Mauro Rigato

Circulating Progenitor Cell Count Predicts Microvascular Outcomes in Type 2 Diabetic Patients

CONTEXT Diabetes reduces the levels of circulating progenitor cells (CPCs) and endothelial progenitor cells (EPCs), which promote vascular repair and are inversely correlated with cardiovascular risk. OBJECTIVE The objective of the study was to test whether CPC/EPC levels predict onset/progression of microangiopathy in a cohort of type 2 diabetic (T2D) patients. DESIGN This was a pseudoprospective study with a 3.9-year follow-up. SETTING The study was conducted at a tertial referral diabetes outpatient clinic. PATIENTS A total of 187 T2D patients having a baseline determination of CPCs/EPCs participated in the study. INTERVENTION Baseline data on demographics, anthropometrics, concomitant risk factors, diabetic complications, and medications were collected. MAIN OUTCOME MEASURE Onset or progression of microangiopathy was assessed at follow-up compared with baseline. RESULTS New onset or progression of microalbuminuria, chronic kidney disease, retinopathy, and neuropathy occurred in 70 patients (9.5%/y). After controlling the false discovery rate, baseline CD34(+) CPCs and EPCs were significantly lower in patients with onset/progression of microalbuminuria and any microangiopathy. Patients with baseline CD34(+) CPC or CD133(+)/kinase insert domain-containing receptor(+)/EPC levels below the median were more likely to experience worsening microangiopathy than those with high cell levels. Independently from confounders, including age, sex, glycated hemoglobin, and diabetes duration, CD34(+) cells predicted onset/progression of microalbuminuria, retinopathy, and any microangiopathy in false discovery rate-adjusted analyses. A low CD34(+) cell count limited the beneficial effects of renin-angiotensin system blockers on microalbuminuria progression. CONCLUSIONS Levels of circulating (endothelial) progenitor cells predict microvascular outcomes in T2D. Together with previous studies showing an association with cardiovascular events, these data indicate that CPCs/EPCs represent biomarkers of the global complication burden in diabetes.

Levels of Circulating Progenitor Cells, Cardiovascular Outcomes and Death: A Meta-Analysis of Prospective Observational Studies

Rationale: Circulating progenitor cells (CPCs), including endothelial progenitor cells (EPCs) are biologically related to many aspects of cardiovascular disease, as they promote angiogenesis and vascular repair. Objective: We herein aimed to meta-analyze studies reporting the prognostic role of the CPC/EPC measure on cardiovascular outcomes and death. Methods and Results: We screened the English-language literature for longitudinal studies reporting the association between baseline CPC/EPC levels, future cardiovascular events, and death. We retrieved 28 studies, 21 of which contained poolable data and entered the meta-analysis, for a total of 4155 patients, mostly with a high baseline cardiovascular risk. Sixty percent of the studies met at least 11 of 16 items of quality assessment. Overall, reduced CPC/EPC levels were associated with a ≈2-fold increased risk of future cardiovascular events and cardiovascular death. The most predictive phenotype was CD34+CD133+: low versus high levels predicted cardiovascular events, restenosis after endovascular intervention, cardiovascular death, and all-cause mortality. Heterogeneity among studies and according to the CPC/EPC phenotype was generally high. Excluding studies for which the risk estimate had to be extrapolated or limiting the analyses to higher quality studies still indicated a significant risk for future cardiovascular events and death in patients with low versus high progenitor cell counts. Conclusions: This meta-analysis shows that a reduction in the levels of circulating cells putatively provided with vasculoregenerative properties represents a risk factor for adverse cardiovascular outcomes and death. # Novelty and Significance {#article-title-50}RATIONALE Circulating progenitor cells (CPCs), including endothelial progenitor cells (EPCs) are biologically related to many aspects of cardiovascular disease, as they promote angiogenesis and vascular repair. OBJECTIVE We herein aimed to meta-analyze studies reporting the prognostic role of the CPC/EPC measure on cardiovascular outcomes and death. METHODS AND RESULTS We screened the English-language literature for longitudinal studies reporting the association between baseline CPC/EPC levels, future cardiovascular events, and death. We retrieved 28 studies, 21 of which contained poolable data and entered the meta-analysis, for a total of 4155 patients, mostly with a high baseline cardiovascular risk. Sixty percent of the studies met at least 11 of 16 items of quality assessment. Overall, reduced CPC/EPC levels were associated with a ≈2-fold increased risk of future cardiovascular events and cardiovascular death. The most predictive phenotype was CD34(+)CD133(+): low versus high levels predicted cardiovascular events, restenosis after endovascular intervention, cardiovascular death, and all-cause mortality. Heterogeneity among studies and according to the CPC/EPC phenotype was generally high. Excluding studies for which the risk estimate had to be extrapolated or limiting the analyses to higher quality studies still indicated a significant risk for future cardiovascular events and death in patients with low versus high progenitor cell counts. CONCLUSIONS This meta-analysis shows that a reduction in the levels of circulating cells putatively provided with vasculoregenerative properties represents a risk factor for adverse cardiovascular outcomes and death.

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.

Long-term Prediction of Cardiovascular Outcomes by Circulating CD34+ and CD34+CD133+ Stem Cells in Patients With Type 2 Diabetes

OBJECTIVE Cardiovascular risk varies substantially in the population with diabetes, and biomarkers can improve risk stratification. Circulating stem cells predict future cardiovascular events and death, but data for the population with diabetes are scant. In this study we evaluated the ability of circulating stem cell levels to predict future cardiovascular outcomes and improve risk discrimination in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS A cohort of 187 patients with type 2 diabetes was monitored for a median of 6.1 years. The primary outcome was time to a first cardiovascular event, defined as 3-point major adverse cardiovascular event (cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke) plus hospitalization for cardiovascular causes. At baseline, we measured six stem/progenitor cell phenotypes in peripheral blood based on expression of CD34, CD133, and KDR. RESULTS The primary outcome occurred in 48 patients (4.5/100 patient-years). Patients with incident cardiovascular events had significantly lower CD34+ and CD34+CD133+ cells than those without. Higher rates of cardiovascular events occurred in patients with below median levels of CD34+ and CD34+CD133+. In Cox proportional hazards regression analyses, a reduced CD34+ (hazard ratio 2.21 [95% CI 1.14–4.29]) and CD34+CD133+ (2.98 [1.46–6.08]) cell count independently predicted future events. Addition of the CD34+ cell count to the reference model or the UK Prospective Diabetes Study risk engine improved C statistics, continuous net reclassification improvement, and/or integrated discrimination index. CONCLUSIONS In patients with type 2 diabetes, a reduced baseline level of circulating CD34+ stem cells predicts adverse cardiovascular outcomes up to 6 years later and improves risk stratification.

Autologous Cell Therapy for Peripheral Arterial DiseaseNovelty and Significance: Systematic Review and Meta-Analysis of Randomized, Nonrandomized, and Noncontrolled Studies

Rationale: Critical limb ischemia is a life-threatening complication of peripheral arterial disease. In patients who are ineligible for revascularization procedures, there are few therapeutic alternatives, leading to amputations and death. Objective: To provide a systematic review of the literature and a meta-analysis of studies evaluating safety and efficacy of autologous cell therapy for intractable peripheral arterial disease/critical limb ischemia. Methods and Results: We retrieved 19 randomized controlled trials (837 patients), 7 nonrandomized trials (338 patients), and 41 noncontrolled studies (1177 patients). The primary outcome was major amputation. Heterogeneity was high, and publication bias could not be excluded. Despite these limitations, the primary analysis (all randomized controlled trials) showed that cell therapy reduced the risk of amputation by 37%, improved amputation-free survival by 18%, and improved wound healing by 59%, without affecting mortality. Cell therapy significantly increased ankle brachial index, increased transcutaneous oxygen tension, and reduced rest pain. The secondary analysis (all controlled trials; n=1175 patients) shows that there may be potential to avoid ≈1 amputation/year for every 2 patients successfully treated. The tertiary analysis (all studies; n=2332 patients) precisely estimated the changes in ankle brachial index, transcutaneous oxygen tension, rest pain, and walking capacity after cell therapy. Intramuscular implantation appeared more effective than intra-arterial infusion, and mobilized peripheral blood mononuclear cells may outperform bone marrow–mononuclear cells and mesenchymal stem cells. Amputation rate was improved more in trials wherein the prevalence of diabetes mellitus was high. Cell therapy was not associated with severe adverse events. Remarkably, efficacy of cell therapy on all end points was no longer significant in placebo-controlled randomized controlled trials and disappeared in randomized controlled trials with a low risk of bias. Conclusions: Although this meta-analysis highlights the need for more high-quality placebo-controlled trials, equipoise may no longer be guaranteed because autologous cell therapy has the potential to modify the natural history of intractable critical limb ischemia. # Novelty and Significance {#article-title-68}Rationale: Critical limb ischemia is a life-threatening complication of peripheral arterial disease. In patients who are ineligible for revascularization procedures, there are few therapeutic alternatives, leading to amputations and death. Objective: To provide a systematic review of the literature and a meta-analysis of studies evaluating safety and efficacy of autologous cell therapy for intractable peripheral arterial disease/critical limb ischemia. Methods and Results: We retrieved 19 randomized controlled trials (837 patients), 7 nonrandomized trials (338 patients), and 41 noncontrolled studies (1177 patients). The primary outcome was major amputation. Heterogeneity was high, and publication bias could not be excluded. Despite these limitations, the primary analysis (all randomized controlled trials) showed that cell therapy reduced the risk of amputation by 37%, improved amputation-free survival by 18%, and improved wound healing by 59%, without affecting mortality. Cell therapy significantly increased ankle brachial index, increased transcutaneous oxygen tension, and reduced rest pain. The secondary analysis (all controlled trials; n=1175 patients) shows that there may be potential to avoid ≈1 amputation/year for every 2 patients successfully treated. The tertiary analysis (all studies; n=2332 patients) precisely estimated the changes in ankle brachial index, transcutaneous oxygen tension, rest pain, and walking capacity after cell therapy. Intramuscular implantation appeared more effective than intra-arterial infusion, and mobilized peripheral blood mononuclear cells may outperform bone marrow–mononuclear cells and mesenchymal stem cells. Amputation rate was improved more in trials wherein the prevalence of diabetes mellitus was high. Cell therapy was not associated with severe adverse events. Remarkably, efficacy of cell therapy on all end points was no longer significant in placebo-controlled randomized controlled trials and disappeared in randomized controlled trials with a low risk of bias. Conclusions: Although this meta-analysis highlights the need for more high-quality placebo-controlled trials, equipoise may no longer be guaranteed because autologous cell therapy has the potential to modify the natural history of intractable critical limb ischemia.

Comparative effectiveness of liraglutide in the treatment of type 2 diabetes.

Type 2 diabetes is characterized by a progressive decline in beta cell function, with consequent worsening of glycemic control. The ideal antihyperglycemic treatment should achieve good and sustained glycemic control, with a low risk of hypoglycemia and no weight gain. This paper reviews the efficacy and tolerability of liraglutide, a glucagon-like peptide-1 receptor agonist approved for the treatment of type 2 diabetes. Once-daily injection of liraglutide (at doses of 1.2 mg and 1.8 mg), as monotherapy or in combination with one or two oral antihyperglycemic agents, was associated with greater improvements in glycemic control compared with active comparators or placebo in several controlled, randomized Phase III trials, including the six trials of the LEAD (Liraglutide Effect and Action in Diabetes) program. Liraglutide also improved beta cell function, body weight, systolic blood pressure, and lipid profile, thereby achieving many of the goals of ideal antihyperglycemic therapy. Liraglutide was generally well tolerated in the Phase III trials. The most common adverse events were nausea, vomiting, and diarrhea, usually of mild to moderate intensity. The observed rate of pancreatitis was low and comparable with that of the general diabetic population. In conclusion, although most trials were relatively short and focused on surrogate endpoints, liraglutide emerges as an effective and well tolerated treatment for type 2 diabetes, carrying a low risk of hypoglycemia, weight loss, and possible reduction of cardiovascular risk.

Characteristics and mortality of type 2 diabetic patients hospitalized for severe iatrogenic hypoglycemia

AIMS Severe hypoglycemia can be dramatic in diabetic patients, but its long-term outcome is unknown. We aimed to describe clinical characteristics of type 2 diabetic patients hospitalized for iatrogenic hypoglycemia, and find predictors of long-term mortality, with a special regard to anti-hyperglycemic regimens. METHODS We retrospectively analyzed 126 episodes of severe hypoglycemia in type 2 diabetic patients. We collected data on the event (coma, pre-hospital fall, glucose level, duration of hypoglycemia), concomitant risk factors, diabetic complications and chronic comorbidities. We divided patients according to the use of insulin or oral agents (OHAs). In-hospital outcomes were acute coronary syndrome (ACS) and duration of hospitalization. We finally assessed long-term mortality. RESULTS Hypoglycemia due to OHA was associated with higher prevalence of coma and longer duration than hypoglycemia due to insulin. OHA use was also associated with a longer hospital stay, but no increase in the incidence of ACS. Overall mortality after a 2-year median follow-up was 42.1%. Despite the apparent worse presentation of hypoglycemic episodes associated with OHA use, this did not lead to an increased long-term mortality. CONCLUSIONS Severe iatrogenic hypoglycemia in OHA-treated patients has a worse presentation, but is not associated with a higher long-term mortality than in insulin-treated patients.

Dipeptidyl peptidase-4 inhibitors moderate the risk of genitourinary tract infections associated with sodium-glucose co-transporter-2 inhibitors

Genitourinary tract infections (GUTIs) are the most common adverse event (AE) occurring during therapy with sodium‐glucose co‐transporter‐2 (SGLT2) inhibitors. We evaluated whether dipeptidyl peptidase‐4 inhibitors moderate the risk of GUTI during SGLT2 inhibitor therapy, using two approaches. First, we screened the literature for randomized controlled trials (RCTs) directly comparing the frequency of GUTIs in patients receiving DPP‐4 inhibitor/SGLT2 inhibitor combination therapy vs those receiving an SGLT2 inhibitor only. In the five trials we retrieved, the pooled risk ratio for genital tract infections (GTIs) in patients on DPP‐4 inhibitor/SGLT2 inhibitor combination therapy vs those on SGLT2 inhibitors alone was 0.51 (95% confidence interval [CI] 0.28‐0.92). Second, we found that within the Food and Drug Administration AE Reporting System, the frequency of GUTIs among reports listing both SGLT2 and DPP‐4 inhibitors as suspect or concomitant drugs was significantly lower than among reports listing SGLT2 inhibitors without DPP‐4 inhibitors, with a proportional reporting ratio of 0.74 (95% CI 0.61‐0.90). In conclusion, in RCTs and in a large pharmacovigilance database, combination therapy with a DPP‐4 inhibitor appears to reduce the frequency of G(U)TIs associated with SGLT2 inhibitors.

The molecular signature of impaired diabetic wound healing identifies serpinB3 as a healing biomarker.

Aims/hypothesisChronic foot ulceration is a severe complication of diabetes, driving morbidity and mortality. The mechanisms underlying delaying wound healing in diabetes are incompletely understood and tools to identify such pathways are eagerly awaited.MethodsWound biopsies were obtained from 75 patients with diabetic foot ulcers. Matched subgroups of rapidly healing (RH, n = 17) and non-healing (NH, n = 11) patients were selected. Proteomic analysis was performed by labelling with isobaric tag for relative and absolute quantification and mass spectrometry. Differentially expressed proteins were analysed in NH vs RH for identification of pathogenic pathways. Individual sample gene/protein validation and in vivo validation of candidate pathways in mouse models were carried out.ResultsPathway analyses were conducted on 92/286 proteins that were differentially expressed in NH vs RH. The following pathways were enriched in NH vs RH patients: apoptosis, protease inhibitors, epithelial differentiation, serine endopeptidase activity, coagulation and regulation of defence response. SerpinB3 was strongly upregulated in RH vs NH wounds, validated as protein and mRNA in individual samples. To test the relevance of serpinB3 in vivo, we used a transgenic mouse model with α1-antitrypsin promoter-driven overexpression of human SERPINB3. In this model, wound healing was unaffected by SERPINB3 overexpression in non-diabetic or diabetic mice with or without hindlimb ischaemia. In an independent validation cohort of 47 patients, high serpinB3 protein content was confirmed as a biomarker of healing improvement.Conclusions/interpretationWe provide a benchmark for the unbiased discovery of novel molecular targets and biomarkers of impaired diabetic wound healing. High serpinB3 protein content was found to be a biomarker of successful healing in diabetic patients.

Short-term statin discontinuation increases endothelial progenitor cells without inflammatory rebound in type 2 diabetic patients

Type 2 diabetes (T2D) is characterized by impaired vascular regeneration owing to reduced endothelial progenitor cells (EPCs). While statins are known to increase EPCs, the effects of statin withdrawal on EPCs are unknown. Herein, we evaluated the effects of statin discontinuation on EPCs, inflammation and in vivo angiogenesis. Thirty-four T2D patients were randomized to 5-day discontinuation or continuation of statin treatment. At baseline and at day 5, we determined lipid profile, EPC levels, monocyte-macrophage polarization, and concentrations of hsCRP, VEGF, SDF-1α, and G-CSF. Angiogenesis by human circulating cells was assessed in vivo. At day 5, patients who stopped statins showed raised total and LDL cholesterol and EPCs compared to baseline, while no changes were observed in patients who continued statins. No changes were observed in hsCRP, VEGF, SDF-1α, G-CSF, M1 and M2 macrophages and classical, intermediate and nonclassical monocytes in both groups. In vivo angiogenesis by circulating cells was increased in patients who stopped statin treatment. In vitro, cholesterol supplementation stimulated mobilizing signals in human bone marrow mesenchymal stem cells. In conclusion, a brief statin withdrawal increases circulating EPCs and functional proangiogenic cells in T2D. These findings identify statin-sensitive pathways as reverse target mechanisms to stimulate vascular repair in diabetes.