Addition of either pioglitazone or a sulfonylurea in type 2 diabetic patients inadequately controlled with metformin alone: impact on cardiovascular events. A randomized controlled trial.
OBJECTIVE
Metformin is the first-line therapy in type 2 diabetes. In patients inadequately controlled with metformin, the addition of a sulfonylurea or pioglitazone are equally plausible options to improve glycemic control. However, these drugs have profound differences in their mechanism of action, side effects, and impact on cardiovascular risk factors. A formal comparison of these two therapies in terms of cardiovascular morbidity and mortality is lacking. The TOSCA.IT study was designed to explore the effects of adding pioglitazone or a sulfonylurea on cardiovascular events in type 2 diabetic patients inadequately controlled with metformin.


METHODS
Multicentre, randomized, open label, parallel group trial of 48 month duration. Type 2 diabetic subjects, 50-75 years, BMI 20-45 Kg/m(2), on secondary failure to metformin monotherapy will be randomized to add-on a sulfonylurea or pioglitazone. The primary efficacy outcome is a composite endpoint of all-cause mortality, nonfatal myocardial infarction, nonfatal stroke, and unplanned coronary revascularization. Principal secondary outcome is a composite ischemic endpoint of sudden death, fatal and non-fatal myocardial infarction and stroke, endovascular or surgical intervention on the coronary, leg or carotid arteries, major amputations. Side effects, quality of life and economic costs will also be evaluated. Efficacy, safety, tolerability, and study conduct will be monitored by an independent Data Safety Monitoring Board. End points will be adjudicated by an independent external committee.


CONCLUSIONS
TOSCA.IT is the first on-going study investigating the head-to-head comparison of adding a sulfonylurea or pioglitazone to existing metformin treatment in terms of hard cardiovascular outcomes.


BACKGROUND
Clinicaltrials.gov ID NCT00700856.
Department of Clinical and Experimental Medicine, Federico II University, Naples, Italy. ovaccaro@unina.it
O
O
Vaccaro
M
M
Masulli
E
E
Bonora
S
S
Del Prato
C B
CB
Giorda
A P
AP
Maggioni
P
P
Mocarelli
A
A
Nicolucci
A A
AA
Rivellese
S
S
Squatrito
G
G
Riccardi
D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000139:chemically induced; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D004359:Drug Therapy, Combination; D023381:Endpoint Determination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D008875:Middle Aged; D000077205:Pioglitazone; D011788:Quality of Life; D012307:Risk Factors; D013453:Sulfonylurea Compounds / Q000009:adverse effects / Q000627:therapeutic use*; D011795:Surveys and Questionnaires; D045162:Thiazolidinediones / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D045162:Thiazolidinediones; D008687:Metformin; D000077205:Pioglitazone