Medtronic ( MDT) shares were marginally higher on Friday after studies showed its insulin pump outperformed injected insulin when used to treat young diabetics. A study by the Yale School of Medicine found Medtronic's insulin pump therapy improved blood sugar levels in young type 1 diabetics better than the more-commonly used daily injection therapy using Lantus insulin, a product of Aventis SA ( AVE). Results from the first-ever study of the effects of the two types of treatments on children and adolescents will be published in the July 2004 issue of Diabetes Care. In reaction to the study, shares of Medtronic rose 11 cents, or 0.2%, to $49.63. Aventis shares rose 54 cents, or 0.7%, to $76.57. The 16-week study of 32 patients found that those using Medtronic's pumps saw blood sugar levels, as measured using the hemoglobin A1c, drop from 8.1% to 7.2%, while those taking multiple insulin injections saw A1c fall from 8.2% to 8.1%. At the end of the study, 50% of those using Medtronic's pumps met the American Diabetes Association's target blood sugar levels vs. 13% for those taking Lantus. "We have long known that insulin pumps improve glycemic control in both adults and children. Now a definitive study indicates that insulin pumps more effectively control blood sugar than multiple daily injections with Lantus in young patients," said Elizabeth Doyle of the Yale School of Medicine.