We appreciate Pankaj Madan's supplementary information to our article on oral antihyperglycemic therapy.1 As Madan has correctly outlined, the studies comparing pioglitazone (monotherapy or combination therapy) with placebo have demonstrated no changes in LDL cholesterol,2,3,4whereas studies comparing rosiglitazone (monotherapy or combination therapy) with placebo have demonstrated an increase, ranging from 8% to 19%, in LDL cholesterol.5,6,7 In clinical practice, this elevation may have a small impact, if any, for patients with diabetes mellitus using lipid-lowering therapy (statins) to achieve target LDL levels.8,9
The lack of direct-comparison studies makes it difficult to draw definitive conclusions regarding the lipid differences between the 2 medications. Similarly, significantly elevated triglyceride levels might best be targeted directly with fibrates.
Alice Y.Y. Cheng Division of Endocrinology and Metabolism Department of Medicine St. Michael's Hospital Toronto, Ont. I. George Fantus Division of Endocrinology Department of Medicine Mount Sinai Hospital and University Health Network University of Toronto Toronto, Ont.
Footnotes
Competing interests: Dr. Fantus has received an honorarium for a lecture from Bristol Myers Squibb (distributor of metformin in the United States). None declared for Dr. Cheng.
References
- 1.Cheng AYY, Fantus IG. Oral antihyperglycemic therapy for type 2 diabetes mellitus. CMAJ 2005;172(2):213-26. [DOI] [PMC free article] [PubMed]
- 2.Rosenblatt S, Miskin B, Glazer NB, Prince MJ, Robertson KE; Pioglitazone 026 Study Group. The impact of pioglitazone on glycemic control and atherogenic dyslipidemia in patients with type 2 diabetes mellitus. Coron Artery Dis 2001;12:413-23. [DOI] [PubMed]
- 3.Kipnes MS, Krosnick A, Rendell MS, Egan JW, Mathisen AL, Schneider RL. Pioglitazone hydrochloride in combination with sulfonylurea therapy improves glycemic control in patients with type 2 diabetes mellitus: a randomized, placebo-controlled study. Am J Med 2001;111:10-7. [DOI] [PubMed]
- 4.Rosenstock J, Einhorn D, Hershon K, Glazer NB, Yu S. Efficacy and safety of pioglitazone in type 2 diabetes: a randomised, placebo-controlled study in patients receiving stable insulin therapy. Int J Clin Pract 2002;56:251-7. [PubMed]
- 5.Lebovitz HE, Dole JF, Patwardhan R, Rappaport EB, Freed MI; Rosiglitazone Clinical Trials Study Group. Rosiglitazone monotherapy is effective in patients with type 2 diabetes [published errata appear in J Clin Endocrinol Metab 2001;86:1659, 2002;87:iv]. J Clin Endocrinol Metab 2001;86:280-8. [DOI] [PubMed]
- 6.Fonseca V, Rosenstock J, Patwardhan R, Salzman A. Effect of metformin and rosiglitazone combination therapy in patients with type 2 diabetes mellitus: a randomized controlled trial [published erratum appears in JAMA 2000;284: 1384]. JAMA 2000;283:1695-702. [DOI] [PubMed]
- 7.Raskin P, Rendell M, Riddle MC, Dole JF, Freed MI, Rosenstock J. A randomized trial of rosiglitazone therapy in patients with inadequately controlled insulin-treated type 2 diabetes. Diabetes Care 2001;24:1226-32. [DOI] [PubMed]
- 8.Heart Protection Study Collaborative Group. MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20,536 high-risk individuals: a randomised placebo-controlled trial. Lancet 2002;360:7-22.12114036
- 9.Colhoun HM, Betteridge DJ, Durrington PN, Hitman GA, Neil HA, Livingstone SJ, et al. Primary prevention of cardiovascular disease with atorvastatin in type 2 diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS): multicentre randomised placebo-controlled trial. Lancet 2004;364:685-96. [DOI] [PubMed]