PARIS - France's Sanofi-Aventis said the results of a study on the link between its Lantus diabetes drug and retinopathy, which causes blindness, showed the risk for patients was not greater than with human insulin.

The results of the long-term, 5-year study of Lantus versus NPH insulin on progression of retinopathy in patients with type 2 diabetes, published on-line in Diabetologia, showed similar effects on retinopathy and overall safety in the two treatment groups, the French drugmaker said in a statement on Monday.

The U.S. Food and Drug Administration last week cast doubt on recent studies that suggested possible cancer risk with Sanofi-Aventis' widely used Lantus diabetes drug, boosting investor confidence in the blockbuster product.

Lantus is a top seller for Sanofi, and it is seen as particularly important as other key Sanofi products -- blood thinners Plavix and Lovenox -- face possible generic competition. Lantus tallied 2.45 billion euro in 2008 sales, a figure analysts have expected to grow over the next five years.

Shares in Sanofi-Aventis were down 0.61 percent in early trade on Monday, to 42.55 euros. (Reporting by Michel Rose; Editing by Hans Peters)