Posted on Sep 08, 2010, 6 a.m.
People with insulin resistance and type-2 diabetes appear to be at an increased risk of developing plaques in the brain that are associated with Alzheimer's Disease.
Kensuke Sasaki, from Kyushu University (Japan), and colleagues examined the association between diabetes-related factors and the pathology of Alzheimer’s Disease. The team studied 135 people, average age 67 years, from Hisayama, Japan. The participants had several diabetes glucose tests to measure blood sugar levels. They were also monitored for symptoms of Alzheimer's disease over the next 10 to 15 years. During that time, about 16% developed Alzheimer's disease. After the participants died, researchers examined their autopsied brains for the physical signs of Alzheimer's disease, namely the telltale plaques and tangles. While 16 percent had symptoms of Alzheimer's disease while alive, a total of 65% had plaques. Further, the study found that people who had abnormal results on three tests of blood sugar control had an increased risk of developing plaques. Plaques were found in 72% of people with insulin resistance and 62% of people with no indication of insulin resistance. The researchers conclude that: “The results of this study suggest that hyperinsulinemia and hyperglycemia caused by insulin resistance accelerate [neuritic plaque] formation in combination with the effects of APOE e4 [gene].”
T. Matsuzaki, K. Sasaki, Y. Tanizaki, J. Hata, K. Fujimi, Y. Matsui, A. Sekita, S.O. Suzuki, S. Kanba, Y. Kiyohara, and T. Iwaki. “Insulin resistance is associated with the pathology of Alzheimer disease: The Hisayama Study.” Neurology, Aug 2010; 75: 764 - 770.