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.
