Pioglitazone may accelerate disease course of slowly progressive type 1 diabetes

Background It has been reported that intervention with insulin in slowly progressive type 1 diabetic (SPIDDM) patients delays the progression to an insulin‐dependent state compared to that with sulfonylureas. However, the rate of progression to SPIDDM with the use of insulin‐sensitizing agents is unknown. The aim of this study was to determine the effect of insulin‐sensitizing agents on SPIDDM patients. Methods The enrolled SPIDDM patients were randomly allocated to a pioglitazone or metformin group. When the haemoglobin A1C level was more than 8% on two consecutive occasions, the case was considered to reach the end point. Results By 4 years post‐intervention, all patients had reached the end point in the pioglitazone group, whereas only 20% of patients had reached the end point in the metformin group (p < 0.05). Conclusions Pioglitazone may accelerate the disease course of SPIDDM. Copyright © 2011 John Wiley & Sons, Ltd.