High Prevalence of Mild Cognitive Impairment and Alzheimer's Disease in Arabic Villages in Northern Israel: Impact of Gender and Education

Article type: Research Article

Authors: Afgin, Anne E.^a | Massarwa, Magda^a | Schechtman, Edna^b | Israeli-Korn, Simon D.^a | Strugatsky, Rosa^a | Abuful, Amin^c | Farrer, Lindsay A.^d | Friedland, Robert P.^e | Inzelberg, Rivka^{a; c; *}

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

Correspondence: [*] Correspondence to: Prof. Rivka Inzelberg, The Sagol Neuroscience Center, Department of Neurology Sheba Medical Center, Tel Hashomer, 52621, Israel. Tel.: +972 3 5304753; Fax: +972 3 5304718; Cell: +972 523 483767; E-mail: inzelber@post.tau.ac.il.

Abstract: The prevalence of mild cognitive impairment (MCI) and Alzheimer's disease (AD) have not been well been studied in Arab populations. In a door-to-door study of all residents aged ≥ 65 years in Wadi-Ara, an Arab community in northern Israel, we estimated the prevalence of AD, MCI, and the risk of conversion to AD. Subjects were classified as cognitively normal, MCI, AD, or other based on neurological and cognitive examination (in Arabic). MCI subjects were re-examined (interval ≥ 1 year) to determine conversion to AD and contributions of age, gender, and education to the probability of conversion. Of the 944 participants (96.6% of those approached; 49.4% men), 92 (9.8%) had AD. An unusually high prevalence of MCI (n = 303, 32.1%) was observed. Since the majority of women (77.2%) had no schooling, we estimated the effect of gender on the risk of AD and MCI among subjects without schooling and of school years among men. Among subjects with no schooling (n = 452), age (p = 0.02) and female gender (p < 0.0001) were significant predictors of AD, whereas risk of MCI increased only with age (p = 0.0001). Among men (n = 318), age increased the risk (p < 0.0001), school years reduced the risk of AD (p = 0.039) and similarly for MCI [age (p = 0.0001); school years (p = 0.0007)]. Age (p = 0.013), but not gender or school years, was a significant predictor of conversion from MCI to AD (annual rate 5.7%). The prevalence of MCI and AD are unusually high in Wadi Ara, while the rate of conversion from MCI to AD is low. Yet unidentified genetic factors might underlie this observation.

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

DOI: 10.3233/JAD-2011-111667

Journal: Journal of Alzheimer's Disease, vol. 29, no. 2, pp. 431-439, 2012