Diabetes Associated with Brain Pathology, but Not Amyloid Accumulation

Rosebud O Roberts, M.B., Ch.B. Professor of Epidemiology Professor of Neurology Mayo ClinicMedicalResearch.com Interview with:
Rosebud O Roberts, M.B., Ch.B.
Professor of Epidemiology
Professor of Neurology
Mayo Clinic


MedicalResearch.com: What are the main findings of the study?

Dr. Roberts: We found that among persons 70 years and older, people with type 2 diabetes had a reduced glucose uptake (hypometabolism) in  brain cells.  We also found a similar association for people without type 2 diabetes but who had elevated hemoglobin A1c levels levels at the time of enrollment (HBA1c is a measure of glucose control, and represents the average blood glucose levels over a 3 month period). However, we did not find an association of diabetes with increased brain amyloid accumulation.  Our findings were based on an investigation of the association of type 2 diabetes with markers of brain pathology: brain hypometabolism was assessed by 18F-fluorodeoxyglucose positron emission tomography [PET] and amyloid accumulation was assessed by 11-C Pittsburgh Compound B PET imaging.

MedicalResearch.com: Were any of the findings unexpected?

Dr. Roberts: We were surprised that we did not to observe an association of diabetes with amyloid accumulation. Our previous studies and reports from other investigators have shown associations of type 2 diabetes with mild cognitive impairment and Alzheimer’s disease. Thus, we expected that type 2 diabetes would also be associated with amyloid accumulation, one of the hallmarks of Alzheimer‘s disease.

MedicalResearch.com: What should clinicians and patients take away from your report?

Dr. Roberts: Physicians need to know that diabetes increases brain pathology, and that prevention and control of diabetes are important strategies that may reduce brain pathology and prevent cognitive impairment in late life.  In addition, the findings on elevated HBA1c in non-diabetics suggest that early detection of diabetes in those at increased risk is also important in the effort to reduce late life cognitive impairment.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Dr. Roberts: Our findings suggest that they may be multiple mechanisms by which diabetes impacts brain pathology and thereby, Alzheimer‘s disease.  We need further studies of the brains of persons with and without diabetes to more fully understand these disease mechanisms. This knowledge will be important for efforts at early detection and may inform efforts directed at drug development for late life cognitive impairment.

Citation:

Diabetes and Elevated Hemoglobin A1c Levels Are Associated with Brain Hypometabolism but Not Amyloid Accumulation
Roberts RO1, Knopman DS, Cha RH, Mielke MM, Pankratz VS, Boeve BF, Kantarci K, Geda YE, Jack CR Jr, Petersen RC, Lowe VJ.

J Nucl Med. 2014 Mar 20. [Epub ahead of print]