Effectiveness of sitagliptin compared to sulfonylureas for type 2 diabetes mellitus inadequately controlled on metformin: a systematic review and meta-analysis.

OBJECTIVE: To assess the effectiveness of sitagliptin compared to sulfonylureas as add-on to metformin in adults with type 2 diabetes mellitus from both randomised controlled trials (RCTs) and 'real-world' non-randomised studies. METHODS AND ANALYSES: We conducted a systematic review of EMBASE, MEDLINE, CENTRAL and grey literature for RCTs and non-randomised studies. We reported outcomes relating to change in HbA1c, fasting glucose, weight, blood pressure and lipids from baseline and need for treatment change. No study investigating macrovascular and microvascular diabetes complications was found. Meta-analysis was used where studies were sufficiently homogenous. RESULTS: Seven RCTs and five non-randomised studies were eligible for inclusion from 1335 articles retrieved. Meta-analysis of three homogenous RCTs revealed a statistically significant decrease in weight with sitagliptin when compared to sulfonylureas (weighted mean difference (WMD) -2.05 kg; 95% CI -2.38 to -1.71); however, a similar change from baseline in HbA1c (WMD 0.05; 95% CI -0.03 to 0.12), fasting glucose (WMD 0.11; 95% CI -0.08 to -0.29), blood pressure, lipids and the proportion achieving HbA1c <7% by study end (OR 0.98; 95% CI 0.85 to 1.13) was observed.Non-randomised studies identified consisted of four prospective and one retrospective cohort study. Three of these five studies were of moderate/high quality, and results though less precise suggested similar real-world comparative glycaemic and weight effectiveness for both treatments. Data from two cohort studies suggested that treatment change (HR 0.65; 95% CI 0.57 to 0.73) and insulin initiation (HR 0.76; 95% CI 0.65 to 0.90) were less likely among those prescribed sitagliptin; however, inadequate reporting of HbA1c at time of treatment change made interpreting results challenging. CONCLUSION: Sitagliptin users experienced modest weight loss compared to gain with sulfonylureas; however, this difference was around 2 kg, which may not be of major clinical significance for most individuals. Similar change was observed across most other effectiveness outcomes reported. Further studies are needed to address longer-term effectiveness outcomes for sitagliptin compared to sulfonylureas as add-on to metformin. PROSPERO REGISTRATION NUMBER: CRD42016033983.

CXCR2 Inhibition - a novel approach to treating CoronAry heart DiseAse (CICADA): study protocol for a randomised controlled trial.

BACKGROUND: There is emerging evidence of the central role of neutrophils in both atherosclerotic plaque formation and rupture. Patients with lower neutrophil counts following acute coronary syndromes tend to have a greater coronary flow reserve, which is a strong predictor of long-term cardiovascular health. But so far, no data are available regarding the impact of neutrophil inhibition on cardiovascular clinical or surrogate endpoints. Therefore, the aim of this study is to investigate the effects of AZD5069, a cysteine-X-cysteine chemokine receptor 2 (CXCR2) inhibitor, on coronary flow reserve and coronary structure and function in patients with coronary artery disease. METHODS/DESIGN: Ninety subjects with coronary artery disease undergoing percutaneous coronary intervention will be included in this investigator-driven, randomised, placebo-controlled, double-blind, phase IIa, single-centre study. Participants will be randomised to receive either AZD5069 (40 mg) administered orally twice daily or placebo for 24 weeks. Change in coronary flow reserve as determined by 13N-ammonia positron emission tomography-computed tomography will be the primary outcome. Change in the inflammatory component of coronary plaque structure and the backward expansion wave, an invasive coronary physiological measure of diastolic function, will be assessed as secondary outcomes. DISCUSSION: Cardiovascular surrogate parameters, such as coronary flow reserve, may provide insights into the potential mechanisms of the cardiovascular effects of CXCR2 inhibitors. Currently, ongoing trials do not specifically focus on neutrophil function as a target of intervention, and we therefore believe that our study will contribute to a better understanding of the role of neutrophil-mediated inflammation in coronary artery disease. TRIAL REGISTRATION: EudraCT, 2016-000775-24 . Registered on 22 July 2016. International Standard Randomised Controlled Trial Number, ISRCTN48328178 . Registered on 25 February 2016.