WEDNESDAY, Nov. 30 (HealthDay News) — Could Alzheimer’s be a form of diabetes? disorder, or another type of diabetes,” she added. …
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Alzheimers Could Be Diabetes-like Illness, Study Suggests
Brain insulin levels fall as the disease progresses By Steven Reinberg HealthDay Reporter
WEDNESDAY, Nov 30 HealthDay News — Could Alzheimers be a form of diabetes? Thats the tantalizing suggestion from a new study that finds insulin production in the brain declines as Alzheimers disease advances Insulin disappears early and dramatically in Alzheimers disease, senior researcher Suzanne M de la Monte, a neuropathologist at Rhode Island Hospital and a professor of pathology at Brown University Medical School, said in a prepared statement And many of the unexplained features of Alzheimers, such as cell death and tangles in the brain, appear to be linked to abnormalities in insulin signaling This demonstrates that the disease is most likely a neuroendocrine disorder, or another type of diabetes, she added The discovery that the brain produces insulin at all is a recent one, and de la Montes group also found that brain insulin produced by patients with Alzheimers disease tends to fall below normal levels Now
her group has discovered that brain levels of insulin and its related cellular receptors fall precipitously during the early stages of Alzheimers Insulin levels continue to drop progressively as the disease becomes more severe — adding to evidence that Alzheimers might be a new form of diabetes, she said In addition, the Brown University team found that low levels of acetylcholine — a hallmark of Alzheimers — are directly linked to this loss of insulin and insulin-like growth factor function in the brain The report appears in the November issue of the Journal of Alzheimers Disease In its study, de la Montes team autopsied the brain tissue of 45 patients diagnosed with different degrees of Alzheimers called Braak Stages They compared those tissues to samples taken from individuals with no history of the disease The team analyzed insulin and insulin receptor function in the frontal cortex of the brain, a major area affected by Alzheimers They found that as the severity of Alzheimers increased, the levels of insulin receptors and the brains ability to respond to insulin decreased In the most advanced stage of Alzheimers, insulin receptors were nearly 80 percent lower than in a
normal brain, de la Monte said In addition, the researchers found two abnormalities related to insulin in Alzheimers First, levels of insulin dropped as the disease progressed Second, insulin and its related protein — insulin-related growth factor-I -lose the ability to bind to cell receptors This creates a resistance to the insulin growth factors, causing the cells to malfunction and die Were able to show that insulin impairment happens early in the disease, de la Monte said 
Were able to show its linked to major neurotransmitters responsible for cognition Were able to show its linked to poor energy metabolism, and its linked to abnormalities that contribute to the tangles characteristic of advanced Alzheimers disease This work ties several concepts together and demonstrates that Alzheimers disease is quite possibly a Type 3 diabetes, she said One expert believes declining insulin levels may be an important feature of Alzheimers, but not the whole story There is now increasing evidence primarily from observational studies that diabetes, its predecessor metabolic syndrome, and insulin resistance are implicated in increasing risk for Alzheimers disease, said Dr Hugh C Hendrie He is
a professor of psychiatry and co-director of the Center for Alzheimers Disease and Related Neuropsychiatric Disorders at Indiana University Center for Aging Research, in Indianapolis This study adds support to these biological hypotheses and has perhaps treatment implications for the use of certain types of anti-diabetes drugs that influence insulin resistance, Hendrie said
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There are many other factors also implicated in Alzheimers disease, such as hypertension and inflammation, so I think its a bit of a stretch at the moment to describe Alzheimers disease as an endocrinological disorder like diabetes, he said Another expert thinks that insulin and insulin-like growth factors may be the key to slowing the progression of Alzheimers We have shown that insulin-like growth factors regulate learning and memory, said Douglas N Ishii, a professor in the Department of Biomedical Sciences at Colorado State University in Fort Collins We had shown that by blocking insulin-like growth factors in the brain you block learning and memory When Ishiis
group treated rats with insulin-like growth factors, the researchers found that the intervention prevented the loss of both learning and memory In addition, we showed that insulin normally regulates brain weight in adults, he said The clinical potential is that by injecting insulin-like growth factors into patients, one might be able to prevent the loss of learning and memory, Ishii said In particular, we have a paper coming out showing that insulin-like growth factors can not only prevent the loss of learning and memory, but prevent the loss of a protein in the brain This may lead to the slowing down of the progression of Alzheimers More information For more on Alzheimers disease, visit the Alzheimers Association wwwalzorg
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