DIABETES AS A RISK FACTOR FOR COGNITIVE DECLINE
IN OLDER PATIENTS
F. Limongi, A. Marseglia, S. Maggi, M. Noale, G. Romanato, P. Siviero,
G. Crepaldi
CNR, Institute of Neuroscience, Padova (Italy)
MGSD 2011
Casablanca, Morocco
• Prospective studies found that people with diabetes have a greater
rate of decline in cognitive function; a 1.5-fold greater risk of
cognitive decline; and a 1.6-fold greater risk of future dementia;
• Moreover, diabetes and Alzheimer’s Disease share some common
features such as increased prevalence with aging, a genetic
predisposition, and comparable pathological features in the islet and
brain;
• The aim of the present work is to assess the role of type 2 diabetes
as a risk factor for cognitive decline
MATERIAL AND METHODS
•
The analyses are based on the Italian Longitudinal Study on Aging (ILSA):
Sample (Maggi et al, 1994) :
 5,632 free-dwelling and institutionalised individuals
 aged 65-84
 resident in 8 centers
 randomly selected from the local anagraphic lists, equal allocation by sex
and 5-year-age groups
 with two phases


Screening phase, with personal interview, laboratory test, diagnostic
tests (neurological tests, GDS, ADL, IADL, spirometry, retinography,
electrocardiography) and cognitive assessment: Mini Mental State
Examination, Prose memory Test and Attention Matrix Test.
Clinical confirmation by geriatrician or neurologist for those subjects
screened positive for heart failure, angina, arrhythmia, hypertension,
myocardial infarction, diabetes, stroke, parkinsonism, distal symmetric
neuropathy of lower limbs, dementia.
MILANO
PADOVA
GENOVA
FIRENZE
FERMO
BARI
NAPOLI
CATANIA
• Sex-specific analyses were carried out. The difference between the mean values observed in
the diabetic group versus the non-diabetic group was evaluated by the GLM procedure. The
mean scores on the 3 tests, at baseline and follow-ups, were compared between diabetics
and non-diabetics according to the GLM. Mean changes in each test, between baseline and
follow-ups, were assessed by a GLM corrected for baseline scores;
• Logistic regression models were then constructed to assess the influence of diabetes and of
glycated hemoglobin on cognitive decline in the MMSE, Prose Memory Test and Matrix Test, at
both follow-ups, adjusting for other variables and baseline scores.
RESULTS
• At baseline, diabetic women had significantly worse scores
on all cognitive tests compared to non-diabetic women,
but did not show worsening over time;
• At baseline men with diabetes did not show worse scores
on cognitive tests compared to non-diabetic males;
• Diabetes in men was associated with a risk of cognitive
decline over time, particularly in attention;
• A poor glycaemic control was associated with poorer
performance on Prose memory tests at follow-up in both
sexes.
CONCLUSIONS
• The impact of diabetes on cognitive status might differ in older
men and women, probably because of a survival effect, with a
higher mortality at a younger age among diabetic men;
• The metabolic and cardiovascular abnormalities associated with
diabetes might be responsible for the cognitive decline, at
different rates and ages, in men and women;
• The association between a poor glycaemic control and the risk of
cognitive decline is extremely important, since impairment in even
a single domain may favour progressive and overall decline in
cognitive capacities;
• A routine assessment of diabetes complications in the elderly
should include cognitive evaluation in both sexes.