September 29, 2011

Intensively Lowering Blood Sugar Doesn’t Help Brain

(Ivanhoe Newswire) -- People with type 2 diabetes who intensively lower their blood sugar are not preventing cognitive decline, according to new research.

Individuals with type 2 diabetes who are older than age 70 are twice as likely to develop cognitive impairment that is linked to their disease than those without diabetes.

A team of researchers studied nearly 3,000 patients aged 55 years who had type 2 diabetes and were at risk for cardiovascular disease. These individuals also had high blood sugar levels, with a hemoglobin A1c greater than 7.5 percent. Hemoglobin A1c is a test is used as a standard tool to determine blood sugar control for patients with diabetes.

The patients were randomly assigned to receive an intensive treatment strategy that ensured their hemoglobin A1c levels remained lower than 6 percent or standard treatment that ensured their A1c levels stayed between 7 percent and 7.9 percent. The researchers ended up switching all the participants to the standard glucose-lowering strategy after 39 months because of an increased risk of death in the intensive therapy group.

Overall, the results showed no difference in cognitive ability between the two groups. The patients in the intensive group had a significantly larger brain volume at 40 months. However, the increased risk of dying and other factors kept the researchers from recommending the intensive therapy.

"We feel it is reasonable to suggest that a larger decline in brain capacity will lead to earlier loss of function and possibly dementia -- the MIND participants at an average age of 62 years are already experiencing an annual decline of TBV [total brain volume] in the range reported for people 15 years older," the authors of the study were quoted as saying.

They concluded: "Cognitive function affects the ability of patients to follow complex disease management protocols, and impaired cognition predicts cardiovascular disease and severe hypoglycemic events. Early prevention strategies to reduce the risk of cognitive impairment are needed because, as the longevity of patients with diabetes increases, so too does the number reaching an age at which cognitive disorders become clinically apparent. Optimum treatment strategies for brain health in older people with type 2 diabetes are needed and should be assessed in the context of a comprehensive assessment of therapeutic strategies to manage type 2 diabetes and its consequences."

SOURCE: The Lancet Neurology, September 2011