Effect of thiazolidinediones on lipid profile
=============================================

* Pankaj Madan

In their review of oral hypoglycemic therapy in type 2 diabetes mellitus, Alice Cheng and George Fantus1 mention the effect of thiazolidinediones on high-density lipoprotein (HDL) cholesterol; I would like to add some comments about the effects of these agents on low-density lipoprotein (LDL) cholesterol and triglycerides.

In fact, the effect of thiazolidinediones on serum lipids and lipoproteins varies with the agent used (pioglitazone or rosiglitazone). As noted by Cheng and Fantus, HDL levels increase with either of these 2 drugs.2,3,4,5,6,7 However, LDL cholesterol levels remain unchanged with pioglitazone monotherapy or a combination of pioglitazone with other oral hypoglycemic agents or insulin.2,3,4 In contrast, LDL cholesterol levels increase with rosiglitazone monotherapy or combination therapy.5,6,7 Although pioglitazone has been associated with a decrease in triglyceride levels,2,3,4 the effects of rosiglitazone on triglycerides have been variable, ranging from a 2% increase to a 19% decrease.6,7

Studies directly comparing the 2 agents are scant, and the cause of this variation in lipid levels is unknown.

## Footnotes

*   *Competing interests:* None declared.

## References

1.  1. Cheng AYY, Fantus IG. Oral antihyperglycemic therapy for type 2 diabetes mellitus. CMAJ 2005;172(2):213-26.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxNzIvMi8yMTMiO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTczLzQvMzQ0LjEuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  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.
    
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3.  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.
    
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4.  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.
    
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5.  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.
    
    

6.  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.
    
    [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1001/jama.284.11.1384&link_type=DOI) 

7.  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.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NzoiZGlhY2FyZSI7czo1OiJyZXNpZCI7czo5OiIyNC83LzEyMjYiO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTczLzQvMzQ0LjEuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9)