Glycemic control and treatment failure with pioglitazone versus glibenclamide in type 2 diabetes mellitus: a 42-month, open-label, observational, primary care study

• Published in: Current medical research and opinion 2006-06, Vol.22 (6), p.1211-1215
• Main Authors: Hanefeld, M., Pfützner, A., Forst, T., Lübben, G.
• Format: Article
• Language: English
• Subjects: Aged; Blood Glucose - analysis; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - drug therapy; Female; Glyburide - administration & dosage; Glycated Hemoglobin A - analysis; Humans; Hypoglycemic Agents - administration & dosage; Insulin - administration & dosage; Insulin - metabolism; Insulin Resistance; Insulin Secretion; Insulin-Secreting Cells - metabolism; Insulin-Secreting Cells - pathology; Male; Metformin - administration & dosage; Middle Aged; Pioglitazone; Primary Health Care; Prospective Studies; Thiazolidinediones - administration & dosage; Treatment Outcome
• ISSN: 0300-7995; 1473-4877
• DOI: 10.1185/030079906X112598

ABSTRACT Background: Insulin resistance and declining β-cell function are the core defects in type2 diabetes mellitus. It has been suggestedthat deteriorating glycemic control is relatedto baseline hemoglobin A1c (HbA1c) values andremaining β-cell function. Patients and methods: We report glycemic data from a 3.5‐year, open-label, observational, primary care study comparing 30 mg/day pioglitazone with 3.5 mg/day glibenclamide add-on to stable metformin monotherapy in 500 patients with type 2 diabetes. Insulin commencement was considered for patients with HbA1c ≥ 8.0% or when vascular complications occurred. The change in HbA1c compared with baseline and the difference in time to failure to maintain glycemic control were calculated. Results: At endpoint, HbA1c had decreased by 1.0% in the pioglitazone group ( p < 0.005) and by 0.6% in the glibenclamide group ( p < 0.05). Annual progression rates to insulin treatment were 6.6% (pioglitazone) and 16.4% (glibenclamide; p < 0.001 between-group difference). Mean weight increases of 3.5 ± 0.42 kg in the pioglitazone group and 3.3 ± 0.38 kg in the glibenclamide group were noted. Overall, both treatments were well tolerated. Conclusions: Pioglitazone add-on to metformin revealed significant benefits in long-term glycemic control compared with glibenclamide. This difference may be explained by a large between-group difference in HOMA-S, which was shown to correlate significantly to the change in HbA1c. This suggests that a strategy to reduce insulin resistance to lower the burden of the β‐cell is superior to treatment with glibenclamide.