Re: correlation between ankle-brachial index and microalbuminuria in type 2 diabetes mellitus.

415 Iranian Journal of Kidney Diseases | Volume 7 | Number 5 | September 2013 type 2 diabetic patients are under the treatment of metformin too. Similar results were also found in the study of Bruckbauer and colleagues to evaluate the synergistic effects of metformin, resveratrol and hydroxymethylbutyrate on insulin sensitivity.14 They suggested that resveratrol-hydroxymethylbutyrate combined with metformin might act synergistically on adenosine monophosphate-activated protein kinase-dependent pathways, leading to increased insulin sensitivity, which might reduce the therapeutic doses of metformin necessary in the treatment of diabetes. Thus, according to the renoprotective efficacy of silymarin in our study and hypoglycemic effect of this medicinal plants in the study conducted by Sheela and colleagues, it is possible that the combination of metformin and silymarin may have additive renoptective efficacy beyond better controlling the diabetes.13-16 In this regard, to better understand the renoprotective properties of silymarin, especially in combination with metformin, more experimental rat models and clinical studies are suggested.