Open Access Highly Accessed Study protocol

Actos Now for the prevention of diabetes (ACT NOW) study

Ralph A DeFronzo1*, MaryAnn Banerji2, George A Bray3, Thomas A Buchanan4, Stephen Clement5, Robert R Henry6, Abbas E Kitabchi7, Sunder Mudaliar6, Nicolas Musi1, Robert Ratner8, Peter D Reaven9, Dawn Schwenke9, Frankie B Stentz7 and Devjit Tripathy1

Author Affiliations

1 Texas Diabetes Institute and University of Texas Health Science Center, San Antonio, TX, USA

2 Suny Health Science Center at Brooklyn, Brooklyn, NY, USA

3 Pennington Biomedical Research Center/LSU, Baton Rouge, LA, USA

4 University of Southern California Keck School of Medicine, Los Angeles, CA, USA

5 Division of Endocrinology & Metabolism, Georgetown University, Washington, DC, USA

6 VA San Diego Healthcare System and University of California at San Diego, USA

7 University of Tennessee, Division of Endocrinology, Diabetes and Metabolism, Memphis, TN, USA

8 Medstar Research Institute, Hyattsville, MD, USA

9 Phoenix VA Health Care System, Phoenix, AZ and W.P. Carey School of Business, Arizona State University, Tempe, AZ, USA

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BMC Endocrine Disorders 2009, 9:17  doi:10.1186/1472-6823-9-17

Published: 29 July 2009



Impaired glucose tolerance (IGT) is a prediabetic state. If IGT can be prevented from progressing to overt diabetes, hyperglycemia-related complications can be avoided. The purpose of the present study was to examine whether pioglitazone (ACTOS®) can prevent progression of IGT to type 2 diabetes mellitus (T2DM) in a prospective randomized, double blind, placebo controlled trial.


602 IGT subjects were identified with OGTT (2-hour plasma glucose = 140–199 mg/dl). In addition, IGT subjects were required to have FPG = 95–125 mg/dl and at least one other high risk characteristic. Prior to randomization

subjects had measurement of ankle-arm blood pressure, systolic/diastolic blood pressure, HbA1C, lipid profile and a subset had frequently sampled intravenous glucose tolerance test (FSIVGTT), DEXA, and ultrasound determination of carotid intima-media thickness (IMT). Following this, subjects were randomized to receive pioglitazone (45 mg/day) or placebo, and returned every 2–3 months for FPG determination and annually for OGTT. Repeat carotid IMT measurement was performed at 18 months and study end. Recruitment took place over 24 months, and subjects were followed for an additional 24 months. At study end (48 months) or at time of diagnosis of diabetes the OGTT, FSIVGTT, DEXA, carotid IMT, and all other measurements were repeated.

Primary endpoint is conversion of IGT to T2DM based upon FPG ≥ 126 or 2-hour PG ≥ 200 mg/dl. Secondary endpoints include whether pioglitazone can: (i) improve glycemic control (ii) enhance insulin sensitivity, (iii) augment beta cell function, (iv) improve risk factors for cardiovascular disease, (v) cause regression/slow progression of carotid IMT, (vi) revert newly diagnosed diabetes to normal glucose tolerance.


ACT NOW is designed to determine if pioglitazone can prevent/delay progression to diabetes in high risk IGT subjects, and to define the mechanisms (improved insulin sensitivity and/or enhanced beta cell function) via which pioglitazone exerts its beneficial effect on glucose metabolism to prevent/delay onset of T2DM.

Trial Registration

clinical identifier: NCT00220961