BACKGROUND: The cardiovascular safety and efficacy of many current antihyperglycemic agents, including saxagliptin, a dipeptidyl peptidase 4 (DPP-4) inhibitor, are unclear. METHODS: We randomly assigned 16,492 patients with type 2 diabetes who had a history of, or were at risk for, cardiovascular events to receive saxagliptin or placebo and followed them for a median of 2.1 years. Physicians were permitted to adjust other medications, including antihyperglycemic agents. The primary end point was a composite of cardiovascular death, myocardial infarction, or ischemic stroke. RESULTS: A primary end-point event occurred in 613 patients in the saxagliptin group and in 609 patients in the placebo group (7.3% and 7.2%, respectively, according to 2-year Kaplan-Meier estimates; hazard ratio with saxagliptin, 1.00; 95% confidence interval [CI], 0.89 to 1.12; P=0.99 for superiority; P<0.001 for noninferiority); the results were similar in the "on-treatment" analysis (hazard ratio, 1.03; 95% CI, 0.91 to 1.17). The major secondary end point of a composite of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, coronary revascularization, or heart failure occurred in 1059 patients in the saxagliptin group and in 1034 patients in the placebo group (12.8% and 12.4%, respectively, according to 2-year Kaplan-Meier estimates; hazard ratio, 1.02; 95% CI, 0.94 to 1.11; P=0.66). More patients in the saxagliptin group than in the placebo group were hospitalized for heart failure (3.5% vs. 2.8%; hazard ratio, 1.27; 95% CI, 1.07 to 1.51; P=0.007). Rates of adjudicated cases of acute and chronic pancreatitis were similar in the two groups (acute pancreatitis, 0.3% in the saxagliptin group and 0.2% in the placebo group; chronic pancreatitis, <0.1% and 0.1% in the two groups, respectively). CONCLUSIONS: DPP-4 inhibition with saxagliptin did not increase or decrease the rate of ischemic events, though the rate of hospitalization for heart failure was increased. Although saxagliptin improves glycemic control, other approaches are necessary to reduce cardiovascular risk in patients with diabetes. (Funded by AstraZeneca and Bristol-Myers Squibb; SAVOR-TIMI 53 ClinicalTrials.gov number, NCT01107886.)

S U M M A R YThe recent success of pancreatic islet transplantation has generated considerable enthusiasm. To better understand the quality and characteristics of human islets used for transplantation, we performed detailed analysis of islet architecture and composition using confocal laser scanning microscopy. Human islets from six separate isolations provided by three different islet isolation centers were compared with isolated mouse and non-human primate islets. As expected from histological sections of murine pancreas, in isolated murine islets ␣ and ␦ cells resided at the periphery of the ␤ -cell core. However, human islets were markedly different in that ␣ , ␤ , and ␦ cells were dispersed throughout the islet. This pattern of cell distribution was present in all human islet preparations and islets of various sizes and was also seen in histological sections of human pancreas. The architecture of isolated non-human primate islets was very similar to that of human islets. Using an image analysis program, we calculated the volume of ␣ , ␤ , and ␦ cells. In contrast to murine islets, we found that populations of islet cell types varied considerably in human islets. The results indicate that human islets not only are quite heterogeneous in terms of cell composition but also have a substantially different architecture from widely studied murine islets.

iabetes mellitus (DM) adds incremental risk of the development and subsequent exacerbation of heart failure even after adjusting for common risk factors, such as ischemic heart disease and hypertension.1 Although incompletely understood, cardiac metabolic dysregulation of glycolysis and fatty acid oxidation observed in the heart of patients with Background-Diabetes mellitus and heart failure frequently coexist. However, few diabetes mellitus trials have prospectively evaluated and adjudicated heart failure as an end point. Methods and Results-A total of 16 492 patients with type 2 diabetes mellitus and a history of, or at risk of, cardiovascular events were randomized to saxagliptin or placebo (mean follow-up, 2.1 years). The primary end point was the composite of cardiovascular death, myocardial infarction, or ischemic stroke. Hospitalization for heart failure was a predefined component of the secondary end point. Baseline N-terminal pro B-type natriuretic peptide was measured in 12 301 patients. More patients treated with saxagliptin (289, 3.5%) were hospitalized for heart failure compared with placebo (228, 2.8%; hazard ratio, 1.27; 95% confidence intercal, 1.07-1.51; P=0.007). Corresponding rates at 12 months were 1.9% versus 1.3% (hazard ratio, 1.46; 95% confidence interval, 1.15-1.88; P=0.002), with no significant difference thereafter (time-varying interaction, P=0.017). Subjects at greatest risk of hospitalization for heart failure had previous heart failure, an estimated glomerular filtration rate ≤60 mL/min, or elevated baseline levels of N-terminal pro B-type natriuretic peptide. There was no evidence of heterogeneity between N-terminal pro B-type natriuretic peptide and saxagliptin (P for interaction=0.46), although the absolute risk excess for heart failure with saxagliptin was greatest in the highest N-terminal pro B-type natriuretic peptide quartile (2.1%). Even in patients at high risk of hospitalization for heart failure, the risk of the primary and secondary end points were similar between treatment groups. Conclusions-In the context of balanced primary and secondary end points, saxagliptin treatment was associated with an increased risk or hospitalization for heart failure. This increase in risk was highest among patients with elevated levels of natriuretic peptides, previous heart failure, or chronic kidney disease. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01107886.

The peptide hormone, glucagon-like peptide 1 (GLP-1), has been shown to increase glucose-dependent insulin secretion, enhance insulin gene transcription, expand islet cell mass, and inhibit beta-cell apoptosis in animal models of diabetes. The aim of the present study was to evaluate whether GLP-1 could improve function and inhibit apoptosis in freshly isolated human islets. Human islets were cultured for 5 d in the presence, or absence, of GLP-1 (10 nm, added every 12 h) and studied for viability and expression of proapoptotic (caspase-3) and antiapoptotic factors (bcl-2) as well as glucose-dependent insulin production. We observed better-preserved three-dimensional islet morphology in the GLP-1-treated islets, compared with controls. Nuclear condensation, a feature of cell apoptosis, was inhibited by GLP-1. The reduction in the number of apoptotic cells in GLP-1-treated islets was particularly evident at d 3 (6.1% apoptotic nuclei in treated cultures vs. 15.5% in controls; P < 0.01) and at d 5 (8.9 vs. 18.9%; P < 0.01). The antiapoptotic effect of GLP-1 was associated with the down-regulation of active caspase-3 (P < 0.001) and the up-regulation of bcl-2 (P < 0.01). The effect of GLP-1 on the intracellular levels of bcl-2 and caspase-3 was observed at the mRNA and protein levels. Intracellular insulin content was markedly enhanced in islets cultured with GLP-1 vs. control (P < 0.001, at d 5), and there was a parallel GLP-1-dependent potentiation of glucose-dependent insulin secretion (P < 0.01 at d 3; P < 0.05 at d 5). Our findings provide evidence that GLP-1 added to freshly isolated human islets preserves morphology and function and inhibits cell apoptosis.

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OBJECTIVEThis study compared the efficacy and safety of dual add-on of saxagliptin plus dapagliflozin versus saxagliptin and dapagliflozin added on alone in patients with type 2 diabetes poorly controlled with metformin. RESEARCH DESIGN AND METHODSThis was a double-blind trial in adults with HbA 1c ‡8.0% and £12.0% (64-108 mmol/mol), randomized to saxagliptin (SAXA) (5 mg/day) plus dapagliflozin (DAPA) (10 mg/day; n = 179), or SAXA (5 mg/day) and placebo (n = 176), or DAPA (10 mg/day) and placebo (n = 179) on background metformin extended release (MET) ‡1,500 mg/day. Primary objective compared changes from baseline in HbA 1c with SAXA+DAPA+MET versus SAXA+MET and DAPA+MET. RESULTSPatients had a mean baseline HbA 1c of 8.9% (74 mmol/mol), diabetes duration of 7.6 years, and a BMI of 32 kg/m 2 . At week 24, the adjusted mean change from the baseline HbA 1c was -1.5% (-16.1 mmol/mol) with SAXA+DAPA+MET versus -0.9% (-9.6 mmol/mol) with SAXA+MET (difference 20.59% [-6.4 mmol/mol], P < 0.0001) and -1.2% (-13.1 mmol/mol) with DAPA+MET (difference 20.27% [3.0 mmol/mol], P < 0.02). The proportion of patients achieving HbA 1c <7% (53 mmol/mol) was 41% with SAXA+DAPA+MET versus 18% with SAXA+MET and 22% with DAPA+MET. Urinary and genital infections occurred in £1% of patients receiving SAXA+DAPA+MET. Hypoglycemia was infrequent, with no episodes of major hypoglycemia. CONCLUSIONSIn this first report of adding a well-tolerated combination of saxagliptin plus dapagliflozin to background metformin therapy in patients poorly controlled with metformin, greater improvements in glycemic control were obtained with triple therapy by the dual addition of saxagliptin and dapagliflozin than dual therapy with the addition of saxagliptin or dapagliflozin alone.

ANCREATIC TRANSPLANTATION IS a therapeutic option for patients with complicated diabetes mellitus. The American Diabetes Association supports the procedure for patients with diabetes who have had, or need, a kidney transplant. In the absence of kidney failure, pancreas transplantation may be considered for patients with diabetes and severe and frequent metabolic instability (ie, hypoglycemia, ketoacidosis). 1 Despite current controversy, and while the annual number of simultaneous pancreas-kidney transplants remained stable from 1995 to 2002, over that same interval the annual number of solitary pancreas transplants (ie, pancreas transplant alone or pancreas-after-kidney transplant) increased 5-fold (United Network for Organ Sharing/Organ Procurement and Transplantation Network [UNOS/OPTN] data as of May 2, 2003).Specific US transplant numbers document this trend: 910 simultaneous pancreas-kidney transplants were performed in 1995 and 902 were performed in 2002 . In contrast, in 1995

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