Clinical effects of low body mass index on geriatric status in elderly patients

Abstract

Background: There is limited information on the relationship of low body mass index (BMI) to the geriatric conditions in elderly patients.

Objective: The objective of this study is to investigate whether low BMI associates with geriatric status in elderly patients by calculating suitable cut-off point of BMI for assessment of geriatric conditions.

Method: A total of 1223 elderly patients was enrolled (male/female: N = 472/751), and cut-off point of the BMI values to assess the geriatric status such as aspiration pneumonia, cognitive impairment was determined by receiver operating characteristic (ROC) analyses. Logistic regression analyses were performed to examine the association between several geriatric status and low BMI. Of these patients, 262 patients (male/female: 101/161) had received standard rehabilitation treatment. Functional Independence Measure (FIM) scores were measured both at admission and discharge to calculate FIM gain and efficiency, and retrospective cohort study was performed.

Results: Cut-off point of BMI value to assess the geriatric status was determined (19.0 kg/m²). Significant associations of low BMI to several geriatric factors such as loss of posterior occlusion, cognitive impairment were observed in both male and female. FIM scores in above cut-off point group were significantly higher than in below cut-off point group in female (FIM gain, P = 0.0005; FIM efficiency, P = 0.0025, Mann-Whitney U test). On the other hand, there were no significant differences between low and above BMI cut-off point in FIM scores of male patients.

Conclusion: Low BMI might be a useful parameter to evaluate the geriatric status, and the viewpoint would contribute to decide the care plan for the good end-of-life of elderly.

Keywords: Body mass index (BMI); Cut-off value; Elderly patients; Geriatric status.