Patient factors associated with hemoglobin A1C change with pioglitazone as adjunctive therapy in type 2 Diabetes Mellitus

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Mongthuong T. Tran
Thomas Delate
Shakti Bachmann


Diabetes Mellitus, Type 2, Thiazolidinediones, Regression Analysis, United States


Objective: To identify patient factors associated with change in hemoglobin A1C (A1C) with adjunct pioglitazone therapy in routine clinical practice.

Methods: This was a retrospective analysis of adult type 2 diabetes mellitus patients in a health maintenance organization setting who were newly-initiated on pioglitazone between January 2002 and December 2005. Eligible patients were receiving at least one other oral antihyperglycemic medication prior to initiating pioglitazone and maintained a stable dose of pioglitazone for 90 days. Data on eligible patients’ characteristics, pharmacy purchases, comorbidities, and A1C measurement 90 days prior to the pioglitazone purchase date (baseline) and 90 days after achieving a stable dose (follow-up) were obtained from electronic records. Multivariate regression modeling was used to assess factors independently associated with: 1) absolute change in A1C, 2) achieving a ≥1 percentage point decrease in A1C, and 3) achieving an A1C<7%.

Results: Baseline and follow-up A1Cs were available for 128 patients. At baseline, mean age was 65 years, 38% were female, mean A1C was 8.4%, and 74% had an A1C>8%. At follow-up, the mean A1C change was -1.2 percentage points (interquartile range= -0.4, -2.1), 59% achieved a ≥1 unit decrease in A1C, and 44% achieved an A1C<7%. Independent predictors in all models were baseline A1C and time (in days) between baseline and follow-up A1C measurements (p<0.05).

Conclusions: Adjunct pioglitazone therapy in routine clinical practice was associated with clinically meaningful reductions in A1C levels. Patients with higher baseline A1C achieved the greatest absolute reduction in A1C but were less likely to achieve levels <7%.


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1. United Kingdom Prospective Diabetes Study (UKPDS) Group. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). Lancet. 1998;352:837-853.

2. Genuth S, Eastman R, Kahn R, Klein R, Lachin J, Lebovitz H, Nathan D, Vinicor F. Implications of the United Kingdom prospective diabetes study. Diabetes Care. 2003;26 (Suppl. 1):S28-S32.

3. The Diabetes Control and Complications Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. N Engl J Med. 1993;329:977-986.

4. American Diabetes Association. Standards of medical care for patients with diabetes mellitus. Diabetes Care. 2008;31 (Suppl. 1):S5-S11.

5. Nathan DM, Buse JB, Davidson MB, Heine RJ, Holman RR, Sherwin R, Zinman B. Management of hyperglycemia in type 2 diabetes: a consensus algorithm for the initiation and adjustment of therapy. Diabetes Care. 2006;29:1963-1972.

6. Product information for Actos. Takeda Pharmaceuticals America, Inc. Lincolnshire, IL 60069. August 2004.

7. Product information for Avandia. GlaxoSmithKline. Research Triangle Park, NC 27709. September 2007.

8. Einhorn D, Rendell M, Rosenzweig J, Egan JW, Mathisen AL, Schneider RL. Pioglitazone hydrochloride in combination with metformin in the treatment of type 2 diabetes mellitus: a randomized, placebo-controlled study: the Pioglitazone 027 Study Group. Clin Ther. 2000;22:1395-1409.

9. 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;111:10-17.

10. Aljabri K, Kozak S, Thompson D. Addition of pioglitazone or bedtime insulin to maximal doses of sulfonylurea and metformin in type 2 patients with poor glucose control: a prospective, randomized trial. Am J Med. 2004;116:230-235.

11. Hanefeld M, Brunetti P, Schernthaner GH, Matthews DR, Charbonnel BH, QUARTET Study Group. One-Year Glycemic Control with a Sulfonylurea Plus Pioglitazone Versus a Sulfonylurea Plus Metformin in Patients With Type 2 Diabetes. Diabetes Care. 2004;27(1):141-147.

12. Karter AJ, Moffet HH, Liu J, Parker MM, Ahmed AT, Ferrara A, Selby JV. Achieving Good Glycemic Control: Initiation of New Antihyperglycemic Therapies in Patients With Type 2 Diabetes From the Kaiser Permanente Northern California Diabetes Registry. Am J Manag Care. 2005;11(4):262-270.

13. Riedel AA, Heien H, Wogen J, Plauschinat CA. Secondary Failure of Glycemic Control for Patients Adding Thiazolidinedione or Sulfonylurea Therapy to a Metformin Regimen. Am J Manag Care. 2007;13(8):457-463.

14. Tack CJ, Smits P. Thiazolidinedione derivatives in type 2 diabetes mellitus. Neth J Med. 2006 Jun;64(6): 166-174.

15. Goldstein BJ. Closing the gap between clinical research and clinical practice: can outcome studies with thiazolidinediones improve our understanding of type 2 diabetes? Int J Clin Pract. 2006;60(7):873-883.

16. Richter B, Bandeira-Echtler E, Bergerhoff K, Clar C, Ebrahim SH. Pioglitazone for type 2 diabetes mellitus. Cochrane Database Syst Rev. 2006;(4):CD006060.

17. Quandt SA, Bell RA, Snively BM, Smith SL, Stafford JM, Wetmore LK, Arcury TA. Ethnic disparities in glycemic control among rural older adults with type 2 diabetes. Ethn Dis. 2005;15(4):656-663.

18. O'Connor PJ, Asche SE, Crain AL, Rush WA, Whitebird RR, Solberg LI, Sperl-Hillen JM. Is patient readiness to change a predictor of improved glycemic control? Diabetes Care. 2004;27(10):2325-2329.

19. Sidney S, Sorel M, Queensberry SP Jr, DeLuise C, Lanes S, Eisner MD. COPD and incident cardiovascular disease hospitalizations and mortality: Kaiser Permanente Medical care Program. CHEST. 2005;128:2068-2076.

20. First DataBank (Medispan). Generic Product Identifier Number. San Bruno, CA; 2004.

21. Von Korff M, Wagner EH, Saunders K. A chronic disease score from automated pharmacy data. J Clin Epidemiol. 1992;45:197-203.

22. Johnson JA, Majumdar SR, Simpson SH, Toth EL. Decreased mortality associated with the use of metformin compared with sulfonylurea monotherapy in type 2 diabetes. Diabetes Care. 2002;25:2244-2248.

23. Jaccard J, Becker MA: Statistics for the Behavioral Sciences, 3rd edition. Pacific Grove (CA), Brooks/Cole Publishing Company, 1997.

24. Zangeneh F, Kudva YC, Basu A. Insulin sensitizers. Mayo Clinic Proc. 2003;78:471-479.

25. Schwartz S, Sievers R, Strange P, Lyness W, Hollander P. Insulin 70/30 mix plus metformin versus triple oral therapy in the treatment of type 2 diabetes after failure of two oral drugs. Diabetes Care. 2003;26:2238-2243.

26. Charbonnel B, Schernthaner G, Brunetti P, Matthews DR, Urquhart R, Tan MH, Hanefeld M. Long-term efficacy and tolerability of add-on pioglitazone therapy to failing monotherapy compared with addition of gliclazide or metformin in patients with type 2 diabetes. Diabetologia. 2005;48:1093-1104.