A vast diabetes study which looked at the effects of aggressively lowering blood glucose levels to normal values in diabetics had to be halted abruptly after researchers have found out that the treatment increased the risk of death.

The phase one of the ACCORD (Action to Control Cardiovascular Risk in Diabetes) Trial has stopped 18 months early. The National Heart, Lung, and Blood Institute (NHLBI), which is part of the National Institutes of Health in the US, said an early analysis of the data showed the aggressive treatment of type-2 diabetes increased the risk of death compared with a less intensive treatment strategy.

"It’s confusing and disturbing that this happened," said Dr. James Dove, president of the American College of Cardiology to New York Times. "For 50 years, we’ve talked about getting blood sugar very low. Everything in the literature would suggest this is the right thing to do," he added.

NHLBI said that over an average treatment period of four years, there were 3 deaths per 1,000 more in the intensive treatment group compared to the standard treatment group. This amounted to 54 more deaths for the ~5,000 patient study group which was treated more aggressively versus the other five thousand patients who were treated milder.

"It's profoundly disappointing," said Richard Kahn, chief scientific and medical officer for the American Diabetes Association, to The Washington Post. "This presents a real dilemma to patients and their physicians. How intensive should treatment be? We just don't know."

Diabetes mellitus, usually referred to as diabetes, is a syndrome characterized by disordered metabolism which leads to inappropriately high blood sugar. Specifically, Type 2 Diabetes, which is the most common form and the target of the ACCORD Trial, is primarily characterized by insulin resistance, relative insulin deficiency and hyperglycemia. The disease is chronic and progressive and has no clearly established cure.

Treatment focuses only on preservation of quality of life and reduction of mortality and concomitant morbidity from complications.