This cross-sectional observational study aimed to identify factors associated with oral frailty in patients with rheumatoid arthritis (RA). Oral frailty, characterized by a decline in oral function involving chewing, swallowing, and speech, is increasingly recognized as a component of overall frailty and is closely linked with physical decline, cognitive impairment, and mortality 1, 2. As Japan faces rapid population aging, understanding oral frailty in RA is important because both patients with RA and the general population are becoming older, and RA itself may increase the risk of oral health deterioration. A total of 597 patients with RA meeting established classification criteria underwent comprehensive assessments, including oral frailty evaluation using the Oral Frailty Index-8 (OFI-8), physical frailty assessment using the Kihon Checklist (KCL), and clinical profiling. Oral frailty was defined as an OFI-8 score ≥ 4 3, 4. Clinical data included demographics, RA disease duration, BMI, smoking status, income, RA-related medications, Clinical Disease Activity Index (CDAI), physical function (HAQ-DI), bone mineral density, vitamin D levels, and frailty according to KCL assessment. Univariate analysis compared characteristics between the oral frailty (+) and (−) groups. Variables with p < 0.05 based on univariate analysis were included in multivariate logistic regression analysis. The model showed good discrimination (AUC, 0.772) and calibration. The prevalence of oral frailty was 36.7%. Patients with oral frailty were significantly older (Figure 1) and more likely to exhibit frailty according to the KCL assessment. In the multivariate analysis, age (p < 0.001) and frailty according to KCL (p < 0.001) were independently associated with oral frailty (Table 1). The prevalence of frailty according to the KCL in the oral frailty (+) group was compared with that in the oral frailty (−) group (56.6% vs. 22.2%). Comparisons with previous studies showed that oral frailty is relatively common in patients with RA, similar to or higher than rates seen in older community-dwelling adults 5, 6. Prior studies have also linked oral frailty with adverse outcomes such as physical frailty, diminished recovery capacity, and increased vulnerability 6-8. Because patients with RA are at a higher risk of physical frailty due to chronic inflammation and functional limitations, assessing oral frailty in this population is particularly important. Although methotrexate (MTX) use and RA disease activity appeared significant in univariate analysis, these associations disappeared after multivariate adjustment, suggesting confounding effects. Prior research indicates limited direct impact of MTX on periodontal disease, while high RA disease activity is associated with poorer oral health, including increased periodontitis and dental caries 9, 10. The lack of significance in adjusted models suggests overlapping influences with age or physical frailty. These factors are widely recognized in general populations. This study specifically demonstrates that traditional frailty determinants continue to play a dominant role in patients with RA, suggesting that general geriatric mechanisms may outweigh disease-specific factors. This has important implications for clinical management, highlighting the need for comprehensive geriatric assessment in RA care. The study has several limitations. First, oral frailty was defined using OFI-8, which, although validated, may not fully align with other oral health assessment tools. The OFI-8 score ≥ 4 demonstrated a sensitivity of 80% and a specificity of 80% for identifying individuals at risk of oral frailty 3. Second, other known risk factors for oral health decline, such as diabetes, history of cancer, malnutrition, oral interventions, and cognitive impairment, were not evaluated. Third, being a single-center, cross-sectional study relying partly on self-reported assessments, it may be subject to selection and reporting biases and cannot establish causality. Nonetheless, it adds valuable data to the limited literature on the relationship between RA and oral frailty. In conclusion, a substantial proportion of patients with RA exhibit oral frailty, and its presence is strongly associated with older age and frailty according to the KCL. Because oral frailty can affect nutrition, activities of daily living, and mortality, routine evaluation and early management, especially in older patients with RA or those exhibiting frailty, are essential. Multidisciplinary collaboration among medical, dental, and rehabilitation professionals may help improve outcomes. Future longitudinal studies are needed to clarify causal pathways and examine changes in oral frailty over time in RA populations. Study concept and design: Takeshi Mochizuki, Katsunori Ikari, and Ken Okazaki. Acquisition of subjects and the data: Takeshi Mochizuki. Analysis and interpretation of the data: Katsunori Ikari and Koichiro Yano. Preparation of the manuscript: Takeshi Mochizuki, Katsunori Ikari, and Ken Okazaki. This study was conducted in accordance with the principles stated in the Declaration of Helsinki, and written informed consent was obtained from all the patients (approval number: TGE00652-064). T. Mochizuki received honoraria for lectures from AbbVie, Asahi Kasei, Astellas, Bristol-Myers, Eisai, Eli Lilly, Pfizer, Mochida, and UCB. K. Yano received honoraria for lectures from AbbVie, Chugai, Eisai, Gilead Sciences, Janssen, Kaken, Pfizer, and UCB. K. Ikari received honoraria for lectures from Asahi Kasei, Astellas, AbbVie, Ayumi, Bristol Myers, Chugai, Eisai, Eli Lilly, Janssen, Kaken, Mitsubishi Tanabe, Pfizer, Takeda, Teijin, and UCB. The other authors declare that they have no conflicts of interest. Research data are not shared.
Mochizuki et al. (Sun,) studied this question.