Outcome over seven years of healthy adults with and without subjective cognitive impairment

Alzheimer's & Dementia - Tập 6 - Trang 11-24 - 2010
Barry Reisberg1, Melanie B. Shulman1, Carol Torossian1, Ling Leng2, Wei Zhu1,2
1Silberstein Aging and Dementia Research Center, New York University School of Medicine, New York, NY, USA
2Department of Applied Mathematics and Statistics, State University of New York at Stony Brook, Stony Brook, NY, USA

Tóm tắt

Background

Subjective cognitive impairment (SCI) in older persons without manifest symptomatology is a common condition with a largely unclear prognosis. We hypothesized that (1) examining outcome for a sufficient period by using conversion to mild cognitive impairment (MCI) or dementia would clarify SCI prognosis, and (2) with the aforementioned procedures, the prognosis of SCI subjects would differ significantly from that of demographically matched healthy subjects, free of SCI, termed no cognitive impairment (NCI) subjects.

Methods

A consecutive series of healthy subjects, aged ≥40 years, presenting with NCI or SCI to a brain aging and dementia research center during a 14‐year interval, were studied and followed up during an 18‐year observation window. The study population (60 NCI, 200 SCI, 60% female) had a mean age of 67.2 ± 9.1 years, was well‐educated (mean, 15.5 ± 2.7 years), and cognitively normal (Mini‐Mental State Examination, 29.1 ± 1.2).

Results

A total of 213 subjects (81.9% of the study population) were followed up. Follow‐up occurred during a mean period of 6.8 ± 3.4 years, and subjects had a mean of 2.9 ± 1.6 follow‐up visits. Seven NCI (14.9%) and 90 SCI (54.2%) subjects declined (P < .0001). Of NCI decliners, five declined to MCI and two to probable Alzheimer's disease. Of SCI decliners, 71 declined to MCI and 19 to dementia diagnoses. Controlling for baseline demographic variables and follow‐up time, Weibull proportional hazards model revealed increased decline in SCI subjects (hazard ratio, 4.5; 95% confidence interval, 1.9–10.3), whereas the accelerated failure time model analysis with an underlying Weibull survival function showed that SCI subjects declined more rapidly, at 60% of the rate of NCI subjects (95% confidence interval, 0.45–0.80). Furthermore, mean time to decline was 3.5 years longer for NCI than for SCI subjects (P = .0003).

Conclusions

These results indicate that SCI in subjects with normal cognition is a harbinger of further decline in most subjects during a 7‐year mean follow‐up interval. Relevance for community populations should be investigated, and prevention studies in this at‐risk population should be explored.


Tài liệu tham khảo

10.1002/1099-1166(200011)15:11<983::AID-GPS238>3.0.CO;2-5 10.1159/000110373 10.1017/S0033291700035029 10.1177/089826439700900202 Reisberg B, 1985, Geriatric psychiatry: ethical and legal issues, 37 10.1212/WNL.56.9.1133 10.1016/S0140-6736(06)68542-5 10.1001/archneur.1991.00530130069022 10.1001/archpsyc.1990.01810150024005 10.1002/gps.930060505 Jorm AF, 2001, Memory complaints as a precursor of memory impairment in older people: a longitudinal analysis over 7-8 years, Psychol Med, 31, 441, 10.1017/S0033291701003245 10.1016/j.jalz.2007.01.011 10.1002/gps.559 10.1111/j.1532-5415.2000.tb02649.x Reisberg B, 1986, Dementia: a systematic approach to identifying reversible causes, Geriatrics, 41, 30 10.1212/WNL.41.7.1006 10.1017/S1041610204000092 10.1177/089198879901200402 10.1056/NEJMoa050151 10.1002/ana.410070516 10.1111/j.2044-8341.1959.tb00467.x 10.1176/ajp.139.9.1136 10.1017/S1041610296002566 10.1017/S1041610207005261 Reisberg B, 1988, The Brief Cognitive Rating Scale (BCRS), Psychopharmacol Bull, 24, 629 10.1177/0891988706291083 10.1016/0022-3956(75)90026-6 Reisberg B, 1987, Behavioral symptoms in Alzheimer's disease: phenomenology and treatment, J Clin Psychiatry, 48, 9 10.1093/geronj/26.1.70 10.1037/11167-000 10.1002/ddr.430150203 10.1214/aoms/1177728170 Hsieh HK, 1988, Savage test Encyclopedia of statistical sciences. Vol 8, 267 10.1212/WNL.34.7.939 Cox DR, 1984, Analysis of survival data Braak H, 1997, Connections, cognition and Alzheimer's disease. (Research and perspectives in Alzheimer's disease), 1 10.1016/j.biopsych.2008.07.004 10.1016/j.neurobiolaging.2004.11.003 10.1016/j.biopsych.2007.05.030 10.1017/S1041610207006394 10.1001/archneur.56.3.303 10.1111/j.1365-2796.2004.01380.x 10.1111/j.1532-5415.2005.00589.x 10.1017/S1041610208008065 10.1212/WNL.43.1_Part_1.13 Mortimer JA, 1993, Education and other socioeconomic determinants of dementia and Alzheimer's disease, Neurology, 43, S39 10.1001/jama.1994.03510370056032 Thomson Healthcare Inc, 2008, Physicians’ desk reference 10.1523/JNEUROSCI.4405-07.2008 10.1016/j.jalz.2008.03.005