Effects on the incidence of cardiovascular events of the addition of pioglitazone versus sulfonylureas in patients with type 2 diabetes inadequately controlled with metformin (TOSCA.IT): a randomised, multicentre trial.
Vaccaro Olga,Masulli Maria,Nicolucci Antonio,Bonora Enzo,Del Prato Stefano,Maggioni Aldo P,Rivellese Angela A,Squatrito Sebastiano,Giorda Carlo B,Sesti Giorgio,Mocarelli Paolo,Lucisano Giuseppe,Sacco Michele,Signorini Stefano,Cappellini Fabrizio,Perriello Gabriele,Babini Anna Carla,Lapolla Annunziata,Gregori Giovanna,Giordano Carla,Corsi Laura,Buzzetti Raffaella,Clemente Gennaro,Di Cianni Graziano,Iannarelli Rossella,Cordera Renzo,La Macchia Olga,Zamboni Chiara,Scaranna Cristiana,Boemi Massimo,Iovine Ciro,Lauro Davide,Leotta Sergio,Dall'Aglio Elisabetta,Cannarsa Emanuela,Tonutti Laura,Pugliese Giuseppe,Bossi Antonio C,Anichini Roberto,Dotta Francesco,Di Benedetto Antonino,Citro Giuseppe,Antenucci Daniela,Ricci Lucia,Giorgino Francesco,Santini Costanza,Gnasso Agostino,De Cosmo Salvatore,Zavaroni Donatella,Vedovato Monica,Consoli Agostino,Calabrese Maria,di Bartolo Paolo,Fornengo Paolo,Riccardi Gabriele, ,
The lancet. Diabetes & endocrinology
BACKGROUND:The best treatment option for patients with type 2 diabetes in whom treatment with metformin alone fails to achieve adequate glycaemic control is debated. We aimed to compare the long-term effects of pioglitazone versus sulfonylureas, given in addition to metformin, on cardiovascular events in patients with type 2 diabetes. METHODS:TOSCA.IT was a multicentre, randomised, pragmatic clinical trial, in which patients aged 50-75 years with type 2 diabetes inadequately controlled with metformin monotherapy (2-3 g per day) were recruited from 57 diabetes clinics in Italy. Patients were randomly assigned (1:1), by permuted blocks randomisation (block size 10), stratified by site and previous cardiovascular events, to add-on pioglitazone (15-45 mg) or a sulfonylurea (5-15 mg glibenclamide, 2-6 mg glimepiride, or 30-120 mg gliclazide, in accordance with local practice). The trial was unblinded, but event adjudicators were unaware of treatment assignment. The primary outcome, assessed with a Cox proportional-hazards model, was a composite of first occurrence of all-cause death, non-fatal myocardial infarction, non-fatal stroke, or urgent coronary revascularisation, assessed in the modified intention-to-treat population (all randomly assigned participants with baseline data available and without any protocol violations in relation to inclusion or exclusion criteria). This study is registered with ClinicalTrials.gov, number NCT00700856. FINDINGS:Between Sept 18, 2008, and Jan 15, 2014, 3028 patients were randomly assigned and included in the analyses. 1535 were assigned to pioglitazone and 1493 to sulfonylureas (glibenclamide 24 [2%], glimepiride 723 [48%], gliclazide 745 [50%]). At baseline, 335 (11%) participants had a previous cardiovascular event. The study was stopped early on the basis of a futility analysis after a median follow-up of 57·3 months. The primary outcome occurred in 105 patients (1·5 per 100 person-years) who were given pioglitazone and 108 (1·5 per 100 person-years) who were given sulfonylureas (hazard ratio 0·96, 95% CI 0·74-1·26, p=0·79). Fewer patients had hypoglycaemias in the pioglitazone group than in the sulfonylureas group (148 [10%] vs 508 [34%], p<0·0001). Moderate weight gain (less than 2 kg, on average) occurred in both groups. Rates of heart failure, bladder cancer, and fractures were not significantly different between treatment groups. INTERPRETATION:In this long-term, pragmatic trial, incidence of cardiovascular events was similar with sulfonylureas (mostly glimepiride and gliclazide) and pioglitazone as add-on treatments to metformin. Both of these widely available and affordable treatments are suitable options with respect to efficacy and adverse events, although pioglitazone was associated with fewer hypoglycaemia events. FUNDING:Italian Medicines Agency, Diabete Ricerca, and Italian Diabetes Society.
Sulfonylureas and the Risks of Cardiovascular Events and Death: A Methodological Meta-Regression Analysis of the Observational Studies.
Azoulay Laurent,Suissa Samy
Recent randomized trials have compared the newer antidiabetic agents to treatments involving sulfonylureas, drugs associated with increased cardiovascular risks and mortality in some observational studies with conflicting results. We reviewed the methodology of these observational studies by searching MEDLINE from inception to December 2015 for all studies of the association between sulfonylureas and cardiovascular events or mortality. Each study was appraised with respect to the comparator, the outcome, and study design-related sources of bias. A meta-regression analysis was used to evaluate heterogeneity. A total of 19 studies were identified, of which six had no major design-related biases. Sulfonylureas were associated with an increased risk of cardiovascular events and mortality in five of these studies (relative risks 1.16-1.55). Overall, the 19 studies resulted in 36 relative risks as some studies assessed multiple outcomes or comparators. Of the 36 analyses, metformin was the comparator in 27 (75%) and death was the outcome in 24 (67%). The relative risk was higher by 13% when the comparator was metformin, by 20% when death was the outcome, and by 7% when the studies had design-related biases. The lowest predicted relative risk was for studies with no major bias, comparator other than metformin, and cardiovascular outcome (1.06 [95% CI 0.92-1.23]), whereas the highest was for studies with bias, metformin comparator, and mortality outcome (1.53 [95% CI 1.43-1.65]). In summary, sulfonylureas were associated with an increased risk of cardiovascular events and mortality in the majority of studies with no major design-related biases. Among studies with important biases, the association varied significantly with respect to the comparator, the outcome, and the type of bias. With the introduction of new antidiabetic drugs, the use of appropriate design and analytical tools will provide their more accurate cardiovascular safety assessment in the real-world setting.
Cardiac Effects of Sulfonylurea-Related Hypoglycemia.
Middleton Timothy L,Wong Jencia,Molyneaux Lynda,Brooks Belinda A,Yue Dennis K,Twigg Stephen M,Wu Ted
OBJECTIVE:To determine the effect of sulfonylurea-related hypoglycemia on cardiac repolarization and ectopy in the setting of well-controlled type 2 diabetes. RESEARCH DESIGN AND METHODS:Thirty subjects with sulfonylurea-treated type 2 diabetes underwent 48 h of concurrent continuous glucose monitoring and ambulatory electrocardiography. Ventricular repolarization (QTc) and QT dynamicity were analyzed during periods of hypoglycemia (<3.5 mmol/L for >20 min) and compared with periods of euglycemia and hyperglycemia combined. Cardiac ectopy rates during hypoglycemia were compared with ectopy rates when blood glucose was 4-10 mmol/L. RESULTS:Mean HbA was 6.9% (52 mmol/mol). Hypoglycemia was detected in 9 of 30 subjects (30%); episodes were typically nocturnal (67%) and asymptomatic (73%). Hypoglycemia-associated QTc prolongation was seen in five of nine subjects with a large variation in individual response. Higher QT dynamicity, a poor prognostic factor in cardiac disease, was seen in subjects who experienced hypoglycemia compared with subjects who did not (0.193 vs. 0.159 for the nocturnal period; = 0.01). This finding persisted after the hypoglycemic event. The rates of ventricular and supraventricular ectopy demonstrated a nonsignificant trend toward an increase during hypoglycemia (median rate ratio 1.58 and 1.33, respectively). Similar, nonsignificant results were observed in a separate insulin-treated cohort. CONCLUSIONS:Hypoglycemia, often unrecognized, is a frequent finding in well-controlled sulfonylurea-treated type 2 diabetes. It is associated with the novel finding of increased QT dynamicity and QTc prolongation in some individuals. Our findings suggest sulfonylurea-related hypoglycemia can have detrimental cardiovascular sequelae. Similar effects are also seen in the setting of insulin therapy.
Pharmacologic Differences of Sulfonylureas and the Risk of Adverse Cardiovascular and Hypoglycemic Events.
Douros Antonios,Yin Hui,Yu Oriana Hoi Yun,Filion Kristian B,Azoulay Laurent,Suissa Samy
OBJECTIVE:Sulfonylureas have been associated with an increased risk of cardiovascular adverse events and hypoglycemia, but it is unclear if these risks vary with different agents. We assessed whether the risks of acute myocardial infarction, ischemic stroke, cardiovascular death, all-cause mortality, and severe hypoglycemia differ between sulfonylureas grouped according to pancreas specificity and duration of action. RESEARCH DESIGN AND METHODS:Using the U.K. Clinical Practice Research Datalink, linked with the Hospital Episodes Statistics and the Office for National Statistics databases, we conducted a cohort study among patients with type 2 diabetes initiating monotherapy with sulfonylureas between 1998 and 2013. Adjusted hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards models, comparing use of pancreas-nonspecific, long-acting sulfonylureas (glyburide/glimepiride) to pancreas-specific, short-acting sulfonylureas (gliclazide/glipizide/tolbutamide). RESULTS:The cohort included 17,604 sulfonylurea initiators (mean [SD] follow-up 1.2 [1.5] years). Compared with specific, short-acting sulfonylureas (15,741 initiators), nonspecific, long-acting sulfonylureas (1,863 initiators) were not associated with an increased risk of acute myocardial infarction (HR 0.86; CI 0.55-1.34), ischemic stroke (HR 0.92; CI 0.59-1.45), cardiovascular death (HR 1.01; CI 0.72-1.40), or all-cause mortality (HR 0.81; CI 0.66-1.003), but with an increased risk of severe hypoglycemia (HR 2.83; CI 1.64-4.88). CONCLUSIONS:The nonspecific, long-acting sulfonylureas glyburide and glimepiride do not have an increased risk of cardiovascular adverse events compared with the specific, short-acting sulfonylureas gliclazide, glipizide, and tolbutamide. However, nonspecific, long-acting sulfonylureas glyburide and glimepiride have an increased risk of severe hypoglycemia.