Tooth loss trajectories and their association with frailty risk: A 10‐year population‐based cohort study

BACKGROUND: Previous studies concerning tooth loss and frailty risk primarily employed the number of teeth to categorize the extent of tooth loss. However, tooth loss is a dynamic process. Hence, this study aimed to identify the dynamic trajectories of tooth loss and analyze the relationship between tooth loss trajectories and frailty risk. METHODS: This analysis included 3355 participants enrolled in the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The number of teeth and the frailty index were evaluated in 2008, 2011, 2014, and 2018, and the tooth loss trajectories were established using the group-based trajectory model. The Cox model was used to analyze the relationship between tooth loss trajectories and frailty risk. RESULTS: Four tooth loss trajectories were identified, specifically the Persistently Mild Loss trajectory, the Progressively Severe Loss trajectory, the Persistently Moderate Loss trajectory, and the Edentulous trajectory. Compared with the Persistently Mild Loss trajectory, the Progressively Severe Loss trajectory (hazard ratio [HR] = 2.285, 95% confidence interval [CI]: 1.775-2.942), the Persistently Moderate Loss trajectory (HR = 1.215, 95%CI: 1.037-1.425), and the Edentulous trajectory (HR = 1.914, 95% CI: 1.481-2.475) were all related to higher frailty risk. CONCLUSION: Older adults with the Progressively Severe Loss trajectory had a greater risk of frailty compared with those with the Persistently Mild Loss trajectory. This finding suggests that tooth loss could be used as a predictor for frailty and other diseases in future research. PLAIN LANGUAGE SUMMARY: Previous studies on the link between tooth loss and frailty risk mainly focused on the number of teeth at 1 time point, ignoring that tooth loss is a dynamic process. Based on 4 waves of repeated measures of the number of teeth, this study identified 4 distinct trajectories of tooth loss. After adjustments, compared with the Persistently Mild Loss trajectory, the other 3, especially the Progressively Severe Loss trajectory, had a higher frailty risk. These findings thereby strengthen the evidence for the association between tooth loss and frailty risk, highlighting the importance of oral health protection and confirming tooth loss as a useful predictor of frailty. It should be noted that these findings are limited by data primarily coming from 1 ethnic group, Han (93.6%).