Effects of an oral exercise intervention on pre-frailty or frailty in older people: a randomized clinical trial

Background: Frailty is often experienced by older adults, which can lead to long-term health problems. We aimed to examine associations with improvements in nutritional status, sarcopenia (age-related loss of skeletal muscle mass and strength), and frailty in four groups with different oral exercise frequencies.
Methods: We conducted a prospective, parallel multi-arm randomized controlled trial (Japan Registry of Clinical Trials (jRCT) 1062210063) to test the effects of oral exercise on frailty in older adults. Each intervention consisted of a standardized oral exercise protocol including neck exercises, lip exercises, and tongue movements, designed to improve oral function and reduce frailty. The primary outcome was the change in the number of frailty criteria from baseline to follow-up. Individuals aged ≥60 years were screened for frailty status using standardized criteria at the Department of Preventive Dentistry at Okayama University Hospital between October 2022 and December 2023. Those identified as pre-frailty or frailty were eligible and enrolled in the study. After screening 60 individuals, 58 eligible participants were randomly assigned using block randomization to one of four oral exercise frequency groups: 3 times/day & everyday, 3 times/day & 3 days/week, once/day & everyday, and once/day & 3 days/week. A two-way repeated measures analysis of variance was used to evaluate the impact of the four frequencies of oral exercise methods on frailty in older adults. Outcome assessors were blinded; participants were not.
Results: Here we show the results of the 58 participants. Group sizes are: 3 times/day & everyday (n = 14), 3 times/day & 3 days/week (n = 15), once/day & everyday (n = 14), once/day & 3 days/week (n = 15). The trial is completed as planned, and all randomized participants are analyzed. The main effect of time is significant for the number of frailty criteria (F = 14.803, p < 0.001, partial eta squared = 0.215). The mean changes from baseline to follow-up are −0.357 (95% Confidence Interval −0.787 to 0.073) in the 3 times/day & everyday group, −0.600 (95% Confidence Interval −1.255 to 0.055) in the 3 times/day & 3 days/week group, −0.571 (95% Confidence Interval −1.379 to 0.236) in the once/day & everyday group, and −0.600 (95% Confidence Interval −1.008 to −0.192) in the once/day & 3 days/week group. The main effect of time is also significant for the number of oral hypofunction criteria (F = 16.456, p < 0.001, partial eta squared = 0.234). No important adverse events or side effects related to the intervention were observed.
Conclusions: After conducting oral exercises for 3 months on older adults with pre-frailty or frailty, improvements in frailty are observed. Overall, these exercises could be a simple, low-cost way to support healthy aging in the community.