Overlap Between Apolipoprotein Eε4 Allele and Slowing Gait Results in Cognitive Impairment

Ryota Sakurai; Yutaka Watanabe; Yosuke Osuka; Yu Taniguchi; Hisashi Kawai; Hunkyung Kim; Akihiko Kitamura; Hiroki Inagaki; Manuel Montero-Odasso; Shuichi Awata; Shoji Shinkai

doi:10.3389/fnagi.2019.00247

Overlap Between Apolipoprotein Eε4 Allele and Slowing Gait Results in Cognitive Impairment

Front Aging Neurosci. 2019 Sep 13:11:247. doi: 10.3389/fnagi.2019.00247. eCollection 2019.

Authors

Ryota Sakurai^{1

2}, Yutaka Watanabe^{3

4}, Yosuke Osuka³, Yu Taniguchi¹, Hisashi Kawai⁵, Hunkyung Kim³, Akihiko Kitamura¹, Hiroki Inagaki³, Manuel Montero-Odasso^{2

6}, Shuichi Awata³, Shoji Shinkai¹

Affiliations

¹ Research Team for Social Participation and Community Health, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
² Gait and Brain Lab, Parkwood Institute, Lawson Health Research Institute, London, ON, Canada.
³ Research Team for Promoting Independence and Mental Health, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
⁴ Gerodontology, Department of Oral Health Science, Faculty of Dental Medicine, Hokkaido University, Sapporo, Japan.
⁵ Research Team for Human Care, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
⁶ Department of Medicine, Division of Geriatric Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada.

Abstract

Background: Although apolipoprotein E polymorphism ε4 allele (ApoE4) and slow gait are well-known risk factors for cognitive impairment, examination of their combined effect on cognitive function is lacking. Our objective was to elucidate whether a combination of ApoE4 phenotyping and slow gait resulted in greater cognitive impairment. Methods: Overall, 1,085 community-dwelling older adults, either ApoE4 carriers (n = 167, 15.4%) or non-ApoE4 carriers, were included from the "Takashimadaira study." Gait speed was assessed with an electronic walkway and slow gait was defined as <1 m/s. Cognitive performance was also assessed using the Mini-Mental State Exam (MMSE) and the Trail Making Test (TMT)-A and -B. A two-way analysis of covariance (ANCOVA; ApoE and gait velocity factors) adjusted for covariates was performed for each analysis. Results: Gait and cognitive performances were similar for ApoE4 and non-ApoE4 carriers. A two-way ANCOVA of the MMSE showed a significant interaction between the two factors. ApoE4 carriers with slow gait had lower MMSE scores than ApoE4 carriers without slow gait and non-ApoE4 carriers with slow gait. Also, a significant main effect of gait velocity on TMT-A was observed, indicating that slow gait is associated with lower scores irrespective of the presence of ApoE4. There was no main effect or interaction observed on the TMT-B. Conclusions: Our results suggest that the concurrent presence of at least one copy of ApoE4 and slow gait can define a subgroup with the lowest cognition. Elucidating the mechanisms underlying these associations may point out modifiable factors in populations at risk of dementia.

Keywords: aging; apolipoprotein E; cognitive impairment; cohort study; older adults; slow gait.