Body Mass Index and Mortality Rate in Korean Patients with Alzheimer’s Disease

Article type: Research Article

Authors: Jang, Hyemin^a | Kim, Jong Hun^{b; *} | Choi, Seong Hye^c | Lee, Yunhwan^d | Hong, Chang Hyung^e | Jeong, Jee Hyang^f | Han, Hyun Jeong^g | Moon, So Young^h | Park, Kyung Wonⁱ | Han, Seol-Hee^j | Park, Kee Hyung^k | Kim, Hee Jin^a | Na, Duk L.^a | Seo, Sang Won^{a; l; m; *}

Affiliations: [a] Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea | [b] Department of Neurology, Dementia Center, Stroke Center, Ilsan hospital, National Health Insurance Corporation, Goyang-shi, South Korea | [c] Department of Neurology, Inha University School of Medicine, Incheon, Korea | [d] Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea | [e] Department of Psychiatry, Ajou University School of Medicine, Suwon, Korea | [f] Department of Neurology, Ewha Womans University School of Medicine and Ewha Medical Research Institute, Seoul, Korea | [g] Department of Neurology, Myongji Hospital, Goyang | [h] Department of Neurology, Ajou University School of Medicine, Suwon, Korea | [i] Department of Neurology, Dona-A University College of Medicine, Pusan, Korea | [j] Department of Neurology, Konkuk University College of Medicine, Seoul, Korea | [k] Department of Neurology, Gachon University of Medicine and Science, Gil Medical Center, Incheon | [l] Neuroscience Center, Samsung Medical Center | [m] Department of Clinical Research Design and Evaluation, SAIHST, Sungkyunkwan University

Correspondence: [*] Correspondence to: Jong Hun Kim, MD, PhD, Department of Neurology, Dementia Center, Stroke Center, Ilsan Hospital, National Health Insurance Service, 1232 Baeksok-dong, Ilsandong-gu, Koyang-Shi 410-719, South Korea. Tel.: +82 31 900 0213; Fax: +82 31 900 0343; [email protected]

Correspondence: [*] Correspondence to: Sang Won Seo, MD PhD, Department of Neurology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, South Korea. Tel.: +82 2 3410 1397; Fax: +82 2 3410 0052; [email protected]

Abstract: Background: A relationship between body weight, cognitive impairment, and the onset of Alzheimer’s disease (AD) was recently reported. However, to our knowledge, no studies have investigated the relationship between body weight and mortality in Asian AD patients. Objective: We evaluated the relationship between body mass index (BMI) and mortality rate in Korean AD cohorts. Methods: Participants were consecutively included from two Korean representative registries: 579 AD patients from Samsung Medical Center and 1911 AD patients from the Clinical Research Center for Dementia of South Korea study. We combined these two AD cohorts to evaluate the association between BMI and mortality. BMI was used to categorize the participants into underweight, normal-weight, overweight, and obesity subgroups. All deaths were confirmed through the nationwide mortality database of Statistics Korea. Results: 53 of 181 (29.3%), 208 of 1,127 (18.5%), 88 of 626 (14.1%), and 115 of 556 (20.7%) patients died in the underweight, normal-weight, overweight, and obese subgroups during 43.7 months of follow-up. The time-dependent cox proportional hazards model showed that, relative to the normal-weight subgroup, the underweight group had higher mortality (HR 1.82 (95% CI, 1.07–3.09)) while overweight group had lower mortality rate (HR 0.60 (95% CI, 0.38–0.95)) The effects of underweight and overweight were prominent in younger and older elderly group, respectively. However, there were no interactive effects of dementia severity or gender and BMI on survival rate. Conclusion: Relative to AD patients of normal weight, those who were underweight had an increased mortality rate, and overweight predicted decreased mortality in AD patients. Furthermore, our findings may help facilitate mortality stratification in AD patients by using baseline BMI.

Keywords: Alzheimer’s disease, body mass index, mortality, obesity, survival analysis

DOI: 10.3233/JAD-142790

Journal: Journal of Alzheimer's Disease, vol. 46, no. 2, pp. 399-406, 2015