Estimating the Risk for Conversion from Mild Cognitive Impairment to Alzheimer's Disease in an Elderly Arab Community

Article type: Research Article

Authors: Inzelberg, Rivka^{a; b; *} | Massarwa, Magda^c | Schechtman, Edna^d | Strugatsky, Rosa^b | Farrer, Lindsay A.^e | Friedland, Robert P.^f

Affiliations: [a] Department of Neurology, Sackler Faculty of Medicine, Tel Aviv University, Israel | [b] The Sagol Neuroscience Center, Department of Neurology, Sheba Medical Center, Israel | [c] Department of Neurology, Hillel Yaffe Medical Center, Hadera, Israel | [d] Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, Beer Sheva, Israel | [e] Departments of Medicine (Genetics Program), Neurology, Ophthalmology, Genetics & Genomics, Epidemiology, and Biostatistics, Boston University Schools of Medicine and Public Health, Boston, USA | [f] Department of Neurology, University of Louisville, Kentucky, USA

Correspondence: [*] Correspondence to: Prof. Rivka Inzelberg, Mordechai 8, Ramat Hasharon, 4744108, Israel. Tel.: +972 3 5304753; Fax: +972 3 5304752; E-mail: rivka.inzelberg@gmail.com.

Abstract: Background:Vascular risk factors and lack of formal education may increase the risk of Alzheimer’s disease (AD). Objective:To determine the contribution of vascular risk factors and education to the risk of mild cognitive impairment (MCI) and AD and to estimate the risk for conversion from MCI to AD. Methods:This door-to-door survey was performed by an Arab-speaking team in Wadi Ara villages in Israel. All consenting residents aged ≥ 65 years were interviewed for medical history and underwent neurological and cognitive examinations. Individuals were cognitively classified as normal (CN), MCI, AD, vascular dementia, or unclassifiable. MCI patients were re-examined at least one year later to determine conversion to AD. The contributions of age, gender, school years, and vascular risk factors to the probability of conversion were estimated using logistic regression models. Results:Of the 906 participants, 297 (33%) had MCI and 95 (10%) had AD. Older age (p = 0.0008), female gender (p = 0.023), low schooling (p < 0.0001), and hypertension (p = 0.0002) significantly accounted for risk of MCI versus CN, and diabetes was borderline (p = 0.051). The risk of AD versus CN was significantly associated with age (p < 0.0001), female gender (p < 0.0001), low schooling (p = 0.004) and hypertension (p = 0.049). Of the 231 subjects with MCI that were re-examined, 65 converted to AD. Conclusions:In this population, age, female gender, lack of formal education, and hypertension are risk factors for both AD and MCI. Conversion risk from MCI to AD could be estimated as a function of age, time interval between examinations, and hypertension.

Keywords: Aging, Alzheimer's disease, Arab, mild cognitive impairment, neuroepidemiology, prevalence, risk factors

DOI: 10.3233/JAD-142871

Journal: Journal of Alzheimer's Disease, vol. 45, no. 3, pp. 865-871, 2015