People with type 2 diabetes may lose more brain volume than is expected as they age, new research indicates, but treating for cholesterol and blood pressure didn’t benefit diabetics with cognitive problems, and the aggressive BP treatment actually is linked to more brain atrophy. This study suggests that chronic high levels of insulin and sugar may be directly toxic to brain cells.
“Both heart disease and diabetes are closely linked to cognitive problems (see Jan 2014 webinar; see AlzRisk analysis). To learn what is gained from treating these disorders, the ACCORD trial recruited more than 10,000 older people with Type 2 diabetes and cardiovascular risk factors. Nearly 3,000 of them participated in the MIND substudy. Their average age was 62 and they had struggled with diabetes for about 10 years, with poor control of blood sugar and blood pressure. The researchers split the cohort in half to test two interventions, one targeting blood pressure and the other, cholesterol. In the hypertension study, half the participants received high-dose medication that dropped systolic pressure below 120 mm Hg, while the other half received standard treatment aiming for the 130-140 mm range. In the cholesterol study, the control group took statins while the rest took statins plus fenofibrate, a drug that further lowers cholesterol and other fats in the blood.
After 40 months of treatment, all participants performed worse on cognitive tests than they had at baseline. There were no significant differences between standard and treatment arms in either study.
More than 500 MIND participants volunteered for MRI as well. These scans showed that whole brain volume shrank over 40 months in all participants, but the intensive blood pressure-intervention group had significantly more atrophy. Although treatment has since ended, the researchers continue to follow the cohort to see if cognitive differences between arms will show up over time, and if such changes will reflect the alterations in brain volume. Participants recently completed 75-month follow-up cognitive tests and brain scans; those results may be available within the year, Williamson told Alzforum.”