Plasma cobalamin levels affect information processing speed in a longitudinal study of HIV-1 disease.
OBJECTIVE
To determine whether information processing speed is influenced by change in plasma cobalamin status in human immunodeficiency virus type 1 disease.


METHODS
A longitudinal study, using autoregression, to evaluate the relationship between plasma cobalamin status and change in information processing speed assessed by Posner Letter Matching, Sternberg Short-Term Memory Search, Figure Visual Scanning and Discrimination of Pictures, and continuous paired associates learning tasks.


METHODS
University of Miami (Fla) School of Medicine from fall 1987 through summer 1991.


METHODS
Eighty-four human immunodeficiency virus type 1-infected homosexual men aged 20 to 55 years. None of the subjects displayed acquired immunodeficiency syndrome-defining symptoms at baseline; over the course of the study, 9.5% progressed to acquired immunodeficiency syndrome.


METHODS
Biochemical measurement of plasma cobalamin; performance on information processing speed tasks.


RESULTS
Significant improvement in the Posner Letter Matching NI-PI (Name Identity minus Physical Identity) differential was associated with becoming cobalamin adequate or remaining adequate. Becoming cobalamin deficient, in contrast, was associated with a significant decline in the speed of accessing overlearned name codes.


CONCLUSIONS
Normalization of plasma cobalamin inadequacy in human immunodeficiency virus type 1 disease may provide significant improvement in the speed of retrieving overlearned information from long-term memory.
Department of Epidemiology, University of Miami (Fla) School of Medicine.
G
G
Shor-Posner
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R
Morgan
F
F
Wilkie
C
C
Eisdorfer
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MK
Baum
D000328:Adult; D015658:HIV Infections / Q000097:blood* / Q000523:psychology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008606:Mental Processes; D008875:Middle Aged; D009483:Neuropsychological Tests; D014805:Vitamin B 12 / Q000097:blood*
D014805:Vitamin B 12