The extended release metformin (XR), used in the present study was Bigsens XR® (Zydus CND), comprising a dual hydrophilic polymer matrix system. The starting dose of metformin (XR) was 0.5g twice daily after meal; the dose was gradually increased to the maximal tolerated dose. Those patients who were on some other anti-diabetic drug therapy; a 4 weeks washout period was given. All the subjects were informed that at the beginning of the study there was a possibility of initial increase in their blood glucose values, but the same would settle down as they adhere to our lifestyle protocol and as the dose of metformin is increased on subsequent visits. They were also informed about the possible passage of "ghost tablet" in their stool. Patients were told to withhold metformin for at least 5 days prior to any iodinated contrast radiographic study. Every patient was asked to perform urine dip stick test for acetone, at least every week and if found positive to contact this clinic immediately. They were also asked to report immediately in case of developing dyspnoea, marked vomiting, lethargy or fatigue.