There is a growing body of scientific evidence that links Alzheimer’s and diabetes, which may enable already approved diabetes therapies to be quickly tested for effectiveness against the deadly brain disease. New data from drug trials and long-term population studies were presented at “ICAD” being held in Madrid, Spain.

Weili Xu, M.D., and colleagues from the Karolinska Institute and the Stockholm Gerontology Center, Sweden, followed 1,173 individuals and found that borderline diabetes was associated with an almost 70% increased risk of developing dementia and Alzheimer’s disease in this population.

Further analysis revealed that such a significant association was present only among non-carriers of APOE e4 allele, a gene that increases the risk for the most common form of Alzheimer’s. The risk for Alzheimer’s was especially high when borderline diabetes occurred with severe systolic hypertension.

Another study by Rachel A, Whitmer, Ph.D., of Kaiser Permanente’s division of research, and colleagues suggests that people with type 2 diabetes have an increased risk of dementia and Alzheimer’s disease and among those, the patients with poor blood sugar control are at the greatest risk.

Dr. Whitmer studied 22,852 patients with type 2 diabetes for eight years and compared the levels of glycosylated hemoglobin with the risk for dementia. They found that in patients with elevated glycosylated hemoglobin levels the risk for dementia increased and those with levels above 15% had an 83% higher risk.

A third study, presented by Donald R. Miller, Sc.D., from the Boston University School of Public Health and the Center for Health Quality, Outcomes, and Economic Research, and colleagues found that patients treated with thioazolidinediones, such as pioglitazone (Actos) or rosiglitazone (Avandia), were 20% less likely to develop Alzheimer’s disease than those on insulin.