Alzheimer's, Dementia & Mental Health
Mental Deficits Appear Early in Diabetes Patients;
Last Into Old Age
Confirms previous reports that diabetes impairs
mental process
Jan 5, 2009 - Adults with diabetes experience a
slowdown in several types of mental processing, which appears early in
the disease and persists into old age, according to new research. Given
the sharp rise in new cases of diabetes, this finding means that more
adults may soon be living with mild but lasting deficits in their
thought processes.
A full analysis appears in the January issue of
Neuropsychology, which is published by the American Psychological
Association.
Researchers at Canadas University of Alberta
analyzed a cross-section of adults with and without adult-onset Type 2
diabetes, all followed in the Victoria Longitudinal Study. At three-year
intervals, this study tracks three independent samples of initially
healthy older adults to assess biomedical, health, cognitive and
neurocognitive aspects of aging.
The Neuropsychology study involved 41 adults with
diabetes and 424 adults in good health, between ages 53 and 90.
The research confirmed previous reports that
diabetes impairs cognition and added two important findings. First, it
teased out the specific domains hurt by diabetes. Second, it revealed
that the performance gap was not worse in the older group. Thus, the
reductions in executive function and processing speed seem to begin
earlier in the disease.
Healthy adults performed significantly better than
adults with diabetes on two of the five domains tested: executive
functioning, with significant differences across four different tests,
and speed, with significant differences or trends across five different
tests. There were no significant differences on tests of episodic and
semantic memory, verbal fluency, reaction time and perceptual speed.
When researchers divided participants into
young-old and old-old, with age 70 as the cutoff, they found the same
pattern of cognitive differences between young-old and old-old in the
diabetes and control groups. Thus, the researchers concluded, the
diabetes-linked cognitive deficits appear early and remain stable.
Speed and executive functioning are thought to be
among the major components of cognitive health, says co-author Roger
Dixon, PhD.
With Type 2 diabetes a growing concern among adults
of all ages, but especially those above age 30, Dixon says that public
health programs could check the cognitive status of people with more
advanced or severe cases; ensure that diet and medications are
effectively employed in all early diagnosed cases; and enact possible
cognitive monitoring or training programs for people with diabetes.
According to the U.S. Centers for Disease Control
and Prevention, new cases of diabetes nearly doubled in the past decade,
with nearly one new case for every 100 adults between the years 2005 and
2007.
The normal age-related slowing of thought processes
could be exacerbated by diseases such as Type 2 diabetes, says Dixon.
But, he continues, There could be some ways to compensate for these
declines, at least early and with proper management. The level of
impairment detected, he adds, should not make it hard for people to
manage their condition.
Diabetes is a known risk factor for late-life
neurodegenerative diseases such as Alzheimer's. Although the deficits
detected in the current sample were not clinically significant, they
appear (according to subsequent research by the authors) to foreshadow
additional deficits. Only further study would reveal whether its
possible to connect the dots between mild early deficits in speed and
executive function, and later signs of a progressive cognitive
impairment.
Background Information
Article: Exploring Effects of Type 2 Diabetes on
Cognitive Functioning in Older Adults, Sophie E. Yeung, PhD, Ashley L.
Fischer, PhD, and Roger A. Dixon, PhD, University of Alberta;
Neuropsychology, Vol. 23, No. 1.
The American Psychological Association (APA), in
Washington, DC, is the largest scientific and professional organization
representing psychology in the United States and is the worlds largest
association of psychologists. APAs membership includes more than
148,000 researchers, educators, clinicians, consultants and students.
Through its divisions in 54 subfields of psychology and affiliations
with 60 state, territorial and Canadian provincial associations, APA
works to advance psychology as a science, as a profession and as a means
of promoting human welfare.
