Association between body mass index and cognition function and all-cause mortality in Korean elderly people

Abstract

ObjectiveAccording to previous research, lower cognitive function and body mass index have been related to increase in mortality in elderly people. However, little has been reported about compounding effects of BMI and cognitive function. This study explores the association between body mass index (BMI), cognitive function and mortality in the elderly population. MethodsData from the Korean Longitudinal Study of Aging (KLoSA) from 2006 to 2014 was assessed using longitudinal data analysis and 3,121 research subjects were included at baseline 2006. Our modeling approach was based on Cox proportional hazard model for mortality. ResultsThe hazard ratio (HR) for mortality among individuals with thin and cognitive impairment, or normal/overweight and cognitive impairment was 2.666 and 2.470, respectively (p < 0.0001), and that among individuals with thin and cognitive decline was 2.153 (p: 0.001). The likelihood of mortality increased within each level of BMI, as the cognitive function deteriorated. ConclusionThe presence of dementia does explain a protective effect of the association between low BMI and higher mortality. Therefore, because both BMI and cognitive function are modifiable, preventive approaches may be necessary.