Acetyl L-carnitine slows decline in younger patients with Alzheimer's disease: a reanalysis of a double-blind, placebo-controlled study using the trilinear approach.
OBJECTIVE
To assess the longitudinal effects of acety-L-carnitine (ALC) on patients diagnosed with Alzheimer's disease.


METHODS
Longitudinal, double-blind, parallel-group, placebo-controlled.


METHODS
Twenty-four outpatient sites across the United States.


METHODS
A total of 334 subjects diagnosed with probable Alzheimer's disease by NINCDS-ADRDA criteria. These data were originally reported by Thal and colleagues (1996).


METHODS
Cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS) given every 3 months for 1 year.


RESULTS
The average rate of change was estimated using the trilinear approach, which allows for periods of both change and stability. Both the ALC group and the placebo group exhibited the same mean rate of change on the ADAS (0.68 points/month). However, a multiple regression analysis revealed a statistically significant Age x Drug interaction characterized by younger subjects benefiting more from ALC, significant, cutpoint for ALC benefit was 61 years of age.


CONCLUSIONS
ALC slows the progression of Alzheimer's disease in younger subjects, and the use of the trilinear approach to estimate the average rate of change may prove valuable in pharmacological trials.
Stanford University School of Medicine, California, USA. johnbrks@stanford.edu
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Brooks
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Yesavage
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D000108:Acetylcarnitine / Q000627:therapeutic use*; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000188:drug therapy*; D003072:Cognition Disorders / Q000209:etiology / Q000517:prevention & control*; D018450:Disease Progression; D005260:Female; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D015233:Models, Statistical; D018697:Nootropic Agents / Q000627:therapeutic use*; D012372:ROC Curve; D012044:Regression Analysis
D018697:Nootropic Agents; D000108:Acetylcarnitine