A new study published in the journal JAMA Internal Medicine, suggests that the rigorous treatment of blood pressure and cholesterol levels in people with type 2 diabetes does not lower the risk of impaired memory and thinking.
"The finding that intensive blood pressure lowering did not impact [mental] decline in patients with diabetes seems to be consistent with recent trials in patients with diabetes that [showed that] lower is not necessarily better," said Dr. Kevin Marzo, chief of cardiology at Winthrop-University Hospital in Mineola, N.Y. Marzo, who was not involved in the new research.
The researchers monitored nearly 3,000 individuals with type 2 diabetes who had no deficits in memory or thinking and showed no other signs of dementia at the beginning of the study.
The individuals were part of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial. Some received intensive therapy to lower their systolic blood pressure - the top number in a reading - to below 120 millimeters of mercury (mm/Hg), while a comparison group got standard blood pressure therapy with a goal of lower than 140 mm/Hg.
Other individuals with type 2 diabetes received intensive therapy to battle high cholesterol, which meant adding a drug to a statin medication to bring blood cholesterol levels to below 100 milligrams per deciliter. A comparison group got standard cholesterol treatment - the statin alone - plus a placebo.
The researchers followed-up the individuals three years after and observed no differences in the mental function of people who received intensive therapies versus those who got standard treatments. The total brain volume of some people in each group was also monitored, because lessening brain volume has been linked to mental decline.
Although these types of treatments might be helpful for people with heart disease or stroke, the researchers said, the current study showed no overall reduction in the rate of mental decline linked to type 2 diabetes after intensive blood pressure and cholesterol control.
"Furthermore, the damage exerted in the brain by diabetes and its associated hypertension and cholesterol disorders may already be irreversible," Dr. Valentin Fuster, director of the division of cardiology at Mount Sinai Hospital in New York City said. "If so, one could not expect significant changes with treatment."
"More studies need to be performed in this area of diabetic research," Dr. Spyros Mezitis, an endocrinologist and diabetes specialist at Lenox Hill Hospital in New York City said.