Medical advisor, clinician, researcher
It is well known that INSULIN IS PRODUCED by mammalian neurons.
On the other hand German neuroscientist Siegfried Hoyer in 1998 proposed that AD is so called insulin resistant brain state (Hoyer S (1998) Is sporadic Alzheimer disease the brain type of non-insulin dependent diabetes mellitus? A challenging hypothesis. J Neural Transm 105: 415-422)
DEVASKAR SU, GIDDINS SJ, RAJAKUMAR PA, CANAGHI LR, MENON RK, ZAHM DS 1994 Insulin gene expression and insulin synthesis in mammalian neuronal cells. J Biol Chem 269: 8445-8454
Wozniak M, Rydzewski B, Baker SP, Raizada MK (1993) The cellular and physiological actions of insulin in the central nervous system. Neurochem Int 22: 1-10
Schechter R, Whitmire J, Holtzelaw L, George M, Devaskar SU (1992) Developmental regulation of insulin in the mammalian central nervous system. Brain Res 582:27-37
GEROZISSIS K 2003 Brain insulin: regulation, mechanisms of action and functions. Cell Mol Neurobiol 23: 1-25
OAK BROOK, Ill -- April 29, 2014 -- Type 2 diabetes may be associated with brain degeneration, according to a study published in the online edition of the journal Radiology.
The study also found that, contrary to common clinical belief, diabetes may not be directly associated with small vessel ischemic disease, where the brain does not receive enough oxygenated blood.
“We found that patients having more severe diabetes had less brain tissue, suggesting brain atrophy,” said lead author R. Nick Bryan, MD, University of Pennsylvania, Philadelphia, Pennsylvania. “They did not seem to have more vascular disease due to the direct effect of diabetes.”
“As diabetes becomes more common, better understanding of the disease and its management becomes even more important in order to minimise its effect on patient health,” he added.
For the study, Dr. Bryan and colleagues used magnetic resonance imaging (MRI) to investigate the association between severity and duration of type 2 diabetes and brain structure in 614 patients (mean age, 62 years) at 4 participating centres in the US.
The mean duration of disease in the study group was 9.9 years. The researchers specifically tested whether more severe diabetes was inversely correlated with brain volumes and positively correlated with ischaemic lesion volumes.
The results showed that longer duration of diabetes was associated with brain volume loss, particularly in the gray matter. However, the study found no association of diabetes characteristics with small vessel ischaemic disease in the brain.
“Diabetes duration correlated primarily with brain atrophy,” said Dr. Bryan. “Stated another way, our results suggested that, for every 10 years of diabetes duration, the brain of a patient with diabetes looks approximately 2 years older than that of a non-diabetic person, in terms of gray matter volume.”
The researchers noted that their findings may have implications for future decline of cognitive function in patients with diabetes and raise the possibility that such cognitive changes might not be strongly related to vascular dementia but to neurodegenerative disorders, such as Alzheimer’s disease.
SOURCE: Radiological Society of North America
Senad Hasanagic