Background

Extensive research has investigated the association between age changes in various domains, including lung function and motor function. However, a few analyses have tested models that incorporate bidirectional longitudinal influences between lung and motor function to test the temporal chain of events in the disability process. Dual change score models (DCSM) assist with identification of leading indicators of change by leveraging longitudinal data to examine the extent to which changes in one variable influence subsequent changes in a second variable, and vice versa.

Aims

The purpose of the current-analysis study was to apply DCSM to data from the Swedish Adoption/Twin Study of ageing to examine the nature of the longitudinal relationship between motor functioning and lung function.

Methods

Three motor functioning factors were created from 20 performance measures, including measures of balance, flexibility, and fine motor skills. Peak expiratory flow measured lung function. Participants were 829 adults aged 50–88 at the first of 9 waves of testing covering a 27-year follow-up period; 80% participated in at least three waves.

Results

Model comparisons indicated that decline in lung function preceded and contributed to subsequent decline in motor function.

Discussion

Combined with previous results, these results suggest that declining lung function results in increasing difficulties in motor function, which contribute to subsequent declines in multiple domains.

Conclusion

Understanding the cascade of events that can lead to dependence can help in the development of interventions targeted early in the disablement process.