Association between oral health markers and decline in muscle strength and physical performance in later life: longitudinal analyses of two prospective cohorts from the UK and the USA

Background
Poor oral health could be associated with changes in musculoskeletal health over time. This aim of this study was to investigate the longitudinal relationship between oral health and decline in physical function in later life.

Methods
We did a prospective analysis of two cohorts of older adults (aged 70 years or older) including men from the British Regional Heart Study (BRHS; n=612), and men and women from the Health, Aging and Body Composition (Health ABC) Study (n=1572), followed up for about 8 years. Data were available for clinical or self-reported oral health measures, muscle (grip) strength, and physical performance (chair stand and gait speed). ANCOVA models were used to assess the association between oral health and follow-up physical function scores. Multivariate logistic regression models were used to examine the associations between oral health and decline in physical function over the follow-up period. In the BRHS, changes in oral health and physical function were also assessed. All models were adjusted for relevant sociodemographic, behavioural, and health-related factors.

Findings
In the BRHS, complete tooth loss and difficulty eating were associated with weaker grip strength at follow-up, and periodontal status was associated with decline in gait speed. In the Health ABC Study, complete tooth loss, poor self-rated oral health, and the presence of one oral health problem were associated with slower gait speed at follow-up. In both studies, dry mouth was associated with declines in physical function. In the BRHS, deterioration of dentition (tooth loss) over the follow-up period was associated with decline in chair stand speed (adjusted odds ratio 2·34 [95% CI 1·20–4·46]), as was deterioration in difficulty eating (2·41 [1·04–5·60]).

Interpretation
Oral health problems are associated with poorer physical function and greater decline in physical function in older adults, and could be an indicator of individuals at risk of reduced physical capacity and subsequent frailty and disability in later life.