No definitive answer is forthcoming about the cardiovascular safety of the popular diabetes drug Avandia following the release of preliminary data from the RECORD (Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of glycemia in Diabetes) study. Avandia has been on the market since 1999. Its maker, British-based GlaxoSmithKline, calls the findings “reassuring.” But an article and three accompanying editorials in today’s New England Journal of Medicine suggest otherwise.

RECORD, which is funded by GSK, includes about 4,500 type 2 diabetics from Europe, Asia and Australia. The study is meant to run through 2009, but preliminary results were released after a meta-analysis conducted by Dr. Steven Nissen and published by the NEJM indicated that Avandia is associated with a 42% increased risk of heart attack. After a subsequent furor, the study authors chose to release data early.

The lead author of the study, Dr. Philip D. Home of Newcastle University, found no evidence that Avandia raises the risk of heart attack or death from heart disease. Dr. Ronald Krall, the chief medical officer for GSK, says that Avandia has now been exonerated by the study’s findings.

The NEJM editorials, however, paint a much different picture.

According to Dr. David Nathan, the RECORD study has a number of flaws: “The interim results of the RECORD trial do not provide any assurance of the safety of treatment with [Avandia].”

Drs. Bruce Psaty and Curt Furberg were concerned about RECORD’s very low number of heart disease events. Combined with a high dropout rate, the study may not have enough statistical power to prove Avandia’s heart safety. And that is what GSK hoped to do.

Moreover, they suggest that the study findings, when combined with data from previous studies, show that people taking Avandia are still at a significant risk of heart attack.

A third editorial, written by the Journal’s editor-in-chief, Dr. Jeffrey M. Drazen, says, “even a small increase in cardiovascular risk in a fragile population of patients with type 2 diabetes is of considerable concern…. There is continued uncertainty about the cardiovascular safety of [Avandia].”