Dr. John Buse, a recognized diabetes expert, has claimed that the manufacturer of Avandia tried to quash his criticism of the drug. This claim has led to a congressional investigation and the doctor’s testimony before Congress next week. According to a story published in the NY Times, “Congressional investigators have been looking into what they have called “very serious” claims that Avandia’s maker ‘silenced one or more medical professionals who attempted to speak out about the potential for cardiovascular problems with Avandia,’ according to a letter to Glaxo last week from the Senate Finance Committee.”