Effect of Low (7.5 mg/day), Standard (15 mg/day) and High (30 mg/day) Dose Pioglitazone Therapy on Glycemic Control and Weight Gain in Recently-Diagnosed Type 2 Diabetes Patients.

OBJECTIVE To study the effect of different daily doses of pioglitazone on glycemic control and weight gain in newly-diagnosed type 2 diabetes mellitus (DM) patients. RESEARCH DESIGN AND METHODS Chart reviews were performed of recently-diagnosed (< 24 months) type 2 DM patients receiving oral therapy including pioglitazone. Patients were excluded if they had heart disease, liver dysfunction or renal insufficiency; or were being treated with insulin or the incretin drugs. Patients had received 7.5 mg/day (Group A), 15 mg/day (Group B) or 30 mg/day (Group C) of pioglitazone. Characteristics including demographics, weight, body mass index and glycated hemoglobin (HbA1c) were recorded at baseline and at six months. RESULTS At the end of six months, there was significant weight gain in all groups from baseline (P< 0.01). Weight gain was greatest in Group C (2.72 kg; SD=2.97), intermediate in Group B (1.62 kg; SD=2.91) and least in Group A (0.88 kg; SD=2.77). The difference was statistically significant between Groups A and C; and Groups B and C; but not between Groups A and B. There was no difference between HbA1c lowering in the three groups (P>0.05). Dose correlated with weight gain (r=0.254; P< 0.001) but not with HbA1c reduction (r=0.012; P=0.85). There was no correlation between HbA1c reduction and BMI increase (r = -0.024; P=0.72). CONCLUSIONS The glycemic effect of pioglitazone is preserved even at lower doses, while the propensity to cause weight gain increases with dose. We suggest that low-dose pioglitazone (7.5 mg/day) should be the preferred dose at which to initiate therapy in recently-diagnosed patients. Pioglitazone is an extremely useful agent in the treatment of type 2 diabetes mellitus (DM) through its actions on alleviating insulin resistance.