Continuous glucagon-like peptide-1 receptor agonism with ExQW resulted in superior glycemic control, with less nausea, compared with ExBID in patients with type 2 diabetes. Both groups lost weight.
OBJECTIVE
Traditional blood glucose–lowering agents do not sustain adequate glycemic control in most type 2 diabetic patients. Preclinical studies with exenatide have suggested sustained improvements in β-cell function. We investigated the effects of 52 weeks of treatment with exenatide or insulin glargine followed by an off-drug period on hyperglycemic clamp–derived measures of β-cell function, glycemic control, and body weight.
RESEARCH DESIGN AND METHODS
Sixty-nine metformin-treated patients with type 2 diabetes were randomly assigned to exenatide (n = 36) or insulin glargine (n = 33). β-Cell function was measured during an arginine-stimulated hyperglycemic clamp at week 0, at week 52, and after a 4-week off-drug period. Additional end points included effects on glycemic control, body weight, and safety.
RESULTS
Treatment-induced change in combined glucose- and arginine-stimulated C-peptide secretion was 2.46-fold (95% CI 2.09–2.90, P < 0.0001) greater after a 52-week exenatide treatment compared with insulin glargine treatment. Both exenatide and insulin glargine reduced A1C similarly: −0.8 ± 0.1 and −0.7 ± 0.2%, respectively (P = 0.55). Exenatide reduced body weight compared with insulin glargine (difference −4.6 kg, P < 0.0001). β-Cell function measures returned to pretreatment values in both groups after a 4-week off-drug period. A1C and body weight rose to pretreatment values 12 weeks after discontinuation of either exenatide or insulin glargine therapy.
CONCLUSIONS
Exenatide significantly improves β-cell function during 1 year of treatment compared with titrated insulin glargine. After cessation of both exenatide and insulin glargine therapy, β-cell function and glycemic control returned to pretreatment values, suggesting that ongoing treatment is necessary to maintain the beneficial effects of either therapy.
Type 2 diabetes mellitus (T2DM) is characterized by a progressive failure of pancreatic β-cell function (BCF)
with insulin resistance. Once insulin over-secretion can no longer compensate for the degree of insulin resistance, hyperglycemia
becomes clinically significant and deterioration of residual β-cell reserve accelerates. This pathophysiology has
important therapeutic implications. Ideally, therapy should address the underlying pathology and should be started early
along the spectrum of decreasing glucose tolerance in order to prevent or slow β-cell failure and reverse insulin resistance.
The development of an optimal treatment strategy for each patient requires accurate diagnostic tools for evaluating the
underlying state of glucose tolerance. This review focuses on the most widely used methods for measuring BCF within the
context of insulin resistance and includes examples of their use in prediabetes and T2DM, with an emphasis on the most
recent therapeutic options (dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists). Methods of
BCF measurement include the homeostasis model assessment (HOMA); oral glucose tolerance tests, intravenous glucose
tolerance tests (IVGTT), and meal tolerance tests; and the hyperglycemic clamp procedure. To provide a meaningful
evaluation of BCF, it is necessary to interpret all observations within the context of insulin resistance. Therefore, this review
also discusses methods utilized to quantitate insulin-dependent glucose metabolism, such as the IVGTT and the
euglycemic-hyperinsulinemic clamp procedures. In addition, an example is presented of a mathematical modeling approach
that can use data from BCF measurements to develop a better understanding of BCF behavior and the overall
status of glucose tolerance.
AimsIn the initial 26-week, double-blind, double-dummy assessment period of the DURATION-2 trial in patients with Type 2 diabetes on metformin, the once-weekly glucagon-like peptide 1 (GLP-1) receptor agonist exenatide once-weekly resulted in greater HbA1c improvement and weight reduction compared with maximum approved daily doses of sitagliptin or pioglitazone. This subsequent, 26-week, open-label, uncontrolled assessment period evaluated the safety and efficacy of (i) continued exenatide once-weekly treatment and (ii) switching from sitagliptin or pioglitazone to exenatide once-weekly.MethodsRandomised oral medications were discontinued and all patients received exenatide once-weekly. Of the 364 patients [original baseline HbA1c 8.5 ± 1.1% (70 mmol/mol), fasting plasma glucose 9.0 ± 2.5 mmol/l, weight 88 ± 20 kg) who continued into the open-label period, 319 patients (88%) completed 52 weeks.ResultsEvaluable patients who received only exenatide once-weekly demonstrated significant 52-week improvements (least square mean ± se) in HbA1c (−1.6 ± 0.1%), fasting plasma glucose (−1.8 ± 0.3 mmol/l) and weight (−1.8 ± 0.5 kg). Evaluable patients who switched from sitagliptin to exenatide once-weekly demonstrated significant incremental improvements in HbA1c (−0.3 ± 0.1%), fasting plasma glucose (−0.7 ± 0.2 mmol/l) and weight (−1.1 ± 0.3 kg). Patients who switched from pioglitazone to exenatide once-weekly maintained HbA1c and fasting plasma glucose improvements (week 52: −1.6 ± 0.1%, −1.7 ± 0.3 mmol/l), with significant weight reduction (−3.0 ± 0.3 kg). Exenatide once-weekly was generally well tolerated and adverse events were predominantly mild or moderate in intensity. Nausea was the most frequent adverse event in this assessment period (intent-to-treat: exenatide once-weekly-only 5%; sitagliptin → exenatide once-weekly 11%; pioglitazone → exenatide once-weekly 10%). No major hypoglycaemia was observed.ConclusionsPatients who switched to once-weekly exenatide from daily sitagliptin or pioglitazone had improved or sustained glycaemic control, with weight loss.
Aims
There are no treatments for the extreme hyperphagia and obesity in Prader-Willi syndrome (PWS). The bestPWS trial assessed the efficacy, safety, and tolerability of the methionine aminopeptidase 2 (MetAP2) inhibitor, beloranib.
Materials and Methods
Participants with PWS (12–65 years) were randomly assigned (1:1:1) to biweekly placebo, 1.8 mg beloranib, or 2.4 mg beloranib injection for 26 weeks at 15 US sites. Coprimary endpoints were the changes in hyperphagia (measured by Hyperphagia Questionnaire for Clinical Trials [HQ-CT]; possible score 0–36) and weight by intention-to-treat. ClinicalTrials.gov registration: NCT02179151.
Results
107 were included in the intention-to-treat analysis: placebo (n=34), 1.8 mg beloranib (n=36), or 2.4 mg beloranib (n=37). Improvement (reduction) in HQ-CT total score was greater in the 1.8 mg (mean difference −6.3, 95% CI −9.6 to −3.0; p=0.0003) and 2.4 mg beloranib groups (−7.0, 95% CI −10.5 to −3.6; p=0.0001) vs placebo. Compared to placebo, weight change was greater with 1.8 mg (mean difference −8.2%, 95% CI −10.8 to −5.6; p<0.0001) and 2.4 mg beloranib (−9.5%, 95% CI −12.1 to −6.8; p<0.0001). Injection site bruising was the most frequent adverse event with beloranib. Dosing was stopped early due to an imbalance in venous thrombotic events in beloranib-treated participants (two fatal events of pulmonary embolism and two events of deep vein thrombosis) compared to placebo.
Conclusions
MetAP2 inhibition with beloranib produced statistically significant and clinically meaningful improvements in hyperphagia-related behaviors and weight loss in participants with PWS. Although investigation of beloranib has ceased, inhibition of MetAP2 is a novel mechanism for treating hyperphagia and obesity.
Pulmonary surfactant has two distinct functions within the lung: reduction of surface tension at the air-liquid interface and participation in innate host defense. Both functions are dependent on surfactant-associated proteins. Pseudomonas aeruginosa is primarily responsible for respiratory dysfunction and death in cystic fibrosis patients and is also a leading pathogen in nosocomial pneumonia. P. aeruginosa secretes a number of proteases that contribute to its virulence. We hypothesized that P. aeruginosa protease IV degrades surfactant proteins and results in a reduction in pulmonary surfactant host defense and biophysical functions. Protease IV was isolated from cultured supernatant of P. aeruginosa by gel chromatography. Incubation of cell-free bronchoalveolar lavage fluid with protease IV resulted in degradation of surfactant proteins (SP)-A, -D, and -B. SPs were degraded in a time- and dose-dependent fashion by protease IV, and degradation was inhibited by the trypsin-like serine protease inhibitor Nalpha-p-tosyl-L-lysine-chloromethyl ketone (TLCK). Degradation by protease IV inhibited SP-A- and SP-D-mediated bacterial aggregation and uptake by macrophages. Surfactant treated with protease IV was unable to reduce surface tension as effectively as untreated surfactant, and this effect was inhibited by TLCK. We speculate that protease IV may be an important contributing factor to the development and propagation of acute lung injury associated with P. aeruginosa via loss of surfactant function within the lung.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.