Risk factors for Alzheimer's Disease: Brief summaries of research reports
This section is offshoot of my gathering of news items about memory. I am not a medical expert. My background is in psychology. The information I have gathered here should not be taken as providing any advice.
You can check out words you don't know in the glossary of terms used in Alzheimer's research
Risk factors
Cholesterol / Fat / Calories
High cholesterol in your 40s increases risk of Alzheimer's disease
Obesity significantly increases dementia risk
Larger belly in mid-life increases risk of dementia
High blood pressure or irregular heartbeat linked to Alzheimer's disease progression
Alzheimer’s most often found in combination with other disease
More on why high cholesterol might increase your risk of Alzheimer’s
How mental and physical stimulation slows Alzheimer's
Loss of body mass linked to development of Alzheimer's disease
Alzheimer's, cardiovascular disease share risk factors
Why diet, hormones, exercise might delay Alzheimer’s
Low blood pressure risk factor for Alzheimer's
High cholesterol risk factor for the development of Alzheimer-related amyloid deposits
Cholesterol not a risk factor for Alzheimer's
New study counters previous research linking intake of dietary fat with increased risk of dementia
High blood pressure and cholesterol are risk factors for Alzheimer's disease
April 2008
High cholesterol in your 40s increases risk of Alzheimer's disease
A study involving nearly 10,000 people who underwent health
evaluations between 1964 and 1973 when they were between the ages of 40 and 45,
has found that those with total cholesterol levels between 249 and 500
milligrams were one-and-a-half times more likely to develop Alzheimer's disease
than those people with cholesterol levels of less than 198 milligrams. People
with total cholesterol levels of 221 to 248 milligrams were more than
one-and-a-quarter times more likely to develop Alzheimer's disease. High
cholesterol increased risk regardless of midlife diabetes, high blood pressure,
obesity, smoking and late-life stroke.
The research was presented at the American Academy of
Neurology Annual Meeting in Chicago, April 12 – April 19.
http://www.eurekalert.org/pub_releases/2008-04/aaon-hci040208.php
Obesity significantly increases dementia risk
A review of 10 international studies published since 1995,
covering just over 37,000 people, has found that obesity increased the relative
risk of dementia by an average of 42% compared with normal weight. Being
underweight increased the risk by 36%. For Alzheimer's Disease and
vascular
dementia, specifically, obesity was an even more significant risk: 80% and 73%,
respectively. With regards to Alzheimer’s, obesity was more likely to be a risk
factor for women, but men were more affected when it came to vascular dementia.
The study appeared in the May issue of Obesity Reviews.
April 2008 news report
http://www.physorg.com/news129376360.html
March 2008
Larger belly in mid-life increases risk of dementia
A study involving 6,583 people measured abdominal fat at
age 40 to 45, and dementia occurrence some 36 years later. Those with the
highest amount of abdominal fat were found to be nearly three times more likely
to develop dementia than those with the lowest amount of abdominal fat. Having a
large abdomen increased the risk of dementia regardless of overall weight and
existing health conditions, although being obese as well did increase the risk.
Those more likely to have abdominal obesity, were women, non-whites, smokers,
people with high blood pressure, high cholesterol or diabetes, and those with
less than a high school level of education.
The study was published online March 26 in Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-03/aaon-lbi031808.php
November 2007
High blood pressure or irregular heartbeat linked to Alzheimer's disease progression
A study of 135
men and women newly diagnosed with Alzheimer’s found that those with high blood
pressure at the time of diagnosis showed a rate of memory loss roughly 100%
faster than those with normal blood pressure, and those with atrial fibrillation
(an irregular heartbeat) showed a rate of memory decline that was 75% faster
than those with normal heartbeats. The findings suggest that treating these
conditions may also slow memory loss in Alzheimer’s sufferers.
The results were
published in the November 6 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-11/jhmi-hbp103007.php
http://www.eurekalert.org/pub_releases/2007-11/aaon-hbp103007.php
June 2007
Alzheimer’s most often found in combination with other disease
Post-mortem data from a large, long-running study has found that only
30% of people with signs of dementia had Alzheimer’s disease alone. 42%
had Alzheimer’s disease with cerebral infarcts (strokes) and 16% had
Alzheimer’s disease with Parkinson’s disease (including two people with
all three conditions). Infarcts alone caused another 12% of the cases.
Vascular dementia caused another 12%. In those without dementia, brain
autopsy revealed the presence of Alzheimer’s in 24% of cases, and
infarctions in 18%. The finding that Alzheimer’s pathology with cerebral
infarcts is a very common combination in people with dementia adds to
emerging evidence that dementia risk might be reduced with the same
tools we use for cardiovascular disease such as control of blood
cholesterol levels and hypertension.
The findings appeared online ahead of print June 13 in
Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-06/nioa-sfm061207.htm
February 2007
More on why high cholesterol might increase your risk of Alzheimer’s
A cell study provides more understanding of why there might be a link
between cholesterol and Alzheimer's disease. The study found that proteins
which help control cholesterol levels in arterial walls were also present in
neurons, and when the genes for these proteins were over-expressed,
production of amyloid beta protein fell. The finding suggests a new approach
to slowing Alzheimer’s. The study also showed that the apoE protein is
extremely good at regulating cholesterol removal from neurons — the gene for
this protein is a well-known genetic risk factor for Alzheimer's.
The study appeared in the February issue of the
Journal of Biological Chemistry.
http://www.newscientist.com/article/mg19325905.200?DCMP=NLC-nletter&nsref=mg19325905.200
July 2006
Predicting dementia risk
A large Scandinavian study has succeeded in calculating middle-aged
people's chances of developing dementia later in life with 70% accuracy.
The study confirms the importance of lifestyle factors. The study
assessed factors such as blood pressure, body fat and cholesterol levels
in 1,400 middle-aged Finns in the 1970s and 1980s, and found that those
who at 40 were obese, or had high blood pressure, or high cholesterol
levels, were twice as more likely to develop dementia by the age of 60.
Having all three of these risk factors increased their chances six-fold.
Other risk factors were age and low education.
The study was published online ahead of print on 3 August in
Lancet Neurology.
Full reference
http://society.guardian.co.uk/health/story/0,,1836464,00.html
September 2005
Loss of body mass linked to development of Alzheimer's disease
People with Alzheimer's disease are known to lose weight and body
mass after they have the disease, but now the Religious Orders Study has
revealed that loss in body mass index is associated with a greater risk
of developing the disease. People who lost approximately one unit of BMI
per year had a 35% greater risk than people with no change in BMI; those
with no change in BMI had a 20% greater risk of developing the disease
than that of people who gained six-tenths of a unit of BMI per year. A
similar relationship was also found between changes in BMI and rate of
cognitive decline. The findings are supported by recently published
findings of the Honolulu-Asia Aging Study, showing that
dementia-associated weight loss in Japanese-American men begins before
the onset of dementia and accelerates by the time of diagnosis.
The research was reported in the September 27 issue of
Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2005-09/nioa-lob092105.htm
July 2004
Alzheimer's, cardiovascular disease share risk factors
A study of 4,081 women aged 65 years and older has investigated the relationship between cardiovascular risk factors and cognitive function. The researchers found a consistent increase in cognitive health paralleling higher levels of HDL (“good” cholesterol). A less robust correlation was seen for lower levels of LDL (or "bad") cholesterol and better cognitive performance. Triglyceride levels did not appear to influence cognition.
A study of over 700 elderly men and women has investigated the relationship between diabetes and cardiovascular disease risk factors and cognitive health. Researchers found that the presence of coronary heart disease, high cholesterol, or hypertension increased the risk of later cognitive decline, with a particularly strong effect in African Americans. They also found that although the diagnosis of diabetes increased the risk of cognitive decline by as much as two fold, the presence of high levels of fasting glucose (therefore, low insulin levels) substantially decreased the risk of cognitive decline in diabetic patients.
Data from a 24-week pilot trial of the diabetes drug rosiglitazone in patients with mild cognitive impairment (MCI) or very mild Alzheimer's disease found those who received rosiglitazone – a drug that boosts insulin activity – did not decline in their performance on memory and attention tests.
Data from an ongoing study of memory and aging among more than 3,300
residents age 65 and over from Cache County, Utah, has found that those who had
used anti-hypertension medications had a lower risk of getting Alzheimer's. This
benefit seemed most closely related to the use of diuretics. Among this group of
drugs, "potassium-sparing" diuretics were associated with the greatest reduction
in Alzheimer risk. The use of other hypertension drugs, such as ACE (angiotensin
converting enzyme) inhibitors, calcium channel blockers, and beta-blockers, did
not affect Alzheimer risk.
References
http://www.eurekalert.org/pub_releases/2004-07/aa-acd070804.htm
February 2004
Why diet, hormones, exercise might delay Alzheimer’s
A theory that changes in fat metabolism in the membranes of
nerve cells play a role in Alzheimer's has been supported in a
recent study. The study found significantly higher levels of
ceramide and cholesterol in the middle frontal gyrus of
Alzheimer's patients. The researchers suggest that alterations
in fats (especially cholesterol and ceramide) may contribute to
a "neurodegenerative cascade" that destroys neurons in
Alzheimer's, and that the accumulation of ceramide and
cholesterol is triggered by the oxidative stress brought on by
the presence of the toxic beta amyloid peptide. The study also
suggests a reason for why antioxidants such as vitamin E might
delay the onset of Alzheimer's: treatment with Vitamin E reduced
the levels of ceramide and cholesterol, resulting in "a
significant decrease in the number of neurons killed by the beta
amyloid and oxidative stress.
The study was published in the February 17 issue of
Proceedings of the National Academy of Sciences.
Full reference
http://www.eurekalert.org/pub_releases/2004-02/aaft-nsm021004.htm
December 2003
Low blood pressure risk factor for Alzheimer's
A long-term study of 488 adults over 75 (the Bronx Aging Study)
found that 122 participants developed dementia (65 Alzheimer’s, 28 vascular
dementia, 29 other), and that the relative risk of dementia increased as a
function of decreases in blood pressure (diastolic and mean arterial). Low
diastolic BP significantly increased the risk of developing Alzheimer’s, but not
vascular dementia. Those with mildly to moderately raised systolic BP had a
reduced risk of developing Alzheimer’s. The risk of developing dementia was
higher in those who had persistently low BP over 2 years.
The report appeared in the December 23 issue of Neurology.
Full reference
July 2003
High cholesterol risk factor for the development of Alzheimer-related amyloid deposits
A review of autopsy
cases of patients over 40 years old found that high blood cholesterol levels
were correlated with the presence of amyloid deposits in the brain in the
youngest subjects (aged 40-55).
The report appeared in the July 22 issue of Neurology.
Full reference
May 2003
Cholesterol not a risk factor for Alzheimer's
Previously, the
long-running, large-scale Framingham study found people with elevated levels of
homocysteine in the blood had nearly double the risk of developing Alzheimer’s
disease (AD). The study now clarifies the inconclusive results from previous
studies regarding whether plasma cholesterol levels are associated with
increased risk of Alzheimer disease (AD). They found that, after adjustment for
age, sex, APOE
genotype, smoking, body mass index, coronary heart disease, and diabetes, there
was no significant association between AD risk and cholesterol level.
The study was reported in the May 12 issue of the
Archives of Internal Medicine.
Full reference
http://archinte.ama-assn.org/cgi/content/abstract/163/9/1053
December 2002
New study counters previous research linking intake of dietary fat with increased risk of dementia
Previous studies suggesting that
fat may be involved in the development of dementia and Alzheimer’s disease
have been contradicted by a new study involving over 5,000 elderly people over a
period of six years. The study found no correlation between fat and cholesterol
intake and risk of dementia, and no evidence for a reduction in risk for those
taking cholesterol lowering medication.
The study was reported in the December 24 issue of
Neurology.
Full
reference
http://www.eurekalert.org/pub_releases/2002-12/aaon-nsc121602.htm
August 2002
High calorie consumption associated with higher risk of Alzheimer’s in those genetically disposed to Alzheimer’s
980
elderly individuals without Alzheimer’s participated in a
four-year study to investigate whether there was any link
between caloric intake and Alzheimer’s. During the course of the
study, 242 patients developed Alzheimer’s, and 28% tested
positive for the APOE epsilon 4 gene. Participants were divided
into four groups depending on how many calories they consumed
daily. 263 of the participants tested positive for the APOE
epsilon 4 gene, and among them, those who consumed the most
calories had a 2.3 times greater chance of developing
Alzheimer’s compared to those who ate the fewest calories. For
those without the ApoE e gene, calorie and fat intake were not
associated with a greater risk of Alzheimer’s.
The study was reported in the August issue of the
Archives of Neurology.
http://www.eurekalert.org/pub_releases/2002-08/jota-cmc081202.htm
March 2002
Cholesterol bad for brain too
An
analysis of data on 1037 older women who had participated in a clinical trial of
hormone replacement therapy found that high cholesterol levels increase the risk
of cognitive impairment. It is speculated that, in addition to clogging
arteries, and possibly leading to vascular changes in the brain, cholesterol may
promote the clumping of a protein called beta-amyloid, which is believed to
damage the brain in Alzheimer’s disease patients.
The study was published in the March issue of Archives
of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2002-03/uoc--cbf031302.htm
July 2001
High blood pressure and cholesterol are risk factors for Alzheimer's disease
A large-scale Finnish study
following 1449 men and women over 21 years found that raised systolic blood
pressure and high serum cholesterol concentration, particularly in combination,
in midlife, increase the risk of Alzheimer's disease in later life. Raised
diastolic blood pressure had no significant effect.
The study was reported in the British Medical Journal.
http://www.bmj.com/cgi/content/full/322/7300/1447
Homocysteine / B12 / Folate
Folates more effective in limiting Alzheimer's disease risk than antioxidants, other nutrients
Moderately high homocysteine linked to Alzheimer’s risk
Folic acid possibly a key factor in preventing Alzheimer's disease
High homocysteine levels may double Alzheimer's ris
Research ties vitamin B12 and folate deficiencies with Alzheimer's disease
High homocysteine levels are associated with decreased memory capability after age 60
August 2005
Folates more effective in limiting Alzheimer's disease risk than antioxidants, other nutrients
Analysis of data from the Baltimore Longitudinal Study of Aging has
revealed that those with higher intake of
folates, vitamin E and vitamin B6 had a lower risk of developing
Alzheimer’s. When the three vitamins were analyzed together, only
folates were associated with a significantly decreased risk. Those who
had at least 400mcg of folates a day (the recommended daily allowance)
had a 55% reduction in risk of developing Alzheimer’s. Unfortunately,
most people who reached that level did so by taking supplements,
suggesting the difficulty of doing so through diet alone. Folates are
abundant in foods such as liver, kidneys, yeast, fruits (like bananas
and oranges), leafy vegetables, whole-wheat bread, lima beans, eggs and
milk; however, they are often destroyed by cooking or processing. No
association was found between vitamin C, carotenoids (such as
beta-carotene) or vitamin B-12 intake and decreased Alzheimer's risk.
Results appear in the inaugural issue of
Alzheimer's & Dementia: The Journal of the Alzheimer's Association.
Full reference
http://www.eurekalert.org/pub_releases/2005-08/uoc--fme081105.htm
October 2002
Moderately high homocysteine linked to Alzheimer’s risk
A
study of 83 Alzheimer’s patients, 78 patients with vascular dementia, 64
stroke patients, and 71 healthy controls, found that elevated levels of
homocysteine were associated with a more than five-fold increase in the risk for
stroke, a nearly five-fold risk for vascualr dementia, and almost triple the
risk for Alzheimer's disease. High blood levels of homocysteine have been found
to be associated with an increased heart attack risk in several studies. High
levels of homocysteine have been found to be associated with deficiencies in
vitamin B12 and folate, and also with smoking.
The report appeared in the October issue of Stroke.Full
reference
http://www.eurekalert.org/pub_releases/2002-10/aha-mhh092602.htm
March 2002
Folic acid possibly a key factor in preventing Alzheimer's disease
Experiments
with mice bred with mutant genes that cause Alzheimer's disease
found that those mice fed on a diet deficient in folate had
fewer neurons in the hippocampus ( a brain region critical for
learning and memory that is destroyed as plaques accumulate
during Alzheimer’s disease), and elevated levels of
homocysteine. Researchers suspect that increased levels of
homocysteine in the brain caused damage to the DNA of nerve
cells in the hippocampus. In the mice fed an adequate amount of
folate, nerve cells in this brain region were able to repair the
damage. But in those mice fed a folate-deficient diet, nerve
cells were unable to repair this damage. A human study is being
planned.
Green leafy vegetables, citrus fruits and juices, whole wheat
bread and dry beans are good sources of folate. In the U.S.,
since 1998, the Food and Drug Administration has required the
addition of folic acid to enriched breads, cereals, flours, corn
meals, pastas, rice, and other grain products.
The study was published in the March 1 issue of the
Journal of Neuroscience.
Full reference
http://www.eurekalert.org/pub_releases/2002-03/nioa-fap030102.htm
February 2002
High homocysteine levels may double Alzheimer's risk
Findings from the long-running Framingham
study found people with elevated levels of homocysteine in the blood had nearly
double the risk of developing Alzheimer’s disease (AD). This study is the first
to tie homocysteine levels measured several years before with later diagnosis of
AD and other dementias, and provides the most powerful evidence yet of the link
between high homocysteine levels and AD.
The report appeared in the February 14, 2002, issue of
The New England Journal of Medicine.
Full reference
http://www.eurekalert.org/pub_releases/2002-02/nioa-hhl021202.htm
May 2001
Research ties vitamin B12 and folate deficiencies with Alzheimer's disease
People with low levels of B12 or
folate may have a higher risk of developing Alzheimer's
disease. A 3-year Swedish study of 370 people 75-years-old and
older found that more than half (46 out of 78) of those
diagnosed with dementia during the timeframe of the study had
both low levels of vitamin B12 or folate and Alzheimer's type
dementia. Low vitamin B12 and folate levels have long been
observed in elderly people, and it has been theorized that this
vitamin deficiency might be tied to neurological or psychiatric
disorders. This study breaks new ground by connecting these
deficiencies with Alzheimer's disease.
Vitamins B12 and folate (a form of water-soluble vitamin B) are
found in common foods. Vitamin B12 is naturally found in animal
foods including fish, milk and milk products, eggs, meat, and
poultry. Leafy greens such as spinach and turnip greens, dry
beans and peas, fortified cereals and grain products, and some
fruits and vegetables are rich food sources of folate.
The study was reported in the May 8 issue of
Neurology.
http://www.eurekalert.org/pub_releases/2001-05/AAoN-RtvB-0705101.htm
High homocysteine levels are associated with decreased memory capability after age 60
Recent studies have linked Alzheimer disease and dementia
after multiple strokes to extremely high
serum homocysteine concentrations. A survey of 1299 men and
women aged 60 and over, none of who had previously had a stroke,
found an independent relationship between very high homocysteine
levels and poor performance on cognitive tests. The folate
status of the participants was checked as folate has been shown
to significantly modify homocysteine levels. Story recall was
worse among subjects with a combination of low folate and high
homocysteine than in those whose homocysteine levels were normal
or low. Homocysteine levels increased with age and were
accompanied by a comparable decline in folate status. The
researchers found independent associations between the highest
levels of homocysteine and poorer recall. Among subjects with
the highest level of homocysteine, the odds of passing a word
delayed-recall test were identical whether their folate status
was high or low.
This study appeared in the American
Journal of Clinical Nutrition.
http://www.eurekalert.org/pub_releases/2001-04/AJoC-Hhla-2504101.htm
Insulin
Diabetes in mid-life linked to increased risk of Alzheimer's disease
Significant dementia risk attributable to small blood vessel damage
Link between diabetes and Alzheimer's disease
Support for view of Alzheimer's as form of diabetes
Diabetes associated with increased risk of mild cognitive impairment
High blood sugar linked to MCI and dementia
Reduced insulin in the brain triggers Alzheimer's degeneration
Link between insulin and Alzheimer's
Diabetics at significantly higher risk for Alzheimer's disease
Insulin-degrading enzyme may affect risk of Alzheimer’s disease
April 2008
Diabetes in mid-life linked to increased risk of Alzheimer's disease
A large Swedish study involved over 2000 men has found that
those with low insulin secretion capacity at age 50 were nearly one-and-a-half
times more likely to develop Alzheimer’s disease than people without insulin
problems. The risk remained significant regardless of blood pressure,
cholesterol, body mass index and education, and was strongest in people who did
not have the APOE4 gene.
The study was published online April 9 in Neurology.
April 2008 news report
http://www.eurekalert.org/pub_releases/2008-04/aaon-dim040108.php
Significant dementia risk attributable to small blood vessel damage
Autopsy data of 221 men and women found that the brains of
one-third of individuals who had dementia before death showed evidence of small,
cumulative blood vessel damage that can arise from hypertension or diabetes.
The findings were reported at the
annual meeting of the American Society for Biochemistry and Molecular Biology,
April 5-9, San Diego.
http://www.eurekalert.org/pub_releases/2008-04/asfb-sdr040208.php
Link between diabetes and Alzheimer's disease
A mouse study has shed light on the connection between
diabetes and Alzheimer’s. It appears that the elevated blood glucose levels
characteristic of diabetes interacts with
beta amyloid in a way damaging to
blood vessels in the brain.
The study was published online 26 March in Neurobiology of
Aging. April 2008
news report
http://www.eurekalert.org/pub_releases/2008-04/si-ssl043008.php
September 2007
Support for view of Alzheimer's as form of diabetes
Research in the
last few years has raised the possibility that Alzheimer’s memory loss could be
due to a third form of diabetes. A new study clarifies the connection between
insulin and Alzheimer’s. It seems that the toxic protein
ADDL, found in the
brains of individuals with Alzheimer’s, removes insulin receptors from nerve
cells, rendering those neurons insulin resistant. The findings
suggest that some existing drugs now used to treat diabetic patients may be
useful for Alzheimer’s treatment.
The findings were published online August 24 in FASEB Journal.
Full reference
http://www.eurekalert.org/pub_releases/2007-09/nu-dst092607.php
April 2007
Diabetes associated with increased risk of mild cognitive impairment
A study involving 918 individuals older than 65 years (average age 75.9)
who did not have mild cognitive disorder or dementia when they enrolled has
found that, over some 6 years, diabetes was related to a significantly
higher risk of developing amnestic mild cognitive impairment, after
controlling for other risk factors. The results support other findings that
type 2 diabetes mellitus increases the risk of Alzheimer's.
The report appeared in the April issue of Archives of
Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2007-04/jaaj-dmb040507.htm
August 2006
High blood sugar linked to MCI and dementia
The first study to investigate the association over time between
blood sugar and the risk of cognitive difficulties involved 1,983
post-menopausal women (mean age 67 years) and found that each 1%
increase in their glycosylated hemoglobin level at the start of the
four-year study period was associated with a 40% increased risk of
developing MCI or dementia four years later. The glycosylated hemoglobin
test gives a more stable measure of blood sugar level than the standard
test, which measures blood sugar it the time of testing. A result of 7%
or less indicates good long-term blood sugar control. Those with a level
of 7% or more were four times more likely to develop MCI or dementia
than women who tested at less than 7%.
The report appeared in the
Journal of Nutrition, Health, and Aging.
Full reference
http://www.eurekalert.org/pub_releases/2006-08/uoc--chb080906.htm
March 2006
Reduced insulin in the brain triggers Alzheimer's degeneration
By depleting insulin and its related
proteins in the brain,
researchers have replicated the progression of Alzheimer's disease –
including plaque deposits,
neurofibrillary tangles,
impaired cognitive functioning, cell loss and overall brain deterioration –
in an experimental animal model. Brain deterioration was not related to the
pancreas, raising the possibility that Alzheimer's is a neuroendocrine
disorder, or a Type 3 diabetes.
The study was published in the
Journal of Alzheimer's Disease.
Full reference
http://www.eurekalert.org/pub_releases/2006-03/l-rii031606.htm
March 2005
Link between insulin and Alzheimer's
A new study has found that insulin and its related proteins
are produced in the brain as well as the pancreas, and that
reduced levels of these contribute to the degeneration of brain
cells, an early symptom of Alzheimer's disease. The finding
raises the possibility of a Type 3 diabetes.
The findings are reported in the March issue of the
Journal of Alzheimer's Disease.
Full reference
http://www.eurekalert.org/pub_releases/2005-03/l-rdl030205.htm
May 2004
Diabetics at significantly higher risk for Alzheimer's disease
New findings
from the Religious Orders Study add to research suggesting a link between
diabetes mellitus and an increased risk of developing Alzheimer's disease. Some
aspects of cognitive function appear to be affected differently than others, in
particular perceptual speed declined significantly faster in those with
diabetes.
The study appeared in the May issue of the
Archives of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2004-05/rpsl-das051204.htm
May 2003
Insulin-degrading enzyme may affect risk of Alzheimer’s disease
A new mouse study suggests that low levels of insulysin, an
enzyme that degrades insulin, could increase the risk for
Alzheimer's, and points to a new mechanism linking diseases like
diabetes and Alzheimer's — the competition of multiple
substrates, such as insulin and amyloid-beta, for a limiting
amount of the insulysin enzyme. The insulysin enzyme, it seems,
also degrades amyloid-beta peptides, and even a partial decrease
in insulysin activity was found to raise amyloid-beta peptide
levels in the brain.
The study was published online before print in
Proceedings of the National Academy of Sciences.
Full reference
http://www.eurekalert.org/pub_releases/2003-05/uots-iem050603.htm
