We are grateful to Ulas et al. [1] for their comments on our recent study [2] concerning the beneficial effects of metformin on vascular en-dothelial function and cardiopulmonary performance in patients with insulin resistance (IR). This study, performed in a population with ab-normal carbohydrate metabolism and IR, showed that 1. metformin is able to positively affect the endothelial function and that 2. the favor-able result does not translate into an improved physical performance in all individuals, but only in those with a higher HOMA-IR. If the results are confirmed in a larger population and following an extended follow-up, assessment of HOMA-IR would prove crucial to identify people who may get the most benefit by treatment with insulin sensitizers. All of our patients, consecutively recruited from the Diabetic Center of our University Hospital, showed impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG). All of them were affected by IR, calculated according to the homeostatic model assessment (HOMA) index. The IR was defined according to the values of Bonora et al. [3]. These authors reported a HOMA-IR value of 2.77 for Italian individuals, and we felt that this population was the most similar to that of our study. In response to comments by Ulas, we confirm that all our patients had a HOMA-IR> 2.77. It should be noted that the large standard devi-ation of the results was due to several high values of HOMA-IR. Finally, we believe that our group had a normal distribution, since the median value (4.22) was close to the average HOMA-IR. Regarding the dosage of metformin, please note that the dose of 150 mg was erroneously inserted in the text, while the true dosage ad-ministered to our patients was 850 mg, twice a day, with only 2 drops out for severe diarrhea induced by the drug.