INTRODUCTION: Lipid profile is an important determinant of cardiovascular risk 
in type 2 diabetic patients. Available glucose-lowering agents can affect lipid 
levels. Dipeptidyl peptidase-4 (DPP-4) inhibitors have been reported to reduce 
total cholesterol, but results are inconsistent across trials. The present 
metaanalysis was designed to assess the effect of DPP-4 inhibitors on blood 
lipids, verifying possible differences across compounds of this class.
METHODS: An extensive search of Medline and the Cochrane Library (any date up to 
December 31, 2010, restricted to randomized clinical trials, published in 
English) was performed for all trials containing, in any field, the words 
"sitagliptin," "vildagliptin," "saxagliptin," "alogliptin," "linagliptin," 
and/or "dutogliptin." Completed but unpublished trials were identified through a 
search of the ClinicalTrials.gov website, using the same keywords as above. 
Differences in the endpoint levels and absolute or percent variations of lipids 
were assessed. A metaregression was performed on the trials specified above to 
assess the effect of putative moderators on the effect of DPP-4 inhibitors on 
plasma lipids, considering all drugs together and each one separately.
RESULTS: Although the number of trials of appropriate size and duration was high 
(n=53), only a small fraction of those (n=17) reported data on endpoint total, 
high-density lipoprotein, and low-density lipoprotein cholesterol, and 
triglyceride. The difference-in-means for endpoint versus baseline total 
cholesterol in patients on DPP-4 inhibitors treatment was significantly higher 
in comparison with controls, meaning that treatment with DPP-4 inhibitors is 
associated with a significant reduction in total cholesterol (-0.18 [-0.29; 
-0.06] mmol/L (-7.0 [-11.2; -2.50] mg/dL); P=0.002).
CONCLUSIONS: This meta-analysis suggests a possible beneficial effect of DPP-4 
inhibitors on cholesterol, which, although small, could contribute to the 
reduction of cardiovascular risk.