Does Intensive Blood Sugar Control Improve Cognitive Decline in Diabetes?



No significant difference in cognitive outcome was observed between patients with type 2 diabetes who received intensive versus standard glycemic control.

Intensive control of blood sugar levels beyond standard targets provides no additional protection against cognitive decline in older people with diabetes compared with standard treatment, according to research published in the November 10 Lancet Neurology.

“We know that people with type 2 diabetes have a much higher risk of dementia and memory loss than people without diabetes,” said coauthor Jeff D. Williamson, MD, Chief of the Department of Geriatrics and Gerontology, Wake Forest Baptist Medical Center, Winston-Salem, North Carolina. “What we didn’t know was, if you intensively control blood sugar levels in people who have had a history of trouble controlling them, does the added cost and effort to control blood sugar result in a slowed rate of memory loss? After conducting this study, there remains no evidence that it does.

“We also learned, however, that the intensive blood sugar control does preserve brain volume,” he added. “What that means for the long-term preservation of cognitive function of these patients, we’re still trying to figure out.”

The Action to Control Cardiovascular Risk in Diabetes–Memory in Diabetes (ACCORD–MIND) trial was designed to examine the effects of different glucose-lowering strategies on the risk for cardiovascular disease. The research team recruited nearly 3,000 people with long-standing type 2 diabetes and a high risk for heart disease. Participants were assigned either to an “intensive” program to maintain their hemoglobin A1c lower than standard targets below 6%, or to a “standard” program to maintain the levels between 7% and 7.9%. The patients ranged in age from 55 to 80. All participants underwent cognitive testing, and more than 600 also underwent MRI scans to measure any change in brain volume.

The initial study plan was to measure the participants’ cognitive ability and brain volume after 40 months, but an increased risk of dying in the intensive strategy group led the researchers to switch all participants to the standard glucose-lowering strategy at a median treatment time of 39 months.

Cognitive test scores revealed no difference between the groups, though subjects in the intensive treatment group had greater total brain volume. However, this result—when weighed against the lack of cognitive benefit, the increased risks of cardiovascular problems, and increased mortality in the intensive treatment group—did not support use of the more intensive therapy, the researchers concluded.

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