Tightly controlling your blood glucose levels soon after being diagnosed with Type 2 diabetes can lead to lower risks of diabetes complications—including heart disease and death—years later, according to new follow-up results from a major clinical trial. This new study was published online this week in The New England Journal of Medicine, and looked at participants in the United Kingdom Prospective Diabetes Study (UKPDS) 10 years after that study had ended.
The original UKPDS randomly assigned over 4,000 people newly diagnosed with Type 2 diabetes to intensive blood glucose control (using sulfonylurea drugs, insulin, or if they were overweight, metformin) or standard control (using diet alone). Over the course of the 10-year study, the intensive-control group achieved an HbA1c level of 7.0%, while the standard-control group’s HbA1c level was 7.9%. The people who took sulfonylureas or insulin had a significant, 25% reduction in diabetic eye disease and kidney disease (”microvascular” complications) compared to the standard-control group, and the people who took metformin had an even bigger decrease in these complications.
In the new UKPDS follow-up study, researchers monitored over 3,000 participants from the original trial for an average of 10 years after the UKPDS ended. Within one year of the original study ending, the differences in HbA1c levels between the intensive- and standard-control groups disappeared. (After five years, all groups had HbA1c levels of around 7.5% to 8%.) However, at the end of the 10-year follow-up period, the people who had been in the intensive blood glucose control group had significantly lower rates of microvascular complications, heart attack, and death from any cause than people who had been in the standard-control group. Those who had taken metformin had even greater reductions in these risks than those who had taken sulfonylureas or insulin during the original study.
The researchers concluded that blood glucose control in Type 2 diabetes is important, and when undertaken soon after diagnosis may provide a “legacy effect” on health decades down the road. The findings of a reduced risk of heart attack, especially, can be contrasted with the findings of other large studies published earlier this year, such as the ACCORD and ADVANCE trials, in which intensive blood glucose control in people who had already had diabetes for several years did not significantly reduce their cardiovascular risks (and in the ACCORD trial, even appeared to raise risk of death).
You can read more about the original UKPDS in our article “The Benefits of Tight Control: No End in Sight.”