Diabetes - Risk Factors For Alzheimers Disease: Alzheimers

Content provided by the Faculty of the Harvard Medical School

Diabetes

People with either type 1 or type 2 diabetes face a greater risk of Alzheimer's disease and vascular cognitive impairment. Research indicates that this increase in risk may be due to a shared mechanism: a deficiency or dysfunction of insulin, the hormone that enables cells in the body to use blood sugar (glucose).

Brain cells need blood sugar in order to function, and in particular to execute a high-energy task such as learning a skill or forming a memory. Yet a 2005 study in the Journal of Alzheimer's Disease provides evidence that the brain's ability to use blood sugar may be compromised as Alzheimer's disease develops. The researchers found that insulin levels and the number of insulin receptors in the brain fall dramatically in the early stage of Alzheimer's disease, and they continue to plummet as the disease progresses. In the advanced stage of Alzheimer's disease, there are 80% fewer insulin receptors in the brain than is normal. The researchers think that the decline in insulin and insulin receptors in the brain may be linked somehow to the death of neurons and appearance of tangles in the brain — the signs of Alzheimer's disease.

Last updated:	January 23, 2007