Cognitive impairment and poor oral health are common problems in older adults and are associated with malnutrition. However, it is unclear how they are related to cachexia in community-dwelling older adults. The aim of this study was to examine the relationships among cachexia, cognitive function, and oral health in community-dwelling older adults.

This study is a secondary analysis of a data-set. Data were collected in the community setting on older adults who applied for government-funded long-term care services in Hong Kong in 2017. Subjects were community-dwelling and aged ≥60 years. The outcome variable was cachexia. The predictors were cognitive function and oral health. The covariates included demographics and comorbidities associated with cachexia or malnutrition. Path analysis was employed to examine the associations among cachexia, cognitive function, and oral health using the software SAS/STAT and Mplus.

This analysis included 12,940 subjects. The prevalence of cachexia was 1.3%. Cognitive function was also found to have a direct effect on the oral health indicators of chewing problems (OR=1.073, p<0.001), brushing teeth problems (OR=1.349, p<0.001), and swallowing problems (coeff.=0.177, p<0.001). Oral health indicators with a direct effect on cachexia included dry mouth (OR=1.250, p<0.001), brushing teeth problems (OR = 1.185, p<0.01), and swallowing problems (OR=1.231, p<0.001). Cognitive function had no significant direct effect, but had a significant indirect effect on cachexia (OR=1.100, p<0.001) which is mediated by brushing teeth problems (OR=1.052, p<0.001) and swallowing problems (OR=1.038, p<0.001).

Cognitive impairment causes cachexia indirectly through poor oral health. This study recommends adding cognitive function when screening community-dwelling older adults for cachexia. Health policymakers should stress regular oral health screening and interventions, and encourage increased utilization of oral health services by community-dwelling older adults with cognitive problems.