Association Between Oral Frailty and Metrics Derived from Continuous Glucose Monitoring in Older Patients with Type 2 Diabetes

Aims: To investigate the association between oral frailty (OF) and continuous glucose monitoring (CGM)-derived metrics in older patients with type 2 diabetes. Materials and Methods: This cross-sectional study included 93 older outpatients with type 2 diabetes (age 76.9 ± 4.1 years, 55 men) at the diabetes outpatients’ clinic at the National Center for Geriatrics and Gerontology, Japan. OF was assessed using the Oral Frailty Index-8 (OFI-8). CGM-derived metrics included mean sensor glucose (SG), glucose coefficient of variation, percentage values of time in range (%TIR, 70–180 mg/dL), time above range (%TAR), and time below range (%TBR). Multiple linear regression analyses were performed to examine associations between OF and these CGM metrics, with each metric as the dependent variable and OF or individual OFI-8 subitems as the independent variables. Results: In all, 34 older patients (36.6%) had OF. Multiple linear regression analysis found no significant association between OF and CGM-derived metrics or HbA1c. However, the sub-items “How many times do you brush your teeth per day?: <2 times/day” and “Do you visit a dental clinic at least annually?: No” were significantly positively associated with mean SG and %TAR >180 mg/dL, and %TAR >250 mg/dL, and negatively associated with %TIR ( P < 0.05). Conclusions: Poor oral health behaviors in older patients with type 2 diabetes may be linked to CGM-derived hyperglycemic metrics and %TIR, which are not reflected by the HbA1c value.