Background: Explanations for associations found between sensory and cognitive function remain unclear. Objective: To assess in an older Australian population: (1) the correlation between sensory and cognitive function across groups with a narrow age range; (2) any independent association between sensory and cognitive impairment. Methods: We examined 3,509 non-institutionalised residents aged 50+ years in the second cross-sectional survey of the Blue Mountains Eye Study (1997–2000). Visual impairment was defined for best-corrected visual acuity (VA) <6/12 in the better eye, moderate to severe hearing loss for hearing threshold >40 dB (better ear), and likely cognitive impairment for Mini-Mental State Examination (MMSE) <24 points. Results: We found likely cognitive impairment in 3.3%, vision impairment in 2.7% and moderate to severe hearing loss in 10.5% of this population. Correlation between VA or hearing threshold and MMSE score increased with age. After adjusting for age, weak but significant correlation was evident in the normal ageing sample between vision and MMSE (r = 0.12 with vision items included and r = 0.11 with vision items excluded, both p < 0.0001), and between hearing thresholds and MMSE (r = –0.12, p < 0.0001). After adjusting for age, sex, education and history of stroke, persons with vision impairment had a lower mean MMSE score than those with normal vision, regardless of whether vision-related items were included (27.1 vs. 28.6, p < 0.001) or excluded (19.8 vs. 21.0, p < 0.001). Similarly, persons with moderate to severe hearing loss had a lower mean MMSE score than those without hearing loss (28.1 vs. 28.7, p < 0.001). Persons with likely cognitive impairment also had lower mean VA and higher mean hearing threshold than those without, after adjustment. Conclusions: We have documented an age-related correlation between sensory and cognitive function in a normal ageing sample. The association between sensory impairment and likely cognitive impairment remained significant after excluding vision-related MMSE items and adjusting for confounding factors. Our data suggest that age-related decline and the effect of visual impairment on the measurement of cognition only partly explain the association between sensory and cognitive impairments in older persons.

Keywords:
Visual impairment, Hearing loss, Cognitive impairment, Older population, Ageing, Blue Mountains Eye Study
This content is only available via PDF.
© 2006 S. Karger AG, Basel
2006
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.