Just after a massive U.S. study dropped its aggressive treatment of blood glucose levels because of increased deaths among type 2 patients, international researchers announced that their similar intense study of tight blood sugar control showed no increased risk of death.

The seeming contradiction has scientists from both studies scrambling to explain their different data.

The U.S. study, called ACCORD, was experimenting with reducing blood glucose levels in type 2 diabetics through aggressive means such as new medicines, exercise and intense monitoring. The goal was to drive A1c's in selected type 2s down to 6% - fairly close to the A1c's found in non-diabetic people. But when researchers noted a statistically significant increase in deaths among those patients compared to a control group not receiving aggressive treatment, they halted that segment of the study.

Only days later, scientists at the ADVANCE study, managed by the University of Sydney's George Institute for International Health, said that their research could not confirm the ACCORD findings. ADVANCE, which studied 11,140 high-risk type 2 patients who were receiving intense blood glucose control therapy, found no evidence that aggressive treatment led to an increased risk of death.

The American Diabetes Association said that although the discrepancy in the studies' conclusions fuels uncertainty about whether intensive glucose control can harm some people with diabetes, the studies were not identical - a distinction that may help scientists eventually explain their contradictory conclusions.