Circadian disturbances and frailty risk in older adults

Abstract

Frailty is characterized by diminished resilience to stressor events. It is associated with adverse future health outcomes and impedes healthy aging. The circadian system orchestrates ~24-h rhythms in bodily functions in synchrony with the day-night cycle, and disturbed circadian regulation plays an important role in many age-related health consequences. We investigated prospective associations of circadian disturbances with incident frailty in over 1000 older adults who had been followed annually for up to 16 years. We found that decreased rhythm strength, reduced stability, or increased variation were associated with a higher risk of incident frailty and faster progress of frailty over time. Perturbed circadian rest-activity rhythms may be an early sign or risk factor for frailty in older adults.

Fig. 1. Predicted survival curves from the fully adjusted Cox proportional hazards models.

The predicted probabilities of being not frail for two representative participants with circadian metrics (a) amplitude, (b) variation of cycle length, (c) IS, (d) IV, or (e) M10 at the 10th (red lines) and 90th percentiles (blue lines). IS interdaily stability, IV intradaily variability, M10 the average activity during the most active 10-h period. Source data are provided as a Source Data file.

Fig. 2. Predicted trajectory of frailty score from the fully adjusted linear mixed-effects models.

The predicted frailty score for (a) amplitude or (b) M10 for two representative participants. The red lines represent low amplitude or M10 (10th percentile), the blue lines represent high amplitude or M10 (90th percentile), the shaded regions present the 95% confidence intervals. M10 the average activity during the most active 10-h period. Source data are provided as a Source Data file.

Fig. 3. Flow of participants through the study.

A total of 1022 participants were included in the analyses.