Safety of sodium-glucose cotransporter 2 inhibitors in elderly patients with type 2 diabetes: A meta-analysis of randomized controlled trials.

AIM: Sodium-glucose cotransporter 2 inhibitors (SGLT2is) are particularly effective in preventing adverse outcomes of heart failure and chronic kidney disease, which are highly prevalent in the elderly. Here, we aimed to access the safety of SGLT2i in elderly patients with type 2 diabetes. MATERIALS AND METHODS: We performed a meta-analysis of randomized controlled trials (RCTs) reporting safety outcomes of the elderly (≥65 years) patients with type 2 diabetes, randomized to an SGLT2i or placebo. We recorded the incidence of acute kidney injury, volume depletion, genital tract infections, urinary tract infections, bone fractures, amputations, diabetic ketoacidosis, hypoglycaemia and drug discontinuation, by group of treatment. RESULTS: Of the 130 RCTs screened, only six reported data on elderly patients. In total, 19 986 patients were included. The SGLT2i discontinuation rate was approximately 20%. The risk of acute kidney injury was significantly lower among SGLT2i users compared with placebo [risk ratio (RR) 0.73; 95% CI 0.62-0.87]. SGLT2i were associated with a six-fold increased risk of genital tract infections (RR 6.55; 95% CI 2.09-20.5). The rate of amputations was increased only among canagliflozin users (RR 1.94, 95% CI 1.25-3). The risk of fractures, urinary tract infection, volume depletion, hypoglycaemia and diabetic ketoacidosis was similar between SGLT2i and placebo. CONCLUSIONS: SGLT2is were well tolerated in the elderly. However, older patients are underrepresented in most RCTs and a call for action is need to favour clinical trials reporting safety outcomes stratified by age.

Effectiveness of remote screening for diabetic retinopathy among patients referred to Mozambican Diabetes Association (AMODIA): a retrospective observational study.

AIMS: Diabetes represents a growing public health problem in sub-Saharan Africa, where diabetic retinopathy (DR) is a major cause of permanent visual loss. We reported the results of a remote screening of DR among urbanized Mozambican people with diabetes. METHODS: We retrospectively collected retinal images and clinical characteristics from 536 patients screened for DR in Maputo (Mozambique), over a period of 2 years (2018-2019). Retinal photographs were captured, digitally stored, and scored locally and by an expert ophthalmologist in Italy remotely. RESULTS: The overall prevalence of DR was 29% with sight-threatening forms accounting for 8.1% of that number. Inter-reader agreement between the local and the Italian ophthalmologists was poor (k < 0.2). Patients with DR were older, had a longer duration of disease, worse glycaemic control, and a higher prevalence of comorbidities. In the multivariate logistic regression analysis, HbA1c, diabetes duration, and coronary heart disease (CHD) were associated with DR. CONCLUSION: Prevalence of DR among urbanized Mozambican patients was similar to that observed in Western countries. Telediagnosis might partially overcome the paucity of local ophthalmologists with experience in DR.

Changes in markers of hepatic steatosis and fibrosis in patients with type 2 diabetes during treatment with glucagon-like peptide-1 receptor agonists. A multicenter retrospective longitudinal study.

AIMS: Metabolic dysfunction-associated fatty liver disease (MAFLD) is common in people with type 2 diabetes (T2D) and can progress to advanced fibrosis and cirrhosis. In this retrospective study, we explored the longitudinal changes in markers of hepatic steatosis and fibrosis during T2D treatment with glucagon-like peptide-1 receptor agonists (GLP-1RAs). METHODS: We analysed observational data from six diabetes outpatient clinics. In the whole T2D population, we calculated the hepatic steatosis index (HSI), which we previously validated against liver ultrasonography, and the Fibrosis (Fib)-4 index. We then identified patients who initiated a GLP-1RA from 2010 to 2018 and for whom data were available to evaluate changes in both HSI and Fib-4 scores over 24 months. RESULTS: From 83,116 outpatients with T2D, 41,302 (49.7%) had complete data for calculating HSI and Fib-4. Most of these T2D patients (∼70%) had MAFLD (defined as HSI>36), 9.7% of whom had advanced fibrosis based on Fib-4 thresholds. Patients with low compared to high risk of advanced fibrosis were 5-times more likely to be treated with GLP-1RA. In 535 patients who initiated a GLP-1RA, the prevalence of MAFLD based on HSI declined significantly at 6 and 24 months, but Fib-4 categories did not. HSI improved significantly only in patients receiving human-based but not exendin-based GLP-1RA, while patients concomitantly receiving metformin had less worsening in Fib-4 categories. CONCLUSIONS: MAFLD is very common among outpatients with T2D (∼70%) and the estimated prevalence of advanced fibrosis was ∼10%. Treatment with GLP-1RAs significantly improved MAFLD, but not MAFLD-associated advanced fibrosis.

Deintensification of basal-bolus insulin after initiation of GLP-1RA in patients with type 2 diabetes under routine care.

AIMS: We evaluated de-intensification of basal-bolus insulin (BBI) after initiation of a GLP-1 receptor agonist (GLP-1RA) under routine care. RESEARCH DESIGN AND METHODS: This retrospective, multicenter study conducted at outpatient clinics in North-East Italy collected data on patients with T2D on BBI who initiated a GLP-1RA. Patients were divided according to whether they de-intensified BBI at the end of observation by stopping prandial insulin. RESULTS: We included 425 patients with mean age of 61.3 years and 13 years of diabetes duration. Baseline HbA1c was 8.6% and BMI was 35.5 kg/m2. After 14 months. 58.6% of patients de-intensified BBI after initiating GLP-1RA: they were younger, had a shorter disease duration, lower HbA1c and insulin dose, and less frequent microangiopathy than those who continued BBI. A probability estimation based on these variables was validated in an independent cohort of 40 patients. Body weight improved in both groups, but HbA1c and fasting plasma glucose significantly declined only among patients who de-intensified BBI. Patients who de-intensified BBI and persisted on GLP-1RA at the last observation (80.7%) had greater HbA1c reductions. CONCLUSION: Under routine care, GLP-1RA initiation frequently allowed discontinuing BBI, especially among patients with shorter disease duration, lower insulin requirement, and better glucose control.

Stem cell mobilization with plerixafor and healing of diabetic ischemic wounds: A phase IIa, randomized, double-blind, placebo-controlled trial.

Bone marrow-derived cells contribute to tissue repair, but traffic of hematopoietic stem/progenitor cells (HSPCs) is impaired in diabetes. We therefore tested whether HSPC mobilization with the CXCR4 antagonist plerixafor improved healing of ischemic diabetic wounds. This was a pilot, phase IIa, double-blind, randomized, placebo-controlled trial (NCT02790957). Patients with diabetes with ischemic wounds were randomized to receive a single subcutaneous injection of plerixafor or saline on top of standard medical and surgical therapy. The primary endpoint was complete healing at 6 months. Secondary endpoints were wound size, transcutaneous oxygen tension (TcO2 ), ankle-brachial index (ABI), amputations, and HSPC mobilization. Twenty-six patients were enrolled: 13 received plerixafor and 13 received placebo. Patients were 84.6% males, with a mean age of 69 years. HSPC mobilization was successful in all patients who received plerixafor. The trial was terminated after a preplanned interim analysis of 50% of the target population showed a significantly lower healing rate in the plerixafor vs the placebo group. In the final analysis data set, the rate of complete healing was 38.5% in the plerixafor group vs 69.2% in the placebo group (chi-square P = .115). Wound size tended to be larger in the plerixafor group for the entire duration of observation. No significant difference was noted for the change in TcO2 and ABI or in amputation rates. No other safety concern emerged. In conclusion, successful HSPC mobilization with plerixafor did not improve healing of ischemic diabetic wounds. Contrary to what was expected, outside the context of hematological disorders, mobilization of diabetic HSPCs might exert adverse effects on wound healing.

Effectiveness of Dulaglutide in the Real World and in Special Populations of Type 2 Diabetic Patients.

CONTEXT: In randomized controlled trials (RCTs) on type 2 diabetes (T2D) patients, the glucagon-like peptide-1 (GLP-1) receptor agonist (GLP-RA) dulaglutide reduced HbA1c and body weight, but generalizability of such findings to real-world T2D patients is challenging. OBJECTIVE: We evaluated effectiveness of dulaglutide in routine clinical practice, especially in subgroups of patient that are underrepresented in RCTs. DESIGN: Retrospective multicenter study. SETTING: Diabetes outpatient clinics. PATIENTS AND INTERVENTION: All consecutive patients who initiated dulaglutide between 2015 and 2018. MAIN OUTCOME MEASURES: Changes in HbA1c and body weight were assessed up to 30 months after baseline. Effectiveness was analyzed in patient subgroups according to: prior use of GLP-1RA, persistence on treatment and dose, age, sex, disease duration, renal function, obesity, cardiovascular disease, or concomitant use of insulin or sulphonylurea. RESULTS: From a background population of 83,116 patients, 2084 initiated dulaglutide (15.3% switching from another GLP-1RA), 1307 of whom had at least 1 follow-up visit. Overall, dulaglutide reduced HbA1c by 1.0% and body weight by 2.9 kg at the end of observation. These effects were more pronounced in GLP-1RA-naïve patients and in those with shorter disease duration. Improvement in HbA1c was highly significant and consistent across all subgroups, including those aged ≥ 75 years, nonobese, or with chronic kidney disease. Body weight declined in all subgroups and significantly more with the 1.5-mg versus 0.75-mg dose. CONCLUSIONS: In real-world T2D patients, effectiveness of dulaglutide on HbA1c and body weight reduction was highly consistent and significant even in subgroups of patients poorly represented in RCTs.

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 ±â€…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.

Effectiveness of dulaglutide vs liraglutide and exenatide once-weekly. A real-world study and meta-analysis of observational studies.

INTRODUCTION AND AIM: Real-word data on the head-to-head comparisons among glucagon-like peptide-1 receptor agonists (GLP-1RA) are scant. Therefore, we aimed to compare the effectiveness of dulaglutide versus liraglutide and exenatide once weekly (exeOW) in type 2 diabetic (T2D) patients under routine care. METHODS: This was a retrospective, multicenter, real-world study on patients with T2D (aged 18-80) initiating a GLP-1RA between 2010 and 2018 at specialist outpatient clinics. We compared the effectiveness of dulaglutide versus liraglutide and exeOW on the changes in HbA1c (primary outcome), body weight, blood pressure and fasting glucose (secondary outcomes). Average follow-up was 5.9 months. Channelling biases were addressed with propensity score matching or multivariable adjustment. Meta-analyses of observational studies, covering the same comparisons, are also presented. RESULTS: 849, 1371 and 198 patients were included in the dulaglutide, liraglutide and exeOW groups, respectively. The reduction of HbA1c was greater with dulaglutide than with liraglutide (-0.24 ±â€¯0.08%; p = 0.003), and was confirmed in the meta-analysis of observational studies. In our study, dulaglutide showed similar effectiveness compared to exeOW. When these results were pooled with other observational studies, dulaglutide showed a greater reduction of HbA1c (-0.19%; p = 0.003) and body weight (-0.8 kg; p = 0.007). CONCLUSIONS: In a real-world scenario, dulaglutide reduced HbA1c more than liraglutide. Conversely, we found similar effect of dulaglutide and exeOW, with statistical differences arising solely when results were meta-analysed with those from other observational studies. Lack of up-titration for liraglutide and higher discontinuation rate for exeOW likely influenced the estimated treatment difference.

Trend 2010-2018 in the clinical use of GLP-1 receptor agonists for the treatment of type 2 diabetes in routine clinical practice: an observational study from Northeast Italy.

AIMS: Several GLP-1 receptor agonists (GLP-1RA) have become available for the treatment of type 2 diabetes (T2D), and evidence on their beneficial effects has evolved. We evaluated how the clinical phenotype of patients initiating GLP-1RA changed from 2010 to 2018. METHODS: This was a retrospective study conducted at six diabetes outpatient clinics in Northeast Italy. We collected data of T2D patients who initiated new GLP-1RA between 2010 and 2018. We recorded baseline characteristics, including demographics, anthropometrics, cardiovascular risk factors, glucose control, lipid profile, liver enzymes, renal function and concomitant medications. We recorded updated HbA1c and body weight at follow-up. RESULTS: There were 83,116 T2D patients from a general population of ~ 1,380,000 inhabitants. Among 6167 cases of GLP-1RA initiation, 5408 were analyzed after excluding intra-class switchers. Prescription of GLP-1RA increased exponentially, and the change in the type of GLP-1RA reflected waves of their entering the market. From 2010 to 2018, there were significant increases in baseline age, diabetes duration and prevalence of male sex, of cardiovascular disease and of insulin users. Blood pressure and cholesterol levels decreased concomitantly with increasing use of medications for the control of cardiovascular risk. Baseline average HbA1c (8.3% [67 mmol/mol]) and BMI (34 kg/m2) and their improvement after GLP-1RA initiation did not change over time. CONCLUSIONS: Despite the early positioning of GLP-1RA in T2D treatment algorithms, GLP-1RA have been prescribed in patients with progressively more advanced disease stage and especially in the presence of cardiovascular disease. Optimization of GLP-1RA use in routine clinical practice is still needed.

Fixed versus flexible combination of GLP-1 receptor agonists with basal insulin in type 2 diabetes: A retrospective multicentre comparative effectiveness study.

BACKGROUND AND AIMS: The combination of basal insulin (BI) and GLP-1 receptor agonists (GLP-1RAs) is a rational and effective therapy for patients with uncontrolled type 2 diabetes (T2D). We compared the effectiveness of fixed and flexible BI/GLP-1RA combinations using routinely accumulated clinical data. METHODS: This was a retrospective, multicentre, real-world study concerning T2D patients initiating a fixed or flexible BI/GLP-1RA combination (NCT03959865). The primary endpoint was change in HbA1c. Secondary endpoints were changes in body weight, fasting plasma glucose (FPG) and systolic blood pressure (SBP). Confounding was addressed by propensity score matching (PSM) or multivariable adjustment (MVA). RESULTS: A total of 609 patients were included in the study, 131 in the fixed group and 478 in the flexible group. The two groups differed in terms of diabetes duration, body weight and concomitant medications. After 5.7 months, observed HbA1c reductions were 0.6% and 0.8%, and body weight reductions were 2.8 kg and 1.2 kg in the flexible and fixed groups, respectively. Following PSM, HbA1c declined similarly in the two groups, whereas reduction in body weight was significantly in favour of the flexible combination. Findings were robust in sensitivity analyses, with the exception that, with MVA, a significantly higher reduction in HbA1c was detected in the fixed group. Final doses of BI were higher in the fixed group, whereas those of GLP-1RA were higher in the flexible group. CONCLUSIONS: In routine specialist care, initiation of the fixed or flexible BI/GLP-1RA combination allowed similar improvement in glycaemic control, but greater weight loss was observed with the flexible combination. This difference reflected dosages of BI and GLP-1RAs.

Characteristics, prevalence, and outcomes of diabetic foot ulcers in Africa. A systemic review and meta-analysis.

BACKGROUND: Among non-communicable diseases, diabetes represents a growing public health problem in Africa, where diabetes-related needs remain mostly unmet and the disabling features of foot are worsened by hygienic, cultural, and healthcare issues. We aimed to review clinical characteristics, prevalence, and outcomes of patients with diabetic foot ulcer in Africa. METHODS: We searched the literature for cross-sectional and longitudinal studies reporting the characteristics of patients with diabetic foot in African countries, with a particular focus on ulcer prevalence, amputation rate, and mortality. FINDINGS: Fifty-five full-text papers and ten abstracts were retrieved, reporting data from 19 African countries on 56,173 diabetic patients. According to the data collected, the overall prevalence of foot ulcers was 13% and increased over time, especially since 2001. Approximately 15% of patients with foot lesions underwent major amputation and 14.2% died during hospitalization. In patients with diabetic ulcers, insulin therapy was uncommon and neuropathy was the most common predisposing factor, but the prevalence of peripheral arterial disease correlated with amputation rates. Amputation and mortality decreased over time, probably as result of the implementation of screening programs in the last ten years. Mortality was directly related to previous amputation. INTERPRETATION: The diabetic foot disease in Africa is a growing problem and is burden by high rate of in-hospital mortality. Educational interventions and screening programs including evaluation of the vascular status may play a crucial role to counter diabetic foot disease in Africa.

Effects of Hypoglycemia on Circulating Stem and Progenitor Cells in Diabetic Patients.

Context: Iatrogenic hypoglycemia is the most common acute diabetic complication, and it significantly increases morbidity. In people with diabetes, reduction in the levels of circulating stem and progenitor cells predicts adverse outcomes. Objective: To evaluate whether hypoglycemia in diabetes affects circulating stem cells and endothelial progenitor cells (EPCs). Design: We performed an experimental hypoglycemia study (Study 1) and a case-control study (Study 2). Setting: Tertiary referral inpatient clinic. Patients and Other Participants: Type 1 diabetic patients (Study 1, n = 19); diabetic patients hospitalized for severe iatrogenic hypoglycemia, matched inpatient and outpatient controls (Study 2, n = 22/group). Interventions: Type 1 diabetic patients underwent two in-hospital sessions of glucose monitoring during a breakfast meal with or without induction of hypoglycemia in random order. In Study 2, patients hospitalized for hypoglycemia and matched controls were compared. Main Outcome Measure: Circulating stem cells and EPCs were measured by flow cytometry based on the expression of CD34 and kinase insert domain receptor (KDR). Results: In Study 1, the physiologic decline of CD34+KDR+ EPCs from 8 am to 2 pm was abolished by insulin-induced hypoglycemia in type 1 diabetic patients. In Study 2, diabetic patients hospitalized for severe iatrogenic hypoglycemia had significantly lower levels of CD34+ stem cells and CD34+KDR+ EPCs compared with diabetic inpatients or outpatient controls. Conclusions: In diabetic patients, a single mild hypoglycemic episode can compromise the physiologic EPC fluctuation, whereas severe hypoglycemia is associated with a marked reduction in stem cells and EPCs. These data provide a possible link between hypoglycemia and adverse outcomes of diabetes.

Circulating Stem/Progenitor Cells as Prognostic Biomarkers in Macro- and Microvascular Disease: A Narrative Review of Prospective Observational Studies.

BACKGROUND: Circulating progenitor cells (CPCs) and endothelial progenitor cells (EPCs) are immature cells involved in vascular repair and related to many aspects of macro and microvascular disease. OBJECTIVE: We aimed to review studies reporting the prognostic role of CPCs/EPCs measurement on development of cardiovascular disease and microangiopathy. METHODS AND RESULTS: We reviewed the English language literature for prospective observational studies reporting the future development of cardiovascular disease or microangiopathy in patients having a baseline determination of CPCs/EPCs. We retrieved 34 studied reporting on cardiovascular outcomes and 2 studies reporting on microvascular outcomes. Overall, a reduced baseline level of CPCs/EPCs was associated with a significant increased risk of cardiovascular events, all-cause death, and onset/progression of microangiopathy. The most predictive phenotypes were CD34+ and CD34+CD133+. The main limitation was related to the high heterogeneity among studies in terms of patient characteristics and cell phenotypes. CONCLUSION: The present review shows that a reduced level of circulating progenitor cells is a risk factor for the development of future cardiovascular events and death. In addition, low CPCs/EPCs levels predict the onset or worsening of microalbuminuria and retinopathy in diabetic 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.

Shift of monocyte subsets along their continuum predicts cardiovascular outcomes.

BACKGROUND AND AIMS: Distribution of monocyte subsets has been shown to predict cardiovascular outcomes. However, monocytes form a continuum and categorization into discrete subsets may be an oversimplification. We herein aimed at establishing whether distribution of monocytes based on CD14 and CD16 fluorescence intensity provides incremental and complementary information on cardiovascular outcomes beyond enumeration of traditional subsets. METHODS: A cohort of 227 patients at high cardiovascular risk was characterized at baseline and followed for a median of 4 years. We quantified monocytes subsets by flow cytometry based on CD14 and CD16 expression and evaluated the continuous distribution of CD14 and CD16 fluorescence within each subset. RESULTS: A consistent shift toward higher CD16 fluorescence intensity within each monocyte subset was observed in patients with type 2 diabetes, despite no change in their frequencies. Patients with coronary artery disease (CAD) at baseline showed a doubling of CD14++CD16+ intermediate monocytes and a shift of non-classical and classical monocytes towards intermediates ones. During follow-up, cardiovascular death or cardiovascular events occurred in 26 patients, who showed monocyte skewing similar to those of patients with baseline CAD. In fully adjusted Cox proportional hazard regression models, higher CD16 expression on classical monocytes, but not the level of intermediate monocytes or other subsets, independently predicted adverse cardiovascular outcomes. CONCLUSIONS: Shift of monocyte subsets along the CD14/CD16 continuum, more than their frequencies, predicted adverse cardiovascular outcomes. This finding illustrates how the concept of monocyte continuum can be used to model the cardiovascular risk.

Autologous Cell Therapy for Peripheral Arterial Disease: 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.

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.

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.

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.

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.