Continuation or discontinuation of pioglitazone when starting bedtime insulin in patients with poorly controlled type 2 diabetes in an inner-city population.

OBJECTIVE

We studied the impact of continuing versus discontinuing pioglitazone on hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and weight when starting bedtime insulin in patients with poor glycemic control.

METHODS

We retrospectively analyzed data from a 13-month randomized control trial on 77 patients with type 2 diabetes mellitus (DM), who despite maximum doses of three oral diabetes medications (metformin, sulfonylurea and pioglitazone) had HbA1C levels above 7.5%. Patients were randomized to either continuing or discontinuing pioglitazone in addition to starting and up-titrating bedtime insulin. HbA1C, FPG, and weight were assessed at baseline, 3months, 7months and 13months with the differences from baseline for the two groups compared at each of the three time points using the Wilcoxon rank sum test.

RESULTS

We found that HbA1c was significantly lower at the 7-month (p=0.01) and 13-month time points (p=0.036), and FPG was significantly lower at all three time points in the group continuing pioglitazone compared with those discontinuing pioglitazone. Continuing pioglitazone resulted in a greater increase in weight at the 3-month (p=0.002), 7-month (p=0.0001) and 13-month (p=0.00003) time points. Patients with the lowest HbA1c (<8.2%) at baseline were more likely to benefit from continuing pioglitazone than those with higher baseline HbA1c. Patients who started insulin and discontinued pioglitazone had similar HbA1c, FPG and weight at the three time points as at baseline, suggesting that pioglitazone and bedtime insulin has similar glycemic effect in this population.

CONCLUSIONS

We conclude that in patients with uncontrolled type 2 DM, continuing pioglitazone while concurrently starting bedtime insulin within a 13-month period led to a significant decrease in both HbA1c and FPG levels compared with those who did not receive pioglitazone; however weight increased during this period.