Effect of smoking and time on cognitive function in the elderly without dementia.
OBJECTIVE
To examine the association between smoking and changes in cognitive function over time in elderly persons without dementia.


METHODS
The results of neuropsychological tests grouped into domains of memory, abstract-visuospatial, and language, from several intervals over a 5-year period in 791 elderly patients without dementia or cognitive impairment. Smoking history was categorized as never, current, or past smokers and related to the slope of performance in each cognitive domain using generalized estimating equations.


RESULTS
Performance in all cognitive domains declined over time. Memory performance declined more rapidly among current smokers aged >75 years than in nonsmokers similar in age, including those who never smoked or had quit smoking. The effect was stronger among those without an APOE-epsilon4 allele. There was no association between smoking and performance in any cognitive domain in persons aged <75 years, and there was no association between past smoking and performance on any of the three cognitive factors at any time interval in either age group.


CONCLUSIONS
Current smokers aged >75 years perform more poorly on cognitive tests and appear to decline in memory more rapidly than their peers who do not smoke, especially if they lack the APOE-epsilon4 allele. Smoking does not affect cognitive performance in those persons aged <75 years.
Reitz
Christiane
C
Gertrude H. Sergievsky Center, Columbia University College of Physicians and Surgeons, New York, NY, USA.
Luchsinger
Jose
J
Tang
Ming-Xin
MX
Mayeux
Richard
R
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics; D002318:Cardiovascular Diseases / Q000453:epidemiology; D003071:Cognition / Q000187:drug effects / Q000502:physiology; D003072:Cognition Disorders / Q000139:chemically induced* / Q000453:epidemiology / Q000523:psychology; D015897:Comorbidity; D018450:Disease Progression; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced* / Q000453:epidemiology / Q000523:psychology; D009483:Neuropsychological Tests; D044469:Racial Groups; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D013997:Time Factors
D053327:Apolipoprotein E4; D001057:Apolipoproteins E