Midlife and Late-Life Body Mass Index and Late-Life Dementia: Results from a Prospective Population-Based Cohort

Article type: Research Article

Authors: Tolppanen, Anna-Maija^{a; *} | Ngandu, Tiia^{b; c} | Kåreholt, Ingemar^{d; e} | Laatikainen, Tiina^{b; f; g} | Rusanen, Minna^a | Soininen, Hilkka^{a; h} | Kivipelto, Miia^{a; c; d}

Affiliations: [a] Department of Neurology, University of Eastern Finland, P.O. Kuopio, Finland | [b] Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland | [c] Alzheimer Disease Research Center, Karolinska Institutet, Stockholm, Sweden | [d] Aging Research Center (ARC), Karolinska Institutet and Stockholm University, Stockholm, Sweden | [e] Institute for Gerontology, School of Health Sciences, Jönköping University, Jönköping, Sweden | [f] Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland | [g] Hospital District of North Karelia, Joensuu, Finland | [h] Department of Neurology, Kuopio University Hospital, Kuopio, Finland

Correspondence: [*] Correspondence to: Anna-Maija Tolppanen, University of Eastern Finland, School of Medicine Institute of Clinical Medicine – Neurology, P.O. Box 1627, FIN 70211 Kuopio, Finland. Tel.: +358 40 355 2015; Fax: +358 17 162 048; E-mail: [email protected].

Abstract: Background:Obesity has been consistently associated with dementia. The role of certain risk factors of dementia may change during life, and the importance of having a life-course perspective has been acknowledged. Objective:The aim of this study was to investigate the association of midlife and late-life body mass index (BMI) with late-life dementia/Alzheimer’s disease (AD) and whether the association was independent of other obesity-related co-morbidities. Methods:The association between midlife BMI (mean age 50.2, SD 6.0) and late-life BMI (mean age 71.2, SD 4.0) and incident dementia later in life (mean age 75.7, SD 5.0) were investigated among 1,304 participants of the longitudinal population-based Cardiovascular risk factors, Aging and Dementia (CAIDE) study, conducted in Eastern Finland. The duration of follow-up was 26 years. The diagnosis of dementia was based on DSM-IV criteria and the probable and possible AD on the NINCDS-ADRDA criteria. Results:Higher midlife BMI was associated with higher risk of incident dementia (adjusted HR, 95% CI 1.07, 1.00–1.14). However, decrease in BMI from midlife to late-life was associated with higher risk of dementia (1.14, 1.03–1.25 for one-unit decrease) and AD (1.20, 1.09–1.33). High late-life BMI was associated with lower risk of AD (0.89, 0.81–0.98) but the association with dementia was less evident (0.94, 0.86–1.03). Conclusion:Higher midlife BMI is related to higher risk of dementia and AD, independently of obesity-related risk factors and co-morbidities. Steeper decrease of BMI and low late-life BMI are associated with higher risk of dementia and AD. These findings highlight the importance of life-course perspective when assessing the association between BMI and cognition.

Keywords: Alzheimer's disease, body mass index, dementia, obesity

DOI: 10.3233/JAD-130698

Journal: Journal of Alzheimer's Disease, vol. 38, no. 1, pp. 201-209, 2014