The present study describes the effects of sildenafil (viagra) on brachial artery flow-mediated dilatation in people with type 2 diabetes (Desouza, Parulkar, Lumpkin, Akers and Fonseca, 2002, 1336). It was written by researchers at the Tulane University Health Sciences Center in New Orleans, Louisiana, and was supported in part by a gift from Pfizer, and in part by the Tullis-Tulane Alumni Chair in Diabetes and the John C. Cudd Fund, which supports diabetes research at the university. Fonseca is supported in part by a grant-in-aid from the American Heart Association, Southeastern affiliate.
The reason for carrying out the study was that flow-mediated dilatation (FMD), which is induced by occlusion of the brachial artery, is used to assess nitric oxide-dependent endothelial function (DeSouza, Parulkar, Lumpkin, Akers and Fonseca, 2002, 1336). This is often impaired in patients with type 2 diabetes. It is known that sildenafil, a drug which is used to manage erectile dysfunction in type 2 diabetes patients as well as in many other patients, inhibits phosphodiesterase 5 (PDE-5) . However, no one had previously looked at the effects of this drug on endothelial function in these patients.
To look at its effects in type 2 diabetics, the researchers assessed both the acute and the prolonged effects of low doses of sildenafil (25 mg) on FMD in patients with this disease (Desouza, Parulkar, Lumpkin, Akers and Fonseca, 2002, 1336). The study was performed as a double blind, placebo-controlled, cross-over trial, and involved 16 patients with type 2 diabetes, but only 14 patients actually completed the study. All the patients exhibited erectile dysfunction but had no overt evidence of heart disease.
Patients were recruited for the study after approval by the Institutional Review Board and after giving informed consent (Desouza, Parulkar, Lumpkin, Akers and Fonseca, 2002, 1337). They had a mean age of 44 +/- 7 years, type ...