Cerebrospinal fluid beta-amyloid 1-42 concentration may predict cognitive decline in older women.
BACKGROUND
Low levels of cerebrospinal fluid (CSF) beta-amyloid 1-42 (Abeta42) and high total tau (T-tau) are diagnostic for manifest Alzheimer's disease. It is not known, however, whether these biomarkers may be risk indicators for cognitive decline in otherwise healthy older people.


METHODS
The longitudinal relationship between CSF markers, Abeta42 and T-tau, measured in 1992, and change in Mini-Mental State Examination (deltaMMSE) score between 1992 and 2002 were investigated in 55 women (aged 70-84 years, mean (SD) MMSE score = 28.3 (1.5)), who were participants in the Prospective Population Study of Women in Gothenburg, Sweden. These women did not have dementia when they experienced lumbar puncture in 1992-3.


RESULTS
Over the 8-year follow-up period, deltaMMSE (range = +3 to -21 points) was correlated with Abeta42 (Spearman's r = 0.40, p = 0.002), such that lower levels of Abeta42 were related to greater decline. This was also observed after excluding 4 women who developed dementia between 1992 and 2002 (Spearman's r = 0.34, p = 0.019). A multivariate logistic regression model predicting a decline of > or = 5 points on the MMSE (observed in six women), or a risk of developing dementia over the 8-year follow-up period (observed in four women), including age, education, Abeta42 and T-tau as covariates, showed that Abeta42 was the sole predictor of significant cognitive decline or dementia (OR per 100 pg/ml Abeta42 = 2.24, 95% CI 1.19 to 4.22, p = 0.013).


CONCLUSIONS
Low levels of CSF Abeta42 may predict cognitive decline among older women without dementia.
Gustafson
Deborah R
DR
The Institute of Neuroscience and Physiology, Section for Psychiatry and Neurochemistry, Neuropsychiatric Epidemiology Unit, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden. deb.gustafson@neuro.gu.se
Skoog
Ingmar
I
Rosengren
Lars
L
Zetterberg
Henrik
H
Blennow
Kaj
K
D000368:Aged; D000369:Aged, 80 and over; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D003072:Cognition Disorders / Q000134:cerebrospinal fluid*; D003704:Dementia / Q000134:cerebrospinal fluid; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008609:Mental Status Schedule; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D011237:Predictive Value of Tests; D012307:Risk Factors
D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments