Clinical profiles and quality of care of adults with type 1 diabetes according to their cardiovascular Risk: A Multicenter, Observational, retrospective study.

AIMS: The European Society of Cardiology (ESC) recently defined cardiovascular risk classes for subjects with diabetes. Aim of this study was to explore the distribution of subjects with type 1 diabetes (T1D) by cardiovascular risk groups according to the ESC classification and to describe the quality indicators of care. METHODS: The study is based on data extracted from electronic medical records of patients treated at the 258 Italian diabetes centers participating in the AMD (Associazione Medici Diabetologi) Annals initiative. Patients with T1D were stratified by cardiovascular risk. Measures of intermediate outcomes, intensity/appropriateness of pharmacological treatment, and overall quality of care were evaluated. RESULTS: Overall, 29.368 subjects with type 1 diabetes (64.7% at very high cardiovascular risk, 28.5% at high risk and 6.8% at moderate risk) were evaluated. A lack of use of drugs in case of high values and an inadequate control despite the antihypertensive and lipid-lowering treatment was recognized. The overall quality of care tended to be lower as the level of cardiovascular risk increased. CONCLUSION: A large proportion of subjects with T1D is at high or very high risk. Antihypertensive and lipid-lowering treatment seem not adequately used. Several actions are necessary to improve the quality of care.

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.

Clinical profiles and quality of care of subjects with type 2 diabetes according to their cardiovascular risk: an observational, retrospective study.

BACKGROUND: The European Society of Cardiology (ESC) recently defined cardiovascular risk classes for subjects with diabetes. Aim of this study was to explore the distribution of subjects with type 2 diabetes (T2D) by cardiovascular risk groups according to the ESC classification and to describe the quality indicators of care, with particular regard to cardiovascular risk factors. METHODS: The study is based on data extracted from electronic medical records of patients treated at the 258 Italian diabetes centers participating in the AMD Annals initiative. Patients with T2D were stratified by cardiovascular risk. General descriptive indicators, measures of intermediate outcomes, intensity/appropriateness of pharmacological treatment for diabetes and cardiovascular risk factors, presence of other complications and overall quality of care were evaluated. RESULTS: Overall, 473,740 subjects with type 2 diabetes (78.5% at very high cardiovascular risk, 20.9% at high risk and 0.6% at moderate risk) were evaluated. Among people with T2D at very high risk: 26.4% had retinopathy, 39.5% had albuminuria, 18.7% had a previous major cardiovascular event, 39.0% had organ damage, 89.1% had three or more risk factors. The use of DPP4-i markedly increased as cardiovascular risk increased. The prescription of secretagogues also increased and that of GLP1-RAs tended to increase. The use of SGLT2-i was still limited, and only slightly higher in subjects with very high cardiovascular risk. The overall quality of care, as summarized by the Q score, tended to be lower as the level of cardiovascular risk increased. CONCLUSIONS: A large proportion of subjects with T2D is at high or very high risk. Glucose-lowering drug therapies seem not to be adequately used with respect to their potential advantages in terms of cardiovascular risk reduction. Several actions are necessary to improve the quality of care.

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.

Real-World Evaluation of Glycemic Outcomes and Extra-Glycemic Parameters in Diabetic Patients Treated with the Combined Formulation Degludec-Liraglutide (Ideglira).

INTRODUCTION: Combination therapy with both basal insulin (BI) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) is an effective treatment in patients with uncontrolled type 2 diabetes mellitus (T2DM). The recent development and release of a fixed-ratio combination of slow-release insulin degludec and the GLP-1RA liraglutide (IDegLira) represents an improvement to this therapy. We have conducted a real-world evidence study in Italian patients with T2DM to evaluate whether the encouraging clinical trial results obtained with IDegLira, which became available in Italy in January 2018, can be confirmed in Italian clinical practice. METHODS: This was a multicenter, retrospective, observational study in patients with T2DM treated with IDegLira from January to December 2018. Prior to the initiation of IDegLira therapy, patients were treated with BI with or without one or more concomitant oral antidiabetic drugs (BOT group) or according to the basal bolus protocol (BI and rapid-acting insulin treatment; BB group). RESULTS: A total of 244 patients were included in the present study, of whom 186 were in the BOT group and 58 in the BB group. Following the switch to IDegLira therapy, glycemic control improved in both groups, with significant reductions in glycated hemoglobin after 6 and 12 months of treatment in the BOT group and after 6 months of treatment in the BB group. No gain in body weight and body mass index and reductions in fasting plasma glucose and number of concomitant diabetic medications (in BOT patients) were observed. All results obtained during the study were achieved at a moderate dose of IDegLira. CONCLUSION: The findings from this study show that in a real-world setting, the switch to IDegLira treatment is a valid option for patients who are failing to achieve glycemic control targets and/or struggling with the side effects, such as weight gain and hypoglycemia, of other insulin therapies.

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.

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.

Changes in the Prescription of Glucose-Lowering Medications in Patients With Type 2 Diabetes Mellitus After a Cardiovascular Event: A Call to Action From the DATAFILE Study.

Background Evidence accumulated that some glucose-lowering medications protect against cardiovascular events ( CVEs ) in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular disease. The present study evaluated if and how glucose-lowering medication prescription pattern changes in T2DM after a CVE. Methods and Results DATAFILE (Diabetes Therapy After a Cardiovascular Event) was a retrospective multicenter study conducted at 12 diabetes mellitus specialist outpatient clinics in Italy. We identified T2DM patients with an incident CVE for whom a follow-up visit was available after the event. We selected control T2DM patients without an incident CVE , who were matched with cases for age, sex, known diabetes mellitus duration, baseline hemoglobin A1c, kidney function, and follow-up time. We extracted clinical variables and compared prescribed therapies at baseline and follow-up. We included 563 patients with and 497 matched patients without an incident CVE . As expected, patients with a subsequent CVE had a higher baseline prevalence of ischemic heart disease. After a median of 9.5 months, in patients with versus those without a CVE , there was a significant increase in the prescription of beta-blockers, loop diuretics, dual antiplatelet therapy, and, among glucose-lowering medications, a significant decrease in metformin. Hemoglobin A1c marginally declined only in the control group, whereas low-density lipoprotein cholesterol decreased only in patients with CVE . Conclusions This study highlights that occurrence of a CVE in T2DM patients did not prime the prescription of glucose-lowering medications provided with cardiovascular protective effects, even though glucose control remained poor. These data emphasize the need to optimize the therapeutic regimen of T2DM patients with established cardiovascular disease, according to updated guidelines.

Clinical Impact of 5 Years of Liraglutide Treatment on Cardiovascular Risk Factors in Patients with Type 2 Diabetes Mellitus in a Real-Life Setting in Italy: An Observational Study.

INTRODUCTION: Based on existing data regarding the durability of liraglutide in type 2 diabetes, this study aimed to assess its long-term effectiveness at 5 years and its overall impact on cardiovascular (CV) risk. METHODS: This was a multicenter retrospective observational study. Liraglutide was used under routine clinical practice conditions. Changes from baseline to 60 months in HbA1c, fasting plasma glucose (FPG), body weight, blood pressure, and lipid profile were assessed. United Kingdom Prospective Diabetes Study (UKPDS) scores were calculated at baseline and after 60 months to assess changes in the estimated 5- and 10-year risk for fatal and nonfatal coronary heart disease (CHD) and fatal and nonfatal stroke. RESULTS: Overall, 103 patients (age 59.0 ± 7.9 years, diabetes duration 10.4 ± 6.8 years) were involved in the study. After 60 months, HbA1c levels were reduced by - 1.0 ± 1.2%, FPG levels by - 24.5 ± 43.4 mg/dl, body weight by - 5.3 ± 6.4 kg, systolic blood pressure by - 6.5 ± 18.5 mmHg, diastolic blood pressure by - 3.6 ± 11.8 mmHg, and total cholesterol by - 16.9 ± 37.4 mg/dl. The proportion of patients achieving HbA1c levels of < 7% increased from 12.7% to 39.8% (p = 0.02). Based on the UKPDS scores, statistically significant reductions in the 5- and 10-year risk of nonfatal CHD and fatal CHD were found, with no change in the 5- and 10-year risk of fatal and nonfatal stroke. CONCLUSION: In patients prolonging treatment with liraglutide for 5 years, the benefits in relation to metabolic control and CV risk factors are maintained. The UKPDS risk scores suggest that liraglutide is associated with a reduced CHD risk, but not with a reduced stroke risk.

Efficacy and Safety of Insulin Degludec for Hyperglycemia Management in Noncritical Hospitalized Patients with Diabetes: An Observational Study.

INTRODUCTION: To assess the efficacy and safety of insulin degludec administered in a basal-bolus regimen according to the GesTIO protocol in noncritical hospitalized patients with T1DM and T2DM. METHODS: Mean blood glucose levels (BG) and their standard deviations (SD) at admission vs. discharge were compared in 52 subjects (48.1% ≥75 years) managed through a basal-bolus scheme including degludec. The percentages of patients with BG at target (140-180 mg/dl) or below at discharge and the incidence rate (and the 95% confidence interval for it) of hypoglycemia were assessed. RESULTS: From admission to discharge, fasting BG decreased from 237 to 153 mg/dl (p < 0.0001) and SD dropped from 125 to 38 mg/dl (p < 0.0001); average BG decreased from 189 to 145 mg/dl (SD dropped from 57 to 32 mg/dl). At discharge, 28.9% had BG at target, while 50.0% had lower levels (average 119.0 ± 14.4 mg/dl). The incidence rate of hypoglycemia was 0.07 (0.05; 0.11) episodes per person-day; 1 out of 27 episodes occurred during the night. CONCLUSIONS: Degludec in hospitalized, mainly elderly patients is effective and minimizes glucose variability and nocturnal hypoglycemia.

Correlation between baseline characteristics and clinical outcomes in a large population of diabetes patients treated with liraglutide in a real-world setting in Italy.

PURPOSE: Treatment with liraglutide in randomized controlled trials is associated with significant reductions in glycated hemoglobin (HbA1c) and weight loss in type 2 diabetes patients. The aim of this retrospective observational study was to investigate correlations of glycemic control and weight outcomes with baseline characteristics of patients starting liraglutide in outpatient clinics in Italy. METHODS: Type 2 diabetes patients were followed from baseline to 4, 8, and 12 months. Changes in glycemic parameters, weight, blood pressure, and lipids were assessed. Subanalyses were performed according to baseline characteristics. Multivariate linear and logistic regressions were used to assess correlations between glycemic efficacy, weight reduction, and liraglutide discontinuation after 12 months and baseline characteristics. FINDINGS: Four hundred and eighty-one patients were included. Mean (SD) age at baseline was 57.3 (9.2) years, diabetes duration was 9.5 (6.8) years, weight was 106.7 (20.8) kg, body mass index (BMI; calculated as kg/m(2)) was 37.1 (6.6), HbA1c was 8.7% (1.3%), fasting plasma glucose was 168.5 (45.3) mg/dL; 38.2% were treated previously with insulin and 52.2% were treated with metformin alone. After 12 months, mean (SD) changes were HbA1c -1.2% (1.4%), fasting plasma glucose -28.3 (41.1) mg/dL, weight -3.5 (5.8) kg, BMI -1.3 (2.1), waist circumference -2.6 (6.7) cm (all, P < 0.001). Drop in weight and HbA1c did not differ between baseline BMI classes ≤30 or >30. Weight loss was unchanged among diabetes duration quartiles, and HbA1c reduction was significantly greater in patients with ≤4 years of diabetes duration (P = 0.01). Non-insulin-treated patients reached HbA1c ≤7% significantly more often than treated patients (44.2% vs 21.2%; odds ratio = 2.94; P < 0.001) and had significantly greater weight loss (-4.5 [8.2] kg vs -2.6 [5.4] kg; P = 0.03). Patients on metformin reached HbA1c target more frequently than others (43.1% vs 29.7%; odds ratio = 1.80; 95% CI, 1.05-3.07). Significant positive determinants for HbA1c reduction after 12 months were baseline HbA1c, age, and prior metformin monotherapy, and weight loss at 12 months was positively correlated with baseline weight, and negatively correlated with prior insulin treatment. Overall, 5.0% of patients interrupted liraglutide before the 12th month due to lack of glycemic control; they were less frequently treated with metformin only before liraglutide (29.2% vs 50.2%; P = 0.04). IMPLICATIONS: Treatment with liraglutide in a real-world setting is associated with low therapy failure, good glycemic response, weight loss, and improvement in systolic blood pressure and lipid profile. The HbA1c drop did not differ among baseline BMI classes, indicating that efficacy is maintained in patients with lower BMI. The probability of reaching HbA1c ≤7% was significantly higher in patients previously treated with metformin alone and without any previous insulin. This could reinforce the hypothesis that better results with liraglutide could be achieved in patients after early metformin failure.

Independent glucose and weight-reducing effects of Liraglutide in a real-world population of type 2 diabetic outpatients.

The GLP-1 receptor agonist Liraglutide is effective in reducing HbA1c in type 2 diabetic (T2D) patients. In addition, treatment with Liraglutide is associated with significant weight loss. In this study, we analyzed the inter-relationships between glycemic and weight effects of Liraglutide treatment in a population of type 2 diabetic outpatients. T2D patients initiating Liraglutide therapy since September 2010 to July 2012 at 3 outpatient clinics were enrolled and followed-up. We collected baseline information about anthropometric data, cardiovascular risk factors, diabetes duration, prevalence of complications and history of anti-diabetic medications. We collected HbA1c and body weight at baseline and every 4 months. A total of 166 patients were included, who were on average 56.6 ± 8.9 (mean ± SD) years old and had a baseline HbA1c of 8.7 ± 1.3 % and BMI 36.3 ± 6.4 kg/m(2). Mean follow-up was 9.4 ± 4.2 months (range 4-16). Patients lost on average 1.5 ± 1.3 % HbA1c and 4.0 ± 5.0 kg body weight. Most patients (73.5 %) improved HbA1c and loosed weight. Significant independent determinants of HbA1c drop were baseline HbA1c (r = 0.673; p < 0.001) and previous insulin therapy (r = -0.251; p < 0.001). The only independent determinant of weight loss was baseline BMI (r = 0.429; p < 0.001). Drop in HbA1c was unrelated to baseline BMI or weight loss. Weight loss was unrelated to baseline HbA1c or drop in HbA1c. Glycemic improvement and weight reduction obtained with Liraglutide treatment in T2D patients in a real-world setting are independent and possibly mediated by different mechanisms.

Endothelial cells actively concentrate insulin during its transendothelial transport.

OBJECTIVE: We examined insulins uptake and transendothelial transport by endothelial cells in order to: (i) ascertain whether insulin accumulates within the cells to concentrations greater than in the media; (ii) compare trans endothelial insulin transport to that of inulin (using the latter as a tracer for passive transport or leaked); and; (iii) determine whether insulins transported depended on insulin action. METHODS: Using 125I-insulin at physiologic concentrations we measured both the uptake and trans endothelial transport of insulin by bovine aortic endothelial cells and measured cell volume using tritiated 3-O-methylglucose. RESULTS: Bovine aortic endothelial cells accumulate insulin to > five-fold above the media concentrations and the trans endothelial transport of insulin, but not inulin, is saturable and requires intact PI-3-kinase and MEK signaling. CONCLUSION: The insulin receptor and downstream signaling from the receptor regulates endothelial insulin transport. Insulin is accumulated against a concentration gradient by the endothelial cell. We suggest that insulin uptake is rate limiting for insulin trans endothelial transport.

The oral dipeptidyl peptidase-4 inhibitor sitagliptin increases circulating endothelial progenitor cells in patients with type 2 diabetes: possible role of stromal-derived factor-1alpha.

OBJECTIVE: Vasculoprotective endothelial progenitor cells (EPCs) are regulated by stromal-derived factor-1alpha (SDF-1alpha) and are reduced in type 2 diabetes. Because SDF-1alpha is a substrate of dipeptidyl-peptidase-4 (DPP-4), we investigated whether the DPP-4 inhibitor sitagliptin modulates EPC levels in type 2 diabetic patients. RESEARCH DESIGN AND METHODS: This was a controlled, nonrandomized clinical trial comparing 4-week sitagliptin (n = 16) versus no additional treatment (n = 16) in addition to metformin and/or secretagogues in type 2 diabetic patients. We determined circulating EPC levels and plasma concentrations of SDF-1alpha, monocyte chemoattractant protein-1 (MCP-1), vascular endothelial growth factor (VEGF), and nitrites/nitrates. RESULTS: There was no difference in clinical baseline data between the sitagliptin and control arms. After 4 weeks, as compared with control subjects, patients receiving sitagliptin showed a significant increase in EPCs and SDF-1alpha and a decrease in MCP-1. CONCLUSIONS: Sitagliptin increases circulating EPCs in type 2 diabetic patients with concomitant upregulation of SDF-1alpha. This ancillary effect of DPP-4 inhibition might have potential favorable cardiovascular implications.