The results, quoted in Nature, contradict the established theory that diabetics benefit from driving down their excessively high blood sugar levels as forcibly as possible.
The trial, part of ACCORD (Action to Control Cardiovascular Risk in Diabetes), made headlines earlier this year when this segment of the study was halted in February by a safety review board. The results are published by 'The New England Journal of Medicine'.
The results do not mean that diabetics should not work to keep their blood sugar under control, cardiologist Harlan Krumholz of Yale Medical School in New Haven, Connecticut, was quoted as saying but they do illustrate that taking extreme measures to lower blood sugar may not be warranted.
More than 10,000 type 2 diabetics, who either had cardiovascular disease or were at high risk for developing the condition, were enrolled in the trial.
Roughly half used standard treatments to lower their bloodsugar, and achieved an average level of "glycated haemoglobin" a measure of blood sugar of 7.5 per cent, which is thought to be acceptable, if higher than for a non-diabetic.
The other group used higher doses of the same drugs to lower their glycated haemoglobin, reaching levels of 6.4 per cent over the course of a year. They maintained these low levels for just over three years.
Over the course of three and a half years, 257 people in the high-dosing group died compared with only 203 in the group that used standard doses, Nature reported.
