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Am J Neurodegener Dis 2013;2(4):300-306

Original Article
Differences between early and late onset Alzheimer’s disease

Peter K Panegyres, Huei-Yang Chen

Neurodegenerative Disorders Research Pty Ltd, 185 York Street, Subiaco, Perth, Western Australia 6008

Received November 2, 2013; Accepted November 17, 2013; Epub November 29, 2013; Published December 15, 2013

Abstract: Previous studies comparing early-onset Alzheimer’s disease (EOAD) and late-onset AD (LOAD) have been
limited by cross-sectional design and a focus on isolated clinical variables. This study aims to explore differentials in
clinical features between EOAD and LOAD and to examine longitudinally trends in cognitive function. Data from 3,747
subjects with AD from C-Path Online Data Repository was used to compare demographics, body mass index (BMI),
mean arterial pressure (MAP), biochemistry and cognitive assessments, including mini-mental state examination
(MMSE) and Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-Cog), between EOAD and LOAD. The
baseline differences were examined by binominal proportion test and t-test. The trends of cognitive functions,
evaluating by MMSE and ADAS-Cog, were examined by the mixed model, controlling for the effect of repeated
measures of the same person. No significant difference was found in BMI and MAP. C-reactive protein, creatinine and
blood urea nitrogen (BUN) (p<0.05) were significantly higher in LOAD. The APOE ε4 alleles was more likely to be found
among LOAD compared to APOE ε2 or APOE ε3. EOAD had significantly lower MMSE at baseline and this difference
significantly increased over time. Despite an insignificant differential in ADAS-Cog between EOAD and LOAD at
baseline, the differential was enlarged gradually and became more significant with time. Our findings suggest that
elevated inflammatory markers, impaired renal function and APOE ε4 alleles are overrepresented in LOAD, possibly
indicating that different factors determine the development of EOAD and its more rapid cognitive deterioration.

Keywords: Early-onset dementia, late-onset dementia, Alzheimer’s disease, cognitive assessments, EOAD prognosis

Address correspondence to: Dr. Peter K Panegyres, Neurodegenerative Disorders Research Pty Ltd, 185 York Street,
Subiaco, Western Australia 6008. Tel: +61 8 6380 2255; Fax: +61 8 6380 2055; E-mail: research@ndr.org.au