Sitagliptin Compared with Thiazolidinediones as a Third-Line Oral Antihyperglycemic Agent in Type 2 Diabetes Mellitus

ObjectiveTo compare sitagliptin and thiazolidinediones as third-line oral antihyperglycemic agents among ethnic minority patients with poorly controlled type 2 diabetes mellitus.MethodsIn an open-label, single-arm design, we treated type 2 diabetic patients who had suboptimal diabetes control on maximum tolerated dosages of metformin plus sulfonylureas with the addition of sitagliptin, 100 mg daily, and compared their responses with findings from a historical control group of similar patients treated with rosiglitazone, 8 mg daily, or pioglitazone, 45 mg daily, as their third-line oral agent. Patients were assessed bimonthly, and those who achieved hemoglobin A_1c levels less than 7.5% at 4 months continued through 1 year of follow-up.Results:One hundred eight patients were treated with sitagliptin, and 104 patients constituted the historical control group treated with rosiglitazone or pioglitazone. At baseline, sitagliptinand thiazolidinedione-treated patients had identical hemoglobin A_1c levels (mean ± SD) (9.4 ± 1.8% and 9.4 ± 1.9%, respectively) and similar known diabetes duration (6.7 ± 5.0 years and 7.6 ± 5.8 years, respectively). Hemoglobin A_1c was reduced in both groups at 4 months (P < .001), but the reduction was greater with thiazolidinediones than with sitagliptin (-2.0 ± 1.7% vs -1.3 ± 1.8%; P = .006), as was the proportion of patients achieving a hemoglobin A_1c level less than 7.5% (62% vs 46%; P = .026). Of all patients achieving a hemoglobin A_1c level less than 7.5% at 4 months, the same proportions in each group sustained their hemoglobin A_1c level less than 7.5% by 12 months (59% vs 58%). Sitagliptin was well tolerated.ConclusionsAmong ethnic minority patients with poorly controlled type 2 diabetes while taking maximum tolerated dosages of metformin and sulfonylureas, thirdline add-on therapy with a thiazolidinedione controlled hyperglycemia more effectively than sitagliptin after 4 months. (Endocr Pract. 2011;17:691-698)     

Case report of acute necrotizing pancreatitis associated with combination treatment of sitagliptin and exenatide

ObjectiveTo report the first postmarketing case of necrotizing pancreatitis in a patient on combination therapy of sitagliptin and exenatide.MethodsWe describe the patient’s clinical presentation, laboratory test results, imaging, and autopsy findings.ResultsA 76-year-old woman with a history of type 2 diabetes mellitus presented with severe abdominal pain, vomiting, and fever requiring hospital admission. She had been treated with exenatide for 3 years to manage her diabetes mellitus. A few weeks before presentation, sitagliptin was added, presumably to further optimize her glycemic control. Acute pancreatitis was diagnosed during hospital admission. At initial presentation, her serum amylase concentration was 1136 U/L (reference range, 10-130 U/L) and her lipase concentration was greater than 3500 U/L (reference range, 0-75 U/L). In addition, computed tomography of the abdomen and pelvis demonstrated extensive pancreatic parenchymal necrosis. She had undergone previous cholecystectomy, reported no alcohol consumption, and had a normal lipid profile. Although she had a long-standing history of diabetes mellitus, she had no history of pancreatitis or other risk factors that would have caused her to develop the underlying condition. After initial brief improvement, her symptoms worsened, and despite aggressive care, her clinical state deteriorated and she died. Autopsy findings demonstrated acute necrotizing pancreatitis with complete digestion of the pancreas.ConclusionsConsidering the temporal relationship of her symptoms to the addition of sitagliptin to her existing exenatide regimen, this case strongly suggests a possible causal link between exenatide or sitagliptin (or the combination of the 2 drugs) and the etiology of pancreatitis in this patient. (Endocr Pract. 2012;18:e10-e13)     

Reduction of serum FABP4 level by sitagliptin,a DPP-4 inhibitor,in patients with type 2 diabetes mellitus

Fatty acid binding protein 4 (FABP4), also known as adipocyte FABP or aP2, is secreted from adipocytes in association with lipolysis as a novel adipokine, and elevated serum FABP4 level is associated with obesity, insulin resistance, and atherosclerosis. However, little is known about the modulation of serum FABP4 level by therapeutic drugs. Sitagliptin (50 mg/day), a dipeptidyl peptidase 4 (DPP-4) inhibitor that increases glucagon-like peptide 1 (GLP-1), was administered to patients with type 2 diabetes (n = 24) for 12 weeks. Treatment with sitagliptin decreased serum FABP4 concentration by 19.7% (17.8 ± 1.8 vs. 14.3 ± 1.5 ng/ml, P < 0.001) and hemoglobin A1c without significant changes in adiposity or lipid variables. In 3T3-L1 adipocytes, sitagliptin or exendin-4, a GLP-1 receptor agonist, had no effect on short-term (2 h) secretion of FABP4. However, gene expression and long-term (24 h) secretion of FABP4 were significantly reduced by sitagliptin, which was not mimicked by exendin-4. Treatment with recombinant DPP-4 increased gene expression and long-term secretion of FABP4, and the effects were cancelled by sitagliptin. Furthermore, knockdown of DPP-4 in 3T3-L1 adipocytes decreased gene expression and long-term secretion of FABP4. In conclusion, sitagliptin decreases serum FABP4 level, at least in part, via reduction in the expression and consecutive secretion of FABP4 in adipocytes by direct inhibition of DPP-4.     

DPP-4 Inhibitor Therapy in Patients after Pancreatic Transplant

Objective: Management of new onset hyperglycemia after pancreas transplantation (PT) is not well studied. There is a lack of information on effective and safe management options for hyperglycemia after PT. We tested the hypothesis that early intervention for hyperglycemia using a dipeptidyl peptidase-4 (DPP-4) inhibitor prolongs insulin-free graft function in patients after PT.Methods: Twenty-six patients who developed noninsulin-dependent hyperglycemia at least 1 year after PT met the inclusion criteria for this retrospective chart review. Sitagliptin, a DPP-4 inhibitor, was a commonly used therapy for hyperglycemia after PT due to its wide availability and coverage. The standard therapy group included patients who did not receive any oral or noninsulin injection therapy until insulin was clearly required to control hyperglycemia. The intervention group included patients who had received sitagliptin soon after hyperglycemia developed. The median follow-up period was 45 months. The time to hyperglycemia from 1 year after PT and time to insulin requirement after hyperglycemia development were compared between these 2 groups.Results: The time to hyperglycemia after PT was not different between the groups, but the time to insulin requirement was significantly longer in the intervention group compared with the standard therapy group (P<.001). After adjusting for body mass index (BMI), the difference remained significant (P<.001).Conclusion: Early treatment of hyperglycemia after PT with a DPP-4 inhibitor such as sitagliptin prolongs the time to insulin therapy compared with a standard observation approach. Prospective studies are needed to further investigate this observation.Abbreviations: BG = blood glucose BMI = body mass index CV = coefficient of variance DM = diabetes mellitus DPP-4 = dipeptidyl peptidase-4 HbA1c = glycated hemoglobin NODAT = new-onset diabetes after transplantation OHA = oral hypoglycemic agent PT = pancreas transplantation     

Linagliptin prevents left ventricular stiffening by reducing titin cleavage and hypophosphorylation

The metabolic syndrome (MetS) is an escalating problem worldwide, causing left ventricular stiffening, an early characteristic of diastolic dysfunction for which no treatment exists. As diastolic dysfunction and stiffening in MetS patients are associated with increased circulating dipeptidyl peptidase-4 (DPP-4) levels, we investigated whether the clinically approved DPP-4 inhibitor linagliptin reduces left ventricular stiffness in MetS-induced cardiac disease. Sixteen-week-old obese ZSF1 rats, displaying the MetS and left ventricular stiffness, received linagliptin-supplemented or placebo diet for four weeks. Linagliptin significantly reduced obesity, hyperlipidaemia, and hyperglycaemia and improved left ventricular relaxation. This improved relaxation was related to decreased cardiac fibrosis and cardiomyocyte passive stiffness (F_passive). The reduced F_passive was the result of titin isoform switching from the stiff N2B to the more flexible N2BA and increased phosphorylation of total titin and specifically its N2Bus region (S4080 and S3391). Importantly, DPP-4 directly cleaved titin in vitro, resulting in an increased F_passive, which was prevented by simultaneous administration of linagliptin. In conclusion, linagliptin improves left ventricular stiffness in obese ZSF1 rats by preventing direct DPP4-mediated titin cleavage, as well as by modulating both titin isoform levels and phosphorylation. Reducing left ventricular stiffness by administering linagliptin might prevent MetS-induced early diastolic dysfunction in human.     

Decreased Mortality After Long-Term Treatment With Dipeptidyl Peptidase-4 Inhibitors: A Retrospective Study of U.S. Veterans With Type 2 Diabetes

ObjectiveThe prevalence of chronic kidney disease (CKD) in the United States is 13% of the general population. Among those with CKD, diabetic nephropathy is the leading cause of end-stage renal disease. This is a retrospective study examining the effect of long-term use of dipeptidyl peptidase-4 (DPP-4) inhibitors on all-cause mortality and progression of renal disease in the veteran population.MethodsData was extracted using the Veterans Administration Informatics and Computing Infrastructure. A large cohort of veterans diagnosed with type 2 diabetes mellitus were used to identify patients on DPP-4 inhibitors and without DPP-4 inhibitors. Groups were compared to determine the effect of DPP-4 inhibitors on the progression of CKD and all-cause mortality. Data were analyzed using SAS.ResultsSubjects in the treatment group (n = 40 558) had baseline variables (age, body mass index, race) similar to the control group (n = 40 558). Diabetes control improved in the treatment group (HgbA1c, 8.3% [67 mmol/mol] to 7.8% [62 mmol/mol]; P < .001) but not in the control group (HgbA1c, 7.4% [57 mmol/mol] to 7.3% [56 mmol/mol]). New diagnoses of heart failure and coronary artery bypass grafts were clinically significant (odds ratios = 0.66 and 0.52). No change in progression of CKD was seen in either group. All-cause mortality was reduced by 59%.ConclusionWe conclude that DPP-4 inhibitors are associated with a significant reduction in all-cause mortality independent of glucose control, albeit with no clear cause, including obtainable cardiovascular outcomes. Our data is consistent with prior trials in that DPP-4 inhibitors did not show a significant change in serum creatinine or microalbuminuria.     

Synthesis and biological evaluation of novel benzyl-substituted (S)-phenylalanine derivatives as potent dipeptidyl peptidase 4 inhibitors

A series of novel benzyl-substituted (S)-phenylalanine derivatives were synthesized and evaluated for their dipeptidyl peptidase 4 (DPP-4) inhibitory activity and selectivity. It was found that most synthesized target compounds were potent DPP-4 inhibitors with IC₅₀ values in 3.79–25.52 nM, which were significantly superior to that of the marketed drug sitagliptin. Furthermore, the 4-fluorobenzyl substituted phenylalanine derivative 6g not only displayed the potent DPP-4 inhibition with an IC₅₀ value of 3.79 nM, but also showed better selectivity against DPP-4 over other related enzymes including DPP-7, DPP-8, and DPP-9. In an oral glucose tolerance test (OGTT) in normal Sprague Dawley rats, compound 6g reduced blood glucose excursion in a dose-dependent manner.     

Ethnic disparity in hemoglobin A1c levels among normoglycemic offspring of parents with type 2 diabetes mellitus

ObjectiveTo investigate the racial/ethnic disparities in hemoglobin A_1c levels among nondiabetic persons with similar parental history of type 2 diabetes mellitus.MethodsWe studied a community-based sample of adult offspring of parents with type 2 diabetes mellitus. Measurements included anthropometry, hematology assessments, serial fasting plasma glucose, oral glucose tolerance testing, plasma insulin, hemoglobin A_1c, insulin sensitivity, and b-cell function, using a homeostasis model assessment.ResultsThe study included 302 participants (135 white, 167 black). Compared with white participants, black participants had lower fasting plasma glucose levels (91.9 ± 0.51 mg/dL vs 93.6 ± 0.50 mg/dL, P = .015), lower area under the curve of plasma glucose during oral glucose tolerance testing (P = <.001), higher body mass index (31.1 ± 0.61 kg/m² vs 28.5 ± 0.57 kg/m², P = <.001), and similar insulin sensitivity and b-cell function. Hemoglobin A_1c was higher in black participants than in white participants (5.68 ± 0.033% vs 5.45 ± 0.028%, P <.001). The absolute black-white difference in hemoglobin A_1c level of approximately 0.22% persisted after adjusting for age, hemoglobin, hematocrit, body mass index, waist circumference, fasting plasma glucose, glucose area under the curve, and other covariates.ConclusionsAmong healthy offspring of parents with type 2 diabetes mellitus in this study, African American participants had higher hemoglobin A_1c levels than white participants after adjusting for age, adiposity, blood glucose, and known variables. Thus, plasma glucose level is more valid than hemoglobin A_1c for diagnosing prediabetes or diabetes in black persons. (Endocr Pract. 2012; 18:356-362)     

Preadmission Glycemic Control and Changes to Diabetes Mellitus Treatment Regimen After Hospitalization

ObjectiveTo evaluate treatment patterns associated with diabetes medication regimen changes after hospitalization on the basis on preadmission hemoglobin A_1c levels.MethodsIn this retrospective database analysis, patients with a diabetes diagnosis, hospitalization, and documented hemoglobin A_1c level within the 90 days leading up to hospital admission were identified in an administrative claims database. Treatment regimens were assessed before and after hospitalization. The proportion of patients who had progression, reduction, or no change in therapy was compared across hemoglobin A_1c subgroups: hemoglobin A_1c < 7.0%, hemoglobin A_1c 7.0%-7.9%, and hemoglobin A_1c ≥ 8.0%.ResultsFour hundred patients were included (192 in hemoglobin A_1c < 7.0% group, 94 in hemoglobin A_1c 7.0% 7.9% group, and 114 in hemoglobin A_1c ≥ 8.0% group). Demographically, hemoglobin A_1c subgroups did not differ significantly (mean age, 57 years; 47.5% male). With respect to therapeutic regimen overall, 28%, 24%, and 48% of patients experienced progression, reduction, and no change, respectively. Across hemoglobin A_1c subgroups, 37.7% of patients in the hemoglobin A_1c ≥ 8.0% subgroup had therapy progression compared with 26% and 20.2% in the hemoglobin A_1c < 7.0% and hemoglobin A_1c 7.0%-7.9% subgroups, respectively (P = .032 and P = .006, respectively). Within the progression category, progression via insulin initiation was significantly higher in the hemoglobin A_1c ≥ 8.0% subgroup (55.8%) than in the hemoglobin A_1c < 7.0% subgroup (16%, P < .001), but not significantly higher than in the hemoglobin A_1c 7.0%-7.9% subgroup (36.8%, P = .084). In the hemoglobin A_1c ≥ 8.0% subgroup, a lower percentage of patients, 35.1%, experienced no therapy change than in both the hemoglobin A_1c < 7.0% subgroup (52.6%) and the hemoglobin A_1c 7.0%-7.9% subgroup (54.3%) (P = .003 and P = .006, respectively). There was no difference between subgroups in reduction of therapy.ConclusionsA higher proportion of patients with a hemoglobin A_1c level ≥ 8.0% had progression of their antidiabetes therapy after hospitalization and fewer patients had no change in therapy than those in lower hemoglobin A_1c subgroups. These data suggest that clinicians may be using hemoglobin A_1c measurements to guide discharge planning treatment decisions. (Endocr Pract. 2012;18:371-375)     

Synthesis,nitric oxide release,and dipeptidyl peptidase-4 inhibition of sitagliptin derivatives as new multifunctional antidiabetic agents

Nitric oxide (NO) dysfunction has been found to be an important factor in both the development and progression of diabetic complications due to its many roles in the vascular system. Multifunctional compounds with hypoglycemic and endothelial protective action will be promising agents for the treatment of diabetes and its complications. In this study, a series of novel NO-donating sitagliptin derivatives and relevant metabolites were synthesized and evaluated as potential multifunctional hypoglycemic agents. All of synthetic compounds shown remarkable inhibitory activity against dipeptidyl peptidase IV (DPP-IV) in vitro and demonstrated excellent hypoglycemic activities in diabetic mice, similar to the activity of sitagliptin, and compounds T1-T4 shown different extents of NO-releasing abilities and potent antioxidant abilities in vivo. By screening in DPP-4, compound T4 was recognized as a potent DPP-4 inhibitor with the IC₅₀ value of 0.060?μM. Docking study revealed compound T4 has a favorable binding mode. Furthermore, compounds T1-T4 exhibited different extents of NO-releasing abilities and excellent anti-platelet aggregation in vitro. The overall results suggested that T4 could help to the amelioration of endothelial dysfunction by reducing blood glucose, lessening oxidative stress and raising NO levels as well as inhibiting platelet aggregation. Based on this research, compound T4 deserves further investigation as potential new multifunctional anti-diabetic agent with antioxidant, anti-platelet aggregation and endothelial protective properties.     

Natural compounds with DPP-4 inhibitory effects: Implications for the treatment of diabetes

Dipeptidyl peptidase-4 (DPP-4) inhibitors are antidiabetes agents that decrease blood glucose by preventing the degradation of endogenous glucagon-like peptide-1. The first DPP-4 was sitagliptin followed by several other agents in the class introduced to manage diabetes. Recent studies have suggested that naturally occurring compounds can exert an antidiabetes effect through DPP-4 inhibition. Such compounds may have a place in the treatment of diabetes within the diet; however, while DPP-4 inhibition alone is not associated with hypoglycemia, in combinations with other medication hypoglycemia can result, therefore, it is critical to know what herbal or food-based compounds may have these activities in the management of diabetes patients. In this review, we have outlined the compounds that have DPP-4 inhibition that may have utility in the treatment of diabetes.     

Markedly Low Hemoglobin A1c in a Patient with an Unusual Presentation of ß-Thalassemia Minor

ObjectiveTo describe very low hemoglobin A_1c levels in a patient with type 2 diabetes mellitus and an unusual presentation of β-thalassemia minor.MethodsWe present the clinical and laboratory findings of the study patient.ResultsA 64-year-old African American man with type 2 diabetes mellitus was referred to the endocrinology clinic with a hemoglobin A_1c level of 1.6% despite elevated blood glucose concentrations. A red blood cell survival study with chromium-51 revealed that he had a reduced erythrocyte life span less than 25% of normal. He also had a markedly elevated reticulocyte count ranging from 236 to 534 x 10³/μL (reference range, 25-75 x 103/μL). The laboratory findings, which are not characteristic of ß-thalassemia minor, could be the cause of the markedly low hemoglobin A_1c in this patient.ConclusionsAlthough rare, when associated with marked erythrocyte turnover, β-thalassemia minor can lead to a severe reduction in HbA_1c levels. In this scenario, glycemic control is best assessed by measuring fructosamine. (Endocr Pract. 2010;16:89-92)     

Impact of Race/Ethnicity on the Efficacy and Safety of Commonly used Insulin Regimens: A Post HOC Analysis of Clinical Trials in Type 2 Diabetes Mellitus

ObjectiveTo explore the impact of race/ethnicity on the efficacy and safety of commonly used insulin regimens in patients with type 2 diabetes mellitus.MethodsIn this post hoc analysis, pooled data from 11 multinational clinical trials involving 1455 patients with type 2 diabetes were used to compare specific insulin treatments in Latino/Hispanic, Asian, African-descent, and Caucasian patients. Insulin treatments included once daily insulin glargine or neutral protamine Hagedorn (BASAL), insulin lispro mix 75/25 twice daily (LMBID), or insulin lispro mix 50/50 three times daily (LMTID).ResultsRace/ethnicity was associated with significant outcome differences for each of the insulin regimens. BASAL therapy was associated with greater improvement in several measures of glycemic control among Latino/Hispanic patients compared with Caucasian patients (lower end point hemoglobin A1c, greater reduction in hemoglobin A1c from baseline, and a larger proportion of patients achieving hemoglobin A1c level < 7%). In contrast, LMBID therapy was associated with higher end point hemoglobin A_1c and a smaller decrease in hemoglobin A_1c from baseline in Latino/Hispanic and Asian patients than in Caucasian patients. Furthermore, fewer Asian patients attained a hemoglobin A_1c level < 7% than did Caucasians patients. For LMTID therapy, hemoglobin A_1c outcomes were comparable across patient groups. Fasting blood glucose and glycemic excursions varied among racial/ethnic groups for the 3 insulin regimens. Weight change was comparable among racial/ethnic groups in each insulin regimen. During treatment with LMTID, Asian patients experienced higher incidence and rate of severe hypoglycemia than Caucasian patients.ConclusionsLatino/Hispanic, Asian, and African-descent patients with type 2 diabetes show different metabolic responses to insulin therapy, dependent in part on insulin type and regimen intensity. (Endocr Pract. 2010: 818-828:pp)     

Effect of Sitagliptin on Post-Prandial Glucagon and GLP-1 Levels in Patients With Type 1 Diabetes: Investigator-Initiated,Double-Blind,Randomized, Placebo-Controlled Trial

ObjectivePeripheral insulin resistance in type 1 diabetes may be related to a paradoxical postprandial glucagon increase. This study evaluated the effects of sitagliptin (dipeptidyl peptidase-IV [DPP-IV] inhibitor, approved for patients with type 2 diabetes), in adults with type 1 diabetes to improve glycemic control through decreasing postprandial glucagon.MethodsThis investigator-initiated, double-blind, randomized-parallel 20-week study enrolled 141 subjects. Subjects received sitagliptin 100 mg/day or placebo for 16 weeks. A subset of 85 patients wore blinded continuous glucose monitors (CGM) for 5 separate 7-day periods. The primary outcome was post-meal (Boost™) reduction in 4-hour glucagon area under the curve (AUC). Secondary endpoints included changes in glycated hemoglobin (A1c), CGM data, insulin dose, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and C-peptide levels.ResultsThere were no differences at screening between groups; however, after a 4-week run-in phase, A1c was significantly lower in the sitagliptin vs. placebo group. Post-meal GLP-1 levels were higher (P<.001) and GIP levels lower (P = .03), with glucagon suppression at 30 minutes (LS means 23.2 ± 1.9 versus 16.0 ± 1.8; P = .006) in the sitagliptin group at 16 weeks. There were no differences between the groups in change in A1c, insulin dose, weight, or C-peptide after 16 weeks of treatment. However, C-peptide positive patients randomized to sitagliplin had a non-significant trend toward decrease in A1c, mean glucose, and time spent in hyperglycemia.ConclusionSitagliptin use in type 1 diabetes did not change glucagon AUC, A1c, insulin dose, or weight despite post-meal rise in GLP-1 levels. C-peptide positive subjects treated with sitagliptin had a nonsignificant trend in decreasing hyperglycemia, which needs further evaluation. (Endocr Pract. 2013;19:19-28)     

Resolution Of Diabetes After Initiation Of Antiretroviral Therapy In Two Human Immunodeficiency Virus-Infected Patients

ObjectiveTo describe two cases of human immunodeficiency virus (HlV)-infected patients who had diabetes mellitus, which resolved after initiation of antiretroviral therapy.MethodsWe present the clinical and laboratory findings and describe the clinical course of these two patients.ResultsA 48-year-old HIV-infected black woman presented with multiple infections and hyperglycemia. After her acute infections were treated and she was feeling well, she continued to have diabetes that necessitated insulin therapy. Administration of a protease inhibitor-based antiretroviral regimen resolved her diabetes and eliminated the need for insulin or oral therapy. Our second patient, a 37-year-old HIV-infected black man, presented with polyuria and polydipsia and a hemoglobin A1c value of 11%. He received antiretroviral therapy, and his diabetes resolved after a period of 2½ months.ConclusionProtease inhibitor-based antiretroviral therapy is associated with diabetes mellitus in up to 6% of HIV-infected patients. Although most HIV-infected patients in whom diabetes develops have this disorder after initiation of protease inhibitor therapy, the current two cases illustrate patients in whom diabetes resolved after use of antiretroviral therapy. This finding supports the presence of other mechanisms that affect glucose metabolism in patients infected with HIV and suggests that control of HIV infection may have a role in controlling diabetes. (Endocr Pract. 2004;10:199-202)     

Continuous Subcutaneous Infusion of Insulin Lispro in Children and Adolescents with Type 1 Diabetes Mellitus

ObjectiveTo provide a comprehensive review of insulin lispro administered by continuous subcutaneous insulin infusion (CSII) in children and adolescents.MethodsWe performed PubMed literature searches to identify clinical studies of insulin lispro administered via CSII within pediatric and adolescent populations.ResultsTwenty-six studies involving 2521 pediatric patients with type 1 diabetes mellitus met inclusion criteria. Of these, 10 were randomized controlled trials (RCTs), 6 of which compared insulin lispro CSII with multiple daily injection (MDI) therapy. We identified 7 additional prospective, nonrandomized studies and 9 retrospective studies. Within the RCTs, endpoint hemoglobin A_1c levels ranged from 6.3% to 8.5% for insulin lispro CSII therapy and from 6.2% to 8.7% for those trials with MDI comparator arms. In those trials that compared insulin lispro CSII with MDI, the endpoint hemoglobin A_1c achieved with insulin lispro was similar or improved compared with observations in the MDI treatment arm. In the RCTs, severe hypoglycemia rates of 0.1 to 0.3 episodes/patient per year were reported for insulin lispro CSII therapy; those trials with MDI comparator arms reported relatively similar severe hypoglycemia rates (0.1 to 0.5 episodes/patient per year). Events of diabetic ketoacidosis (DKA) were rare. Where reported, insulin lispro CSII and MDI therapy demonstrated a similar occurrence of DKA and incidence of severe hypoglycemia. Prospective and retrospective studies demonstrated results similar to the RCT findings.ConclusionsIn 26 studies of more than 2500 pediatric and adolescent patients with type 1 diabetes, with more than 1000 patients specifically receiving insulin lispro CSII, insulin lispro CSII therapy consistently demonstrated similar or improved efficacy and safety vs studied comparators. (Endocr Pract. 2012;18:418-424)     

Mody-3: Novel HNF1A Mutation and the Utility of Glucagon-Like Peptide (GLP)-1 Receptor Agonist Therapy

ObjectiveAn estimated 1 to 2% of cases of diabetes mellitus have a monogenic basis; however, delayed diagnosis and misdiagnosis as type 1 and 2 diabetes are common. Correctly identifying the molecular basis of an individual’s diabetes may significantly alter the management approach to both the patient and his or her relatives. We describe a case of mature onset diabetes of the young (MODY) with sufficient evidence to support the classification of a novel HNF1A (hepatocyte nuclear factor-1-α) mutation as a cause of MODY-3.MethodsA 21-year-old Caucasian female presented to our office with a diagnosis of noninsulin-dependent diabetes mellitus (NIDDM) at age 10; glycemia was initially managed with oral antidiabetic (OAD) agents and insulin detemir. The patient reported a strong family history of early-onset NIDDM in both her mother and maternal grandmother, both of whom eventually required insulin therapy to control glycemia. The patient’s medical and family history were highly suggestive of maturity-onset diabetes of the young (MODY), and genetic testing was performed.ResultsGenetic screening detected a mutation p.Arg200Trp in the HNF1A gene in the patient, her mother, and maternal grandmother, suggesting a diagnosis of MODY-3. This finding resulted in a change of antidiabetic therapy in all 3 patients, including the addition of once-daily liraglutide therapy, which helped improve their glycemic control.ConclusionOur case report supports the classification of the p.Arg200Trp mutation as a cause of MODY-3. The findings also suggest that glucagon-like peptide-1 (GLP-1) receptor agonist therapy may be of value in managing glycemia in patients with MODY-3. (Endocr Pract. 2014;20:107-111)     

Effects of Colesevelam,Rosiglitazone, or Sitagliptin on Glycemic Control and Lipid Profile in Patients with Type 2 Diabetes Mellitus Inadequately Controlled by Metformin Monotherapy

ObjectiveTo evaluate the glycemic effect of colesevelam, rosiglitazone, or sitagliptin when added to metformin monotherapy in patients with type 2 diabetes mellitus (DM) and to examine the effects of these antidiabetes agents on lipid and lipoprotein levels.MethodsThis 16-week, open-label pilot study conducted between May 2007 and April 2008 at 20 sites in the United States, 7 sites in Mexico, and 6 sites in Colombia, enrolled adults with inadequately controlled type 2 DM (glycated hemoglobin [HbA_1c], 7.0%-10.0%) on a stable metformin regimen (1500-2550 mg daily for ≥ 3 months). At Week 0, participants were randomly assigned 1:1:1 to open-label colesevelam hydrochloride, 3.75 g daily; openlabel rosiglitazone maleate, 4 mg daily; or open-label sitagliptin phosphate, 100 mg daily, in addition to existing metformin therapy. The primary efficacy variable was the change in HbA_1c from baseline to Week 16 with last (postbaseline) observation carried forward.ResultsIn total, 169 participants were randomly assigned to treatment groups (colesevelam, n = 57; rosiglitazone, n = 56; and sitagliptin, n = 56), and 141 participants (83.4%) completed the study. Least-squares mean reductions in HbA_1c from baseline were observed in all groups at Week 16 last observation carried forward (colesevelam, -0.3% [P <.031]; rosiglitazone: -0.6% [P <.001]; sitagliptin: -0.4% [P <.009]) At study end, 10 of 56 participants (17.9%) in the colesevelam group, 19 of 54 (35.2%) in the rosiglitazone group, and 15 of 55 (27.3%) in the sitagliptin group achieved HbA_1c < 7.0%. Colesevelam significantly reduced mean low-density lipoprotein (LDL)-cholesterol levels relative to baseline (11.6%), whereas levels were significantly increased with rosiglitazone and sitagliptin at Week 16 last observation carried forward (7.8% and 7.7%, respectively). Twenty-two of 52 participants (42.3%) in the colesevelam group, 12 of 51 (23.5%) in the rosiglitazone group, and 13 of 53 (24.5%) in the sitagliptin group achieved LDL cholesterol < 100 mg/dL at Week 16 last observation carried forward.ConclusionAll 3 antidiabetes agents significantly improved glycemic control, but only colesevelam also significantly reduced LDL-cholesterol levels in patients with type 2 DM. (Endocr Pract. 2010;16:53-63)     

Dipeptidyl Peptidase-4 Inhibitor Decreases Abdominal Aortic Aneurysm Formation through GLP-1-Dependent Monocytic Activity in Mice

Abdominal aortic aneurysm (AAA) is a life-threatening situation affecting almost 10% of elders. There has been no effective medication for AAA other than surgical intervention. Dipeptidyl peptidase-4 (DPP-4) inhibitors have been shown to have a protective effect on cardiovascular disease. Whether DPP-4 inhibitors may be beneficial in the treatment of AAA is unclear. We investigated the effects of DPP-4 inhibitor sitagliptin on the angiotensin II (Ang II)-infused AAA formation in apoE-deficient (apoE^-/-) mice. Mice with induced AAA were treated with placebo or 2.5, 5 or 10 mg/kg/day sitagliptin. Ang II-infused apoE^-/- mice exhibited a 55.6% incidence of AAA formation, but treatment with sitagliptin decreased AAA formation. Specifically, administered sitagliptin in Ang II-infused mice exhibited decreased expansion of the suprarenal aorta, reduced elastin lamina degradation of the aorta, and diminished vascular inflammation by macrophage infiltration. Treatment with sitagliptin decreased gelatinolytic activity and apoptotic cells in aorta tissues. Sitaglipitn, additionally, was associated with increased levels of plasma active glucagon-like peptide-1 (GLP-1). In vitro studies, GLP-1 decreased reactive oxygen species (ROS) production, cell migration, and MMP-2 as well as MMP-9 activity in Ang II-stimulated monocytic cells. The results conclude that oral administration of sitagliptin can prevent abdominal aortic aneurysm formation in Ang II-infused apoE^-/-mice, at least in part, by increasing of GLP-1 activity, decreasing MMP-2 and MMP-9 production from macrophage infiltration. The results indicate that sitagliptin may have therapeutic potential in preventing the development of AAA.