatment was decided on clinical grounds. We collected baseline data (age, sex, BMI, waist, systolic and diastolic blood pressure, lipid profile, data on diabetic complications and concomitant treatment) and HbA1c at subsequent visits. Patients were divided into groups according to the presence/absence of MS. Compared to patients on exenatide, patients on DPP-4 inhibitors were older and had lower BMI, waist, diastolic blood pressure, fasting plasma glucose, and HbA1c. At means of baseline values, HbA1c reduction was similar in patients treated with exenatide or DPP-4 inhibitors. Patients on exenatide showed significantly higher HbA1c reduction if they had MS (-1.55 ± 0.22%; n = 88) than if they had not (-0.34 ± 0.18%; P = 0.002). Conversely, patients on DPP-4 inhibitors showed significantly lower HbA1c reduction if they had MS (-0.60 ± 0.12%; n = 73) than if they had not (-1.50 ± 0.24%; P < 0.001). Type of MS definition (ATP-III, IDF or WHO) poorly influenced these trends. The interaction between type of therapy (exenatide vs. DPP-4 inhibitors) and MS remained significant after adjusting for age, baseline HbA1c, BMI, and concomitant medications. In conclusion, the presence of MS appears to modify the response to incretin-based therapies. Given the non-randomized nature of this study, these data need to be replicated.

Hemodynamics assessed via approximate entropy analysis of impedance cardiography time series: effect of metabolic syndrome

The metabolic syndrome (MS), a predisposing condition for cardiovascular disease, presents disturbances in hemodynamics; impedance cardiography (ICG) can assess these alterations. In subjects with MS, the morphology of the pulses present in the ICG time series is more irregular/complex than in normal subjects. Therefore, the aim of the present study was to quantitatively assess the complexity of ICG times series in 53 patients, with or without MS, through a nonlinear analysis algorithm, the approximate entropy, a method employed in recent years for the study of several biological signals, which provides a scalar index, ApEn. We correlated ApEn computed from ICG times series data during fasting and postprandial phase with the presence of alterations in the parameters defining MS [Adult Treatment Panel (ATP) III (Grundy SM, Brewer HB Jr, Cleeman JI, Smith SC Jr, Lenfant C; National Heart, Lung, and Blood Institute; American Heart Association. Circulation 109: 433–438, 2004) and the International Diabetes Federation (IDF) definition]. Results show that ApEn was significantly higher in subjects with MS compared with those without (1.81 ± 0.09 vs. 1.65 ± 0.13; means ± SD; P = 0.0013, with ATP III definition; 1.82 ± 0.09 vs. 1.67 ± 0.12; P = 0.00006, with the IDF definition). We also demonstrated that ApEn increase parallels the number of components of MS. ApEn was then correlated to each MS component: mean ApEn values of subjects belonging to the first and fourth quartiles of the distribution of MS parameters were statistically different for all parameters but HDL cholesterol. No difference was observed between ApEn values evaluated in fasting and postprandial states. In conclusion, we identified that MS is characterized by an increased complexity of ICG signals: this may have a prognostic relevance in subjects with this condition.

Impaired hemodynamic response to meal intake in insulin-resistant subjects: an impedance cardiography approach

BACKGROUND

In the postprandial state, insulin regulates metabolic and cardiovascular responses. In insulin resistance, the insulin action is impaired at both levels. However, postprandial hemodynamic responses are poorly characterized in this setting.

OBJECTIVE

We investigated fasting and postprandial cardiac and vascular hemodynamic responses in subjects with and without insulin resistance.

DESIGN

Sixty-six atherosclerosis-free, healthy volunteers were studied in a fasted state and ≤180 min after ingestion of a mixed meal. The insulin sensitivity index was determined by using a minimal model analysis; hemodynamic response was monitored by using continuous impedance cardiography that allowed a reliable beat-to-beat noninvasive evaluation of stroke volume, cardiac contractility, and several derived variables.

RESULTS

Subjects were divided into insulin-resistant (IR; n = 33) and insulin-sensitive (IS; n = 33) groups. After fasting, IR subjects had significantly higher values of systolic and diastolic blood pressures and the systemic vascular resistance index (SVRI) than did IS subjects. In the postprandial state, acute vasodilatation was comparable and synchronous (at 30 min) in IR and IS subjects (P = 0.209), but subsequent vascular tone recovery (30-180 min) was significantly impaired in IR subjects (P = 0.018), even after adjustment for age and sex (P = 0.031). Hemodynamic dysregulation was directly correlated with metabolic disturbances in the postprandial state. In basal and postprandial states, hemodynamic variables related to cardiac function were not significantly different in IR and IS subjects.

CONCLUSIONS

IR subjects had a worse fasting vascular performance than did IS subjects. In the postprandial phase, insulin resistance was associated with a shorter duration of vasodilatation in the absence of an altered cardiac performance. Peripheral hemodynamic alterations in fasting and postprandial states may have a negative effect on cardiovascular performance in IR patients.

Widespread increase in myeloid calcifying cells contributes to ectopic vascular calcification in type 2 diabetes

RATIONALE

Acquisition of a procalcific phenotype by resident or circulating cells is important for calcification of atherosclerotic plaques, which is common in diabetes.

OBJECTIVE

We aim to identify and characterize circulating calcifying cells, and to delineate a pathophysiological role for these cells in type 2 diabetes.

METHODS AND RESULTS

We demonstrate for the first time that a distinct subpopulation of circulating cells expressing osteocalcin and bone alkaline phosphatase (OC(+)BAP(+)) has procalcific activity in vitro and in vivo. The study of naïve patients with chronic myeloid leukemia indicated that OC(+)BAP(+) cells have a myeloid origin. Myeloid calcifying OC(+)BAP(+) cells (MCCs) could be differentiated from peripheral blood mononuclear cells, and generation of MCCs was closely associated with expression of the osteogenic transcription factor Runx2. In gender-mismatched bone marrow-transplanted humans, circulating MCCs had a much longer half-life compared with OC(-)BAP(-) cells, suggesting they belong to a stable cell repertoire. The percentage of MCCs was higher in peripheral blood and bone marrow of type 2 diabetic patients compared with controls but was lowered toward normal levels by optimization of glycemic control. Furthermore, diabetic carotid endoarterectomy specimens showed higher degree of calcification and amounts of cells expressing OC and BAP in the α-smooth muscle actin-negative areas surrounding calcified nodules, where CD68(+) macrophages colocalize. High glucose increased calcification by MCCs in vitro, and hypoxia may regulate MCC generation in vitro and in vivo.

CONCLUSIONS

These data identify a novel type of blood-derived procalcific cells potentially involved in atherosclerotic calcification of diabetic patients.

Exon 11 deletion in the myocyte enhancer factor (MEF)2A and early onset coronary artery disease gene in a Sicilian family

AIMS

We investigated the prevalence of the myocyte enhancer factor (MEF)2A exon 11 deletion, a putative coronary artery disease (CAD) susceptibility gene, in patients referred for coronary angiography.

METHODS AND RESULTS

In total, 1079 consecutive patients referred for coronary angiography in the GENICA Study were genotyped and 301 low-risk subjects were used as controls. One patient with early onset three vessels CAD, carrying the MEF2A deletion was found in the GENICA Study cohort and none in the control group.

CONCLUSION

In a cohort of patients undergoing coronary angiography for suspected CAD the MEF2A exon 11 deletion occurred in 0.09%.