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


CONCLUSIONS
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.
Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
Hyemin
H
Jang
Department of Neurology, Dementia Center, Stroke Center, Ilsan hospital, National Health Insurance Corporation, Goyang-shi, South Korea.
Jong Hun
JH
Kim
Department of Neurology, Inha University School of Medicine, Incheon, Korea.
Seong Hye
SH
Choi
Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea.
Yunhwan
Y
Lee
Department of Psychiatry, Ajou University School of Medicine, Suwon, Korea.
Chang Hyung
CH
Hong
Department of Neurology, Ewha Womans University School of Medicine and Ewha Medical Research Institute, Seoul, Korea.
Jee Hyang
JH
Jeong
Department of Neurology, Myongji Hospital, Goyang.
Hyun Jeong
HJ
Han
Department of Neurology, Ajou University School of Medicine, Suwon, Korea.
So Young
SY
Moon
Department of Neurology, Dona-A University College of Medicine, Pusan, Korea.
Kyung Won
KW
Park
Department of Neurology, Konkuk University College of Medicine, Seoul, Korea.
Seol-Hee
SH
Han
Department of Neurology, Gachon University of Medicine and Science, Gil Medical Center, Incheon.
Kee Hyung
KH
Park
Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
Hee Jin
HJ
Kim
Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
Duk L
DL
Na
Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.|Neuroscience Center, Samsung Medical Center.|Department of Clinical Research Design and Evaluation, SAIHST, Sungkyunkwan University.
Sang Won
SW
Seo
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000401:mortality*; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D016016:Proportional Hazards Models; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D015996:Survival Rate; D013851:Thinness / Q000503:physiopathology*
Alzheimer’s disease; body mass index; mortality; obesity; survival analysis